Academic literature on the topic 'Leaf concentrates'
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Journal articles on the topic "Leaf concentrates"
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Hernandez, Teresa, Amelia Hernandez, and Carmen Martinez. "Polyphenols in alfalfa leaf concentrates." Journal of Agricultural and Food Chemistry 39, no. 6 (1991): 1120–22. http://dx.doi.org/10.1021/jf00006a025.
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Sodamade, A. "Proximate Analysis, Mineral Content, Amino Acid Composition and Functional Properties of Vernonia amygdalina Vegetable Leaf Protein Concentrates." Greener Journal of Agricultural Sciences 3, no. 3 (2013): 204–10. https://doi.org/10.15580/GJAS.2013.3.011613386.
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Freshly harvested Vernonia amygdalina green vegetable was authenticated and processed for its vegetable leaf protein concentrates with a view to evaluate its proximate constituents, amino acid content and mineral composition. Proximate analysis was determined using standard analytical technique. The nutrient composition of the protein concentrates revealed the moisture content (66.45±0.07), Crude fat (9.20 ±0.85), Crude fibre (10.46±1.05), Crude protein (44.28 ±2.43), ash (12.48± 0.24) and Carbohydrate (23.58±3.4). The mineral content of the sample indicated that Ca, Mg, K, and Na are the most abundant minerals with the following values Na;57.5±0.34,Ca;151.6±1.40, K; 61.5±0.38, Mg; 96.5±0.96, other minerals that were present in the sample in trace concentration are Fe(2.3 ± 0.42), Zn (1.11± 0.11), Mn (0.1± 0.14), Cu (0.1 ± 0.73), Pb (0.1± 0.63),while Selenium were not detected in the sample indicating that the leaf concentrate is fit for dietary consumption. The amino acid profile reveals favourable nutritional balance with the presence of essential and non-essential amino acid except that tryptophan which was believed to be predominant in animal protein was not detected.
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Coldebella, Priscila F., Simone D. Gomes, Janete A. Evarini, Marney P. Cereda, Sílvia R. M. Coelho, and Anderson Coldebella. "Evaluation of protein extraction methods to obtain protein concentrate from cassava leaf." Engenharia Agrícola 33, no. 6 (2013): 1223–33. http://dx.doi.org/10.1590/s0100-69162013000600015.
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The cassava leaf, waste generated in the harvest of the roots, is characterized by high content of protein, vitamins and minerals; however, its use is limited due to the high fiber content and antinutritional substances, which can be removed by obtaining protein concentrates. In this context, the objective of this study was to evaluate protein extraction processes, aiming the use of cassava leaves (Manihot esculenta Crantz) as an alternative protein. Four methods were tested: 1) Coagulation of Proteins by Lowering the Temperature, 2) Extraction by Isoelectric Precipitation, 3) Solubilization of Proteins and 4) Fermentation of Filter Leaf Juice. To obtain the concentrates, the use of fresh or dried leaves and extraction in one or two steps were also evaluated. The solubilization of proteins (method 3) showed a higher extraction yield; however, with concentrate of low quality. The fermentation of the juice (method 4) produced concentrates with higher quality and lower costs and the isoelectric precipitation (method 2) promoted the obtention of concentrates in less time, both with good prospects for use. The use of two extraction steps was not advantageous to the process and there was no difference between the use of fresh or dried leaf, and the use of fresh leaves is presented as a good option for the simplicity of the method.
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Hernandez, Teresa, and Amelia Hernandez. "Available carbohydrates in alfalfa leaf protein concentrates." Journal of Agricultural and Food Chemistry 42, no. 8 (1994): 1747–49. http://dx.doi.org/10.1021/jf00044a033.
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Adeagbo, A.I., K.A. Bolaji, and O.F. Odoje. "Nutritive Potentials of Allium Cepa and Diplotaxis Tenufolia Vegetable Leaf Protein Concentrates." Greener Journal of Agricultural Sciences 3, no. 3 (2013): 211–14. https://doi.org/10.15580/GJAS.2013.3.011613390.
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Leaf protein concentrates were derived from two vegetable species; Allium ceppa and Diplotaxis Tenuifolia. The two samples were evaluated for their nutritional values using standard analytical techniques for proximate, amino acid and functional properties. In proximate analysis, ash, carbohydrates, proteins, fibre, fats and moisture were assayed, while amino acid was determined using method of Sparkman et al. and functional properties determined using method of coffman Gargia and Beuchat. The highest value of crude protein was recorded in Allium ceppa while Diplotaxis Tenuifolia has highest value of Nitrogen free extract. Other values of proximate analysis were present in significant proportion. The amino acid profile of the leaf protein concentrates indicated favourable nutritional balance except that tryptophan which is the limiting amino acid.The water absorption capacity, fat emulsion capacity foaming and foaming stability reveal good functional properties.
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Dr, Sharjeel Hassan Dr Shaista Qasim Dr Tanzeelah Shamshad. "TREATMENT OF SKIN CONTAMINATIONS AND HUMAN WELL-BEING THROUGH ALOE VERA LEAF GEL AND RIND." INDO AMERICAN JOURNAL OF PHARMACEUTICAL SCIENCES o6, no. 08 (2019): 14811–14. https://doi.org/10.5281/zenodo.3370322.
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<em>Butyric corrosive was recognized by GC/MSD examination from ether concentrate of the gel ageing juices, expecting various gainful impacts of butyric corrosive at the intestinal and additional intestinal dimension. Aloe Vera concentrates have antimicrobial and against parasitic exercises, which might almost certainly treat minor skin contaminations. Present examination displays that day by day admission of the butyric corrosive ageing concentrate from Aloe Vera inward gel with endophytic microbes may give the conceivable potential preventive and helpful jobs in human wellbeing. Regardless of antimicrobial exercises, the internal leaf gel containing acemannan: non-edible polysaccharide, prompts maturation with endophytic microorganisms and results in bacterial development advancement. No short chain unsaturated fats were recognized in the ether concentrates of the ageing stock with the skin.</em> <strong>Keywords: </strong><em>Endophytic bacteria fermentation; Aloe Vera inner gel; Short-chain fatty acids; Butyric acid.</em>
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Nwokoro, S. O., O. W. Agbonghae, N. C. Akaeze, and E. E. Onojeta. "Chemical Compositions of Leaf Protein Concentrate and Bagasse of Pride of Barbados (Caesalpinia pulcherrima) Leaves obtained from three Different Locations in Benin City, Nigeria." Journal of Applied Sciences and Environmental Management 26, no. 5 (2022): 845–49. http://dx.doi.org/10.4314/jasem.v26i5.10.
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To optimize food and feed production in Nigeria and meet protein demands, viable options need to be explored. Therefore, this study aimed to determine the chemical composition of Pride of Barbados leaf protein concentrate and bagasse. Freshly harvested Pride of Barbados leaves were obtained from three different locations in Benin City and processed for its leaf protein concentrate and bagasse using heat coagulated method. Pride of Barbados leaf protein concentrate and bagasse were analysed for proximate and mineral compositions using standard analytical procedures. Proximate analysis revealed that the dry matter, crude protein, ether extract, crude fibre, ash, and nitrogen free extract contents of Pride of Barbados leaf protein concentrates were 91.17%, 31.12%, 8.33%, 7.92%, 8.2%, and 35.3%, respectively. Pride of Barbados bagasse had a lower crude protein (9.22%) but higher fibre content (10.72%) compared to those of Pride of Barbados leaf protein concentrate. Na, K, Ca, and Mg were the most abundant minerals in Pride of Barbados leaf protein concentrate and bagasse. Chromium was very low in the leaf protein concentrate and bagasse. Proximate compositions were significantly (p<0.05) affected by location. Pride of Barbados leaf protein concentrate and bagasse can be used as livestock feed ingredient.
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Naveen B, Anil Kumar A, Abhilash G, Akila CR, and Raja Sheker K. "In-Vitro analysis of medicinal plant for anti-inflammatory properties." International Journal of Novel Trends in Pharmaceutical Sciences 10, no. 3 (2020): 71–74. http://dx.doi.org/10.26452/ijntps.v10i3.1361.
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This examination demonstrations the in vitro mitigating impact of leaf concentrates of Polyalthia longifolia. These were investigated in various measures to decide their mitigating impacts. Protein denaturation and RBC film adjustment were measured. The outcomes were accounted for as % hindrance in triplicate assurance and were exposed to factual additionally, diclofenac Aspirin and sodium were utilized as norms. The consequence of the % restraint of protein denaturation demonstrated that at 1mg/ml diclofenac, ethanolic extricate, new leaf fluid concentrate and dry leaf watery concentrate. Because of dissecting the MS and UV information and in contrast with the legitimate norms, an aggregate of 10 polyphenols were recognized and measured, counting gallic corrosive, catechin, quercetin, kaempferol, and their subordinates. This is the primary investigation looking at the leaves, as opposed to the organic product or seeds reasonably collected yet underutilized by nearby indigenous people groups. The concoction outline of the leaf was thoroughly broke down and prompted the ID of 10 polyphenol mixes, counting phenolic corrosive and flavonoids. The individual polyphenols were effectively quantitated, utilizing UV recognition. Additional bioactivity examinations demonstrated that the concentrates of leaf display cancer prevention agent, antiproliferation, and calming exercises. The primary atomic component may mostly be donated by the hindrance of NF-κB enactment, a typical sign alleyway among multiplication and aggravation. Additional examinations are expected to investigate whether these polyphenol mixes could work synergistically to accomplish significantly better exercises than each solitary segment. The concoction bioactivities and profile decided to help its conventional usage and might assistance for its additional pharmacological investigations and nutraceutical requests.
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Enawati, L. S., Markus M. Kleden, and Marfandi M. Robo. "THE EFFECT OF GIVING CONCENTRATES CONTAINING KELOR LEAF FLOURS WITH DIFFERENT LEVELS ON NITROGEN UTILISATION OF LOCAL GOAT." Journal of Tropical Animal Science and Technology 1, no. 1 (2019): 7–13. http://dx.doi.org/10.32938/jtast.v1i1.294.
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The study aimed to determine the effect of the use of feed concentrates containing Moringa leaf flour on protein consumption, protein digestibility and rumen ammonia concentration. Data were analyzed using a randomized block design (RBD) with 4 treatments and 3 replications, and continued with the Duncan test. The treatments in this study include: K1: Concentrate without the use of Moringa leaf flour; Concentrate with the addition of 10% Moringa leaf flour; K3: Concentrate with the use of Moringa leaf flour 20%; and K4: Concentrate with the use of 30% Moringa leaf flour. The variables determined were Rough Protein Consumption and Digestion and rumen NH3 Concentration. The results showed that protein (g / tail / day) consumption and crude protein digestibility (%) were highest in the treatment of K4: 36.37 and 72.01, then followed by K3: 35.81 da. 71.93; K2: 35.06 and 69.85 and K1: 31.99 and 59.91. The highest rumen NH3 (mM) concentration is also occupied by K4: 19.77 followed; K3: 18.24; K2: 16.48 and K1: 11.16. The results of statistical analysis showed that the treatment had no significant effect (p> 0.05) on consumption and had a significant effect (p<0.05) on the digestibility coefficient of crude protein and rumen NH3. It was concluded that the use of Moringa leaf flour as a constituent component to the level of 30% can be used for animal feed to increase consumption and nutrient digestibility of livestock as well as the provision of rumen NH3.
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Sodamade, A., S. M. Raimi, A. D. |. Owonikoko, and A. T. Adebimpe. "Nutritive Evaluation, Mineral Composition and Phytochemical Analysis of Leaf Protein Concentrates of Daucus carota." International Journal of Trend in Scientific Research and Development 3, no. 5 (2019): 767–72. https://doi.org/10.5281/zenodo.3591075.
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Fresh green leaves of Daucus Carota was harvested and processed with a view to analyse its photochemical constituents and nutritional potentials. Proximate analysis, mineral analysis and phytochemical analysis was determining using standard analytical techniques. The nutrient composition of the leaf protein concentrate revealed Moisture content 8.69±0.03 g 100g, crude protein 18.38±0.08 g 100g, crude fibre 14.81±0.02 g 100g, crude fat 5.69±0.23 g 100g, Ash 19.69±0.02g 100g , and NFE 32.74±0.43 g 100g.The mineral analysis of the sample shows the concentrations of the elements in the following descending order of magnitude Ca P Mg Na Fe K Zn Cu Mn Se while Hg was not detected in the sample. The photochemical constituents also revealed Tanin 3.66±0.16 mg 100g, Saponin 4.34±0.06 mg 100g, Alkaloid 10.49±0.02 mg 100g, Oxalate 6.89±0.04 mg 100g, Phytate 14.62±0.05 mg 100g, Phenolics 3.75±0.82 mg 100g, Flavonoids 3.62±0.43 mg 100g. High Concentration of Calcium and Phosphorus indicates that Daucus carota leaf protein concentrates is fit for consumption by children, pregnant women and weaned infants for good teeth and bone formation. The constituents of Daucus carota leaf protein concentrates present values of significant nutritional benefits and can find application in various food additives, binders, flavonoids and vitamins. It could also be used as additives in some drugs if the active compounds present in it could be analysed to detect its suitability. Sodamade, A. | Raimi, S. M. | Owonikoko, A. D. | Adebimpe, A. T. "Nutritive Evaluation, Mineral Composition and Phytochemical Analysis of Leaf Protein Concentrates of Daucus carota" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26427.pdf
Dissertations / Theses on the topic "Leaf concentrates"
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Khan, M. M. "Selective flocculation of lead-zinc concentrate." Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355440.
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Salomon, de Friedberg Adam Maciej. "Kinetics of lead concentrate oxidation in a stagnant gas reactor." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/28516.
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The behaviour of lead concentrate particles oxidizing in a stagnant gas reactor has been examined and a mathematical model which predicts the kinetics of galena particles developed. The effects of oxygen concentration, particle size, furnace temperature and concentrate composition were studied.
The results showed that the concentrates all exhibited sharply defined ignition points. The ignition points were found to be strongly dependent on oxygen concentration. Reductions in ignition temperature of up to 100 K were observed when the concentrates were reacted in pure oxygen rather than in air. Iron composition was found to have a similar effect on ignition temperature.
The modelling results predict short reaction times for ignited particles (less than 100 milliseconds). Particles which ignited in air attained predicted temperatures in excess of 2600 K. In oxygen, particle temperatures were calculated to be greater than 2800 K. Good agreement was found between experimental results and model predictions.<br>Applied Science, Faculty of<br>Materials Engineering, Department of<br>Graduate
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Tuffrey, Nigel Edwin. "Pyrometry studies of the combustion of lead concentrate particles under controlled conditions." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29309.
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An investigation of the combustion of lead sulphide .concentrates under controlled conditions has been carried out. A fast response, two-wavelength radiation pyrometer and a "laminar flow" furnace were constructed to facilitate the measurement of the temperature of individual particles during combustion. Chemical analysis and electron microscopy studies of the reaction products were also performed.
The combustion of galena, pyrite, pyrrhotite, sphalerite and two commercial concentrates (Brunswick and Sullivan) at 1130K was investigated. The effects of particle size between 63-125μm and gaseous oxygen concentration between 10 and 100% were examined.
For combustion in both air and oxygen a number of different combustion pulses were identified which corresponded to the combustion of different mineral species or to different physical phenomena. An analogous series of pulse classifications was identified for combustion in oxygen however they reflected the greater intensity and temperature of the reactions. The form of combustion was strongly dependent on oxygen concentration. From the results it was not possible to identify the effect of particle size on combustion behaviour.
The vaporisation of lead sulphide appears important to the mechanism of galena combustion. In air the temperature of combustion appears limited to 1500-1700K (of boiling point PbS of 1609K); whereas in oxygen, massive vaporisation results in a heating arrest at 1700-2000K and disintegration into droplets which combust at 2000-2400K. Transition from air-type to oxygen-type combustion occurs at oxygen concentrations between 40 and 65% and is thought to be due to the transition from a liquid to gaseous phase PbO reaction product.
The initial stage of pyrite reaction is thermal decomposition to porous pyrrhotite. The ignition of this porous pyrrhotite was more rapid than dense pyrrhotite, but once molten, the combustion of the two was indistinguishable and the peak temperature observed was very reproducible. In air the peak combustion temperatures of 2400-2600K appeared to coincide with a sudden expansion of the particle, possibly due to the inflation of thin-walled iron oxide cenospheres. In oxygen the reactions are more intense and disintegration typically occurs on reaching a peak temperature of 3000-3400K, Between ~10 and 35% oxygen the maximum combustion temperature increased linearly, but at higher concentrations remained constant at 3000-3400K. The results suggest the maximum temperature reached is limited by the occurrence of a physical phenomenum possibly associated with the vaporisation of iron.
Sphalerite did not ignite at the temperatures considered, but shells of zinc oxide were observed in the reaction products.
For the commercial concentrates pulses of intermediate combustion characteristics and a wide range of combustion temperatures (typically intermediate to those of PbS and FeS) were observed, as well as many pulses similar to those of the constituent minerals. The former were considered to be due to the combustion of agglomerations of many smaller individual particles. The effect of the mineral composition was evident in the combustion results, with increased quantities of iron sulphide tending to result in more intense reactions. The results suggest that metallic lead formation occurs during the initial stages of reaction, probably after melting as the result of reaction between the surface oxides/sulphates and unreacted PbS.
A simple reaction model for iron sulphide combustion suggests that the reaction of the molten drop is controlled by gas-phase oxygen mass transfer with the measured heating rates consistent with the formation of wustite and sulphur dioxide.<br>Applied Science, Faculty of<br>Materials Engineering, Department of<br>Graduate
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Veliz, Yañez Pedro Yunior. "Mejora en el proceso de recepción de camiones para un depósito minero utilizando la metodología Lean Six Sigma." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/653446.
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La empresa en estudio, dedicada a la logística integral de concentrados mineros tiene como uno de sus proceso principales la recepción de camiones con concentrado de Cu, Pb y Zn de las diferentes mineras del Perú cuya demanda diaria es de 170 camiones para lo cual se ha propuesto atenderlo en un periodo de 10 horas cuyo indicador del proceso es de 17 camiones/hora, pero actualmente se viene manejando un indicador en promedio de 15 camiones/hora, esto ocasiona que se incurra en sobrecostos tales como horas extras y utilización de recursos los que equivalen a un sobrecosto anual de S/. 638,655; por este motivo se proponen implementar dos herramientas de la metodología Lean Six Sigma. El diagnostico reveló que el problema del incumplimiento de indicador radica en la ineficiencia y eficacia del proceso de recepción, en el cual el tiempo total de los camiones en todo el circuito del proceso de recepción es alto en promedio 2.4 horas; el análisis causal halló causas raíces como áreas desordenadas, congestión en zona de toma de muestra y zona de descarga, tras lo cual se propone el despliegue de las herramientas propias de la metodología como la implementación de 5S que busca generar cultura de orden y limpieza con y la mejora del flujo de camiones entre etapas con la estandarización de procesos. Al realizar las implementaciones se estima reducir el tiempo promedio de camiones de 2.4 horas a 1.7 horas y optimizar los recursos y reducir los sobre costos.<br>The company under study, dedicated to the integral logistics of mining concentrates has as one of its main processes the reception of trucks with concentration of Cu, Pb and Zn of the different miners in Peru whose daily demand is 170 trucks for which it has set out to serve it in a period of 10 hours whose indicator of the process is 17 trucks/hour, but currently an indicator of 15 trucks/hour has been handled, this results in overruns such as overtime and resource utilization which amount to an annual cost of S/. 638,655; for this reason, they intend to implement two tools of the Lean Six Sigma methodology. The diagnosis revealed that the problem of non-compliance with indicator lies in the inefficiency and effectiveness of the receiving process, in which the total time of trucks throughout the receiving process circuit is high on average 2.4 hours; the causal analysis found root causes such as disordered areas, congestion in sampling area and discharge zone, after which it is proposed the deployment of the methodology's own tools such as the implementation of 5S that seeks to generate culture of order and cleanliness with and the improvement of the flow of trucks between stages with the standardization of processes. When deploying, it is estimated to reduce average truck time from 2.4 hours to 1.7 hours and optimize resources and reduce over-costs.<br>Trabajo de Suficiencia Profesional
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Wu, Zheng-hui. "Fundamental study on extracting lead from cerussite concentrate in methane sulfonic acid based solution." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43660.
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Cerussite (PbCO₃) concentrates may be recovered from oxidized lead ores. These concentrates suffer from the intrinsic fuel shortage via traditional smelting route and may lead to widespread contamination in shipment. Therefore, a hydro-electrometallurgical process to treat cerussite concentrate by methane sulfonic acid (MSA) is proposed to solve the above problems.
The leaching of cerussite concentrate by MSA was first studied. The parameters of stirring speed, temperature, acid concentration, particle sizes and solid concentration were considered. It was found that stirring speed, temperature, particle size and proton concentration had a significant influence on the kinetics while solid concentration showed no effect on the final lead extraction under the experimental conditions. The leaching results indicated that MSA is favourable to treat cerussite concentrate and the lead extraction could achieve the theoretical maximum in just 10 min at ambient conditions. The lead content in solution obtained at high solid concentration was sufficiently high, and easily met the concentration requirements for the subsequent electrolysis process.
After leaching, the residue was subjected to a desulfurization treatment to recover the remaining lead in residue. Using desulfurization agent Na₂CO₃, the remaining lead, mainly in anglesite, was transformed to PbCO₃ that was followed by a re-leaching treatment with MSA. An overall lead recovery of 98% was finally obtained.
In the electrowinning process from MSA based electrolyte, the individual and synergistic effects of two ligninsulfonate salts and two glycol-type agents on lead deposit quality were first investigated. Compared to the other three additives, the individual use of calcium ligninsulfonate most benefited the morphology of lead deposit. The operating parameters in the lead electrowinning process (i.e. temperature, current density, concentrations of lead ion and protons) had a widely acceptable range. The cathodic current efficiency and specific energy consumption in most tests were around 99% and 0.53Wh/kg, respectively. The SEM micrographs showed that the lead deposits obtained under the optimal conditions were compact and even. These results for leaching and electrolysis made the MSA system competitive to the comparable fluoborate and fluosilicate systems.
Finally a simplified flowsheet to extract lead from cerussite concentrate in MSA based solution was proposed.
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Saba, Mojtaba. "The Extraction Behaviour of Zinc, Lead and Silver from Ores and Concentrates by Glycine Leaching Processes." Thesis, Curtin University, 2019. http://hdl.handle.net/20.500.11937/81907.
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This research covers the fundamental aspects of the direct leaching of sphalerite by considering the dissolution of silver, lead, and copper contents and their effects on the process. The effects of independence variables such as sodium hydroxide, potassium permanganate, hydrogen peroxide, lead nitrate, sodium chloride, dissolved oxygen, temperature, glycine concentration, dissolution time, and particle size on the process were investigated. All the outputs have been modelled and optimised through the analysis of variance.
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Garcia, Neto Júlio. "Concentrações e fontes de silício foliar na produção e na qualidade do agrião e do almeirão." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153861.
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Previous issue date: 2018-03-16<br>A pulverização foliar de silício (Si) pode beneficiar a produção e a qualidade das hortaliças folhosas, sendo desconhecidos esses efeitos no agrião-da-terra (Barbarea verna) e no almeirão (Cichorium intybus cv. Spadona). Objetivou-se verificar o efeito da pulverização foliar de silício em diferentes fontes e concentrações no teor foliar de Si, nas variáveis de crescimento, no teor foliar de ascorbato e na perda de água durante o armazenamento das hortaliças agrião e almeirão. Foram realizados dois experimentos, com as duas hortaliças cultivadas em vasos (4 dm3) preenchidos com areia, recebendo solução nutritiva. Durante o cultivo, a média da temperatura máxima atingiu 43,1 °C ± 10,6 °C. Utilizou-se delineamento inteiramente casualizado, em esquema fatorial 2 x 4, sendo duas fontes de silício: silicato de potássio e silicato de sódio e potássio estabilizado, e quatro concentrações de Si foliar: 0 (controle); 0,84; 1,68; 2,52 g L-1 de Si, com quatro repetições. As mudas foram transplantadas após 10 dias da emergência para vasos. Foram realizadas três aplicações foliares de Si, a cada dez dias, sendo a primeira realizada aos 28 dias após o transplantio (DAT). A pulverização foliar de silício é viável, para incrementar o acúmulo deste elemento na planta, o crescimento e a biofortificação, e diminui a perda de água da folha pós-colheita do agrião da terra e do almeirão, destacando-se a concentração de 2,52 g L-1 de Si na forma de silicato de potássio.<br>Silicon (Si) leaf spraying can benefit the production and quality of leafy vegetables. Such knowing is unclear to land cress (Barbarea verna) and root chicory (Cichorium intybus cv. Spadona). This study aimed was verify the effect of silicon leaf spraying under different sources and concentrations in Si leaf content, on growth variables, ascorbate leaf content, and water loss during storage of land cress and root chicory. We carried out two experiments with two vegetables grown in (4 dm3) pots filled with sand, receiving nutrient solution. During growing, the maximum temperature average was 43.1 °C ± 10.6 ºC. A completely randomized design was used in a 2 x 4 factorial scheme, with two sources of silicon: potassium silicate and stabilized sodium and potassium silicate, and four concentrations of leaf spraying Si: 0 (control), 0.84, 1.68, and 2.52 g L-1 of Si, with four replications. The seedlings were transplanted after 10 days of vessel emergence. Three Si leaf sprayings were done every ten days where the first spraying was at 28 days after transplanting (DAT). Silicon leaf spraying is feasible to increase the Si accumulation, plant growth and biofortification and decrease the post-harvest water loss of land cress and root chicory leaves. The Si concentration of 2.52 g L-1 as potassium silicate was highlighted.
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Healy, Daniel Francis. "The depression of sphalerite during carbon pre-flotation and lead flotation at the Century Mine concentrator." Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/1787.
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The differential lead-zinc flotation process has been practised since 1912, yet selectivity in the process remains a significant technical issue in many operations. The minerals processing operation at Zinifex Limited's Century Mine, which uses differential flotation, began in November 1999 and the flotation behavior of the ore remains a major research interest. The present study was aimed to determine the possible mechanisms of sphalerite recovery during carbon pre-flotation and lead flotation in this operation including identification of the variables that affect these two flotation stages and also identify depressants for sphalerite that offer better selectivity during these stages. To achieve this aim, the study was undertaken in two stages: a review of literature related to selectivity during lead-zinc flotation, and an experimental program consisting of bench-scale flotation tests wherein the various experimental variables were systematically varied. A comparison between the data generated to those of the plant was also undertaken. The review of literature revealed four basic mechanisms of sphalerite recovery: activation of the sphalerite surface, composite particle flotation with galena and gangue, graphitic inclusions in the mineral surface and entrainment in the froth. The depression or rejection of sphalerite on the other hand could be affected by grinding, froth washing and the use of chemical depressants including cyanides, zinc sulfate, abraded iron and iron sulfate, sodium sulfide, sodium sulfite and metabisulfite, and organic depressants derived from selective collectors.The results from the experimental program indicate that: (a) activation of the sphalerite surface as a mechanism of sphalerite recovery during lead flotation was not significant at the Century Mine concentrator, (b) the recovery of sphalerite during the carbon pre-flotation was predominantly due to a bulk flotation action and entrainment in the froth, (c) composite particle recovery was a significant contributing factor in the recovery of sphalerite in lead flotation, and (d) mineral oxidation was only significant for galena and occurred mostly during pre-flotation, but the use of cyanide adequately counters any effect on sphalerite recovery. The investigation on the variables that affect the pre-flotation and lead flotation circuits revealed that: (a) reducing the pulp density and the amount of frother added during pre-flotation significantly reduced the bulk flotation action and entrainment of sphalerite in the froth, b) grinding the ore finer (P80 = 40 μm) reduced the recovery of sphalerite as composite particles during lead flotation, and (c) the pulp pH was best maintained at natural pH during pre-flotation and at an elevated alkaline pH (pH 9.5) during lead flotation for optimal selectivity. In terms of depressants it was found that zinc sulfate specifically depressed sphalerite during lead flotation.
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Healy, Daniel Francis. "The depression of sphalerite during carbon pre-flotation and lead flotation at the Century Mine concentrator." Curtin University of Technology, Western Australian School of Mines, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16397.
Full textAbstract:
The differential lead-zinc flotation process has been practised since 1912, yet selectivity in the process remains a significant technical issue in many operations. The minerals processing operation at Zinifex Limited's Century Mine, which uses differential flotation, began in November 1999 and the flotation behavior of the ore remains a major research interest. The present study was aimed to determine the possible mechanisms of sphalerite recovery during carbon pre-flotation and lead flotation in this operation including identification of the variables that affect these two flotation stages and also identify depressants for sphalerite that offer better selectivity during these stages. To achieve this aim, the study was undertaken in two stages: a review of literature related to selectivity during lead-zinc flotation, and an experimental program consisting of bench-scale flotation tests wherein the various experimental variables were systematically varied. A comparison between the data generated to those of the plant was also undertaken. The review of literature revealed four basic mechanisms of sphalerite recovery: activation of the sphalerite surface, composite particle flotation with galena and gangue, graphitic inclusions in the mineral surface and entrainment in the froth. The depression or rejection of sphalerite on the other hand could be affected by grinding, froth washing and the use of chemical depressants including cyanides, zinc sulfate, abraded iron and iron sulfate, sodium sulfide, sodium sulfite and metabisulfite, and organic depressants derived from selective collectors.<br>The results from the experimental program indicate that: (a) activation of the sphalerite surface as a mechanism of sphalerite recovery during lead flotation was not significant at the Century Mine concentrator, (b) the recovery of sphalerite during the carbon pre-flotation was predominantly due to a bulk flotation action and entrainment in the froth, (c) composite particle recovery was a significant contributing factor in the recovery of sphalerite in lead flotation, and (d) mineral oxidation was only significant for galena and occurred mostly during pre-flotation, but the use of cyanide adequately counters any effect on sphalerite recovery. The investigation on the variables that affect the pre-flotation and lead flotation circuits revealed that: (a) reducing the pulp density and the amount of frother added during pre-flotation significantly reduced the bulk flotation action and entrainment of sphalerite in the froth, b) grinding the ore finer (P80 = 40 μm) reduced the recovery of sphalerite as composite particles during lead flotation, and (c) the pulp pH was best maintained at natural pH during pre-flotation and at an elevated alkaline pH (pH 9.5) during lead flotation for optimal selectivity. In terms of depressants it was found that zinc sulfate specifically depressed sphalerite during lead flotation.
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Rezende, Vania Braghini de. "Modulação toxicogenetica das concentrações sanguineas e plasmaticas de chumbo por haplotipos do receptor da vitamina D." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310014.
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Orientador: Jose Eduardo Tanus dos Santos<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas<br>Made available in DSpace on 2018-08-12T08:46:01Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007<br>Resumo: O receptor da vitamina D (VDR) possui um importante papel na toxicidade do chumbo (Pb). Poucos trabalhos avaliaram o efeito dos polimorfismos VDR sobre as concentrações circulantes do metal em populações expostas ambientalmente. Além disso, nenhum estudo avaliou o efeito da combinação desses polimorfismos (haplótipos) sobre os mesmos parâmetros. A análise de haplótipos (combinação de marcadores genéticos dentro de uma determinada região no cromossomo) tem demonstrado ser uma melhor ferramenta em comparação com a análise de polimorfismos (SNPs) vistos isoladamente. Nesse estudo, avaliamos o efeito dos haplótipos estimados a partir dos polimorfismos BsmI , ApaI e FokI do VDR sobre os níveis de Pb-S (chumbo no sangue), Pb-P (chumbo no plasma) e na fração %Pb-P/Pb-S (chumbo no plasma/chumbo no sangue) em 150 voluntários expostos ambientalmente ao chumbo (65 homens e 85 mulheres; idade: 18 a 57 anos). Os genótipos para todos os polimorfismos do VDR foram determinados por PCR seguido por digestão com enzimas de restrição (RFLP). Pb-P e Pb-S foram determinados por espectrometria de massas com plasma indutivamente acoplado (ICP-MS) e espectrometria de absorção atômica com forno de grafite, respectivamente. Os resultados mostraram que os polimorfismos do VDR estão associados às concentrações de Pb circulantes e que o haplótipo H8, formado pelos alelos a, b e f, está associado com menores concentrações de Pb-S, Pb-P e %Pb-P/Pb-S. Estes achados podem apresentar importantes implicações toxicogenéticas, sendo necessários estudos posteriores para elucidar os mecanismos responsáveis por tais efeitos.<br>Abstract: The Vitamin D Receptor (VDR) plays an important role in the toxicity of lead (Pb). Genetic factors, i.e polymorphisms, influence blood lead (Pb-B) concentrations in lead exposed subjects. However, only a few research studies have evaluated the effect of VDR polymorphism on the lead concentration in environmentally. Also, no studies have evaluated the combinatorial effect of these polymorphisms on the same parameters. The haplotype analysis (combination of genetic indicators in a certain region of the chromossome) has been shown to be a better tool if compared with the analyses of single polymorphisms. This study aimed at examining the combined effects (haplotype analysis) of three polymorphisms (BsmI , ApaI and FokI) in vitamin D receptor ( VDR) gene on Pb-B and on the concentrations of lead in plasma (Pb-P), which is more relevant to lead toxicity, in 150 environmentally exposed subjects (65 mens and 85 women). Genotypes were determined by RFLP, and Pb-P and Pb-B were determined by inductively coupled plasma mass spectrometry and by graphite furnace atomic absorption spectrometry, respectively. Subjects with the bb (BsmI ) or ff (FokI) genotypes have lower B-Pb than subjects in the other genotype groups. Subjects with the aa (ApaI ) or ff genotypes have lower P-Pb than subjects in the other genotype groups. Lower Pb-P, Pb-B, and %Pb-P/Pb-B levels were found in subjects with the haplotype combining the a, b, and f alleles for the ApaI , BsmI , and FokI polymorphisms, respectively, compared with the other haplotype groups. These findings may have important toxicogenetic implications and their molecular basis needs to be addressed in further studies.<br>Mestrado<br>Mestre em Farmacologia
Books on the topic "Leaf concentrates"
1
Ellen, Mallory, and Rodale Research Center. New Crops Dept., eds. Vegetable amaranth and leaf protein concentrate, 1886 to 1988: 297 citations with abstracts. The Center, 1990.
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2
United States. Bureau of Mines. and Generic Mineral Technology Center for Pyrometallurgy (U.S.), eds. The application of a submerged lance injection technique to the direct smelting of a Missouri lead concentrate. U.S. Dept. of the Interior, Bureau of Mines, 1991.
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3
United States. Bureau of Mines. and Generic Mineral Technology Center for Pyrometallurgy (U.S.), eds. The application of a submerged lance injection technique to the direct smelting of a Missouri lead concentrate. U.S. Dept. of the Interior, Bureau of Mines, 1991.
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4
Lee, A. Y. Hydrometallurgical process for producing lead and elemental sulfur from galena concentrates. U.S. Dept. of the Interior, Bureau of Mines, 1986.
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5
Lee, A. Y. Pressure leaching of galena concentrates to recover lead metal and elemental sulfur. U.S. Dept. of the Interior, Bureau of mInes, 1990.
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United States. Bureau of Mines. Hydrometallurgical Process For Producing Lead and Elemental Sulfur From Galena Concentrates. s.n, 1986.
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7
Cornell, W. L. Continuous flotation testing to recover a bulk sulfide concentrate from Missouri lead ore tailings. U.S. Dept. of the Interior, Bureau of Mines, 1989.
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Cornell, W. L. Continuous flotation testing to recover a bulk sulfide concentrate from Missouri lead ore tailings. Dept. of the Interior, 1989.
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R, Griffitts Wallace, and Geological Survey (U.S.), eds. Distribution of lead and artifacts in heavy-mineral-concentrate samples from the Charlotte 1. U.S. Dept. of the Interior, Geological Survey, 1985.
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R, Griffitts Wallace, and Geological Survey (U.S.), eds. Distribution of lead and artifacts in heavy-mineral-concentrate samples from the Charlotte 1p0s. U.S. Dept. of the Interior, Geological Survey, 1985.
Find full textBook chapters on the topic "Leaf concentrates"
1
BONELLI, Stéphane, Robin FELL, and Nadia BENAHMED. "Concentrated Leak Erosion." In Erosion in Geomechanics Applied to Dams and Levees. John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118577165.ch4.
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Benahmed, Nadia, Christophe Chevalier, and Stéphane Bonelli. "Concentrated Leak Erosion." In Erosion of Geomaterials. John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118561737.ch5.
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Chuzaemi, S., Mashudi, P. H. Ndaru, and M. Mufidah. "The effect of addition myristic acid and the levels of calliandra leaf meal in concentrates on nutrient content, feed digestibility, and nitrogen retention." In Developing Modern Livestock Production in Tropical Countries. CRC Press, 2023. http://dx.doi.org/10.1201/9781003370048-45.
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Ndaru, Poespitasari Hazanah, Ifar Subagiyo, Mashudi, and Kusmartono. "Effects of Supplementing Concentrates Varying in Ingredients on Blood Urea and Glucose Concentrations in Limousin Crossbred fed Cassava Leaf and Tuber Silage as Basal Diet." In Advances in Biological Sciences Research. Atlantis Press International BV, 2025. https://doi.org/10.2991/978-94-6463-670-3_60.
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Ferron, C. J. "Atmospheric Leaching of Zinc Sulphide Concentrates Using Regenerated Ferric Sulphate Solutions." In Lead-Zinc 2000. John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118805558.ch47.
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Buban, K. R., M. J. Collins, I. M. Masters, and L. C. Trytten. "Comparison of Direct Pressure Leaching with Atmospheric Leaching of Zinc Concentrates." In Lead-Zinc 2000. John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118805558.ch48.
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Haxhiaj, Ahmet, and Bajram Haxhiaj. "The Management of Lead Concentrate Acquisition in “Trepca”." In Rare Metal Technology 2018. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-72350-1_17.
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Haxhiaj, Ahmet, Maoming Fan, and Bajram Haxhiaj. "The Management of Lead Concentrate Acquisition in “Trepca”." In Advances in Molten Slags, Fluxes, and Salts: Proceedings of the 10th International Conference on Molten Slags, Fluxes and Salts 2016. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48769-4_147.
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Haxhiaj, Ahmet, Maoming Fan, and Bajram Haxhiaj. "The Management of Lead Concentrate Acquisition in “Trepca”." In Advances in Molten Slags, Fluxes, and Salts. John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119333197.ch147.
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Haxhiaj, Ahmet, and Jaroslaw Drelich. "Constituents and Porosity of Lead Concentrate Pellets Produced in the Trepce Plant." In 2nd International Symposium on High-Temperature Metallurgical Processing. John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118062081.ch35.
Full textConference papers on the topic "Leaf concentrates"
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Carpenter, Brandon, and Greg Hopkins. "Sulfuric Acid Evaporator Column: A Case Study After 10 Years of Service." In CORROSION 2005. NACE International, 2005. https://doi.org/10.5006/c2005-05523.
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Abstract Costly monthly maintenance of lead lined steel sulfuric acid concentrators lead to the installation of PVDF (polyvinylidene fluoride) lined fiberglass replacements that have been maintenance free after 10 years of service. Spent sulfuric acid is concentrated from 45% to roughly 60% at nearly full vacuum and over 200 °F (93 °C) for recycle back to the process.
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Goodwin, F. E., S. G. Pitman, M. R. Telander, K. H. Pool, and R. E. Westerman. "Corrosion Behavior of Lead in a Multi-Barrier Container for the Yucca Mountain Repository." In CORROSION 1992. NACE International, 1992. https://doi.org/10.5006/c1992-92111.
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Abstract In order for lead to be considered either as a stabilizer or a filler material in high level nuclear waste packages, it must be shown that lead resists corrosion adequately under anticipated repository conditions. A series of irradiated tests simulating rock-water, rock-vapor, and vapor environments of the projected Yucca Mountain, Nevada repository has shown refined lead, impure lead, and lead alloys to have corrosion rates low enough in many cases to be suitable for waste package applications. Also, electrochemical studies have shown that there is no tendency for unalloyed lead in the repository tuff groundwater to undergo crevice corrosion. However, in 20x concentrated groundwater, crevice corrosion is a potential degradation mode. Galvanic corrosion of lead and lead-1.5% Sb alloy occurred when placed in intimate contact with either 70-30 cupronickel or nickel alloy 825 in irradiated concentrated groundwater, but no tendencies for crevice corrosion to occur were observed under these conditions.
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Fowler, T. J., L. S. Houlle, and F. E. Strauser. "Development and Design of a Sulfuric Acid Plant Leak Monitor System." In CORROSION 1992. NACE International, 1992. https://doi.org/10.5006/c1992-92239.
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Abstract Modern sulfuric acid plants utilize a heat recovery system in which heat generated by the process is extracted from concentrated acid to produce medium pressure steam. From a material of construction and corrosion perspective, sulfuric acid at concentrations of greater than 98.5 percent and at elevated temperature can be contained in stainless steel equipment. In contrast, dilute acid is extremely corrosive and will, in a very short period of time, destroy the equipment. The consequence of a leak between the acid and water is a stream of dilute acid, and an unacceptable corrosion situation. Rapid and reliable detection of a leak is thus essential. This paper describes a program to develop technical information for design, calibration, and setup of an acoustic emission leak monitor. Leaks were simulated in a pilot plant and a full-scale plant by injecting water and steam into concentrated acid. Key attributes of the acoustic emission signal generated by these simulated leaks were characterized. The signal was studied over a number of different frequency ranges and representative waveforms, waveform spectra, and hit parameters were recorded. Simulated leaks of cold and hot water, and of steam, were studied together with leaks of varying duration. The acoustic wavepaths in a full-scale heat exchanger were characterized by applying artificial pulses to the equipment and studying the acoustic paths and attenuation. Background noise levels in an operating plant were measured, together with the acoustic characteristics of noise from transient upsets, startups, and shutdowns. An acoustic emission leak monitor was developed and tested under field conditions. The instrument is designed to give a real time alarm when a leak occurs. The paper reports the experimental program and discusses the results of the subsequent analyses which were used to define key acoustic emission parameters and instrument settings. The operational principles of the leak monitor, and the factors influencing its design are also discussed.
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Fabiszewski, A. S., and J. J. Hoffman. "Failure of Brass Gas Cylinder Valves by Commercial Leak Detector Fluids." In CORROSION 2003. NACE International, 2003. https://doi.org/10.5006/c2003-03512.
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Abstract Many commercial leak detection fluids contain trace amounts of ammonia, ammonium salt, or amines for pH control. The leak detection fluids are routinely applied to threaded outlet connections of compressed gas cylinder valves. Cracking was recently discovered in a number of compressed gas cylinder valve outlet connections fabricated from forging brass. Failure analysis indicated the cracking initiated from the external surface of the outlet connection and propagated intergranularly. The crack morphology was indicative of stress corrosion cracking. Exposure to commercial leak detection fluids was the only common link among the cracked brass valves. Thus, a laboratory test program was initiated exposing brass alloy U-bends to commercial leak detection fluids. The test results showed that crack initiation occurred when the leak detection fluids were allowed to concentrate on the stressed u-bend specimens. This testing has become the catalyst to develop an ASTM standard for screening commercial leak detection fluids.
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Howarth, Jonathan. "Some Practical and Economic Aspects of Using Highly Concentrated Liquid Bromine Biocides in Cooling Water Treatment." In CORROSION 2007. NACE International, 2007. https://doi.org/10.5006/c2007-07435.
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Abstract Recent advances in process chemistry have lead to the development of a new generation of single-feed liquid bromine biocides. Highly concentrated stabilized bromine biocides permit the rapid establishment of target residuals. This feature is utilized in a number of case studies for the eradication and control of assorted algae in cooling tower water. Shock dosing to lethally high bromine residuals (&gt; 5 ppm as Cl2) is accomplished quickly and efficiently so that minimal product is wasted in the blowdown.
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Litke, Wes, Joe Bojes, Pierre Blais, John Lerbscher, and Wellington Wamburi. "Aggressive Corrosion Associated with Salt Deposits in Low Water Content Sour Gas Pipelines." In CORROSION 2013. NACE International, 2013. https://doi.org/10.5006/c2013-02339.
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Abstract Low water volumes associated with gas production can lead to salt deposition under conditions that allow water evaporation to occur within a pipeline system. Salt deposits are capable of attracting water vapor from wet gas that has a water content well below the normal dew point. This phenomenon is related to the hygroscopic or deliquescent properties associated with individual salts present in the deposits. The relative humidity at which liquid water starts to accumulate at salt deposits is referred to as the Deliquescence Relative Humidity (DRH). Both MgCl2 and CaCl2 have strong abilities to attract water and are typical components in gas line salt deposits. This means those components will attract water from the gas, even if the water content is well below the theoretical dew point, and form concentrated salt solutions. These concentrated brines lead to aggressive, localized pitting corrosion. In order to better understand the contribution of deliquescence to the corrosion mechanism in gas pipelines where salt deposits can form, a novel laboratory test method was developed to simulate the deliquescence phenomenon in gas pipelines. This paper gives a brief explanation of DRH, reports findings of this laboratory study and concludes that deliquescence is an integral part of the corrosion mechanism.
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Ruel, Fiona, Stéphane Bencteux, Saghi Saedlou, Brahim Malki, and Krzysztof Wolski. "Influence of Magnesium on SCC Susceptibility of Duplex Stainless Steels in Boiling Solutions." In CORROSION 2016. NACE International, 2016. https://doi.org/10.5006/c2016-07193.
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Abstract This paper deals with some problems associated with stress corrosion cracking assessment of duplex stainless steels in boiling concentrated solutions. Electrochemical polarization experiments conducted on UNS(1) S32304 lean duplex stainless steel in NaCl, CaCl2 and MgCl2 boiling solution indicate that the presence of Mg2+ cations has a strong impact on its passive layer properties. This influence has been attributed to a possible incorporation of Mg into the passive film, as evidenced by depth profile analysis using glow discharge optical emission spectroscopy. These findings contrast with those obtained on standard S32205 duplex stainless steel where Mo alloying content appears to prevent Mg insertion behavior and this is supported by theoretical calculations of substitution energies of Mg in Cr2O3 oxide film. This specific interaction between Mo and Mg is regarded to be a good explanation of the negative influence of Mo in boiling concentrated solutions of MgCl2, and suggests that the standard 45 % MgCl2 155 °C boiling solution is unfortunately unsuitable for stress corrosion cracking resistance assessments of stainless steels with different Mo alloying level.
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Dutta, Sreya, Kevin Coscia, and Satish Mohapatra. "Understanding Corrosion and Its Inhibition in Chloride Based Molten Salt Heat-Transfer Fluids Used in Concentrated Solar Power Plants." In CORROSION 2013. NACE International, 2013. https://doi.org/10.5006/c2013-02669.
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Abstract Concentrated Solar Power (CSP) provides an efficient way of converting solar energy to electricity and heat. Using expensive high alloy materials for piping in the solar field requires an immense capital cost, so it is beneficial to use less-expensive materials while still being able to circulate the fluid at high temperatures with minimal corrosion. Compared to the other melts, molten chloride salts provide operating temperatures higher than 600 °C which causes extensive corrosion of stainless steel. SEM, EDS and XRD studies showed that rare earth oxide (La2O3) was incorporated to the melt lead to the formation of La rich crystals on the lamellar oxide layer at temperatures above 600 °C after 100h heat-treatment. The alkaline rare earth addition increased the basicity of the salt which reduced the corrosion attack and leaching of the Cr from the stainless steel UNS S31603. Addition of alkaline oxide (MgO) led to the formation of passivating Mg rich ferrite layer but La based perovskite was not achieved which is possibly due to the fact that the reaction kinetics of the Mg based layer was much faster than the La based perovskite crystals.
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Huizinga, S., and R. K. Ohm. "Qualification and Application Limits of Weldable Supermartensitic 13CR Linepipe Steels." In CORROSION 2001. NACE International, 2001. https://doi.org/10.5006/c2001-01093.
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Abstract Various grades of weldable supermartensitic linepipe steels are available. The assessment needed to ensure suitability for the conditions to which they are to be exposed has been considered. To facilitate efficient qualification and selection, a pre-qualification scheme has been devised, focusing on a number of elemental properties. The procedure is to be performed on base material, girth welds and seam welds (if applicable), and includes basic mechanical tests, microstructural evaluation and corrosion assessments. The scheme has successfully been applied to several weldable supermartensitic products. Based on corrosion results obtained so far, some generalizations can be made: Lean grade weldments have only borderline corrosion resistance at 100 °C in concentrated chloride environments and are not suitable for sour service.Some sweet stress corrosion cracking may occur at elevated temperature, in particular on lean grade weldments with stress raisers.A proper potential range for cathodic protection can be derived.
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Ishiguro, Yasuhide, Takashi Kawano, and Kazuki Fujimura. "Stability of Buffer Solutions for SSC Tests of Stainless Steel OCTG Material by Experimental Approach." In CORROSION 2018. NACE International, 2018. https://doi.org/10.5006/c2018-10836.
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Abstract As an extended report on buffer stability following the previous paper from a theoretical approach in 2016, this paper focuses on the buffering capability of various test buffer solutions from an experimental viewpoint, and presents experimental data supporting the theoretical results, based on the scratch repassivation behavior in electrochemical measurements. In this paper, the stability of buffer solutions for martensitic stainless steel OCTG material, which corresponds to the ability of the solution to maintain the targeted pH throughout the test duration, was experimentally evaluated by the scratch repassivation technique in electrochemical measurements. The measurements were carried out by using a specially-designed electrochemical apparatus with a sharp-pointed crooked dental scaler to make scratches on the surface of stainless steel OCTG material samples in 1 bar CO2-saturated buffer solutions. While rest potential is being measured, a short linear scratch corresponding to artificial pitting corrosion is intentionally applied. The potential drops at the moment of scratching, and then returns to the original rest potential. The stability of the buffer solution is evaluated by the time required for the potential to return to the original level, that is, the time required to repassivate the scratched area. A series of scratch-based electrochemical tests were carried out at pH 3.0, pH 3.5 and pH 4.0 to determine the stability of four kinds of NACE-TM0177-based buffer solutions. The experimental results support the phenomena of buffer stability from the theoretical viewpoint. A buffer solution with a shorter time for repassivation is consistent with the one with a more stable buffering effect from the theoretical approach. Precisely, a rich-rich-pair-based buffer solution, which is composed of a highly-concentrated weak acid and highly-concentrated conjugated base, has greater buffering stability than a lean-lean-pair-based one, which is composed of a dilute weak acid and a dilute conjugated base.
Reports on the topic "Leaf concentrates"
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Li, H., J. Q. Chambers, and D. T. Hobbs. Electroreduction of nitrate ions in concentrated sodium hydroxide solutions at lead, zinc, nickel, and phthalocyanine-modified electrodes. Office of Scientific and Technical Information (OSTI), 1987. http://dx.doi.org/10.2172/665993.
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Ayres, João. Research Insights: How Do Aggregate Shocks Impact Firm Entry and Exit, Affecting Macroeconomic Outcomes During Recessions? Inter-American Development Bank, 2024. https://doi.org/10.18235/0013330.
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Credit shocks and COVID-19 lockdown effects significantly impact firm entry and exit rates, more so than traditional productivity shocks. These shocks lead to substantial reductions in firm entry and increases in exits, concentrated among young and small firms. During the Great Recession, credit constraints particularly affected young firms, reducing their entry and increasing exit rates, which contributed to slower economic recovery by limiting new business formation. Changes in firm entry and exit accounted for 1020% of the decline in output and hours worked during recessions, highlighting the critical role of firm dynamics in shaping macroeconomic outcomes during downturns.
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Pinheiro, Armando Castelar, and Regis Bonelli. New Export Activities in Brazil: Comparative Advantage, Policy or Self-Discovery? Inter-American Development Bank, 2008. http://dx.doi.org/10.18235/0006866.
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This paper examines Brazil's export discoveries in aircraft, cell phones and swine meat. All cases confirm the importance of efficiency gains and sunk costs in the expansion of exports and lead to the following conclusions: both economic policy and comparative advantage played important roles in the emergence of new export activities; economies of scale were a crucial determinant of competitiveness; and a well-known brand helped to overcome information asymmetries and facilitate entry into export markets. Exporters concentrated on design, marketing, R&D, and product assembly, making coordination with suppliers an important element in their strategies. Public policy additionally had a strong if sometimes unintended influence. While governments can foster discoveries, especially in the presence of market failures, policy alone cannot produce a successful exporter.
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Filmer, Deon, James Habyarimana, and Shwetlena Sabarwal. Teacher Performance-Based Incentives and Learning Inequality. Research on Improving Systems of Education (RISE), 2020. http://dx.doi.org/10.35489/bsg-rise-wp_2020/047.
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This study evaluates the impacts of low-cost, performance-based incentives in Tanzanian secondary schools. Results from a two-phase randomized trial show that incentives for teachers led to modest average improvements in student achievement across different subjects. Further, withdrawing incentives did not lead to a “discouragement effect” (once incentives were withdrawn, student performance did not fall below pre-baseline levels). Rather, impacts on learning were sustained beyond the intervention period. However, these incentives may have exacerbated learning inequality within and across schools. Increases in learning were concentrated among initially better-performing schools and students. At the same time, learning outcomes may have decreased for schools and students that were lower performing at baseline. Finally, the study finds that incentivizing students without simultaneously incentivizing teachers did not produce observable learning gains.
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Galiani, Sebastián, Omar O. Chisari, and Sebastián J. Miller. Optimal Adaptation and Mitigation to Climate Change in Small Environmental Economies. Inter-American Development Bank, 2013. http://dx.doi.org/10.18235/0011515.
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This paper compares the optimal dynamic choices between policies of mitigation and adaptation for three economies: Brazil, Chile and the United States. The focus is on the optimal role of mitigation and adaptation for "environmentally small economies", i. e. , economies that are witnessing an exogenous increase in emissions to which they are contributing very little. The simulations lead to three main conclusions. First, small economies should concentrate their environmental efforts, if any, on adaptation. This is not a recommendation that such economies indulge in free-riding. Instead, it is based on considerations of cost effectiveness, ceteris paribus. Second, small economies that are unable to spend enough on adaptation may end up spending less on mitigation owing to their impoverishment as a result of negative climate shocks. Third, higher mitigation expenditures may arise not only as a result of greater optimal adaptation expenditures, but also because of increased adaptation to the incentives for mitigation provided by richer countries.
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Idris, Iffat. Conditions for Elections to Succeed in Reducing Conflict and Instability. Institute of Development Studies, 2022. http://dx.doi.org/10.19088/k4d.2022.124.
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Post-conflict elections can pave the way for democratisation and peacebuilding, but can also lead to renewed conflict. Minimum conditions for ensuring that elections promote the former and reduce conflict and instability include: peace and demilitarisation; international involvement; not holding post-conflict elections too early; holding national and local elections separately – ideally, local before national; election systems (notably proportional representation) that distribute rather than concentrate power; independent, permanent and well-resourced election management bodies; and media that promote voter education, messaging by parties and candidates, and election transparency. However, it is important to stress that specific criteria needed for successful post-conflict elections will be context-dependent.Post-conflict elections have the potential to establish legitimate government and can pave the way for democratisation and sustained peace. However, because they determine the distribution of power, they can also trigger renewed conflict. The risk of this is exacerbated by the difficult circumstances in which post-conflict elections are typically held (e.g. damaged infrastructure, weak institutions). The challenge is how to achieve the potential benefits while avoiding the risks. What are the conditions or criteria needed to ensure that post-conflict elections do not lead to conflict and instability?This review looks at the conditions needed to ensure that post-conflict election reduce conflict and instability. It draws on a mixture of academic and grey literature. While there was substantial literature on the various criteria, notably international involvement and election administration, it was largely gender-blind, as well as disability-blind.
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Bourekba, Moussa. Climate Change and Violent Extremism in North Africa. The Barcelona Centre for International Affairs, 2021. http://dx.doi.org/10.55317/casc014.
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As climate change intensifies in many parts of the world, more and more policymakers are concerned with its effects on human security and violence. From Lake Chad to the Philippines, including Afghanistan and Syria, some violent extremist (VE) groups such as Boko Haram and the Islamic State exploit crises and conflicts resulting from environmental stress to recruit more followers, expand their influence and even gain territorial control. In such cases, climate change may be described as a “risk multiplier” that exacerbates a number of conflict drivers. Against this backdrop, this case study looks at the relationship between climate change and violent extremism in North Africa, and more specifically the Maghreb countries Algeria, Morocco and Tunisia, which are all affected by climate change and violent extremism. There are three justifications for this thematic and geographical focus. Firstly, these countries are affected by climate change in multiple ways: water scarcity, temperature variations and desertification are only a few examples of the numerous cross- border impacts of climate change in this region. Secondly, these three countries have been and remain affected by the activity of violent extremist groups such as Al Qaeda in the Islamic Maghreb (AQIM), the Islamic State organisation (IS) and their respective affiliated groups. Algeria endured a civil war from 1991 to 2002 in which Islamist groups opposed the government, while Morocco and Tunisia have been the targets of multiple terrorist attacks by jihadist individuals and organisations. Thirdly, the connection between climate change and violent extremism has received much less attention in the literature than other climate-related security risks. Although empirical research has not evidenced a direct relationship between climate change and violent extremism, there is a need to examine the ways they may feed each other or least intersect in the context of North African countries. Hence, this study concentrates on the ways violent extremism can reinforce vulnerability to the effects of climate change and on the potential effects of climate change on vulnerability to violent extremism. While most of the existing research on the interplay between climate change and violent extremism concentrates on terrorist organisations (Asaka, 2021; Nett and Rüttinger, 2016; Renard, 2008), this case study focuses on the conditions, drivers and patterns that can lead individuals to join such groups in North Africa. In other words, it looks at the way climate change can exacerbate a series of factors that are believed to lead to violent radicalisation – “a personal process in which individuals adopt extreme political, social, and/or religious ideals and aspirations, and where the attainment of particular goals justifies the use of indiscriminate violence” (Wilner and Dubouloz, 2010: 38). This approach is needed not only to anticipate how climate change could possibly affect violent extremism in the medium and long run but also to determine whether and how the policy responses to both phenomena should intersect in the near future. Does climate change affect the patterns of violent extremism in North Africa? If so, how do these phenomena interact in this region? To answer these questions, the case study paper first gives an overview of the threat posed by violent extremism in the countries of study and examines the drivers and factors that are believed to lead to violent extremism in North Africa. Secondly, it discusses how these drivers could be affected by the effects of climate change on resources, livelihoods, mobility and other factors. Finally, an attempt is made to understand the possible interactions between climate change and violent extremism in the future and the implications for policymaking.
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Pietrobelli, Carlo, Oswaldo Molina, and Jocelyn Olivari. Global Value Chains in the Peruvian Mining Sector. Inter-American Development Bank, 2016. http://dx.doi.org/10.18235/0009308.
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Traditionally the Peruvian context has been unfavorable for innovation by local firms in the mining sector. However, some firms have managed to innovate despite these conditions in recent years. The aim of this paper is to understand the factors and incentives that foster or hinder innovation in the Peruvian mining industry. Through the study of the experiences of a group of local suppliers, the mechanisms that lead to innovative activities are identified and analyzed. Special attention is paid to the role of interaction between contractors and large mining companies in the framework of Global Value Chains, as well as to the innovative efforts of some local suppliers. Evidence shows that innovation by local suppliers in the Peruvian mining sector has a limited scope and some particular characteristics. First, local suppliers who manage to innovate are mainly incumbent firms whose experience in the market allowed them to integrate into the mining value chain. Second, most of these firms are usually supported by their relationships with larger national or international companies. Third, the more important innovations seem to be concentrated in specific sectors where there is less foreign competition because of their specificity to the Peruvian context.
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Fenton, Sam, Joanne Porter, Megan Simic, and Daria Soldatenko. Strategic planning report for the tourism innovation working group: Heyfield & District, 2024. Federation University, 2024. http://dx.doi.org/10.35843/sprtiwh24.
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Tourism is one of six innovation themes identified in the Heyfield and District Context Analysis1, which states the following regarding the opportunity to develop tourism in the area (p. 3): Heyfield’s location, nearby places of scenic beauty, Lake Glenmaggie, forested areas including tracks and trails, can support and add value to tourism ideas. Heyfield is known locally as a Gateway to the Southern Alps. The aim of the Heyfield and District Context Analysis was to “to investigate opportunities that will lead to long-term economic and social benefits, new jobs in sustainable industries, and to support the transition away from native timber harvesting”1. Following the context analysis, the next step for the tourism innovation theme was to identify specific opportunities to leverage the community assets to improve the local economy, employment opportunities and community wellbeing. Through the Heyfield and District’s Local Development Strategy (LDS), a draft for the Heyfield Adventure Hub (Appendix 5) was developed as part of a smart specialisation strategy. An aspect of smart specialisation is identifying where innovative efforts (and funding) should be concentrated. The draft strategy (Appendix 5) represents current efforts by the Heyfield Tourism and Traders Association (HTTA) and the Tourism Innovation Working Group (TIWG) to focus on leveraging natural assets and current businesses to provide a platform for an improved local visitor economy. These efforts are encouraged by current visitor activity through the holiday and long weekend periods and are aimed at developing year-round tourism activity. The proposed Adventure Hub is an adventure and nature-based activity concierge for the Heyfield Region, located in the Wetlands & Information Centre, which, according to the draft strategy, may conduct the following activities: 1. Promote the Heyfield Region and all it has to offer in adventure and nature-based activities and experiences to existing and potential visitors. 2. Link visitors to an adventure together with the relevant information. 3. Hiring out equipment such as mountain bikes or paddleboards to assist visitors experience, their adventure or attract others to deliver services. 4. Work alongside stakeholders to develop and implement new adventure activities fitting in with the Heyfield Region (Heyfield, Cowwarr, Tinamba, Glenmaggie, Coongulla and Licola). This research report represents a community-led study approach, capturing views on local tourism, along with stakeholder and expert views on how to improve the visitor economy, while preserving or enhancing the local culture and the liveability of the region. A brief literature review provides a snapshot of the experiences and lessons learned from towns and regions that have transitioned from extracting resources from nature to support the local economy, to leveraging natural assets for tourism.
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Ningthoujam, J., J. K. Clark, T. R. Carter, and H. A. J. Russell. Investigating borehole-density, sonic, and neutron logs for mapping regional porosity variation in the Silurian Lockport Group and Salina Group A-1 Carbonate Unit, Ontario. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332336.
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The Oil, Gas and Salt Resources Library (OGSRL) is a repository for data from wells licenced under the Oil, Gas and Salt Resources Act for Ontario. It has approximately 50,000 porosity and permeability drill core analyses on bedrock cores. It also has in analogue format, geophysical logs (e.g., gamma ray, gamma-gamma density, neutron, sonic) from approximately 20,000 wells. A significant challenge for geotechnical and hydrogeological studies of the region is the accessibility of digital data on porosity and permeability. Recent work completed on approximately 12,000 core analyses for the Silurian Lockport Group and Salina Group A-1 Carbonate Unit are geographically concentrated within productive oil and gas pools. An opportunity therefore exists to expand the bedrock porosity characterization for southern Ontario by using geophysical logs collected in open-hole bedrock wells that are more geographically dispersed. As part of this study, hard copy files of analog geophysical logs are converted to digital data (LAS format), followed by quality assessment and quality control (QAQC) to obtain meaningful results. From the digitized geophysical data, density, neutron, and sonic logs are selected to mathematically derive porosity values that are then compared with the corresponding measured core porosity values for the same depth interval to determine the reliability of the respective log types. In this study, a strong positive correlation (R²=0.589) is observed between porosity computed from a density log (density log porosity) and the corresponding core porosity. Conversely, sonic log porosity and neutron porosity show weak (R2 = 0.1738) and very weak (R2 = 0.0574) positive correlation with the corresponding core porosity data. This finding can be attributed to different factors (e.g., the condition of the borehole walls and fluids, the type and limitations of the technology at different points in time, knowledge of formation variability for calculations), and as such requires more investigation. The density log measures the bulk density of the formation (solid and fluid phases), and as such the derived porosity values indicate total porosity i.e., interparticle (primary) pore spaces, and vugs and fractures (secondary) pore spaces. The sonic log measures the interval transit time of a compressional soundwave travelling through the formation. High quality first arrival waveforms usually correspond to a route in the borehole wall free of fractures and vugs, which ultimately result in the derived porosity reflecting only primary porosity. As molds, vugs and fractures contribute significantly to the total porosity of the Lockport Group and Salina A-1 Carbonate strata, sonic porosity may not reflect true bulk formation porosity. The neutron porosity log measures the hydrogen index in a formation as a proxy for porosity, however, the current limitations of neutron logging tool fail to account for formation-related complexities including: the gas effect, the chloride effect and the shale effect that can lead to over- or underestimation of formation porosity. As a result, the density log appears to be the most reliable geophysical log in the OGSRL archives for total porosity estimation in the Lockport Group and Salina A-1 Carbonate Unit. Nonetheless, sonic porosity can be combined with density porosity to determine secondary porosity, whereas a combination of density and neutron porosity logs can be used to identify gas-bearing zones.