Dissertations / Theses on the topic 'Harvest technology'

Thesis (MSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Grapes are lost annually due to spoilage by Botrytis cinerea. Botrytis cinerea is currently controlled using fungicides and SO2 fumigation in storage rooms but with limited success. Although these techniques have been used for decades they have been associated with numerous of disadvantages. Fungicides are restricted from being used during storage due to legislation and toxicity of the fungicides present on the surface of the berries. SO2 fumigation does not kill the dormant infections present inside the grape tissue and if the SO2 concentration is too high the berries are damaged. During this study two different polymer nanofibrous platforms was synthesized in an attempt to prevent the rotting effect of B. cinerea. The first polymer was modified to yield a polymer with a positively charged quaternized nitrogen moiety, which was subsequently reacted with sodium metabisulfite through an ion exchange process. The modified polymer was electrospun into nanofibrous mats for the benefit of the nanofibers’ high available surface area. A further functionalization was done to increase the quantity of sodium metabisulfite on the surface of the polymer nanofibers. Sodium metabisulfite salt released SO2 gas upon reaction with water vapour present in the atmosphere which resulted in the inhibition of conidial germination of B. cinerea. The second polymer was synthesized and then electrospun into polymer nanofibrous mats followed by chemical modification of the electrospun polymer nanofibers. This post-electrospun modification resulted in the covalent attachment of a fungicide-derivative to the surface of the polymer nanofibers. The fungicide-derivative showed excellent inhibition of B. cinerea mycelium growth. Anti-fungal studies were conducted using the two modified polymer nanofibrous mats against B. cinerea to evaluate these nanofibrous surfaces as B. cinerea inhibiting membranes. Results indicated that B. cinerea conidial germination and mycelium growth were successfully inhibited.
AFRIKAANSE OPSOMMING: Druiwe bederf jaarliks weens die verrottende effek van die fungi Botrytis cinerea. Botrytis cinerea word tans beheer deur gebruik te maak van swamdoders en swaweldioksied (SO2) besproeiings in stoorkamers, maar met beperkte sukses. Alhoewel hierdie tegnieke al vir dekades in gebruik is, word dit geassosieer met verskeie probleme. Die gebruik van swamdoders word in stoorkamers verbied, weens die moontlike skadelike inname daarvan deur die mens aangesien die swamdoders op die druiwe se oppervlakte teenwoordig is. SO2-gasbesproeiings maak nie dormante infeksies binne-in die druiwe self dood nie en indien SO2 -konsentrasies te hoog is kan dit die druiwe beskadig. Tydens hierdie studie is twee verskillende polimeer-nanoveselplatforms gesintetiseer met die doel om die verrottende effek van B. cinerea te voorkom. Die eerste polimeer is aangepas met ’n primêre amienverbinding met die doel dat dit deur ‘n opvolgende modifikasiereaksie verander om sodoende ’n polimeer met ‘n kwatenêre ammoniumgroep te verkry. Die doel van die kwatenêre eienskap is dat ioniese uitruiling plaasvind tussen die anioon van die polimeer en die natruimmetabisulfiet-anioon van die sout. Die voorbereide kopolimeer is geëlektrospin in nanoveselmatte deur middel van die enkelnaald-en-enkelbal-elektrospintegniek om SMI-qC12 nanovesels te lewer wat gefunksionaliseer is. Die nanoveselmatte is na die elektrospinproses verder aangepas om die hoeveelheid natruimmetabisulfiet op die oppervlak van die nanovesels te verhoog. Die natruimmetabisulfiet stel SO2-gas vry sodra dit in aanraking kom met waterdamp in die lug wat ’n beperkende effek op spoorontkieming van B. cinerea tot gevolg het. Die tweede polimeer is voor en na die elektrospinproses gefunksionaliseer met gesintetiseerde organiese verbindings (swamdoder). Die aanpassing van die polimeer met die organiese verbindings het plaasgevind op ‘n kovalente wyse om te verhoed dat die organiese verbinding vrygelaat word tydens gebruik. Die organiese verbindings het effektiewe beperking van miselium-groei getoon. Anti-swamstudies is uitgevoer tussen die twee gefunksionaliseerde polimeer platforms en B. cinerea om die oppervlaktes van die gefunksionaliseerde polimeer/nanovesels te evalueer as B. cinerea beperkende platforms. Resultate het aangetoon dat spoorontkieming en miselium groei van B. cinerea suksesvol beperk is.

The post-harvest quality of perishable produce changes rapidly due to the accelerated rate of respiration, transpiration and ripening. The objective of this study was to determine the effect of pectin and alginate based composite coatings on the shelf life extension of cherry tomatoes and to study the effect of an abiotic stress on enhancing antioxidant properties of cranberries. Two composite coating formulations were evaluated, a pectin based formulation with 3% pectin, 1.35% sorbitol, 1.2% bees wax and 0.36% monoglycerides, and an alginate based formulation with 2% alginate, 1.35% sorbitol, 1.2% bees wax and 0.36% monoglycerides. Whole cherry tomatoes were coated with one of the composite coatings and air dried at room temperature for a period of 3 h, transferred to preformed plastic containers and stored at selected temperatures (4, 12 and 24°C) along with a control. Alginate coated cherry tomatoes were additionally dipped in 2% CaCl2 before drying to enhance film formation. Several quality parameters of the fruit - weight loss, respiration rate, color, texture, total soluble solids, titratable acidity, pH and total polyphenols were evaluated during selected time intervals. The control had a shelf life of 12, 15 and 18 days, at 24, 12 and 4°C, respectively, whereas both pectin and alginate coated samples had a respective shelf a life of 15, 18 and 21 days at 24, 12 and 4°C respectively demonstrating a 17-25% shelf-life enhancement. Overall, pectin coated cherry tomatoes had better quality in terms than alginate coated samples, both being better than control. Cranberry fruits were subjected to abiotic stress in hot water at 40, 50 and 60°C for 1-10 min and evaluated for enhanced anti-oxidant properties. Treated fruits were removed from the hot water, drained, air dried, packed in plastic containers and stored at 4°C for 24 h allowing the fruits to relax/repair the stress damage. Total polyphenols, color and texture changes were evaluated. The hot water hormesis treatment at 60°C for 1 min resulted in an increment of the total polyphenols from 120 mg (control) to 258 mg and also showed the maximum color difference (ΔE) of 12.8 likely because of the accumulation of polyphenols. Samples treated for 1 min at 40°C also improved the firmness of the fruit. Hence hot water hormesis shows the potential to enhance the nutritive values of the fruits which can be applied at commercial level to improve the marketability of the fresh produce.
La qualité des produits post-récoltes change rapidement due à la vitesse accélérée de la respiration, de la transpiration, et de la maturation. Le but de ce travail était de déterminer l'effet d un enrobage , formé de pectine et d'alginate, sur l'extension de la durée de conservation des tomates cerises et d'étudier l'effet d'un stress abiotique sur l'amélioration des propriétés antioxydantes des canneberges. Deux formulations d' enrobages ont été évaluées : une formulation à base de pectine avec 3% de pectine, 1,35% de sorbitol, 1,2% de cire d'abeille et 0,36% de monoglycérides, et une formulation à base d'alginate avec 2% d'alginate, 1,35% de sorbitol, 1,2% de cire d'abeille et 0,36% de monoglycérides. Des tomates cerises entières ont été enrobées avec une des enrobages composés et ont été séchées à l'aire à température ambiante pour un durée de 3 heures. Les tomates cerises enrobées d'alginate ont été trempées dans 2% CaCl2 avant l'étape du séchage pour améliorer la formation de la pellicule. Ensuite, elles ont été transférées dans des contenants en plastiques et ont été conservées à des températures sélectionnées (4, 12 et 24°C) accompagnées d'un échantillon témoin. Plusieurs paramètres démontrant la qualité du fruit – la perte de poids, le taux de respiration, la couleur, la texture, la quantité totale des solides solubles, l'acidité titratable, le pH et la quantité de polyphénols - ont été evalués durant les intervalles sélectionnés. L'échantillon témoin avait une durée de conservation de 12, 15 et 18 jours, à 24, 12, et 4°C, respectivement, tandis que les échantillons enrobés de pectine et d'alginate avait une durée de conservation de 15, 18, et 21 jours à 24, 12 et 4°C respectivement. Ce qui démontre une amélioration de 17-25% en durée de conservation. En général, les tomates cerises enrobées de pectine avaient une meilleur qualité que les échantillons enrobés d'alginate, et les deux formes d'enrobages ont donnés de meilleurs résultats que les échantillon témoins. Des canneberges fraiches ont été assujetties à un stress abiotique dans l'eau chaude à 40, 50 et 60 °C pour 1-10 minutes et ont été évaluées pour leurs propriétés antioxydantes. Les fruits qui ont été traités ont été enlevés du bain d'eau chaude, ont été séchés à l'air, ont été rangés dans des contenants plastiques et ont été conservés à 4°C pour une durée de 24 heures permettant aux fruits de relaxer/réparer les dommages dus au stresse. La quantité des polyphénols, et le changement de couleur et de texture ont été évalués. L'effet d'hormèse induit avec le traitement d'eau chaude à 60°C pour une minute a donné une augmentation de la quantité de polyphénols de 120 mg (le control) à 258 mg et a aussi démontré un changement de couleur maximal (ΔE) de 12.8 qui est probablement causé par l'accumulation de polyphénols. Les échantillons traités pour une minute à 40°C ont été aussi améliorés en termes de la fermeté du fruit. Par conséquent, l'effet d'hormèse induit avec le traitement d'eau chaude démontre son potentiel pour améliorer les valeurs nutritives des fruits pouvant s'appliquer au niveau commercial pour augmenter la commercialisation des fruits et légumes frais.

[EN] In recent years, persimmon crop has become very relevant in Mediterranean Spain, where the production of this fruit centres on only one variety, persimmon cv. Rojo Brillante, majorly located in the Valencian Community. The main postharvest disorders manifested by 'Rojo Brillante' persimmons are flesh browning, which is associated with mechanical damage and chilling injury displayed after low-temperature storage. Previous research has determined the postharvest conditions that lead fruit to develop such alterations. However, the biochemical process behind flesh browning and chilling injury disorders is still unknown. Currently, there is special interest in introducing cultivars from other countries to broaden the varietal range. Besides, prolonging the fruit storage period to supply the markets according to the demand is one of the main challenges. In this context, the present Thesis approached three main objectives: 1) Studying the biochemical process implied in the main physiological postharvest disorders manifested in persimmon fruits by focusing on changes in the fruit redox state; 2) Evaluating postharvest treatments to preserve fruit quality during cold storage; 3) Assessing the physico-chemical and nutritional quality of persimmon cultivars introduced from other countries to increase the varietal range. Biochemical, chromatographic and microstructural studies have revealed that flesh browning manifested by fruits submitted to mechanical damage after removing astringency is associated with a tannins oxidation process caused by a stress oxidative situation. A new flesh disorder, "pinkish bruising", has been described on fruits submitted to mechanical impacts while showing high astringency levels. Sensitiveness to the flesh browning disorder has also been evaluated on different cultivars introduced from other countries. The implication of the redox system in the chilling injury manifestation on 'Rojo Brillante' persimmon has been determined. Moreover, we described the changes in this system associated with chilling injury alleviation by 1-MCP treatment. The effect of a controlled atmosphere based on 4-5% O2 + N2 to prolong the storage of cultivars 'Rojo Brillante' and 'Triumph' has been seen to strongly depend on variety. The results were highly positive on cultivar 'Triumph', in which the evaluated atmosphere extended the storage period up to 3 months. The use of short-term high CO2 treatments was another technology assayed to alleviate chilling injury in non-astringent cultivar 'Fuyu'. This treatment significantly reduced the main chilling injury symptom manifested by this cultivar, which is flesh gelling. This effect was related to cell structure preservation. Recent studies have shown that ethyl formate treatment is highly effective for pest control of persimmon 'Fuyu'. However, this treatment induces fruit softening, which causes quality loss. This Thesis revealed that ethyl formate treatment induces the activity of ethylene synthesis-related genes and that flesh softening is mediated by this hormone. It also demonstrated that by applying 1-MPC pretreatment, fruit softening associated with ethyl formate can be controlled. Therefore, the combined used of both treatments is seen as a potential treatment to disinfect persimmon fruits while preserving quality. Finally, the study of ten cultivars introduced from other countries helped select the most interesting cultivars to broaden the varietal range according to their maturation date and their response to deastringency treatment. The main nutritional compounds of persimmon and how they are affected by CO2 deastringency treatment are described.
[ES] El caqui es un cultivo de gran relevancia en el área mediterránea de España, estando la producción centrada en una única variedad, el cv. Rojo Brillante, y localizada principalmente en la Comunidad Valenciana. Las principales alteraciones presentadas por el caqui 'Rojo Brillante' durante el periodo postcosecha son el pardeamiento de la pulpa asociado a los daños mecánicos y los daños por frío manifestados tras la conservación a bajas temperaturas. Las investigaciones previas han determinado las condiciones de manejo bajo las cuales se desarrollan dichas alteraciones, sin embargo los procesos bioquímicos involucrados en la manifestación de estos desórdenes no se conocen en profundidad. Actualmente uno de los principales retos es la introducción de nuevas variedades que permitan ampliar la gama varietal, así como prolongar los periodos de conservación del caqui con el fin de poder escalonar la puesta en el mercado en función de la demanda. En la presente Tesis se han abordado tres objetivos principales: 1) Estudiar los procesos bioquímicos implicados en los principales desórdenes postcosecha del caqui, prestando especial atención a los cambios en el sistema redox del fruto; 2) Evaluar diferentes tratamientos postcosecha para preservar la calidad del fruto durante la conservación frigorífica; 3) Evaluar la calidad físico-química y nutricional de diferentes variedades de caqui introducidas desde otros países para ampliar la gama varietal. Estudios bioquímicos, cromatográficos y microestructurales, han revelado que el pardeamiento de la pulpa o "browning", manifestado por la fruta que ha sufrido daños mecánicos tras la eliminación de la astringencia está asociado a un proceso de oxidación de taninos motivado por una situación de estrés oxidativo. Además se ha descrito una nueva alteración de la pulpa, "pinkish bruising", manifestada por los frutos sometidos a daño mecánico con alto nivel de astringencia. También se ha evaluado la sensibilidad al pardeamiento de diferentes variedades introducidas desde otros países. Con el objetivo de prolongar la conservación del fruto se ha ensayado el uso de la atmósfera controlada basada en 4-5% O2 + N2 sobre las variedades 'Rojo Brillante' y 'Triumph', observándose que la respuesta a esta tecnología depende de manera muy importante de la variedad. Los resultados fueron especialmente positivos en el caso del cultivar 'Triumph', en el que la atmósfera ensayada permitió prolongar la conservación frigorífica hasta tres meses. Otra tecnología ensayada para el control de los daños por frío fue la aplicación de choques con altas concentraciones de CO2 en el cultivar no astringente 'Fuyu'. Este tratamiento alivió el principal síntoma de daño por frío manifestado por esta variedad, la gelificación de la pulpa. Este efecto se ha relacionado con la preservación de la estructura celular de la pulpa del fruto. Estudios recientes han mostrado que el tratamiento con etil formato es altamente efectivo en el control de insectos durante la conservación y comercialización del caqui 'Fuyu', sin embargo este tratamiento provoca un ablandamiento del fruto mermando su calidad. En esta Tesis se ha demostrado que las aplicaciones de etil formato activan los genes de síntesis de etileno, siendo está hormona mediadora del ablandamiento. Los estudios también revelaron que la aplicación de un tratamiento previo con 1-MCP reduce el ablandamiento del fruto asociado al etil formato, por lo que el uso combinado de ambos tratamientos puede ser considerado una alternativa para la desinfección de los frutos sin detrimento de su calidad. Por último, el estudio de diez variedades introducidas desde otros países permitió seleccionar en base a su momento de maduración y respuesta al tratamiento de desastringencia aquellas variedades de mayor interés para ampliar la gama varietal. Además, se identificaron los principales compuestos nutricionales del caqui y
[CAT] El caqui s'ha convertit en els últims anys en un cultiu de gran rellevància en l'àrea mediterrània d'Espanya, estant la producció centrada en una única varietat, el cv. Rojo Brillante, i localitzada principalment a la Comunitat Valenciana. Les principals alteracions presentades pel caqui 'Rojo Brillante' durant el període postcollita són l'enfosquiment de la polpa associat als danys mecànics i els danys per fred manifestats després de la conservació a baixes temperatures. Les investigacions prèvies han determinat les condicions de maneig sota les quals es desenvolupen estes alteracions, però els processos bioquímics involucrats en la manifestació d'estos desordres no es coneixen en profunditat. D'altra banda, actualment un dels principals reptes és la introducció de noves varietats que permetin ampliar la gamma varietal, així com prolongar els períodes de conservació del caqui per tal de poder escalonar la posada en el mercat en funció de la demanda. En este context, en la present Tesi s'han abordat tres objectius principals: 1) Estudiar els processos bioquímics implicats en els principals desordres postcollita del caqui, posant especial atenció als canvis en el sistema redox del fruit; 2) Avaluar diferents tractaments postcollita per preservar la qualitat del fruit durant la conservació frigorífica; 3) Avaluar la qualitat fisicoquímica i nutricional de diferents varietats de caqui introduïdes des d'altres països per ampliar la gamma varietal. Estudis bioquímics, cromatogràfics i microestructurals, han revelat que l'enfosquiment de la polpa o "Browning", manifestat per fruita que ha patit danys mecànics després de l'eliminació de l'astringència està associat a un procés d'oxidació de tanins motivat per una situació d'estrès oxidatiu. A més s'ha descrit una nova alteració de la polpa, "pinkish bruising", manifestada pels fruits sotmesos a dany mecànic amb alt nivell d'astringència. També s'ha avaluat la sensibilitat a l'enfosquiment de diferents varietats introduïdes des d'altres països. Amb l'objectiu de perllongar la conservació del fruit s'ha assajat l'ús de l'atmosfera controlada basada en 4-5% O2 + N2 sobre les varietats 'Rojo Brillante' i 'Triumph', observant-se que la resposta a esta tecnologia depèn de manera molt important de la varietat. Els resultats van ser especialment positius en el cas del cultivar 'Triumph', en què l'atmosfera assajada va permetre prolongar la conservació frigorífica fins a tres mesos. Una altra tecnologia assajada per al control dels danys per fred va ser l'aplicació de xocs amb altes concentracions de CO2 en el cultivar no astringent 'Fuyu'. Este tractament va alleujar el principal símptoma de dany per fred manifestat per esta varietat, la gelificació de la polpa. Este efecte s'ha relacionat amb la preservació de l'estructura cel¿lular de la polpa del fruit. Estudis recents han mostrat que el tractament amb etil format és altament efectiu en el control d'insectes durant la conservació i comercialització del caqui 'Fuyu', però este tractament provoca un estovament del fruit minvant la seua qualitat. En esta Tesi s'ha demostrat que les aplicacions d'etil format activen els gens de síntesi d'etilè, sent esta hormona mediadora de l'estovament. Els estudis també van revelar que l'aplicació d'un tractament previ amb 1-MCP redueix l'estovament del fruit associat a l'etil format, per la qual cosa l'ús combinat de tots dos tractaments pot ser considerat una alternativa per a la desinfecció dels fruits sense detriment de la seua qualitat. Finalment, l'estudi de deu varietats introduïdes des d'altres països va permetre seleccionar en base al seu moment de maduració i resposta al tractament de desastringència aquelles varietats de més interès per ampliar la gamma varietal. A més, es van identificar els principals compostos nutricionals del caqui i es va avaluar l'efecte del tractament de desastringència amb CO2 sobre els mat
Novillo Borrás, P. (2015). HARVEST AND POSTHARVEST QUALITY OF PERSIMMON FRUIT:PHYSICOCHEMICAL AND NUTRITIONAL ASPECTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58270
TESIS

Over the last decades the Moroccan agriculture has passed through a complete transformation: due to the low workforce cost and its favourable climate, the sector has attracted the attentions of national and foreign investment and thus has expanded rapidly. Among the different productions, tomatoes proved to be one of the most profitable, generating 4.867 billion dirhams in 2016 from exports. In order to remain competitive and attractive, the sector needs to be constantly monitored and controlled: abuses of the environment and of available resources may affect or even compromise the future of the Moroccan agriculture. Energy in particular has a remarkable role and has to be analysed in order to quantify its impact over costs and environment. The aim of this study is to build a GIS-based model of tomato’s postharvest system and study the agriculture and energy nexus interactions in the Souss-Massa region. Post harvesting activities such as: Transportation, conditioning, packaging, storing and transformation of tomato, occurs within Souss-Massa’s geographical boundaries and have been the focus of in this study. Results of current system highlight the dominance of packaging activity as the main energy consumer with 77%, followed by storing, transportation and transformation with 14 %, 6% and 3% respectively. In terms of cost the transportation becomes the most relevant activity due to the cost of fuels and transport conditions. Energy costs and wastes in transportation represent 15% of the local revenues (9% Transportation, 5% Packaging and 1% Storing). Four different scenarios about the future situation have been implemented to measure the possible impact of changes in the different activities: Business as Usual (BAU), Transport Efficiency (TE), Waste Reduction (WR) and Renewable Penetration (RP). -3- In BAU current trends have been followed to forecast the total production, the export and the power generation. In TE trucks with bigger capacity have been implemented and in WR refrigeration is considered in every transport stage. Finally, in RP higher renewable penetration has been considered
I över ett decennium har en förändring skett i det marockanska jordbruket, kombinerat med låga arbetskostnader och landets gynnsamma klimat har sektorn fått stor uppmärksamhet vilket har resulterat i att både nationell och internationella investeringar och sektorn har därmed kraftigt expanderats. Jordbruksproduktionen som visat sig vara mest gynnsam är produktion av tomater, där export av varan har genererat 4,867 miljarder dirham. För att säkerställa en attraktiv och konkurrenskraftig produktion är konstant övervakning och kontinuerlig kontroll ett måste; missbruk av miljö och dess resurser kan ha betydande påverkan vilket på sikt kan kompromissa framtiden för det Marockanska jordbruket. Energi har en betydande roll i jordbruket och bör därmed analyseras för att förstå dess övergripande inverkan på kostnader och miljö. Syftet med denna studie är att bygga upp en GIS baserad modell över tomatprodukten efter skörd samt att studera relationen mellan energi- & jordbrukssektorn i Souss-Massa regionen. Efter skörd inkluderas följande aktiviteter: transport, konditionering, förpackning, förvaring, och transformering av tomater. Studiens geografiska systemgräns gäller området Souss-Massa. Resultatet av studien visar att den mest energikrävande processen är förpackning av tomater och står för totalt 77% av energikonsumtionen, därefter följer förvaring, transport och transformering av 15%, 6% och 3% respektive. Resultaten visar dessutom att transport är den mest kostsamma aktivitet i processen, detta på grund av höga kostnader för bränsle samt förutsättningar för transport. Energi- och avfallskostnader i transport representerar 15 % av lokala intäkter (9% transport, 5% förpackning och 1% lagring). Fyra framtidsscenarion utformades för att mäta den framtida inverkan hos de olika aktiviteterna: Business as Usual (BAU), Transporteffektivisering (TE), Avfallshantering (WR) och Förnybar energimix i jordbrukssektorn (RP). I BAU scenariot har nuvarande trender följts för att förutse totala produktionen, export och kraftproduktion. I TE scenariot har lastbilar större kapacitet jämfört med de andra scenariona och i WR är konditionering inkluderat i vardera transportsteg. Slutligen i RP har en förnybar energimix integrerats i systemet.

The access to water in the regions around Lake Victoria varies with the rainy seasons. Today the daily labor of fetching water is a heavy burden for people in the rural areas. In the process of this study farmers in the Western and Nyanza provinces in Kenya are interviewed, water samples are analysed and present rainwater harvesting techniques and purification methods are observed. As a result, suitable solutions to the problems found are discussed. An optimal system is chosen for the region with a concept selection matrix. An elaborated dimensioning tool for roof and purpose-built harvesting systems is developed. Finally a summarized manual is attached in order to raise interest for rainwater harvesting among the farmers that the non-governmental organisation SCC-Vi Agroforestry cooperates with.

Tillgången till vatten i områdena kring Victoriasjön varierar med regnperioderna. Det dagliga arbetet med att hämta vatten är idag en stor börda för människor på landsbygden. Under processen av denna studie intervjuas bönder i Western och Nyanza provinserna i Kenya, vattenprover analyseras och nuvarande regnvatteninsamlingstekniker och reningsmetoder observeras. Som ett resultat diskuteras passande lösningar på de problem som hittats. Ett optimalt val av komplett system för regionerna tas fram med hjälp av en konceptvalsmatris. Ett genomarbetat verktyg för dimensionering av tak- och ändamålsbyggda insamlingssystem utvecklas. Slutligen inkluderas en sammanfattande manual för att väcka intresse för regnvatteninsamling bland de bönder som den ideella organisationen SCC-Vi Agroforestry samarbetar med.

Orientador: Marcos David Ferreira
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: O beneficiamento da batata lavada no Estado de São Paulo, destinada ao mercado in natura ou ao processamento, consome volume excessivo de água, provocando danos ao meio ambiente principalmente no descarte da água residual da etapa de lavagem. Tendo em vista a exigência do mercado consumidor por batata lavada, e a necessidade da redução do consumo de água utilizado para este tipo de beneficiamento, a hipótese deste trabalho é a de que é possível reduzir o consumo de água na etapa de lavagem da batata modificando os parâmetros de funcionamento dos equipamentos utilizados atualmente (vazão e rotação), mantendo a eficiência de limpeza, sem afetar a qualidade do produto. Sendo assim, o objetivo deste trabalho foi avaliar a etapa de limpeza em linhas de beneficiamento de batata lavada produzida no Estado de São Paulo, e propor modificações para redução no volume de água com manutenção da qualidade do produto e da eficiência de limpeza. Para tanto, inicialmente foi realizada a avaliação de desempenho da etapa de limpeza em unidades de beneficiamento de batata lavada no Estado de São Paulo, identificando o método de lavagem, os tipos de roletes/escovas, velocidade média do produto, e volume de água consumido. A partir do estudo de desempenho, foram propostas alterações para melhoria na etapa de limpeza com relação ao volume de água consumido e a limpeza do produto. A eficiência de limpeza, o consumo de água, e a influência do beneficiamento na qualidade da batata lavada foram avaliados e comparados nos sistemas propostos, onde foram avaliadas três rotações para as escovas, e três vazões de água na lavagem de tubérculos de dois solos com diferentes teores de argila. A qualidade do produto beneficiado foi avaliada por meio dos parâmetros: perda de massa fresca, coloração, danos físicos e firmeza. Neste trabalho foi possível verificar que o consumo de água nas unidades de beneficiamento pode ser reduzido, mantendo a eficiência de limpeza do produto, apenas com ajustes de vazão e rotação do equipamento de lavagem. Com relação à qualidade, verificou-se o incremento na perda de massa e incidência de brotamento, e redução da e firmeza da batata lavada em comparação aos tubérculos não lavados
Abstract: The washing for potatoes in São Paulo, for the fresh market or industry, consumes excessive amounts of water, causing damage to the environment mainly due to waste water discharge from the washing step. Considering the requirement of the consumer market for washed potatoes, and the need to reduce water consumption, the hypothesis is that it is possible to reduce water consumption on the washing of potato just modifying the configuration of the equipment currently used (flow and rotation), and maintaining the cleaning efficiency without affecting quality. Therefore, the main goal was to evaluate the cleaning step in processing lines of washed potatoes produced in the state of Sao Paulo, and propose modifications to reduce the amount of water and with maintenance of product quality and cleaning efficiency. Therefore, early, characterization of the cleaning step was made in processing and classification units of washed potatoes in the state of Sao Paulo, identifying the method of washing used, types of rollers / brushes, average speed of the product, and water volume consumed on this step. From the characterization study, changes were proposed in the cleaning step that would improve the efficiency with respect to water consumption and cleaning product. The cleaning efficiency, water consumption, and influence of improvement in the quality of washed potatoes were evaluated and compared in the proposed systems. The quality of the processed product was evaluated by the following parameters: weight loss, color, physical damage and firmness. In this study, it was possible to verify that water consumption on processing units can be reduced maintaining cleaning efficiency, only adjusting water flow and rotation of the equipment. Related to tuber quality, it was also observed an increase of mass and firmness loss, and sprouting of washed potatoes compared with unwashed tubers
Mestrado
Tecnologia Pós-Colheita
Mestre em Engenharia Agrícola

Beim Parameter „Druscheignung“ eines Bestandes wird gemeinhin angenommen, dass dieses Kriterium durch die Genetik der Sorte und den Witterungsverlauf, weitgehend unbeeinflusst von Landwirt, festgelegt ist. Und dennoch verändert der Landwirt mit all seinen Entscheidungen von der Auswahl der Sorten, über die Düngung, den Pflanzenschutz bis hin zum Erntemanagement die Druscheignung stetig. Zur Ernte, als letzten Abschnitt der Verfahrenskette, entfaltet die Druscheignung dann außerordentlich große ökonomische Auswirkungen. Anhand verschiedener Beispiele aus Züchtung, Pflanzenernährung, Pflanzenschutz und Erntetechnologie wurde dargestellt, wie auf die Druscheignung Einfluss genommen werden kann und wie diese Auswirkungen monetär zu bewerten sind. Aus dem Bereich der Züchtung wurde die Entwicklung eines neuen Wuchstyps bei den Rapshalbzwergen ausgewählt, der mit weniger Biomasse konkurrenzfähige Erträge erzielt. Die Abreife ist einheitlicher, der Erntetermin kann problemloser fixiert werden, der Drusch ist leistungsstark und verlustarm. Späte und intensiv geführte Sorten sind mit Hilfe einer Sikkation zeitlich früher und leichter zu beernten. Das schafft Erntesicherheit bei geringeren Verlusten, höheren Mähdrescherleistungen und sinkendem Kraftstoffverbrauch. Die bedarfsgerechte Ausbringung des Stickstoffs in Art, Menge und Zeit, entsprechend der kleinräumigen Heterogenität eines Schlages, führt zu einer Homogenisierung der Bestände. Die Bestände reifen gleichmäßiger ab und führen zu etwa 20 Prozent höherer Mähdrescherleistung sowie geringerem Kraftstoffverbrauch. Am Beispiel des Hochschnitts wurde verdeutlicht, wie sich die bessere Beerntbarkeit auf Maschinenkosten, Gesamternteverluste, Qualität und Trocknung auswirkt. Hebt man die Stoppellänge um 10 Zentimeter an, lässt sich die Mähdrescherleistung um ca. 15 bis 20 Prozent steigern. Diese Beispiele unterstreichen zugleich die Forderung, dass die Druscheignung nicht erst zur Ernte diese Führungsrolle übernimmt, sondern auch in den vorgelagerten Verfahrensabschnitten als ein starkes Entscheidungskriterium gelten muss.
The parameter “threshability” of a stand is commonly assumed to be a criterion defined by the genetics of the strain and the weather conditions which is mainly not influenced by the farmer. Nevertheless, the farmer continuously changes the “threshability” with all his decisions, from the selection of the strains, via the use of fertilizers to the harvest management. For harvest, as the last stage of the process chain, the threshability develops extraordinarily high economic effects. On the basis of several examples from cultivation, plant nutrition, plant protection and harvest technology it was described, how the threshability can be influenced and how this effect is to be assessed monetarily. In the field of cultivation, the development of a new growth type of semi-dwarf rape has been selected, which yields competitive returns with less bio mass. Ripeness is more homogeneous, the harvest date can be fixed without problems, threshing is efficient and with low loss. Using the method of siccation, late and intensively controlled strains can be harvested earlier and easier. This offers harvest safety with low loss, higher combine harvester performance and reduced fuel consumption.The need-based spreading of nitrogen referring to type, quantity and time according to the small-scale spatial heterogeneity of a field leads to a homogenisation of the stands. The stands ripen more evenly and this fact causes about 20 percent higher combine harvester performance, as well as reduced fuel consumption. Using the example of high-cut top harvest it was clarified how the better harvestability influences the machine costs, the total harvest losses, the quality, and the drying process. If the length of the stubbles is extended by 10 centimetres, the combine harvester performance can be increased by 15 to 20 percent. These examples also emphasize the requirement that the threshability does not just take over the leading role for the harvest but has also to be considered as a strong decision criterion within the prior stages of the process.

Orientador: Barbara Janet Teruel Mederos, Paulo Ademar Martins Leal
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: A hortaliça folhosa mais consumida e produzida no Brasil é a alface (Lactuca sativa L.) e seu consumo vem crescendo a cada ano devido a uma tendência da população mundial em adquirir hábitos de vida mais saudáveis. Existem diferentes métodos de resfriamento para conservação pós-colheita, já utilizados e aplicados em olerícolas, porém não se tem conhecimento sobre seus efeitos e benefícios para a alface. O objetivo deste estudo foi avaliar a aplicação de diferentes métodos de resfriamento e sua adequação para diferentes variedades de alface. Os tipos de alfaces analisadas foram a repolhuda crespa ou americana, a solta crespa, a repolhuda lisa e a solta lisa, adquiridas de um produtor da região de Campinas-SP. Foram avaliados três métodos de resfriamento seguidos de acondicionamento em câmara fria a 5ºC: resfriamento com ar forçado (com controle da umidade relativa do ar e sem controle da umidade relativa do ar), resfriamento evaporativo em túnel (nebulização e ventilador-meio poroso) e resfriamento com água fria (imersão e aspersão), sendo que o controle consistiu apenas no acondicionamento do produto em câmara fria a 5ºC, e os parâmetros físico-químicos (pH, ácido ascórbico, clorofila e perda de massa). O delineamento experimental foi inteiramente casualizado (DIC) com cinco repetições por tratamento, observando-se a interação entre os métodos de resfriamento e tempo de armazenamento, e estes parâmetros foram submetidos à análise estatística multivariada aplicando-se a análise de componentes principais. Conclui-se que o melhor método para o resfriamento de alface é o do ar forçado com umidificação, pois equilibra eficiência de resfriamento e menor degradação do produto. O resfriamento da alface pelo método evaporativo apresenta uma lenta retirada de calor especifico, desfavorecendo a manutenção da vida útil do produto, assim como o método por água fria que causa acúmulo de água no interior do produto facilitando as reações de deterioração. Com relação à análise de custo energético, o resfriamento de alface pelo método ar forçado se torna mais interessante em termos de aplicabilidade e manutenção da qualidade do produto, mesmo apresentando um maior custo se comparado ao resfriamento de alface pelo método evaporativo
Abstract: The leafy vegetable most consumed and produced in Brazil is the lettuce (Lactuca sativa L.) and its consumption is growing up every year due a tendency of world population to acquire healthier lifestyle. There are different cooling methods for post-harvest quality, already used and applied in vegetable crops, but there is no knowledge about yours effects and benefits for lettuce. The objective of this study was evaluating the application of different cooling methods and their suitability for different varieties of lettuce. The types of lettuce analyzed were "repolhuda crespa" ou "americana", a "solta crespa", a "repolhuda lisa" e a "solta lisa", acquired from a region producer in Campinas-SP. We evaluated three cooling methods followed to a storage in cold chamber at 5 ° C: forced air cooling (with relative humidity control and no relative humidity control), evaporative cooling tunnel (misting and porous-fan) and hydroccoling (immersion and spray), and control consisted in the product cold storage at 5°C, was evaluate the physic-chemical parameters (pH, ascorbic acid, chlorophyll and weight loss). The experimental design was completely randomized, with five replicates per treatment, observing the interaction between cooling methods and storage time, and these parameters were subjected to multivariate statistical analysis with applying the principal component analysis. It is concluded that the best method for cooling lettuce is forced air with humidification it balances cooling efficiency and less degradation of the product. The cooling of the lettuce by evaporative method has a slower specific heat removed, which does not favor the maintenance product shelf-life, as well as the hydrocooling causes water accumulation in the product facilitates the degradation reactions. Regarding the analysis of cost energy, the cooling lettuce by forced air method becomes more interesting in terms of applicability and maintenance at product quality, even with a higher cost compared to the cooling of lettuce evaporative method
Mestrado
Tecnologia Pós-Colheita
Mestre em Engenharia Agrícola

Orientador: Benedito Carlos Benedetti
Texto em português e Inglês
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: Botrytis cinerea Pers, causador da doença conhecida como mofo cinzento, é o principal problema para a conservação pós-colheita de uvas de mesa. A utilização do dióxido de enxofre (SO2) é a prática pós-colheita mais comum para o controle desta doença. Pesquisas buscam alternativas a este produto devido às reações que causa em pessoas alérgicas, danos que pode causar nos frutos e às restrições ao seu uso em sistemas de produção orgânico. Foram avaliados os efeitos da aplicação de uma atmosfera de 40% de CO2 por 24 ou 48 horas (pré-armazenagem) combinado com armazenagem em atmosfera controlada (AC) (12% O2 + 12% CO2) no controle de B. cinerea, e nos atributos de qualidade de uvas 'Flame Seedless' e 'Crimson Seedless'. Também foram avaliados, em uvas 'Crimson Seedless', e os efeitos da associação deste tratamentos com aplicações pré-colheita de cloreto de cálcio (CaCl2) ou dióxido de cloro (ClO2). Os tratamentos foram aplicados em uvas orgânicas infectadas de três formas: infectadas naturalmente, superficialmente inoculadas com conídios e inoculadas com uma baga coberta de micélio. Uvas 'Flame Seedless', naturalmente infectadas, tratadas com 40% de CO2 por 48 horas + AC apresentaram redução da podridão pós-colheita, de 22% para 0,6%, após 4 semanas, e de 100% para 7,4%, após 7 semanas. O pré-armazenamento em 40% de CO2 sozinho também limitou a incidência de mofo cinzento em frutos infectados naturalmente e em uvas inoculadas artificialmente, porém foi menos eficaz do que quando seguido pelo armazenamento em AC. A aplicação de CaCl2 ou ClO2 em pré-colheita reduziu a incidência do mofo cinzento em uvas 'Crimson Seedless' inoculadas com uma solução de conídios, porém não houve controle quando os cachos de uva foram inoculados com micélio. A aplicação de CaCl2 e ClO2 reduziram o mofo cinzento de 45% para 23,2% e 15.6%, respectivamente, em cachos inoculados com conídios e avaliados após 6 semanas armazenadas 0oC. O pré-tratamento com 40% CO2 + CA não afetou as características físico-químicas e sensoriais de uvas 'Crimson Seedless' ou 'Flame Seedless'. Em experimentos in vitro os tratamentos com 40% CO2 por 24 ou 48 h limitaram o crescimento micelial até 72 horas após o tratamento. A germinação dos conídios de B. cinerea foi retardada por 12h. Os resultados mostram que o pré-tratamento com 40% CO2 + CA possui grande potencial para ser adotado como prática comercial para conservação de uvas orgânicas
Abstract: Gray mold, caused by Botrytis cinerea Pers, is the main postharvest decay of table grapes. The use of sulfur dioxide (SO2) is the common post-harvest practice for its control. Several researchers are looking for alternative methods of control, because SO2 can cause allergic reactions, damage fruits and also it cannot be applied in organic production system. In this thesis, it was evaluated the effects of applying an atmosphere of 40% CO2 for 24 or 48 hours (pre-storage) combined with controlled atmosphere storage (CA = 12% O2 + 12% CO2) in the control of B. cinerea, and the effects in the quality and sensory attributes of 'Flame Seedless' and 'Crimson Seedless' table grapes. In addition, it was evaluated the efficacy of CaCl2 or ClO2 application in pre-harvest alone or in combination with pre-storage of 40% CO2 for 24 h + CA, to control gray mold on 'Crimson Seedless' table grapes, and the determination of the impact of these treatments on fruit quality. The treatments were applied in certified organic table grapes naturally infected, surface inoculated and nesting inoculated (inoculated with an infected berry). After 4 weeks of storage, the pre-storage in 40% CO2 for 48 hours + CA reduced postharvest rot from 22% to 0.6%, and after 7 weeks, the decay was reduced from 100% to 7.4% in 'Flame Seedless' naturally infected. The pre-storage in 40% CO2 alone also reduced the incidence of gray mold in fruits naturally infected and in artificially inoculated, but it was less effective than combined treatment. The application of CaCl2 or ClO2 pre-harvest reduced the incidence of gray mold on grapes 'Crimson Seedless' inoculated with a spore solution, but there was no control when fruits were nesting inoculated. After 6 weeks at 0oC, the application of CaCl2, and the ClO2 in fruits surface inoculated, reduced the gray mold from 45% to 23.2% and 15.6%, respectively. The pretreatment with 40% CO2 + CA did not affect quality and nor sensory attributes for both varieties tested. In vitro experiments, the treatment with 40% CO2 for 24 or 48 h limited mycelial growth for at least 72 hours after treatment. Conidial germination of B. cinerea was delayed for 12 hours. Our results showed the potential that pre-treatment with 40% CO2 associated with CA has to be adopted in commercial practice for preservation of organic grapes
Doutorado
Tecnologia Pós-Colheita
Doutor em Engenharia Agrícola

A legislação atual exige adequações no sistema de produção da canade- açúcar, proibindo gradativamente a queima como método de despalha antes do corte, com o que a colheita deve ser com corte manual ou mecanizado. 37% das terras da região de Piracicaba apresentam declividade acima de 12%, o que dificulta a mecanização da colheita. Os sistemas agroflorestais (SAFs) apresentam potencial para manter a atividade agrícola na região de Piracicaba, dando maior sustentabilidade ao setor sucroalcooleiro. Através de visitas às unidades fornecedoras da região de Piracicaba, foram realizadas entrevistas com fornecedores de cana-de-açúcar, 25 em total, 7 em Rio das Pedras, 10 em Charqueada, 6 em Iracemápolis e 2 em Ipeúna, que trabalham em área própria e têm a atividade canavieira como principal, cadastrados na Associação de Fornecedores de Cana de Piracicaba (AFOCAPI), nos meses de abril e maio de 2002. Os questionários foram elaborados em base naqueles de Caron (1986) e Darolt (2000), considerando indicadores relacionados com a adoção de Sistemas Agroflorestais. Verifica-se o desconhecimento sobre SAFs. Entretanto, quando alertados das vantagens desses sistemas, os fornecedores se interessam pelas possibilidades de aproveitar melhor as áreas declivosas com SAFs. Também, não demonstra resistência natural à mudança tecnológica. Os entraves para a adoção, não são intrínsecos aos fornecedores, mas são principalmente devido às características da própria tecnologia como a adaptabilidade da tecnologia às condições locais, a segurança do mercado para os produtos e a falta de um programa oficial de assistência técnica. Os fornecedores podem investir, desde que a alternativa tecnológica seja rentável. Porém, tem uma aversão ao risco financeiro para investimentos a longo prazo. Dessa forma, o principal impedimento para a adoção de SAFs é a ausência de comprovação concreta das vantagens agronômicas e econômicas desses sistemas.
Present legislation in Brazil, by gradually preventing the sugarcane burnt, provoke adjustments on the production system, mainly by changing the harvest process from that done by labor to mechanized cutting and collection of the stalks. In the region of Piracicaba 37% of the land has an slope of 12% or above, what makes mechanization very difficult. Agroforestry systems (AFSs) have the potential to preserve the agriculture activity in the region of Piracicaba, improving the sustainability of sugarcane production chain. Sugarcane small growers, who cultivate their own land, and have the sugarcane as their main crop and were associated to the regional growers association (AFOCAPI) were visited and interviewed , 25 in total, being 7 in Rio das Pedras., 10 in Charqueada, 6 in Iracemápolis and 2 in Ipeúna sub-regions. A questionnaire, considering indicators related to the adoption of SAFs. It was observed a nonacquaintance about AFSs. However, when warned about the advantages of these systems, growers are interested about the possibilities of better utilize the undulating and steep areas with AFSs. Besides, they do not demonstrate natural opposition to technological changes. Restraint for adoption are not intrinsic to growers but mainly due to the characteristics of the technology itself, as the adaptability of technology to local conditions, the market safety for their products, and the inexistence of a official program of technical assistance. Growers may invest, since the alternative technology is profitable. Nevertheless, the have aversion to financial risk for long term investments. Thus, the major restraint for adoption of AFSs is the inexistence of concrete confirmation of the agronomical and economical advantages of these production systems.

Un des défis majeurs de l’Internet des Objets et, plus généralement, des tous les réseaux de capteurs sans fils, c’est l’alimentation de chaque nœud connecté. La solution la plus commune est d’équiper chaque dispositif d’une batterie mais cela introduit plusieurs contraintes, qui mettent en question la faisabilité de cette approche sur le long terme (durée de vie limité, couts de gestion élevé, empreinte écologique).Cette thèse développe une possible solution basée sur la transmission sans-fils de l’énergie. Un récupérateur d’énergie RF, composé d’une antenne, un redresseur haute-fréquence et un convertisseur élévateur, est présenté. Ce système permet de récupérer les ondes électromagnétiques et de produire une tension continue en sortie, qui peut être utilisé pour alimenter des microcontrôleurs ou des capteurs. L’absence d’une batterie interne augmente la flexibilité globale, surtout pour les situations où le remplacement n’est pas possible (ex. dispositifs implantés, nombre élevé de nœuds, milieux dangereux). Une étude approfondie sur les redresseur intégrés ultra-haute-fréquence de type Schottky et MOS a été mené ; plusieurs topologies ont été analysées et optimisées. De plus, l’utilisation d’un convertisseur élévateur a été envisagée, dans le but d’accroitre la tension en sortie ; une première version discrète et puis une plus compacte version intégrée, ont été abordées et testées. Ces développements ont permis d’aboutir à un récupérateur complet, potentiellement capable d’alimenter un microcontrôleur du commerce
One of the challenges of the Internet of Things and, more in general, of every wireless sensor network is to provide electrical power to every single one of its smart nodes. A typical solution uses batteries but various major concerns reduce the long-term feasibility of this approach (limited lifetime, maintenance and replacement costs, and environmental footprint).This thesis develops a possible solution based on the wireless transmission of power. A complete RF harvester composed of an antenna, a UHF rectifier and a step-up voltage converter is presented. This system captures electromagnetic waves and converts them to a stable DC voltage to supply power to common logic circuits like microcontrollers and sensors. The lack of an internal battery provides an extended flexibility, especially when its replacement is not a viable option (ex. implanted devices, large number of nodes, dangerous environments, etc.). An in-depth study of integrated Schottky and CMOS UHF rectifiers is carried out; various topologies and optimizations are analyzed. Moreover, the use of an additional step-up converter is proposed in order to increase the system output voltage; an early discrete implementation and a final, more compact, integrated version are discussed and tested. These developments lead to a complete system capable of potentially powering an application with an off-the-shelf microcontroller

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Outra
A Batata-doce é um alimento versátil, de fácil aquisição e produção, entretanto, as raízes apresentam inconvenientes como desuniformidade, descasque e rápido escurecimento após o corte, por isso, esse vegetal mostra-se um produto com características a serem superadas pelo processamento mínimo. O uso de agentes antioxidantes e/ou tratamento térmico tem apresentado efeitos satisfatórios na qualidade pós-colheita de produtos hortícolas. Os ácidos cítrico e ascórbico atuam na inativação de enzimas responsáveis pelo escurecimento, devido à redução de pH e ação antioxidante, respectivamente. O tratamento térmico moderado que age na inativação de enzimas do escurecimento sem alterar a textura do vegetal. Nesse contexto, o objetivo desse estudo foi avaliar o efeito do ácido cítrico, ascórbico e tratamento térmico em diferentes concentrações e tempos na qualidade de batata-doce minimante processadas. As raízes de casca rosada e polpa amarela, foram, higienizadas, descascadas e feitos cortes transversais ao eixo principal obtendo rodelas de 1 cm de espessura, que foram submetidas a diferentes tratamentos, à saber, imersão em soluções de ácido citrico (AC) à 0, 1, 2 e 3% por 1 min; ácido ascórbico (AA) à 0, 1, 2 e 3% por 1min e tratamento térmico (TT) à 50°C por 0, 1, 3 e 5 min. Em seguida as batatas-doce foram centrifugadas e armazenadas em bandejas de tereftalado de polietileno (PET) a temperatura de 5 °C e 85% UR por um período de 8 dias. A cada 2 dias avaliou-se a perda acumulada de massa fresca, firmeza, índice de brancura, o pH, acidez titulável, sólidos solúveis, atividade respiratória. Amostras foram congeladas e armazenadas para análises posteriores de compostos fenólicos, atividade das enzimas peroxidase (POD), polifenoloxidase (PPO) e açucares solúveis. Batata-doce minimamente processada tratadas com 2% de ácido cítrico mostraram melhores resultados no escurecimento enzimático e qualidade do vegetal, enquanto o ácido ascórbico na concentração de 2%, apresentou melhor resultado na diminuição da atividade enzimática e qualidade do vegetal. O tratamento térmico a 50°C por 3 min, mostrou-se eficiente na qualidade de batata-doce minimamente processada.
Sweet potato is a versatile food, easy to acquire and produce, however, the roots present disadvantages such as unevenness, peeling and fast darkening after cutting, so this vegetable shows a product with characteristics to be overcome by the minimally processed. The use of antioxidants and / or heat treatment has shown satisfactory effects on the post-harvest quality of vegetables. The citric and ascorbic acids act in the inactivation of enzymes responsible for darkening, due to the reduction of pH and antioxidant action, respectively. The moderate heat treatment that acts in the inactivation of darkening enzymes without changing the texture of the vegetable. Therefore, this study aims to evaluate the effect of the acids citric and ascorbic combine with heat treatment at different concentrations and times in the quality of sweetened sweet potato processed. The roots with rosy peel and yellow pulp were cleaned, peeled and cut transversally around the principal axis, obtaining slices with 1 cm of thickness. The slices were submitted to different treatments, namely immersion in citric acid solutions (AC) at 0, 1, 2 and 3 % for 1 min; ascorbic acid (AA) at 0, 1, 2 and 3 % for 1min and, heat treatment (TT) at 50 °C for 0 (immersion in water at room temperature), 1, 3 and 5 min. Then, the pretreated sweet potatoes were centrifuged and stored in polyethylene terephthalate trays (pet) at 5°c and 85±5 % RH for a period of 8 days. Every 2 days the loss of accumulated fresh mass, firmness, whiteness index, pH titratable acidity, soluble solids and respiratory activity were evaluated. Samples were frozen and stored for further analysis of phenolic compounds, peroxidase enzyme activity (POD), polyphenoloxidase (PPO) and soluble sugars. The acid citric concentration of 2% provided the best whiteness index of the slices. Minimally processed sweet potato treated with 2% citric acid presented better results in enzymatic darkening and vegetable quality, while ascorbic acid at 2% concentration showed better results in the decrease of the enzymatic activity and the quality of the vegetable. The heat treatment at 50 °C for 3 min was efficient in the quality of the minimally processed sweet potato.

Derome Skog AB is a purchase company whose main task is to provide Derome Timber's sawmills in Halland with timber raw material. Because of the very hard competition in the roundwood market it is important to know what kind of purchase offers are required in order to buy a valuable product from forest owners. This study aims to elucidate the crucial factors when private forest owners choose to harvest and sell their forest. As base for this study, a questionnaire has been performed with private forest owners. The result of the study shows that it is not particularly often that the timber price is the crucial factor why the forest owners choose to harvest and sell the forest products; i.e. timber, pulpwood as well as energy assortments. Most often, it is entirely other reasons which drive the forest owner to harvest. The price of timber is however very important and can very well be the factor that determine to whom the forest owner chooses to sell his timber.

Recent advances in wireless sensor nodes, data acquisition devices, wearable and implantable medical devices have paved way for low power (sub 50uW) devices. These devices generally use small solid state or thin film batteries for power supply which need replacement or need to be removed for charging. RF energy harvesting technology can be used to charge these batteries without the need to remove the battery from the device, thus providing a sustainable power supply. In other cases, a battery can become unnecessary altogether. This enables us to deploy wireless network nodes in places where regular physical access to the nodes is difficult or cumbersome. This thesis proposes a design of an RF energy harvesting device able to charge commercially available thin film or solid-state batteries. The energy harvesting amplifier circuit is designed in Global Foundry 0.13um CMOS technology using Cadence integrated circuit design tools. This Application Specific Integrated Circuit (ASIC) is intended to have as small a footprint as possible so that it can be easily integrated with the above-mentioned devices. While a dedicated RF power source is a direct solution to provide sustainable power to the harvesting circuit, harvesting ambient RF power from TV and UHF cellular frequencies increases the possibilities of where the harvesting device can be placed. The biggest challenge for RF energy harvesting technology is the availability of adequate amount of RF power. This thesis also presents a survey of available RF power at various ultra-high frequencies in San Luis Obispo, CA.The idea is to determine the frequency band which can provide maximum RF power for harvesting and design a harvester for that frequency band.

La production de dattes ne cesse d’augmenter d’une saison à une autre ce qui engendre des pertes essentiellement lors des étapes de manutention et de commercialisation. De plus, l’étape de manutention post-récolte joue un rôle important dans le maintien de la qualité des dattes. Dans ce cadre et afin de préserver les qualités organoleptique et nutritionnelle des dattes après récolte tout en améliorant leur valeur commerciale, des essais de conservation et de traitement post-récolte ont été mis en place. L’effet de la conservation des dattes en fonction de la température, du temps, de l’utilisation d’atmosphère modifiée lors du stockage et d’un traitement thermique sur la fermeté, la couleur, et les teneurs en sucres, acides organiques, polyphénols et parois cellulaires a été étudié. Les dattes du cultivar ‘Deglet Nour’ récoltées en 2017 et 2018 au stade Tamr ainsi que les dattes communes ‘Arichti’, ‘Bouhattam’, ‘Bser Hlou’ consommées à un stade de maturité précoce (stade Khalal) ont été conservées à -18, 0, 2 et 4 °C pendant 3, 6 et 9 mois et à 2 °C pendant 30 et 60 jours, respectivement. La spectroscopie Moyen Infrarouge (MIR) en tant que méthode non destructive et non ciblée a permis de mettre en évidence l’effet de l’année de récolte par rapport à la composition chimique et de discriminer les échantillons de dattes ‘Deglet Nour’ conservés à 4 et 2 °C. Le rendement en parois cellulaires assimilées aux fibres, ainsi que les procyanidines représentant 98% des polyphénols totaux sont stables durant la conservation du cultivar ‘Deglet Nour’ et du cultivar ‘Arichti’ quel que soit la température et la durée de conservation. En revanche, ces composants sont ceux qui sont les plus affectés par les conditions de conservations dans le cas des cultivars ‘Bouhattam’ et ‘Bser Hlou’. Ce dernier est le cultivar le plus ferme et le plus apprécié par les consommateurs, en raison notamment de l’augmentation des teneurs en sucres réducteurs affectant son goût sucré lors de la conservation. De ce fait, une conservation des dattes ‘Deglet Nour’ à -18 °C pourrait être une solution pour un stockage à long terme, par contre en raison des coûts énergétiques élevés, 2 °C est la température optimale de conservation. En outre, afin de bien valoriser les dattes communes et prolonger leur durée de vie, la durée de conservation peut être prolongée pour le cultivar ‘Arichti’, une optimisation de la température de conservation pour le cultivar ‘Bser Hlou’ et ‘Bouhattam’ sera cependant nécessaire. Les dattes précédemment citées ont été également conservées dans différents types d’emballages à atmosphère modifiée (EAM) à 2 °C pendant 3, 6 et 9 mois pour le cultivar ‘Deglet Nour’ et pendant 30 et 60 jours pour les cultivars ‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’. D’une façon générale, ces résultats ont montré que les EAM ont le même impact que la température et la durée de conservation sur la qualité des dattes. Par conséquent, leur utilisation dans les industries de conditionnement de dattes va entrainer des coûts supplémentaires sans effets bénéfiques. L’impact d’un traitement d’hydratation sur les qualités organoleptique et nutritionnelle des dattes a également été évalué. Le traitement des dattes ‘Deglet Nour’ de trois usines de conditionnement différentes, à une vapeur d’eau saturée à 60-62 °C pendant 4 heures a montré qu’elles deviennent plus souples comme attendu, tandis que les paramètres nutritionnels sont resté stables. La spectroscopie Moyen Infrarouge (MIR) a permis de discriminer les dattes des trois usines et il est suggéré qu’elle soit adoptée par les stations de conditionnement comme une nouvelle technique prédictive et non destructive. Ce résultat confirme que le traitement d’hydratation pourrait être fortement recommandé pour valoriser les dattes sèches de faible valeur commerciale, cependant il doit être optimisé pour les dattes très sèches
The production of dates is increasing every season, causing losses especially during post-harvest handling andmarketing. Post-harvest handling plays an important role in maintaining date palm. In order to preserve organolepticand nutritional quality of date palm fruits after harvest with improving their commercial value, storage experiments andpost-harvest treatments have been assayed.The effect of different storage conditions of temperature, time and modified atmosphere, as well as the effectof heat treatment of dates, on firmness, colour, sugars, organic acids, polyphenols and cell walls and compositions havebeen studied.‘Deglet Nour’ date palm fruits of two harvest seasons (2017 and 2018) as well as common date cultivars‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’ consumed at early maturity stage (Khalal stage), were stored at -18, 0, 2 and 4°C for 3, 6 and 9 months and at 2 °C for 30 and 60 days, respectively. Mid Infrared Spectroscopy (MIR) as a nontargetedmethod allowed to highlight a year effect on 'Deglet Nour’ chemical composition and to discriminate samplesstored at 4 and 2 °C regarding to major components (moisture, sugar, organic acids...). Cell wall yields (assimilated tofiber) as well as procyanidins, accounting for 98% of total polyphenols, were stable during ‘Deglet Nour’ and ‘Arichti’cultivars storage regardless of temperature and time conditions. However, these same components were the mostaffected by storage conditions for ‘Bouhattam’ and ‘Bser Hlou’ cultivar. This latter, was the softest cultivar and themost appreciated by consumers, may be because of reducing sugars increase affecting its sweet taste. Thus, stored fruitsat -18 °C could be the solution for a long-term storage but due to its high energetic costs, 2 °C must be the optimaltemperature. Moreover, in order to valorize common dates palm and prolong their shelf life, storage time could beprolonged for ‘Arichti’ cultivar with temperature storage ptimization for ‘Bser Hlou’ and ‘Bouhattam’ cultivars.Date palm fruits mentioned above, were also stored under Modified Atmosphere packaging (MAP) at 2°Cduring 3, 6 and 9 months for ‘Deglet Nour’ and during 30 and 60 days for commons cultivars (‘Arichti’, ‘Bouhattam’and ‘Bser Hlou’). In general, differences were observed on physical and chemical parameters using different MAPstreatments for ‘Deglet Nour’date palm fruits. Dates became darke with MAPT and MAPA storage. Dates palm storedunder this latter MAP bag showed an increase on procyanidins, some cell walls compositions, fructose and citric acid.Firmness loss of this cultivar was delayed with MAPZ storage with polyphenols stability. This latter bag type conservedfirmness and colour of the three studied cultivars (‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’) were stabe with no differencecomparing to control (without MAP). Organic acids, cell walls yield and composition, polyphenols were also stableduring storage. Only sugars contents of every cultivars had different behaviour.These results showed that MAP bags had very lower benefical effects than storage time and temperature on ‘date palmquality. So, their use in date processing industries could have more costs with no apparent effects.The organoleptic and nutritional quality of ‘Deglet Nour’ date palm was also evaluated before and afterhydration treatment commonly used in date prcessing units (DPU), in order to become more commercially valued andto minimize waste generated along the date palm fruit supply chain. Hydration treatment under saturated steam at 60-62°C for 4 hours impoved date fruits texture as expected while nutritional parameters were quite stable. Mid InfraredSpectroscopy (MIR) allowed to discriminate samples from the three DPUs suggesting to be adopted in DPU as a newpredictive and no destructive technique. So, hydration treatment could be highly recommended to valorize fruit byproducts.However, it needs to be optimized for the very hard-type dates
انتاج التمور في ارتفاع مستمر من موسم الى اخر مما يجعل مراكزالفرز و التخزين تتخلص من كميات هائلة من التمور المتضررة أثناءعمليات الفرز والتسويق. هذه العمليات تلعب دورا هاما في الحفاظ على جودة التمور. ومن أجل الحفاظ على الجودة الغذائية للتمور بعد الجنيمع تحسين قيمتها التسويقية، تم القيلم بتجارب التخزين وبعض معالجات ما بعد الجني.وقد تم دراسة تأثير ظروف التخزين المختلفة من درجة الحرارة، مدة الخزن وتقنية الجو الهوائي المعدل، وكذلك تأثير معالجة التمور الجافةعلى الصلابة، اللون، السكريات، الأحماض العضوية، البوليفينول وجدران الخلايا النباتية (الالياف) ومكوناتها.تم تخزين تمور ’ دقلة النور’ لصابة 2017 و 2018 والأصناف الأخرى من التمور الأقل انتشارا مثل ’ الارشتي’، ’ بو حتم’، ’ بسر حلو’18 درجة مائوية وفي 2 درجة مائوية لمدة - ,0 ,2 , التي تستهلك في مرحلة متقدمة من النضج (خلال)، لمدة ثلاثة، ستة وتسعة أشهر في 430 و 60 على التوالي. اثبت التحليل الطيفي بالأشعة تحت الحمراء الوسطى ان سنة الجني لها تاثير على العناصر الكيميلئية للتمور’ دقلةالنور’ وقامت بتمييز التمور المخزنة في 2 و 4 درجة مائوية بالنسبة لاهم مكوناتها (الماء، السكريات، الأحماض العضوية...). اثبت النتائجان جدران الخلايا النباتية (الالياف) وان أكبر مكونات البوليفينول (بروسيانيدين) كانت مستقرة اثناء تخزين تمور’ دقلة النور’ و ’ الارشتي’،بغض النظر عن درجة حرارة ومدة التخزين. نفس هذه العناصر كانت الأكثر تاثرا بعوامل التخزين بالنسبة لاصناف’ بو حتم’ و ’ بسرحلو’. هذا الصنف الأخير كان الأكثر ليونة مع تغير بنية جدران الخلايا على الرغم من انه أكثر صنف قابلية لدى المستهلك، من الممكنبسبب ارتفاع كمية السكريلت السريعة التي اثرت على مذاقه الحلو.فبحيث ان تخزين التمور ’ دقلة النور’ في - 18 درجة مائوية من الممكن ان يكون أحسن حل على مدى طويل، لكن نظرا لتكاليفة الطاقيةالباهضة، تخزين التمور في 2 درجة مائوية يجب ان يكون أفضل حل. بصفة عامة لم يكن هناك خسائر هامة للقيمة الغذائية بالنسبة لاصنافالتمور الاخرى اثناء التخزين، مما يجعل التمديد في مدة التخزين ممكنا بالنسبة اصنف’ الارشتي’ مع البحث عن درجة حرارة تخزين ناجعةالصنف ’ بسر حلو’ و’ بو حتم’.تم ايضا تخزين انواع التمور المذكورة اعلاه بتقنية الجو الهوائي المعدل في 2 درجة مائوية لمدة ثلاثة، ستة وتسعة أشهربالنسبة ’ لدقلةالنور’ ولمدة 30 و 60 يوم بالنسبة للاصناف الأخرى. بصفة عامة هناك اختلافات في العناصر الفيزيلئية والكيميلئية ’ لدقلة النور' المخزنةفي كل أنواع تقنيات الجو الهوائي. ' دقلة النور' المخزنة في أكياس ترندلايف و ايباك. أصبحت داكنة الون.دقلة النور المخزنة في أكياس ' سجلت ارتفاعا في مكونات جدران الخلايل, بروسيانيدين, الفروكتوز و حامض السيتريك. تخزين' دقلة النور'في أكياس زويباك اخرت في ليونتها مع استقرار في البوليفينول. هذه النتائج اثبتت ان تخزين التمور في اكياس الجو الهوائي المعدل لم تكنذو نجاعة عالية مقارنة بعوامل الحرارة والمدة الزمنية.لون وصلابة التمور من اصناف ’ الارشتي’، ’ بو حتم’، ’ بسر حلو’ اثبتت استقرارها بعد تخزينها في أكياس زويباك, لكن بعدم ايجاد فرقمقارنة بالتمور المخزنة بدون اكياس الجو الهوائي المعدل, مثلها مثل بقية العناصر الفيزيلئية والكيميلئي بصفة عامة. هذا يثبت ان استعمالهافي مصانع تخزين التمور ليس له جدوى اقتصادية واضحة.تم دراسة مدى تاثر القيمة الغذائية لتمور ’ دقلة النور’ الجافة على إثر معالجتها وترطيبها بالطريقة الهعتدة في اغلب مصانع تخزين التمور62 درجة مائوية لمدة 4 ساعات - لتكون ذات قيمة تسويقية عالية ولتقليص كمية الخسائر. تقنية ترطيب التمور على طريقة البخار في 60اثبتت نتائج ناجعة كما كان متوقع مع المحافضة على استقرار المكونات الغذائية. طريقة معالجة التمور بترطيبها هي طريقة متصوح بهالكنها غير ناجة للتمور الأكثر جفافا التي تحتاج تطوير في هذه التقنية

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This research had the objective of evaluating the organic fertilization effects on the production, quality, post-crop conservation and acceptability of fruits of the yellow passion fruit plant (Passiflora edulis, Sims f. flavicarpa Degener). The experiment was established in March 2004, in a red yellow Latosol of Sementeira Experimental Farm - UFV, in Visconde do Rio Branco, MG. The experimental design was completely randomized with 4 repetitions. The treatments were formed by three types of fertilizations applied in the orchard: Mineral (MIN) suitable for the culture (control); Organic (ORG), equivalent to the potassic fertilization suitable for the culture and 2 times organic (2XORG), where was used the ORG treatment double dose. The organic fertilizer used was the bovine fertilizer. In May 2005, fruits from each treatment were transported to the Agro-ecology Laboratory UFV, for quality and post-crop conservation evaluation. In June 2005 fruits from each treatment were selected and transported to the Sensorial Analysis Laboratory of the Food Technology Department UFV, for juice acceptability and fruits appearance evaluation. The yellow passion fruit plant production fertilized with 2XORG and MIN was 26% superior when compared to the plants fertilized with ORG production. The fruits classification (mass and number of defects), was not influenced by the fertilizations. The fruits mass loss from plants fertilized with bovine manure (ORG and 2XORG) was smaller than fruits from plants fertilized with MIN. The fruits fertilized with bovine manure chemicals characteristics (pH, SST, ATT, Vitamin C) were similar to the one of the fruits from plants fertilized with MIN. The fruits juice acceptability from the 3 fertilizations was similar, however, with relation to the appearance, the acceptability was larger for the fruits of the treatment 2XORG.
A pesquisa teve o objetivo de avaliar os efeitos da adubação orgânica sobre a produção, qualidade, conservação pós-colheita e aceitabilidade de frutos do maracujazeiro amarelo (Passiflora edulis, Sims f. flavicarpa Degener). O experimento foi estabelecido em março de 2004, num latossolo vermelho amarelo da Fazenda Experimental da Sementeira UFV, situada em Visconde do Rio Branco, MG. O delineamento experimental foi inteiramente ao acaso com 4 repetições. Os tratamentos foram formados por três tipos de adubações aplicados no pomar: Mineral (MIN) indicada para a cultura (testemunha); Orgânica (ORG), equivalente à adubação potássica indicada para a cultura e 2 vezes orgânica (2XORG), onde foi utilizado o dobro da dose do tratamento ORG. O adubo orgânico utilizado foi o esterco bovino. Em maio de 2005, frutos provenientes de cada tratamento foram transportados ao Laboratório de Agroecologia da UFV para avaliação da qualidade e conservação pós- colheita. Em junho 2005 foram selecionados frutos de cada tratamento e transportados ao Laboratório de Análise Sensorial do Departamento de Tecnologia de Alimentos da UFV para avaliação da aceitabilidade do suco e aparência dos frutos. A produção do maracujazeiro amarelo adubado com 2XORG e MIN foi 26% superior quando comparada com a produção de plantas adubadas com ORG. A classificação dos frutos (massa e No de defeitos), não foi influenciada pelas adubações. A perda de massa dos frutos provenientes de plantas adubadas com esterco bovino (ORG e 2XORG) foi menor do que frutos provenientes de plantas adubadas com MIN. As características químicas (pH, SST, ATT, Vitamina C) dos frutos adubados com esterco bovino foram semelhantes às dos frutos de plantas adubadas com MIN. A aceitabilidade do suco dos frutos provenientes das 3 adubações foram semelhantes, no entanto, com relação a aparência, a aceitabilidade foi maior para os frutos do tratamento 2XORG.

This thesis deals with the fast-growing trees (FGT). The aim of the work will be to create a list of parameters, limiting or conditioning the creation of supply chains (or clusters), focused on the exploitation of local renewable energy sources. The theoretical part will focus on the harvest of FGT and their possible utilization. The practical part includes the views of people, representing different areas. The practical part will also include the calculation of area performance and initial costs in setting up FGT at the village of Smilovy Hory. In conclusion, findings will be summarized and evaluated.

La bioluminescence, production de lumière visible par des organismes vivants, est un phénomène fascinant, en particulier chez les bactéries qui l’émettent de façon continue. Pour ce projet interdisciplinaire, ces travaux de thèse ont mêlé recherche fondamentale et appliquée, et se sont articulés autour de la problématique suivante : la bioluminescence bactérienne peut-elle être mise au service d’un modèle d’habitat durable ?Ce manuscrit se compose (i) d’un premier chapitre introductif sur le phénomène de bioluminescence, intégrant notamment une synthèse bibliographique sur l’importance écologique des bactéries bioluminescentes dans le milieu marin ; (ii) d’un second chapitre montrant que les gènes impliqués dans la bioluminescence ne sont pas toujours régulés par le quorum sensing ; (iii) d’un troisième chapitre se focalisant sur les effets de l’oxygène sur la physiologie de la souche modèle (iv) d’un quatrième chapitre regroupant les informations relatives à une application de la bioluminescence bactérienne et les prototypes développés au cours de cette thèse. Dans ce dernier chapitre, les avantages, ainsi que les limites actuelles, de l’utilisation de la bioluminescence comme source d’éclairage sont énoncés. Les résultats obtenus au cours de ces trois années ont mis en avant des premiers éléments de réponse et ont permis d’acquérir de nouvelles connaissances sur la souche utilisée, et sur les bactéries bioluminescentes d’une façon générale. Ces travaux visent à être poursuivis et approfondis par d’autres recherches, davantage encore axées vers un objectif pratique et appliqué de la bioluminescence
Bioluminescence, the emission of light by living organisms, is a fascinating phenomenon, especially in bacteria that emit it continuously.For this interdisciplinary project, this thesis work mixed fundamental and applied research, and was structured around the following problem: can bacterial bioluminescence be used at the service of a sustainable-habitat model? This manuscript is composed of (i) a first introductory chapter on the bioluminescence phenomenon, including a bibliographical synthesis on the ecological importance of bioluminescent bacteria in the marine environment; (ii) a second chapter showing that the genes involved in bioluminescence are not, in P. photobacterium ANT-2200, under quorum sensing control; (iii) a third chapter focusing on the effects of oxygen on the physiology of the model strain through the use of an semi-automated culture platform allowing controlled and regulated conditionsb; (iv) a fourth chapter gathering information relating to an application of bacterial bioluminescence and the prototypes developed during this thesis. In this last chapter, the advantages, as well as the current limitations, of the use of bioluminescence as a source of illumination are stated. The results obtained during these three years have highlighted initial elements of response and have led to new knowledge on the used strain, and on bioluminescent bacteria in general. This work is intended to be continued and deepened by further research, even more focused on the practical and applied objective of bioluminescence

För att kontrollera så gallringar utförs på ett korrekt sätt genomförs kontinuerliga kvalitetskontroller, dels som enkla egenuppföljningar av maskinförarna men även som mer omfattande gallringsuppföljningar av skogsbolag och skogsägarföreningar. Eftersom dessa kontroller är tidskrävande så görs i dagsläget enbart stickprovskontroller. Skogforsk har utvecklat ett program vid namn hprGallring, som utifrån skördardata beräknar beståndsvariabler och gör en prognos för det kvarvarande beståndet. Syftet med den här studien har varit att undersöka om precisionen i hprGallring är tillräckligt bra för att vara tillfredsställande och på så vis kunna minska ner det manuella arbetet. Resultaten pekar på att hprGallring nästan alltid överskattar grundytan och volym något. Allra tydligast blir det i gallringar som är riktade mot ett visst trädslag, dvs. när trädslagsfördelningen i gallringsuttaget skiljer sig avsevärt från trädslagsfördelningen i det ursprungliga beståndet. I dessa fall stämmer även den prognostiserade trädslagsfördelningen i det kvarvarande beståndet dåligt.
Continuous controls are made to see if the thinning is done as specified. This is made by self-controls by the harvester drivers or more comprehensive controls by the logging companies. Those controls are done by random samples since they are very time consuming. Skogforsk has developed software named hprGallring, which uses harvester data and mathematical algorithms to calculate stand variables and forecasting the remaining stand after thinning. The purpose with this study has been to investigate if hprGallrings forecast is good enough to reduce the manual work. The results show that hprGallring seems to overestimate the basal area and volume. This is most obvious in stands were the thinning are concentrated against a specific sort of wood. The forecast for tree composition in the remaining stand are in these cases very inaccurate.

Rising from the “excess demand” modern societies and economies place on limited road resources, congestion causes increased vehicle emissions, decreases national efficiency, and wastes time (Downs, 2004). In order to minimise congestion’s impacts, traffic management systems gather traffic data and use it to implement efficient management algorithms (Downs, 2004). This dissertation’s purpose has been the development of a distributable vehicle presence detection sensor, which will wirelessly provide vehicle presence information in real time. To address the sensor’s wireless power requirements, the feasibility of self-powering the device via harvested energy has been investigated. Piezoelectric, electrostatic, and electromagnetic energy harvesting devices’ principles of operation and underlying theory has been investigated in detail and an overview presented alongside a literature review of previous vibration energy harvesting research. An electromagnetic energy harvesting device was designed, which consists of: a nylon reinforced rubber bladder, hydraulic piston, neodymium magnets, and wire-wound coil housing. Preliminary testing demonstrated a harvested energy between 100mJ and 205mJ per axle. This amount is able to be transferred to a 100O load when driven over at speeds between 10km/h and 50km/h. Combined with an embedded circuit, the energy harvester facilitated the development of a passive sensor, which is able to wirelessly transmit a vehicle’s presence signal to a host computer. The vehicle detected event is displayed via a graphical user interface. Energy harvesting’s ability to power the embedded circuit’s wireless transmission, demonstrated the feasibility of developing systems capable of harvesting energy from their environment and using it to power discrete electronic components. The ability to wirelessly transmit a vehicle’s presence facilitates the development of distributable traffic monitoring systems, allowing for remote traffic monitoring and management.

Ces travaux de thèse portent sur le développement de nouveaux systèmes piézoélectriques récupérateurs d’énergie à partir de vibrations mécaniques environnementales. L’objectif recherché est d’apporter des solutions à certaines contraintes fortes liées à la miniaturisation de ces systèmes, en vue de leur intégration en technologie MEMS. Les 2 axes majeurs suivis lors de ces travaux sont :(i) la nanostructuration par porosification du substrat silicium. Ce procédé permet de créer des zones fonctionnalisées possédant des propriétés locales de masse volumique et de rigidité plus faibles que celles du substrat silicium. Ceci permet d’une part d’améliorer le coefficient de couplage électromécanique global de la structure et, d’autre part, de maintenir la fréquence de résonance du mode fonctionnel dans une gamme fréquentielle basse (< que 1KHz) compatible avec le spectre de nombreuses sources vibratoires usuelles. Une série de modélisation par éléments finis d’un convertisseur type (poutre avec masse sismique) a établi les paramètres dimensionnels optimaux de la zone nanostructurée. L’efficacité de ce procédé de nanostructuration localisée a ensuite été évaluée expérimentalement sur des membranes en silicium. Il a été observé une réduction de la fréquence de résonance du mode fondamental, tout en minimisant les pertes par un choix judicieux de l’emplacement et de la largeur de la zone poreuse. (ii) Le développement de dispositifs récupérateurs à sensibilité multidirectionnelle. Ces dispositifs permettent de récupérer l’énergie quel que soit la direction de la sollicitation externe. Ils exploitent 3 modes propres distincts de flexion sollicités chacun par une composante particulière (ax, ay ou az) du vecteur accélération caractéristique de la sollicitation. Ces dispositifs basés sur une structure planaire de type double poutres orthogonales avec masse sismique centrale sont facilement intégrables et peuvent être déclinés de l’échelle centimétrique à l’échelle millimétrique en utilisant dans ce cas les technologies de type MEMS. Un modèle analytique simple a d’abord mis à jour les mécanismes énergétiques qui permettent d’obtenir une quantité d’énergie constante lorsque le dispositif est soumis à un vecteur sollicitation de direction quelconque. L’optimisation du coefficient de couplage électromécanique de chaque mode fonctionnel, ainsi que l’ajustement de leur fréquence de résonance ont été obtenu à l’aide d’un modèle à éléments finis. L’ensemble de ces résultats théoriques a été expérimentalement validé à l’aide de prototypes centimétriques
This thesis work focuses on the development of new piezoelectric energy recovery systems from environmental mechanical vibration. The goal is to provide solutions to some strong constraints on the miniaturization of these systems, their integration in MEMS technology. The 2 major lines followed in this work are: (i) the nanostructuring by porosification silicon substrate. This method allows to create functionalized areas having local properties of density and lower rigidity than those of the silicon substrate. This allows on the one hand to improve the overall electromechanical coupling coefficient of the structure and, secondly, to maintain the resonant frequency of the operational mode in a low frequency range (< 1KHz) compatible with the spectrum of Many conventional vibratory sources. A series of finite element modeling of a type converter (beam with seismic mass) established the optimum dimensional parameters of nanostructured area. The effectiveness of this localized nanostructuring method was then evaluated experimentally on silicon membranes. It was observed a reduction of the resonance frequency of the fundamental mode, while minimizing losses by a judicious choice of the location and the width of the porous zone. (Ii) The development of recovery devices multidirectional sensitivity. These devices allow to recover energy regardless of the direction of the external load. They use 3 different eigenmodes bending each solicited by a particular component (ax, ay and az) vector solicitation characteristic acceleration. These devices based on a planar structure type double orthogonal beams with central seismic mass can be easily integrated and can be broken down to centimeter scale at the millimeter scale using in this case the MEMS technologies. A simple analytical model was first updated energy mechanisms that enable a constant amount of energy when the device is subjected to a bias vector in any direction. The optimization of the electromechanical coupling coefficient of each functional mode, and the adjustment of their resonance frequency were obtained using a finite element model. All these theoretical results has been experimentally validated using centimeter prototypes

Récepteurs récupérateurs d’énergie sans fil (WPR) détiennent un avenir prometteur pour la génération d'énergie électrique continue afin d’alimenter complètement ou partiellement les circuits compris dans les systèmes de communication sans fil. Applications importantes telles que l'identification par radiofréquence (RFID) et les réseaux de capteurs sans fils (WSN) fonctionnant aux bandes de fréquences UHF et SHF sont apparues, nécessitant un important effort sur la conception de WPRs d’haute efficacité pour étendre la distance de fonctionnement ou de la durée de vie de ces applications portables. Dans ce contexte, les redresseurs intégrés et les antennes sont d'un intérêt particulier, car ils sont responsables pour la tâche de conversion d'énergie. Ce travail de thèse vise à faire progresser l'étatde l'art à travers de la conception et réalisation de WPRs d’haute efficacité, dès l'antenne jusqu’au stockage de la puissance DC convertie, en explorant les défis d’interconnexion avec leur pleine intégration sur PCBs
Wireless Powered Receivers (WPR) hold a promising future for generating a small amount ofelectrical DC energy to drive full or partial circuits in wirelessly communicating electronic devices.Important applications such as RFIDs and WSNs operating at UHF and SHF bands have emerged,requiring a significant effort on the design of high efficient WPRs to extend the operating range or thelifetime of these portable applications. In this context, integrated rectifiers and antennas are of aparticular interest, since they are responsible for the energy conversion task. This thesis work aims tofurther the state-of-the-art throughout the design and realization of high efficient WPRs from the antennaup to the storage of the converted DC power, exploring the interfacing challenges with their fullyintegration into PCBs

碩士
國立屏東科技大學
熱帶農業暨國際合作研究所
94
This research is focused on the examination of the growth process of the‘ pink’ and ‘da-li’ Waxapple fruit, and to understand the harvesting quality of the ‘pink’ Waxapple fruit in different seasons of various regions. Further, in order to promote exportation, a study of how low temperature storage and packing method can help to prolong the life of the‘pink’ Waxapple fruit after harvest is conducted, which is concluded with a sea transport simulation. The growth curve of ‘ pink’and‘da-li’Waxapple fruits is single S type. During the initial growth stage (within 40 days after flowering), the ‘da-li’Waxapple growth rate is far exceeding the‘ pink’ Waxapple fruit. Both ‘ pink’and‘da-li’Waxapple growth rate stabilized between 65 days after flowering and maturity (late growth stage). As the fruits matured, the ‘da-li’Waxapple shows larger width, volume and weight than the‘ pink’Waxapple ; however, there is no apparent difference between the two Waxapple in the TSS、TA of the fruits, nor the level of vitamin C and the color. The quality of the Waxapple fruit is highly related to the growing region and season. In the Kua-Ping region (i.e. Liugui, Chaozhou, and Linbian areas), for example, the fruit length, weight and volume during the summer time is far more superior than the winter. On the other hand, the TSS level of winter fruit, averaging 10.26°Brix, is higher than the summer fruit, averaging 9.72°Brix, in the tested areas. As for the level of color changes, as compared between different regions, Waxapples grown in the Linbian area during summer time show the darkest color with charms angle of 38.75 degree. For fruits grown in Liugui and Chaozhou areas during winter show a darker color with charms angles of 34.44 degree and 34.52 degree, respectively. The fruit quality shows different level of changes after storing under different temperatures (0 ℃ , 5 ℃, 10 ℃ and 15 ℃) fourteen days after harvest. The degree of hardness of the fruit decreases as the storing temperature increases. Further, after restoring to the normal temperature (25 ℃ for two days), the hardness of the fruit reduced significantly. The storing temperature and length of time (14 days) has no apparent influence on the TSS ; however, the level of TA tends to be reduced. Storing Waxapple fruit under low temperature could cause cold damage. After storing Waxapple fruit at 0 ℃ for seven days, regardless if restoration to the normal temperature (25 ℃ for two days) takes place, the fruit suffers severe cold damage. Storing the fruit at 5 ℃ for seven days, some symptoms of cold damage are seen, and after restoration back to normal temperature (25 ℃ for two days), the symptoms deepened. For storing conditions under 10 ℃ and 15 ℃ for 21days, no symptoms of cold damage are found; however, slight molding and signs of disease infections were found. As for the effect on the Waxapple fruit quality and storage life under storage, different methods and material of packaging are compared. As a result, the thickness of the PE bags, whether the bags were being sealed, and whether adding non-woven fabrics and ethylene absorbent, no significant effect on the fruit hardness, density, the ratio of dry weight and water content is found. Further, fruits under various methods of packaging stored under 13℃ show no significant reduction in quality; however, fruits stored at 13℃ without any packaging for 14 days were all gone rotten. In an empty container, the speed of temperature reduction at the bottom of mid-rare section is the fastest; on the contrary, the upper-front section is slowest. To simulate transporting Waxapple via sea freight (setting the storage temperature at 12℃), fruits were boxed and placed in the container for 21 days. After the shipping period, the quality of the fruit was severely damaged, which were mostly rotten or showed symptoms of pitting, reducing the commercial value of the fruit to less than 20%.

碩士
國立中興大學
園藝學系
92
The objectives of this study were to investigate the effects of temperatures on the storage life and fruit quality of the ‘Fuyu’ persimmon with a view to defining the best storage temperature and condition, reducing chilling injury and fruit softness, and improving the quality as well as commercial value of the fruits. The best time to harvest of ‘Fuyu’ persimmon fruit in the medium elevation mountain regions of central Taiwan should begin on 25th of November as far as maturity is concerned. At this time the average fruit weight reaches 285.2g, its total soluble solid content approaches more than 14.7∘Brix, and its peel color turns orange red. All these promises better economical values. However, in terms of storage, it is more preferable to picj them from 9 to 23, December. During this period, the fruits remain firm, with lower respiration rate and more red skin color, heavier weight, way ahead of the pre-climacteric and closer to Chinese New Year. The results indicated that persimmon fruits, which were stored at 6-15℃ for 4 weeks, developed the symptoms of translucent peel and softening flesh soon after returning to the room temperature. Softness also occurring in fruits stored at 1 or 3℃, but the damage was less extensive. It is concluded that suitable storage temperature for persimmon cv. ‘Fuyu’ should be below 1℃. The storage life of highly mature fruits is 4 weeks at 1℃. The persimmon fruits when soaked in AVG before storage could delay the occurrence of climacteric peak by inhibiting respiration and ethylene production. The same effects were obtained by spraying AVG solution on the tree 2-3 weeks before harvest. Treatment of persimmon with 1-MCP and hot water (53℃, 50min) before storage could delayed softening and turning of fruit color and prevented chilling injury from occurring. However, black scorch could appear on the peel of some fruits, which affected the appearance and marketing values. In addition, 1-MCP treatment inhibited ethylene action thus retained the firmness of ‘Fuyu’ fruits. Hot water (53℃, 50min) treatment of persimmon fruits harvested on 22nd December, the storage life was prolonged to 8 weeks under 1℃ storage condition.

Using piezoelectric materials to harvest the energy of vibration is a popular and fast-growing field of study. This report details an attempt to use piezoelectric energy harvesting techniques to support an interesting and engaging lab experience for high school engineering students in which the vibration of musical instruments (specifically drums, for this report) is harnessed to power a string of decorative LEDs. The likelihood of the energy harvesting actually being successful enough to light the LEDs was not known before undertaking this lab, so the goals of the project became twofold: 1. Conduct the experiment from scratch to determine if a substantial amount of energy can be harvested from the instruments (enough to reach the goal of lighting the LEDs), and 2. Identify how this lab experience (or one similar to it, if the goal of lighting the LEDs is unattainable) can be beneficial to high school engineering students. The purpose of this report is to summarize the research that was carried out to harvest energy from drums using piezoelectric technology, and to outline how similar lab exercises can be utilized in the high school engineering classroom setting.
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This thesis describes the Operational Harvest Scheduling (OHS) problem and develops an algorithm that solves instances of the problem. The solution to an OHS problem is an Operational Harvest Schedule (OHS). An OHS: ² assigns forest harvesting crews to locations within a forest in the short-term (4-8 weeks); ² instructs crews to harvest specific log-types and allocates these log-types to customers; ² maximises profitability while meeting customer demand. The OHS problem is modelled as a Mixed Integer Linear Program (MILP). The formulation given in this thesis differs significantly from previous literature, especially with regard to the construction of the problem variables. With this novel formulation, the problem can be solved using techniques developed in previous work on aircraft crew scheduling optimisation (Ryan 1992). These techniques include constraint branching and column generation. The concept of relaxed integer solutions is introduced. A traditional integer solution to the OHS problem will require harvesting crews to move between harvesting locations at the end of a week. However, a relaxed integer solution allows crews to move at any time during a week. This concept allows my OHS model to more effectively model the practical problem. The OHS model is formulated for New Zealand and Australian commercial forestry operations,though the model could be applied to other intensively managed production forests. Three case studies are developed for two companies. These case studies show improvements in profitability over manual solution methods and a significant improvement in the ability to meet demand restrictions. The optimised solutions increased profit (revenue less harvesting and transportation costs) by between 3-7%, while decreasing the total value of excess or shortfall logs by between 15-86%.

A replacement for silver thiosulphate as a commercial post-harvest treatment needs to be found. The longevity of cut carnation flowers is extended by all concentrations of ethanol tested. Compared to a water control, the vase-life of ethanol-treated flowers is between 150 and 250% longer. The greatest longevity increases are recorded with 3% ethanol. The use of ethanol as a post-harvest treatment was tested. The longevity increase as a result of ethanol application only occurs if the ethanol is applied as a holding solution. Pulse treatments are not effective at delaying the senescence of the flowers. The sooner the ethanol is applied, the greater the increase in vase life. If ethanol treatment is halted at any point during the experiment, the longevity of the flowers is reduced. It was observed that the longer the stems of ethanol-treated flowers, the greater the longevity increases. The ethanol holding solution does not prevent the action of external ethylene, thereby restricting the potential of ethanol as a commercial post-harvest treatment. Physiologically, flowers treated with ethanol exhibit a different senescence process to control flowers. The typical in-rolling of the petals of carnation flowers is not seen, instead the petals appear burnt. The ovaries are also notably effected by ethanol, being smaller and more yellow in colour. Ethanol treatment results in longevity increases by inhibiting the formation of ethylene, the plant hormone responsible for senescence. The concentration of the direct precursor to ethylene, ACC, as well as the activity of the enzyme that converts ACC to ethylene, ACC oxidase, is reduced to almost zero in the tissues of treated flowers. Another physiological factor affected by ethanol treatment is the carbohydrate status of the flowers. The normal sink activity of the ovary is inhibited by ethanol treatment. Although the carbohydrate content of the petals is found to decrease sharply in ethanol-treated flowers, these carbohydrates are not relocated to the ovary. The ovary does not increase in dry matter or chlorophyll content. The carbohydrate content decreases as a result of ethanol treatment, and when ¹⁴C sucrose was applied to petals, no radioactivity was recovered in the ovary. The petals and ovary are the organs most effect by ethanol activity, as when ¹⁴C ethanol was applied to cut carnation flowers as a pulse, the majority of the radioactivity was discovered here. The protein content of cells of both organs decreases significantly compared to control flowers. This is a total protein loss, rather than the destruction of specific systems. If the activity of alcohol dehydrogenase is prevented in ethanol-treated flowers, inhibiting the conversion of ethanol to acetaldehyde, no longevity increases are seen. The airspace surrounding treated flowers was found to contain ethanol and small amounts of acetaldehyde. The tissues of flowers treated with ethanol show an increase in the acetaldehyde content, as well as the ethanol content, especially in the ovary. The application of acetaldehyde directly to cut carnation flowers as a holding solution resulted in the vase life of the flowers increased by 150%. To determine the effectiveness of acetaldehyde as a post-harvest treatment, various concentrations of acetaldehyde were applied to cut carnation ftowers as a pulse treatment and a holding solution. Pulse treatments did not increase the vase life of flowers, and resulted in a number of negative effects in the flower. A holding solution of acetaldehyde does increase the longevity of cut carnation flowers, provided it is above a certain concentration. Treatments at concentrations below 1% acetaldehyde appear to promote flower senescence. The use of acetaldehyde as a post-harvest treatment has many of the same disadvantages as ethanol treatment. Acetaldehyde must also be applied as a holding solution for as long as possible. If removed from this solution, death of the organ occurred quickly. Acetaldehyde is also ineffective against external ethylene. A negative effect of acetaldehyde not found in ethanol-treated flowers, is that the longer the stem of cut carnation flowers, the shorter the resultant vase life. Physiologically the responses in cut carnation flowers were very similar to those seen in ethanol-treated flowers. Acetaldehyde inhibited the formation of ethylene completely. Almost no ACC can be found in treated tissues, and the action of ACC oxidase is completely reduced. The petals of acetaldehyde-treated flowers suffer from severe petal browning, rather than in rolling. The ovaries are particularly badly effected by treatment. There are large scale losses in fresh weight and chlorophyll content. The latter results in the ovaries appearing yellow in colour. They also show a loss in structure. The sink activity of these ovaries is destroyed. Like ethanol-treated flowers, the carbohydrate content of both the petals and ovaries are dramatically reduced. When ¹⁴C sucrose was applied to one of the. petals, almost no radioactivity was recorded in the ovary. There. is also a major loss in general protein content, slightly more severe than in ethanol-treated flowers. The conversion of ethanol to acetaldehyde is necessary in order to achieve longevity increases in ethanol-treated flowers. If the conversion of this acetaldehyde to ethanol is prevented in acetaldehyde-treated flower there is once again no longevity increase. Both ethanol and acetaldehyde are required within the system to result in increased longevity. Although ethanol and acetaldehyde treatments result in decreases in the total protein content of the flowers, certain enzymes remain active. Alcohol dehydrogenase is a bi-directional enzyme, capable of converting ethanol to acetaldehyde and then back to ethanol again. The activity of this enzyme, in both orientations, is increased in ethanol and acetaldehyde-treated flowers. The activity of pyruvate decarboxylase, which converts pyruvate to acetaldehyde, is also increased as a result of both treatments. The similarities of the physiological response of cut carnation flowers to ethanol and acetaldehyde post-harvest treatments, and the increased activity of these enzymes, indicate that the effect of both compounds on longevity is closely linked.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2000.

Apples stored onshore in Australia and New Zealand, are maintained at optimal storage conditions with the aid of low temperatures; controlled atmospheres (CA) and new technologies that retard the production or effect of ethylene (AVG and 1-MCP respectively). These technologies allow distribution of the highest quality apples to local and export markets on a year round basis. However, during distribution, maintenance of optimal storage conditions may be lost due to refrigeration system breakdown, operational constraints or management decisions. This thesis quantifies the influence of commercially realistic breaks in optimal storage conditions (temperature and CA) on fruit physiology and quality, both at the time of the break and in subsequent optimal storage conditions. The ‘Cripps Pink’ (‘Pink Lady™’) apple cultivar was chosen for consideration in this thesis because it is a high value cultivar that is of considerable importance to the Australian apple industry. The knowledge of the behaviour of ‘Cripps Pink’ apples in coolstorage conditions (in air and CA) was confirmed through comparison of physiological and quality change behaviour of fruit from three harvests collected in this research and those reported recently by other authors. The investigation of the influence of breaks in temperature control during storage in air at 0°C, revealed that preclimacteric apples exposed to a break in temperature control, were advanced towards the establishment of the climacteric. Postclimacteric apple, responded by doubling ethylene production a short time after return to coolstorage. Harvest maturity, timing of break during coolstorage, length of break of temperature control and multiple breaks in temperature control, had little influence on the increase ethylene production response. Quality factors (firmness, background hue angle, and titratable acidity) were all reduced as a result of exposure to warmer temperatures, but on return to coolstorage temperatures rates of loss in these quality factors were not influenced by the increased ethylene production. Short-term (3-day) breaks in CA while fruit remained at refrigerated temperatures were shown to have no substantial effect on fruit physiology or quality, either during the period of the break in CA or in subsequent CA storage. Breaks in temperature control in combination with breaks in CA were observed to cause a doubling of ethylene production on CA stored apples regardless of being returned to 0°C in air or CA. Those apples that were exposed to a break in temperature control and returned to air storage at refrigerated temperature lost quality (firmness and background hue angle) more rapidly than apples not exposed to breaks in temperature control and transferred to air storage. This result strengthened the knowledge of the influence of ethylene on changes in apple quality, as found for many other apple cultivars. The influence of the decision to transport fruit in CA or air atmosphere shipping containers was initially investigated with a laboratory simulation. Physiology (respiration rate and ethylene production) of air shipped fruit was found not only to be more rapid, but more variable between fruit, than for apples shipped in CA. This more rapid and larger variation of possible fruit physiologies, suggests that in addition to losing quality at a faster rate, the variation in the quality of fruit shipped in air will also enlarge during shipment. This hypothesis was confirmed with data pooled from treatments subjected to 0°C and 3°C, simulating the likely temperature variability within a shipping container. Validation of the influence of shipping atmosphere on delivered fruit quality, was conducted in the commercial environment. This trial found that the length of time to ship fruit from Australia and New Zealand to European markets was not sufficient to induce commercially significant differences between ‘Cripps Pink’ apples shipped in the two atmospheres. Finally, as ethylene production was influenced by fluctuations in temperature control and subsequently affected quality of apples previously stored in CA, an investigative attempt to model ethylene production in temperature variable scenarios was conducted. Published models of ethylene production in apples were adapted to the variable temperature storage scenario and a new model was proposed. Unfortunately, none of the models investigated were able to predict all of the consistent behaviours of ethylene production observed during the experimental work, indicating that more knowledge of the ethylene production pathway is required, before modelling of ethylene production and subsequently apple quality can be conducted successfully.

The South African Citrus Industry is the second largest exporter of citrus, after Spain. The industry is under pressure to supply high quality fruit as well as to expand into new, high paying markets. However, high paying markets such as Japan and the USA require cold sterilised fruit as obligatory quarantine treatments against Mediterranean fruit fly (Ceratitis capitata) in order to reduce any possible spread of the pest. Citrus fruit originated from tropical climates and hence are chilling susceptible. Chilling injury symptoms appear as dark brown spots, pitting and/or decay when fruit are transferred to shelf temperatures; thus reducing the marketability of citrus fruit. Therefore, there is need for methods to mitigate chilling injury. Previous studies have shown silicon to mitigate many forms of stress without any hazardous effect on human health. Thus, the aim of the study was to investigate the potential of post-harvest silicon dips in mitigating chilling symptoms in citrus fruit. Briefly, fruit from two sources (Ukulinga Research Farm and Ithala Farm) were dipped in different silicon concentrations (0, 50, 150, and 250 mg ℓ-1) for 30 minutes and thereafter stored at -0.5 or 2⁰C for up to 28 days with weekly evaluation for chilling injury symptoms. Total antioxidants were determined using FRAP, ABTS, and DPPH assays under spectrophotometer. In addition, sugars, ascorbic acid, phenolics and flavonoids were analysed using High Performance Liquid Chromatography (HPLC). Fruit from Ukulinga Research Farm showed significantly higher total antioxidants (ascorbic acid total phenolics and specific flavonoids hesperidin and naringin) and sugars relative to fruit from Ithala Farm. Low concentrations of silicon dips significantly reduced the appearance of chilling injury symptoms by inducing an enzymatic conversion of glucose to ascorbic acid, thereby increasing the antioxidant capacity of chilling susceptible fruit. Moreover, silicon increased the concentration of total antioxidants, total phenolics and total flavonoids. High silicon concentrations had a negative effect on post-harvest quality of lemons by increasing fruit weight loss and electrolyte leakage, resulting in appearance of chilling symptoms. In conclusion, the study showed that silicon had potential to reduce chilling injury. However, high silicon concentrations raised concern, in particularly, on fruit appearance.
Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
Coffee is a major source of foreign currency of Timor-Leste and is the primary source of income for about one quarter of the population. This study characterized the Ermera’s coffee and assesses the impact of soil and climatic conditions and post-harvest technology especially in physical and organoleptic characteristics of green coffee. In the first part of the work, I was accompanied the post-harvest technology practiced by the companies and farmers, picking up 13 samples. Proceeded to the physical analysis of green coffee (weight of 100 grains, bean size, defects and humidity), roasting and sensory analysis. Also evaluated the effect of roasting by the change in volume and weight, color, defects, acidity and moisture content. Concluded that most samples can be classified in the higher classes for export due to high mass values (14.6 and 19.5 g/100 grains) and coarse-grained (17-20 sieves) and low number of defects. In sensory analysis, detected the bitterness is medium, due to presence of “Híbrido Timor”. The samples prepared by the traditional method stood out mainly due to contain a greater number and variety of defects, although this has not been reflected in the organoleptics characteristics. It was not possible to draw conclusions about the effect of fermentation and mechanics un-mucilage. The characteristics of the samples are more related to the production region, which are dependent on the characteristics of cherry and processing.

Active packaging systems can offer significant advantages in preventing quality loss in horticultural products through control of microbial and/or physiological activity. By delivering and sustaining volatile active agents at effective levels in a package atmosphere, significant shelf life extension can thus be achieved. Design of these systems is complicated by the number of possible package, product, active agent and carrier combinations that can be employed and the significant interactions that may occur between these components. Mathematical modelling can be used to simplify system design and reduce the number of experimental trials required to achieve optimal active packaging systems. In this study a generalised modelling methodology was developed and validated to facilitate the design of active controlled volatile release packaging systems for horticultural products. The modelling methodology was developed using an example system which comprised tomatoes packed under a modified atmosphere (MA; 5 % (v/v) CO2 and 10 % (v/v) O2) in a LDPE bag with a polymer film sealed sachet containing silica gel pre-saturated with the antifungal agent hexanal. Experimental trials showed that for this system a target sustained hexanal concentration of 40-70 ppm was required. This was shown to be (i) the minimum inhibitory concentration (MIC) for controlling Botrytis cinerea growing on tomatoes stored at 20°C and ~99%RH, (ii) to have only a relatively minor influence on the postharvest quality of tomatoes under these active MA conditions, and (iii) to promote only a small apparent uptake of hexanal from the atmosphere by the tomatoes. The effective hexanal permeabilities of Tyvek , LDPE and OPP sachet films were characterised using the isostatic method and shown to exhibit a dependence on both temperature (10 and 20°C) and concentration (over a range of 0.01-0.22 mol m[superscript -3). Average permeabilities decreased in the order of Tyvek > LDPE > OPP, respectively, at all temperatures at comparable hexanal partial pressures. Hexanal sorption isotherms for silica gel at both 10 and 20ºC were determined using the gravimetric method and were reasonably well described by the Langmuir equation. The equilibrium amount adsorbed was significantly reduced at the higher temperature but the pre-adsorption of water vapour on hexanal uptake on silica gel showed no uniform trend on the sorption characteristics suggesting that multicomponent sorption is complex. A generalised modelling methodology was developed through conceptualising key mass transfer processes involved in these active MA packaging systems. Quantitative methods for deciding the relative importance of each process were established together with guidelines for when simplifying assumptions could be made. This information was formalised into a decision tree to allow appropriate assumptions to be made in model formulation without unacceptable loss of model accuracy. Methods to develop generalised equations from these assumptions to describe changes in the sachet, package headspace and outer bag film with respect to an active agent and MA gases were then identified. The mathematical modelling methodology was applied to the example hexanal release active MAP tomato packaging system. For these systems there was a high initial peak in package headspace concentration during the first 24 h which declined to a quasi steadystate concentration over a period of days. The quasi steady-state headspace concentrations were generally in the MIC range and were well predicted by the model. Interactions between water vapour and silica gel may have been responsible for the relatively higher hexanal concentration at the onset of release from the Tyvek sachet (a highly porous material). However the influence of water vapour (>95% RH in the MA bag containing tomatoes) during the quasi steady-state period appeared to be insignificant for all sachet films. The model was successfully applied to a range of packaging configurations and storage temperatures. A lack of fit was evident between model predictions and experimental trials during the initial (unsteady-state) stages of the release pattern for both headspace vapour concentrations and adsorbed mass on the silica gel. These differences were attributed to (i) model input uncertainties, chiefly with regard to the estimated coefficients of both the Langmuir isotherm equation and film permeability, and (ii) overestimated effective permeability values predicted by extrapolation of the concentration dependence of film permeability beyond the conditions for which the permeability was measured. These results suggest improved models for the effective permeabilities of the films, quantified under a range of vapour concentrations and concentration gradients, are required for better describing fluxes across the sachet film. Despite these limitations, the model did describe the general release pattern. The model was then used to pose a range of ‘what-if’ scenarios investigating the release patterns predicted for different active packaging designs. This analysis gave useful insights into how sorption isotherm shape and package/sachet design parameters can be manipulated to achieve different volatile release platforms. The work clearly demonstrated the importance of accurate data for permeability of volatile compounds through polymer films and for sorption of the active agent on the carrier phase. More work on characterising these systems is recommended to further improve modelbased design methods for active MAP systems. Overall the generalised methodology developed can be confidently adopted for constructing a mathematical model that provides sufficient accuracy and simplicity to be implemented for designing active packaging systems for horticultural and food products.

This Master's thesis deals with harvester technology used for forest harvesting, mainly with its efficiency (performance). The thesis describes various types of harvesting in which harvesters are used the most and compares their usage for forest harvesting with the usage of chainsaws. Efficiency is very closely related to the series of inner and outer factors, which influence it both positively and negatively. The impact of these factors is evaluated based on the individual cycles during the harvest and field observations during the variety of harvesting operations. Amongst the most prominent factors are for example operator's experience, type of harvested wood and its characteristics, engine power, performance of hydraulic systems, type of chassis, terrain quality or the influence of meteorological conditions. The aim of this Master's thesis is to perform all necessary measurements and, while using corrected coefficients, alter the calculation of theoretical efficiency to correlate with the actual efficiency.

We followed up with about 2,000 smallholder households in Senegal, two years after these households participated in a randomized controlled trial (RCT) aimed at reducing levels of aflatoxins in smallholders’ stored maize. In the initial intervention, treated households were provided with training on proper post-harvest practices, low-cost moisture meters for testing if maize was sufficiently dry to store, plastic tarps for drying maize of the ground, and hermetic (airtight) storage bags to mitigate aflatoxin development in stored maize. Using cross-sectional follow up data on aflatoxins levels and drying and storage practices from 2019 along with baseline demographic data from 2016, we estimate both the longer-term intention-to-treat (ITT) effects and the treatment on the treated (TOT) effects that the four inputs provided on households’ aflatoxins levels in stored maize. The ITT analyses estimate the intervention’s average effect by treatment group, but this may underestimate the true impact for households who complied with recommended post-harvest practices and adopted the recommended technologies. The TOT analyses estimate the local average treatment effects (LATE) of the intervention, that is its impacts on those who were driven by the intervention to follow best practices or use a given technology. Since the decision to follow these practices or adopt a technology was not random, we instrumented the usage decision with the exogenous, random treatment group assignment to get an unbiased estimate. Outside of our main models, we conducted a heterogeneity analysis to test if households with different characteristics benefit differently from the intervention. We interacted each treatment assignment with various household characteristics, including the woman’s level of involvement in the intervention. Additionally, we estimate the cost-effectiveness of providing training and a tarp, according to WHO guidelines for public health interventions.

碩士
國立中山大學
機械與機電工程學系研究所
101
Small and efficient energy harvesters, as a renewable power supply, draw lots of attention in last few years. This thesis presents a planar rotary electromagnetic generator with copper coils fabricated by printed circuit board (PCB) as inductance and Nd-Fe-B magnets as magnetic member. Coils are fabricated on PCB, which is presumably cost-effective and promising methods. 28-pole Nd-Fe-B magnets with outer diameter of 50 mm and thickness of 2 mm was sintered and magnetized, which can provide magnetic field of 1.4 Tesla. This harvester consists of planar multilayer with multi-pole coils and multi-pole permanent magnet, and the volume of this harvester is about 50x50x2.5 mm3. Finite element analysis is used to design energy harvesting system, and simulation model of the energy harvester is established. In order to confirm the simulation, experiment data are compared with simulation result. The PCB energy harvester prototype can generate induced voltage 1.11 V and 26.54mW output power at rotary speed of 4,000 rpm, and the efficiency of this energy harvester is 31.5%.