Dissertations / Theses on the topic 'Thermal treatment'

Plasma generated in contact with water has been extensively investigated in various electrode geometries and various discharge types for water treatment, of which the applications have been employed industrially on different scales. The reactive species such as OH radicals, O3, H2O2 and HO2 can be generated from the reactions that occur at the plasma-water interface. For discharges above water, the effect of positive gas ions, which lead to the formation of positive water ions, is considered the main pathway for OH radical formation; while for the discharge under water, the water dissociation by electron collisions is considered as the main pathway. However, the reaction zone for the production of reactive species (gas or liquid phase) is still controversial. This thesis presents a study of the plasma generated in the gas phase in contact with water by various discharge types for water treatment. The discharge characteristics, OH radical and H2O2 production, and solution conductivity and pH variation were investigated and compared under different experimental conditions. The degradation of methylene blue dye was investigated under DBD. The transition of impulsive current discharges into impulsive-diffuse discharges was recorded by increasing the solution conductivity; a further transition of the discharge type into a spark was recorded when the solution conductivity was increased to >2.4 mS/cm. The H2O2 energy efficiency of 1.1 g/kWh was recorded under positive impulsive current discharges in N2 and helium. The highest charge/H2O2 ratio of 1:1.26 was recorded under positive impulsive current discharges in O2 and N2. Under positive DC glow discharges, the H2O2 energy efficiency of 1.9 g/kWh was recorded in air discharges, and was slightly increased to 1.95 g/kWh when using a flow liquid electrode. Increased solution acidity and basicity from neutral solution have negative effects on H2O2 production. A significant amount of water vapour was observed under DC glow discharges, resulting in a negative effect on H2O2 production. Under negative discharges, no H2O2 production was detected in water after O2, N2, air and helium discharge treatments. In DBD, a threshold voltage is required to initiate electrical discharges between the glass plate and the water, through the micro-pores. The H2O2 production yield of 1.1 g/kWh was recorded in O2 discharge treatment. The degradation yield of methylene blue dye of 310 g/kWh was achieved within the first minute of O2 discharge treatment.

Approximately 96,000 tonnes of the UK Higher Activity Waste (HAW) inventory consists of irradiated nuclear graphite. The current Nuclear Decommissioning Authority (NDA) baseline strategy for irradiated graphite in England and Wales is isolation in a future Geological Disposal Facility, with Scottish policy endorsing an alternative decision of near surface long-term storage. Irradiated graphite disposal routes in the UK remain under review, however, as there are concerns surrounding timing and whether deep geological disposal is the most appropriate course of action for graphite. An alternative waste management solution is treatment prior to disposal to separate mobile radioactive isotopes such as 3H and 14C from the bulk material, allowing for HAW volume reduction and concentration. Optimisation of an existing thermal treatment process at the Nuclear Graphite Research Group (NGRG) of the University of Manchester has been effected and a detailed review of the uncertainties associated with quantitative determination of radioisotope releases during thermal treatment of irradiated graphite samples has been conducted. Thermal treatment experiments in both an inert atmosphere and 1% oxygen in argon atmosphere have been conducted for temperatures ranging from 600°C to 800°C, and durations from 4 to 120 hours, to determine the effects of oxidation time and temperature, and the consequent oxidation characteristics on the release rate of prominent radioisotopes, with a focus on the release of 14C. Lower temperature treatments in an oxidising atmosphere have shown that a preferential release of 14C-enriched graphite can be achieved from the bulk material of Oldbury Magnox reactor irradiated graphite, with evidence demonstrating that this liberated 14C-enriched region is located at the graphite surfaces throughout the porous structure. A large proportion of radiocarbon found in this irradiated graphite, however, is uniformly distributed throughout the bulk material and cannot be selectively oxidised. It is found that prominent metallic radioisotopes such as 60Co are not mobile at these temperatures and remain in the bulk graphite material, inclusive of radioactive caesium which the literature suggests will volatilise. The preliminary results were undertaken as part of the EU FP7 EURATOM Project: CARBOWASTE.

This work provides a detailed description of the qualitative and quantitative mineralogical, dynamic, as well as kinetic aspects for the structural transformation of α-spodumene (α-LiAlSi2O6), and advances the industrial processing of spodumene by introducing two novel alternative technologies that are relatively straightforward and potentially cost-effective. Spodumene, the most abundant lithium-containing mineral, usually undergoes calcination at an extreme temperature of about 1100 ºC and strong-acid digestion during industrial processing. The calcination process stimulates the structural transformation of spodumene from its naturally occurring pyroxene-framework α-phase into the relatively more reactive β-spodumene of the keatite (SiO2) structure. On the other hand, the acid digestion approach facilitates the production of water-soluble lithium compounds (mainly lithium sulfate Li2SO4). This study resolves the technical obstacles associated with cheaper (and safer) processing of spodumene concentrates. The project incorporated intensive experiments to analyse the thermally-activated changes during the calcination of spodumene. The combination of hot-stage and high-temperature synchrotron X-ray diffractometry (XRD) enabled in-situ mineralogical analysis of the transformation processes, identifying (and quantifying) the resulting phases at various temperatures. Each of the diffractometry techniques complements the heating rate and temperature limitations of each other. Likewise, accurate calorimetric and thermogravimetric analyses yielded the corresponding thermodynamic and kinetic functions, allowing the precise determination of the minimum energy required for the heat treatment process. Distinctly, the project also involved detailed investigation on roasting of spodumene with the most effective additives, CaO and Na2SO4, for better extraction of lithium. The addition of these chemicals resulted in the formation of water-soluble lithium compounds via the roasting process at a relatively low temperature (800 – 900 ºC). Set of experiments determined the best condition for minimising these additives and maximising the productivity of lithium. Atomic absorption spectrometry (AAS) quantitated the recovered lithium from the roasted spodumene concentrate. Techniques, such as X-ray fluorescence (XRF) and AAS, attested the chemical analyses of the raw spodumene concentrate. The Match! Software allowed phase identification, while HSC 7.1 software facilitated the estimation of energies. The results of this thesis have demonstrated that the transition reaction of spodumene occurs via different pathways, depending on the amorphicity and the thermal history of the mineral. The results have also identified the intermediate species and clarified their appearance as a function of temperature and heating rate, and particle size, relative to the final phase of β-spodumene. For instance, the formation of the recently reported γ-spodumene is initiated by crystallisation of minuscule amorphous materials in the concentrated sample at slow heating conditions, while fast initial heating to 800 ºC prompts the emergence of a newly-identified phase of β-quartzss, at low temperatures of less than 900 ºC. Requiring an operating temperature of above 1000 ºC, the calcination of spodumene concentrate has been elucidated to adopt slow kinetics, with a high activation energy of more than 800 kJ mol-1 and significant dependency on the degree of conversion. The combined outcomes of this study are instrumental in optimising the energy cost of lithium extraction from spodumene mineral in practical operations. In particular, this thesis reveals that, the roasting of spodumene concentrate with a small amount of CaO reduces the transformation temperature by 150 – 200 ºC as determined by in-situ XRD, which translates into important energy saving during the calcination of spodumene in the first step of the commercial acid digestion process. Roasting of spodumene with CaO and Na2SO4 at 882 ºC for 2 h results in producing a water-leachable lithium compound of LiNaSO4 with 94 % lithium recovery. Thus, the roasting of spodumene concentrate with these two additives eliminates the aggressive acidic treatment and decreases the operating temperature of the kiln.

Most physical ablation modalities for cancer treatment are focal and are based on thermal damage. Despite their regular clinical use as an alternative to surgical resection, their thermal principle of operation entails risks regarding the preservation of neighboring vital structures, such as large vessels, critical ducts or nerves. In addition, being focal, their use is unpractical in cases where multiple nodules are present or tumors are difficult to reach with the applicators. This thesis explores non-thermal electrical treatments which can be applied in a non-focal manner. Two treatments have been investigated: the first treatment, proposed by others a few years ago, is based on the permanent application of low magnitude alternating electric fields through surface electrodes. Here, this treatment has been in vivo studied to evaluate its efficacy as well as to discern whether it is non-thermally mediated. The second electrical treatment is based on the electroporation phenomenon and targets liver tumor nodules. Electroporation-based therapies employ brief high magnitude electric fields. These pulsed fields, alone or in combination with chemotherapeutic drugs, are able to kill cells by increasing their membrane permeability. Current electroporation-based therapies for internal tumors are local and are delivered through needle-shaped electrodes. Rather than using needle electrodes to treat liver tumors, here it is explored a novel treatment in which large plate electrodes are used to deliver the field across the whole liver in a non local fashion. The treatment aims at simultaneously destroying all tumors while preserving healthy tissue. Its efficacy is based on selectively enhancing the electric field over the tumors by infusing a solution with high electrical conductivity. The proposed treatment for liver tumors requires a high performance generator which is not currently available. The work presented here includes the design of a new generator topology able to fulfill the requirements.
La majoria del mètodes físics d'ablació tumoral es basen en produir dany tèrmic de manera focalitzada. Tot i ser considerats una alternativa habitual a la resecció quirúrgica, el principi tèrmic de funcionament, comporta un risc per la preservació d'estructures vitals adjacents a la zona de tractament, tals com grans vasos o nervis. A més, el fet de ser focals, fa impracticable la seva aplicació en cas de múltiples nòduls o tumors de difícil accés. Aquesta tesi explora tractaments elèctrics no basats en temperatura, capaços de ser aplicats de manera no focal. S'han investigat dos tractaments: El primer, proposat per altres fa pocs anys, està basat en aplicar permanentment camps elèctrics alterns de baixa magnitud a través d'elèctrodes superficials. Aquí, aquest tractament s'ha estudiat in vivo tant per avaluar la seva eficàcia com per discernir si aquesta resideix en la temperatura. El segon tractament es basa en el fenomen d'electroporació i persegueix el tractament de nòduls hepàtics. En els tractaments basats en electroporació, s’apliquen breus camps elèctrics de gran magnitud per tal de permeabilitzar la membrana cel·lular. Això permet la penetració d’agents quimioterapèutics o produeix directament la mort cel·lular. En lloc d'utilitzar, com és habitual, agulles per tal d'aplicar el tractament, aquí s'explora tractar tot el fetge de forma no localitzada, fent servir grans elèctrodes plans i paral·lels. Utilitzant solucions d'alta conductivitat elèctrica, es pretén magnificar selectivament el camp elèctric sobre els tumors, sent així capaços de destruir tots els tumors i alhora preservar el teixit sà. El tractament proposat per els tumors hepàtics, requereix d'un equip generador actualment no disponible. El presentat treball inclou el disseny d'una nova topologia de generadors capaç de complir amb els requisits.

Obtaining high magnetic susceptibility phases from Hekimhan&
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Deveci siderite orevia preliminary thermal treatment has been the basic target of the thesis study.Thermal decomposition characteristics of samples, determined bythermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC), were referenced in advancement of thestudy. Heat treatment experiments, particularly roasting, were carried out byconventional heating and microwave heating. Results showed that roasting of Hekimhan&
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Deveci siderite samples could not be achieved by microwave energywhilst conventional heating experiments recorded success. Subsequentlow&
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intensity magnetic separation of roasted samples gave recovery above 90%, where low&
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intensity magnetic separation of run&
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of&
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mine sample had failed. Formation of high magnetic susceptibility phases was verified by magneticsusceptibility balance and x&
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ray diffraction analysis (XRD), on roasted samples. Statistical modeling was applied to determine the optimum conditions of roastingin conventional heating system
based on heating temperature, time of heating, particle size as factors.It was concluded that roasting at T= 560 º
C, for t= 45 minutes was adequate toobtain desired results. Particle size was noted to be not much effective on the process as other factors at the studied size range. Kinetics (E, n) and reaction mechanism for the thermal decomposition in conventional heating system were evaluated with different solid&
#8211
state reaction models by interpretation of the model graphs.Three&
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dimensional diffusion reaction models reported to characterize the thermal decomposition well, with values of activation energy (E), E= 85.53 kJ/mol (Jander)
E= 85.49 kJ/mol, (Ginstling&
#8211
Brounshtein).

Considering the high overall costs of radioactive waste disposal and the growing requirements for improved quality of the final waste form, the benefits offered by thermal processing become very significant. Key drivers for the application of thermal treatment processes include the reduced volume, improved passive safety, and superior long term stability of the vitrified wasteform products. Currently, a fundamental lack of scientific knowledge and understanding significantly hinders the uptake of thermal treatment processes for the immobilisation and disposal of plutonium contaminated material waste. The project will contribute to accelerating the acquisition of knowledge and experience required to support the Nuclear Decommissioning Authority (NDA) in deploying thermal technologies as a national asset for intermediate level waste (ILW) treatment. Plutonium contaminated materials (PCM) waste is a sub category of ILW. The current treatment method for PCM is supercompaction and cement encapsulation, however, there are significant concerns regarding the reliability of the treatment method to consistently deliver a waste form suitable for long term performance. This project follows on from previous work which provided proof of concept studies for thermally treating PCM waste. This work uses a soda lime silica (SLS) glass cullet as the glass forming additive to aid vitrification, providing substantial benefits in terms of costs saving compared to previous work. The thermal treatment experiments showed no violent reactions between the waste simulant and the glass additives. The Ce (acting as a Pu surrogate) was effectively partitioned within the slag fractions of the waste form, with crystalline regions present in certain formulations. The Ce was found as trivalent species providing confidence that the slag component of the wasteforms developed here could incorporate Pu at the concentrations expected from treatment of PCM wastes. The materials produced here are broadly comparable, in terms of durability, to other simulant UK ILW glass products considered potentially suitable for geological disposal. The project also investigates the potential to use the glass forming oxides found within the ILW itself to aid vitrification. Using suitable ternary phase diagrams, it is possible to use the waste and any additional additives to create a formulation to ensure a glass is successfully formed at a reasonable operating temperature whilst always maintaining compatibility with currently available technology platforms. This method was utilised to vitrify representative pond scabbling waste. The simulant waste contained high levels of SiO2 which, in combination with glass forming oxides, were successfully vitrified. Characterisation studies were performed to understand the relationship between Na2O and B2O3 and the effect this had on the microstructure of the resultant structure of the glass. Glass dissolution experiments were also performed to test the performance of the glass in conditions expected within a geological disposal facility (GDF). The thesis also includes the results of samples acquired from a three month student placement working with Kurion's geomelt facility at the Workington site (UK). Contained within this PhD are experiments which aim to provide significant information into the mechanism that drive glass alteration. However this data has only been applicable to short-term alteration. The research presented in Chapter 7 aims to understand the long term mechanism of the vitrified PCM waste by using 250 year old slag samples as a glass alteration analogue. The results presented provide evidence for the long term durability of the vitrified PCM waste samples.

Abstract Heavy menstrual bleeding causes significant health and social problems for up to 30% of women at some point of their lives. Medical treatment is not always sufficient or tolerated by women. Hysterectomy is a definitive solution, but it is a major operation associated with long disability and potential severe complications. Endometrial ablation techniques have been developed to avoid the risks related to hysterectomy. Further evolution of these techniques also offers a possibility of a quick and simple outpatient procedure. This study evaluated the long-term effects of endometrial ablation on heavy menstrual bleeding and later endometrial diagnostics. Another aim was to compare the costs when the procedure was performed in different settings. Finally, the effect of hyaluronic acid gel on intrauterine adhesion formation was assessed. Endometrial ablation had a good long-term effect on heavy menstrual bleeding in a retrospective study of 172 women, and up to 84% avoided hysterectomy during the follow-up time mean of 5 years. Seventy-six per cent of the patients were satisfied with the procedure. Due to the formation of intrauterine adhesions, prior endometrial ablation compromised later diagnostics of endometrium, and outpatient endometrial sampling failed in 23% of 57 women who had undergone endometrial ablation a mean of 6 years earlier, but that did not seem to have clinical importance. In a prospective, randomized and double-blind pilot study of 36 patients, hyaluronic acid gel did not prevent the formation of intrauterine adhesions. In a cost-minimisation analysis based on real resource use, performing endometrial ablation as an outpatient procedure under local anaesthetic instead of a day case procedure performed in the operating theatre under general anaesthetic reduced the costs significantly, from 1,865 to 1,065 euros. In conclusion, the results of this study suggest that endometrial ablation is a good alternative for the treatment of heavy menstrual bleeding, and remarkable cost savings can be achieved by taking the procedure out of the operating theatre. The formation of intrauterine adhesions is common and cannot be prevented with hyaluronic acid gel
Tiivistelmä Runsaat kuukautiset aiheuttavat merkittävää terveydellistä ja sosiaalista haittaa jopa kolmasosalle naisista jossain elämänvaiheessa. Lääkehoito ei aina ole riittävä, eivätkä kaikki naiset voi tai halua käyttää sitä. Kohdunpoisto on lopullinen ratkaisu, mutta se on iso leikkaus, johon liittyy pitkä työkyvyttömyys ja vakavien komplikaatioiden riski. Näiden riskien välttämiseksi on kehitetty kohdun limakalvon tuhoavia tekniikoita, joista nykyisin eniten käytetty on limakalvon tuhoaminen lämpöhoidon avulla. Nykytekniikoilla toimenpide voidaan myös tehdä helposti ja nopeasti polikliinisesti. Tässä tutkimuksessa arvioitiin kohdun limakalvon lämpöhoidon pitkäaikaisvaikutuksia runsaiden kuukautisten hoidossa ja sen vaikutusta myöhemmin tapahtuvaan kohdun limakalvon diagnostiikkaan. Niin ikään verrattiin päiväkirurgisen ja polikliinisen toimenpiteen kustannuksia. Lopuksi tutkittiin pystytäänkö hyaluronihappogeelin avulla estämään kohdunsisäisten kiinnikkeiden muodostumista. Lämpöhoidolla oli hyvä pitkäaikaisvaikutus runsaisiin kuukautisiin 172 naista käsittäneessä retrospektiivisessä tutkimuksessa, ja kohdunpoistolta välttyi keskimäärin 5 vuoden seuranta-aikana 84 % naisista. 76 % naisista oli tyytyväisiä hoitoon. Lämpöhoidon aiheuttamat kohdunsisäiset kiinnikkeet vaikeuttivat myöhempää kohdun limakalvon diagnostiikkaa. Polikliininen imunäytteen otto ei onnistunut 23 %:lla 57 potilaasta, joille oli tehty lämpöhoito keskimäärin 6 vuotta aikaisemmin. Tällä ei kuitenkaan näyttänyt olevan juurikaan kliinistä merkitystä. 36 potilasta käsittäneessä, prospektiivisessa, satunnaistetussa kaksoissokkotutkimuksessa hyaluronihappogeelin avulla ei pystytty estämään kohdunsisäisten kiinnikkeiden muodostumista. Todelliseen resurssien käyttöön perustuvassa kustannusten minimointianalyysissa todettiin, että tekemällä lämpöhoito polikliinisesti paikallispuudutuksessa leikkaussalissa nukutuksessa tehtävän toimenpiteen sijasta, kustannukset laskevat 1865 eurosta 1065 euroon. Tämän tutkimuksen perusteella kohdun limakalvon lämpöhoito tarjoaa hyvän vaihtoehdon runsaiden kuukautisten hoitoon, ja sen kustannuksia voidaan merkittävästi pienentää tekemällä toimenpide polikliinisesti. Kohdunsisäisten kiinnikkeiden muodostuminen on tavallista, eikä sitä pystytä estämään hyaluronihappogeelin avulla

De-inking sludge generated from pulp and paper industry is considered hazardous since it may contain heavy metals such as Cd, Cr, and Pb. Hence, the de-inking sludge needs to be treated before being disposed of. Sludge combustion is a proven disposal technology, which generates fly ash containing a portion of the heavy metals that may leach out under uncontrolled conditions. The aim of this thesis is to implement a new multi-zone temperature combustion technique (Low-High-Low temperature combustion, LHL) to help contain and immobilize the heavy metals within fly ash particles. During the LHL, the waste will be initially fed into a low-temperature zone (<1100 K) and then subjected to the high-temperature treatment (~1480 K) that will be followed by another low-temperature zone (~1100 K).
This dissertation describes the detailed design and construction of a novel pilot-scale combustion facility, called the Multi-Mode Combustion Facility (MCF), used as a multidisciplinary research tool for investigating the thermal remediation of contaminated solid residues. The MCF is capable of operating in two different modes: Fluidized-Bed combustion mode (FBC) and Single burner furnace mode (SBF). However, this project focuses on the FBC mode (minimum fluidization velocity of 0.42 m/s and bed temperature of 1073 K).
This research compares the combustion characteristics of de-inking sludge obtained in the LHL and in the conventional combustion techniques. The following properties of particulates were studied: morphological evolution of solid particles, structural porosity, metals interactions with fly ash particles, and leachability.
The LHL's final supermicron spherical fly ash went through a molten phase with submicron particles attached to the fly ash particles surfaces. Thus, reducing its porosity to 19%. However, the amorphous final fly ash obtained in the conventional technique reveals 32% porosity. It was found that the physical characteristics of the final LHL's fly ash are the main cause for the reduced heavy metals leachability rates of 0.18, 0.046, and 0.92% for Cd, Cr, and Pb, respectively. The conventional technique had 53.28, 16.79, and 5.20% of Cd, Cr, and Pb respectively, leaching out due to the high porosity percentages. In conclusion, the LHL technique allows for controlling the heavy metals emission from FBCs, while using a waste to energy approach and maintaining environmentally acceptable gas emission levels.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Diversos fatores têm atraído esforços para o desenvolvimento de novas estruturas para circuitos planares de microondas. Várias propostas são encontradas na literatura técnica, explorando diferentes formas de miniaturização dos circuitos, melhoria de eficiência de acoplamento, aumento de banda ou redução de perdas. Entre elas, encontra-se a utilização de materiais ferroelétricos, cujas propriedades dielétricas podem ser alteradas com a aplicação de uma tensão elétrica, permitindo a fabricação de uma nova classe de dispositivos ativos compactos; contudo, esses materiais têm desvantagens como altas perdas e dificuldades de fabricação. Em paralelo, a disseminação das telecomunicações ópticas gera uma demanda de novos componentes ópticos para os sistemas: mais eficientes, com maior capacidade e menor custo. A utilização de fibras ópticas de sílica em telecomunicações torna desejável que esses novos componentes sejam realizados em materiais compatíveis com a sílica, como por exemplo alguns tipos de vidro. A polarização eletro térmica surgiu como uma forma de produzir dispositivos eletro-ópticos ativos a partir de vidros utilizados como substratos de guias de onda ópticos passivos. Neste trabalho, os processos de tratamento eletro-térmicos utilizados nos substratos ópticos são aplicados a substratos dielétricos para uso em microondas. São verificados os efeitos resultantes nas alterações das propriedades dielétricas na faixa de microondas e a aplicação potencial em componentes e circuitos. Os tratamentos se constituem fundamentalmente na aplicação de alta tensão ao substrato na presença de temperatura elevada, visando à migração controlada de íons no material. Os substratos estudados são a alumina, substrato tradicional de microondas com elevada constante dielétrica, e os vidros, boro-silicato e sodo-cálcico, que estão atualmente sendo utilizados como substratos para guias ópticos e para construção de dispositivos ópticos ativos. É caracterizada a perda dielétrica dos vidros tratados para utilização como substrato para circuitos planares de microondas. O desenvolvimento de dispositivos ópticos ativos em substratos vítreos também implica na fabricação de circuitos elétricos de microondas sobre o mesmo substrato, para alimentar esses dispositivos com dados em altas taxas. Os vidros possuem altas perdas dielétricas nessa faixa devido à presença de íons alcalinos. A criação, pelo tratamento eletro-térmico, de uma camada de depleção de íons, próxima à superfície abaixo do circuito, permite a redução dessas perdas efetivas em circuitos planares. Outro efeito investigado é a possibilidade de se produzir um comportamento similar ao efeito ferroelétrico em um substrato de microondas. A camada de depleção criada pelo tratamento eletro-térmico provoca alterações na estrutura e permite a gravação de um campo elétrico estático devido ao deslocamento de íons. É estudada a influência desse campo dentro do material na variação de suas propriedades dielétricas, e a resposta à aplicação de uma tensão de controle externa. Estuda-se então a possibilidade de substituição por substratos tratados dos materiais ferroelétricos no desenvolvimento de componentes como chaves, acopladores e atenuadores variáveis e filtros de microondas.
Several factors have been attracting research efforts to the development of new planar structures for microwave planar circuits. Various proposals can be found in the technical literature, exploring different ways of miniaturization of circuits, improvement of coupling efficiency, increase of bandwidth or reduction of losses. Among these is the use of ferroelectric materials, whose dielectric properties can be altered with the application of an electrical voltage, enabling the fabrication of a new class of compact active devices; however, such materials present some disadvantages, like very high losses and difficulties in manufacturing. Parallel to that, the dissemination of optical telecommunications generates a demand for new optical components for the systems, with greater efficiency and capacity but lower cost. Due to the use of silica optical fibers in telecommunications, it is desirable that these new components are fabricated in materials compatible to silica, as for example some types of glass. The electro-thermal polarization emerged as a way of producing active electro-optical devices from glass substrates used for passive optical waveguides. In this work, the processes of electro-thermal treatment used in optical substrates are applied to dielectric substrates for microwave use. The resulting effects on the changes in dielectric properties in the microwave frequency range and potential application in components and circuits are assessed. Such treatments are constituted fundamentally by the application of high voltage to the substrate in the presence of high temperature, aiming at the controlled migration of ions in the material. The substrates considered are alumina, conventional microwave substrate with high dielectric constant, and glasses, borosilicate and soda-lime, which are currently being used as substrates for optical waveguides and for the construction of active optical devices. The dielectric loss of treated glasses as substrates for planar microwave circuits is characterized. The development of active optical devices in vitreous substrates also implies the manufacture of microwave electrical circuits on the same substrate, in order to feed these devices with data at high rates. Glasses have high dielectric losses in this frequency range due to the presence of alkali ions. The creation by the electro-thermal treatment of an ion- depleted layer, near the surface below the planar circuit, enables the reduction of the effective losses in planar circuits. Another investigated effect is the possibility of creating a behavior similar to the ferroelectric effect in the microwave substrate. The depletion layer created by the electro-thermal treatment causes alterations in the structure and allows the recording of a static electric field by the displacement of ions. The influence of this field within the material on the variation of its dielectric properties, and the response to the application of an external control voltage are assessed. Then, the substitution for treated substrates of ferroelectric materials in the development of components such as switches, variable couplers and attenuators and microwave filters is considered.

The UK has large volumes of radioactive materials which are classified as Intermediate Level Waste (ILW). The baseline treatment for these wastes is encapsulation via cementation, however, this method is not ideally suited for numerous wastes, both in the UK and globally. Alternative thermal processing methods for these materials may be capable of producing wasteforms with improved properties. This thesis presents a series of scoping studies on the thermal treatment of a diverse range of ILWs in order to identify the potential benefits and pits falls of such processes. The wastes selected were Tri-Structural Isotropic (TRISO) Fuel Particles, Prototype Fast Reactor (PFR) raffinate, SIXEP sand/clinoptilolite ion exchange materials and SrTreat® Ion exchange material. The scoping studies performed showed promise for the thermal treatment of all selected waste streams. A summary of the main results for each waste stream are provided below; TRISO Fuel Particles: Immobilisation focused on encapsulation of the particles in highly durable glass matrices. Alumino-borosilicates were determined to be the most effective glass composition for the production of composites, in terms of both their physical and chemical properties. The ability of Hot Isostatic Pressing (HIPing) to improve composites was investigated. Unfortunately, this was shown to result in severe fracturing within the composite. This was hypothesised to occur as a result of excessive pressurisation during the cooling cycle. The HIP process did show some benefits in terms of particle coating properties and with small alterations to the HIP cycle utilised it should also be possible to eliminate the detrimental fracturing features. PFR Raffinate: The vitrification of PFR raffinate was investigated using the G73 glass composition, a glass which has been previously proposed for the immobilisation of other ILWs. This glass was proven to be capable of accommodating a waste loading of up to 20 wt% PFR raffinate. The glass produced was homogeneous with good waste retention, had no noted crystal formation, an aqueous durability comparable to currently employed HLW glasses and the thermal characteristics necessary for industrial scale up. Further study should be performed on the ability of this waste to retain Cs during processing and in aqueous solution. SIXEP Sand/Clinoptilolite Waste: SIXEP sand/clinoptilolite was processed at 95 wt% with a 50 % volume reduction by HIPing. The waste produced was a phase separated glass-ceramic. The wasteform was deemed to be suitable for ILW immobilisation and had an exceptional Cs ii retention in aqueous solutions. However, the presence of an alkali earth sulphate phase increased the Sr release to solution. Attempts to qualify the suitability of this wasteform for disposal, developed methodologies to investigate the properties of phase separated materials. A combination of vertical scanning interferometry (VSI), dissolution experiments and SEM imaging was shown to be capable of elucidating the dissolution behaviour based upon compositional variation. SrTreat®: SrTreat® was processed at 100% waste loading via HIPing. This aim was to investigate the potential for developing ion exchange columns which could subsequently be HIPed, as such, providing a complete waste treatment solution. The HIP process produced a monolithic, mixed phase sodium titanate ceramic. This ceramic was formed by the sintering of individual grain structures and retained the compositional variations seen in the granular waste stream. The wasteform was porous around the grain edges, determined to occur as a result of carbonate formation prior to HIPing. The carbonation of this material is likely to limit the potential to utilise HIPing as a disposal methodology for these wastes. However the aqueous dissolution behaviour of these wastes was still favourable and the process was shown to create a significant reduction in waste volume. The work performed in this thesis has shown that various methods for thermal treatment can be rapidly investigated to determine the potential benefits and pit falls. The application of thermal treatments was shown to be capable of producing significant improvements in wasteform quality by comparison with the cementitious alternatives.

Perfluorosulfonate ionomer (PFSI) membranes were annealed at elevated temperature for various periods of time in order to investigate the morphological effects of thermal treatments. For Nafion® 117, the DSC thermograms of Na+-, Cs+- and tetramethylammonium(TMA+)-form membranes show an endothermic peak develops upon annealing at 200ºC, indicating the development of crystallinity in the membrane. For these three samples annealed under same conditions, the heat of fusion (ΠH) values of the endothermic event increases with increasing counterion size. Larger tetraalkylammonium ions, tetraethylammonium(TEA+) and tetrapropylammonium(TPA+), result in no significant peak upon annealing at 200ºC. DSC thermograms of annealed Na+-form 3M Ionomer show no peak upon annealing and DSC thermograms of annealed TMA+-form 3M Ionomer show a very small peak that develops with annealing time at high equivalent weights. Annealed TMA+-form Dow Ionomer, which has a side chain shorter than both Nafion® and 3M Ionomer and a smaller mole% of side chains at the same equivalent weight, shows a relatively high ΠH value, which might also be related to its blocky nature. These results show that the isothermal crystallization kinetics of PFSI is affected by the counterion attached to the sulfonate group, the length of side chain, the mole% of side chains and the nature of the membrane. Water uptake analysis has been performed on annealed membranes, and the result shows that water uptake decreases with increasing degree of crystallinity.
Master of Science

Thermal treatment of minerals has been researched over the past few decades, with a view to reducing the energy requirements in the comminution process. The use of microwave radiation has proven especially interesting, due to the differential dielectric heating leading to the generation of intergranular fractures, therefore better liberation of minerals and a reduction in the generation of fines, which are notoriously difficult to process. This thesis specifically investigated the effect of microwave pre-treatment on the efficiency of the downstream separation processes used in the minerals industry. If any energy savings that are made in the comminution process are negated by a severely detrimental effect in the separation of valuable mineral from the gangue then this would not make economic sense for microwave pre-treatment to be utilised. Conventional heat treatment, in air, lead to the formation of oxide mineral phases throughout the bulk of the pyrite, galena, ilmenite and molybdenite samples analysed. This heat treatment had no effect on the mineralogy of the chromite sample. Thermal alteration of the kaolinite sample tested also revealed no significant changes. Dielectric measurements of the minerals showed that all would adsorb microwave radiation, apart from chromite and kaolinite. Exposure to microwave radiation did not induce changes in the bulk mineral, as shown by X-ray diffraction analysis. However, use of scanning electron microscopy showed evidence of oxidation of the pyrite surface, and a mineral liberation analyser showed the formation of pyrrhotite and hematite on the surface of the particles.

This work encompasses the study of a novel thermal driven desalination system to accomplish full separation of water and solute. This process advantageous over other process because it involves zero recirculation and zero liquid discharge, thus having minimum environmental impact. Since this system provides full separation, salts and other valuable products can be obtained in addition to pure water. This system can operate at high energy efficiencies using medium temperature heat source like industrial reject or solar cells. This plant consists of two technologies, the full separation and multi effect distillation which when integrated together 8ive us water and salt separately. Three different configuration of the FS-MED system have been presented, naming concurrent feed, variable feed, and counter current feed. They vary depending on their flow and feed distribution. Numerical procedure has been developed to solve the energy and mass balance equation for steady state condition has been presented.

京都大学
0048
新制・課程博士
博士(工学)
甲第22430号
工博第4691号
新制||工||1732(附属図書館)
京都大学大学院工学研究科都市環境工学専攻
(主査)教授 高岡 昌輝, 教授 米田 稔, 准教授 大下 和徹
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DFAM

The increased demand for advanced techniques in anaerobic digestion over the last few years has led to the employment of various pre-treatment methods prior to anaerobic digestion to increase gas production. These pre-treatment methods alter the physical and chemical properties of sludge in order to make it more readily degradable by anaerobic digestion. The thermal hydrolysis process has been used in several treatment plants around the world, but none currently operate in the US. Thermal hydrolysis causes cell walls to rupture under the effect of high temperature and high pressure and results in highly solubilized product which is readily biodegradable. The performance of the process was evaluated for a treatment plant located in Dallas, TX. The performance assessment was based on various characteristics including pH, solids removal, COD removal and gas production. The study was conducted in two phases to investigate the effect of change in mesophilic temperature (37oC and 42oC) and the effect of solids retention time (SRT) (15 days and 20 days). Thermally hydrolyzed combined (1:1) primary and waste activated sludge was fed to a Thermal Hydrolysis (TH) anaerobic digester and its performance was compared to a conventional mesophilic anaerobic digester receiving non pre-treated sludge. The thermal hydrolysis pre-treatment was found to be more effective as compared to the conventional anaerobic digester. The efficiency of the process varied slightly with increase in temperature but the change in SRT was seen to have a greater impact on the digesterâ s performance. The pre-treatment technique was observed to deliver the best results at a 20 day SRT.
Master of Science

Tourmaline is an aluminoborocyclosilicate mineral with a complex arrangement of atoms. With highly variable chemistry and multiple cation sites, tourmaline is one of the last complex minerals whose structure was unraveled, and its response to changes in Pressure-Temperature-Time (P-T-X) are not well understood. Due to its stability at high temperature and pressure, tourmaline has the potential to be an informative mineral in terms of petrogenetic indicators and could be used in assessing provenance, thermobarometry and geochronology. Three reactions were proposed to understand the cation exchange and disordering between the Y- and Z-sites in the tourmaline structure. These reactions include: 1. YFe2+ + ZAl + OH ; ZFe3+ + YAl + O + H ; in two samples with varying Fe2+ content. 2. YMg + ZAl ; ZMg + YAl. 3. YFe3+ + ZAl ; ZFe3+ + YAl. Using single crystal X-ray diffraction and stepwise heating, the extent and effect of the exchange between the Y- and Z-sites in response to changes in temperature was described. In response to increased temperature, equivalent amounts of Fe2+, Fe3+, Mg2+ of the Y-sites exchange with Al of the Z-sites. This leads to decreases in Y-site average bond length, increases in Z-site average bond length, shortening of a lattice parameters, lengthening of c lattice parameters and decreases in quadratic elongation. Additionally, the T-site experienced an increased in tetrahedral rotation and ditrigonality and changes to the crimping of the tetrahedral ring upon heating. The cation exchange and disordering in these samples relates to the stability of tourmaline at elevated temperatures in that tourmaline will undergo cation exchange and disordering to maintain the stability of the mineral. This has implications on the conditions in which tourmaline is formed as well as stability of tourmaline and other minerals and materials in different P-T-X conditions.

Varicose veins are a common problem affecting approximately 30% of the Western population. The majority of patients present to secondary care complaining of a number of commonly experienced symptoms, however, some present with severe complications of venous disease including venous ulceration. For hundreds of years varicose veins have been treated with compression and surgery. In the last decade, technological advances have lead to the introduction of minimally invasive therapies for varicose veins, with the aim of providing rapid treatment with minimum discomfort to the patient at acceptable cost to the healthcare provider. This study examined the current use of endovenous ablation procedures in the United Kingdom amongst consultant vascular surgeons using an online questionnaire and also explored the patient’s views regarding treatment of varicose veins and potential therapeutic options. Prior to conducting a randomised clinical trial comparing early outcomes following laser and radiofrequency ablation in patients with primary varicose veins, an observational pilot study was carried out in the department. In parallel, the use of disease specific quality of life tools were compared to clinical, anatomical and haemodynamic outcome measures in this cohort of patients. The findings of the study have shown that although endovenous ablation procedures appear to be increasing in popularity, traditional surgery remains the most frequently performed procedure. Overall, patients overall have little knowledge of potential treatment options and the majority would be in favour of a single treatment under a local anaesthetic. However, most would be strongly influenced by the advice and opinion of the surgeon to whom they were referred. Results from the pilot study and a randomised clinical trial showed that radiofrequency ablation is significantly less painful than laser ablation for up to 10 days post procedure. Clinical improvements and gains in quality of life were significantly improved at 6 weeks and 6 months post intervention compared with baseline scores and were comparable between the groups. No significant difference was observed in anatomical outcomes between the two treatments. Although radiofrequency may be less painful than laser ablation, both endovenous thermal ablation treatments result in significant improvements in quality of life and are likely to become increasingly popular in the future.

Upon forming a biofilm, bacteria undergo several changes that prevent them from being eradicated with antimicrobials alone. These biofilms manifest as persistent infections and biofouling in the medical and industrial world, respectively, constituting an ongoing medical crisis and creating a huge financial burden. Biofilms on implanted medical devices cause thousands of patients each year to undergo multiple surgeries to explant and replace the implant, driving billions of dollars in increased health care costs due to the lack of viable treatment options for in situ biofilm eradication. Heat has been used to reliably eliminate biofilms for many years, but the temperatures employed are infeasible for many applications, particularly in vivo medical treatment. Remotely activated localized heat can be applied through a superparamagnetic iron oxide nanoparticle polymer coating when paired with an alternating magnetic field. However, there is very little known about the temperatures required to kill the biofilms and the effects of the heat in conjunction with antibiotics. To better understand the required parameters to effectively kill off bacteria in biofilms a variety of heat treatments were investigated for a variety of Pseudomonas aeruginosa biofilms grown in different conditions. Additionally, these heat treatments were combined with antibiotics to better understand any combined effects of the two orthogonal treatment plans. It was found that heat is an effective method for killing the bacteria in biofilms. Temperatures ranging from body temperature, 37 °C, to 80 °C were used to heat shock the biofilms for 1 to 30 minutes. Higher temperatures for short exposure times yielded similar results to lower temperatures for longer exposure time. Biofilms grown in different conditions did vary in their susceptibility to the heat shocks; however, at the higher temperatures the differences became negligible. Therefore, the more effective treatments were the higher temperature heat shocks with shorter exposure times to maximize bacterial cell death and minimize the potential heat transfer to the surrounding tissue. Regrowth studies indicate a critical post-shock bacterial loading (~103 CFU/cm2) below which the biofilms were no longer viable, while films above that loading slowly regrew to their previous population density. Combined treatments with antibiotics had synergistic effects for all antibiotics across a window of heat shock conditions. Erythromycin in particular, which showed no effect on the biofilm alone, decreased biofilm population by six orders of magnitude at temperatures which had no effect in the absence of antibiotics. These studies will evolve the understanding of biofilms and how to efficiently eradicate them on implant surfaces. The introduction of such a novel coating in conjunction with antibiotics could obviate thousands of surgeries and save billions of dollars spent on explantation, recovery, and re-implantation.

Le champ électrique d'une puissance suffisante peut provoquer une augmentation de conductivité et perméabilité de la membrane cellulaire. L'effet est connu comme l'électroporation, attribuée à la création de voies aqueuses dans la membrane. Quantifier le transport de la matière dans le cadre d'électroporation est un objectif important. Comprendre ces processus a des ramifications dans l’extraction du jus ou l’extraction sélective des composés de cellules végétales, l'amélioration de l'administration de médicaments, et des solutions aux défis environnementaux. Il y a un manque de modèles qui pourraient être utilisés pour modéliser le transport de la matière dans les structures complexes (tissus biologiques) par rapport à l'électroporation. Cette thèse présente une description mathématique théorique (un modèle) pour étudier le transport de la matière et le transfert de la chaleur dans tissu traité par l’électroporation. Le modèle a été développé en utilisant les lois de conservation et de transport et permet le couplage des effets de l'électroporation sur la membrane des cellules individuelles au transport de la matière ou la chaleur dans le tissu. Une solution analytique a été trouvée par une simplification, mais le modèle peut être étendu avec des dépendances fonctionnelles supplémentaires et résolu numériquement. La thèse comprend cinq articles sur l'électroporation dans l'industrie alimentaire, la création de modèle pour le problème de diffusion, la traduction du modèle au problème lié à l’expression de jus, validation du modèle, ainsi que des suggestions pour une élaboration future du modèle. Un chapitre supplémentaire est dédié au transfert de la chaleur dans tissu
An electric field of sufficient strength can cause an increase of conductivity and permeability of cell membrane. Effect is known as electroporation and is attributed to creation of aqueous pathways in the membrane. Quantifying mass transport in connection with electroporation of biological tissues is an important goal. The ability to fully comprehend transport processes has ramifications in improved juice extraction and improved selective extraction of compounds from plant cells, improved drug delivery, and solutions to environmental challenges. While electroporation is intensively investigated, there is a lack of models that can be used to model mass transport in complex structures such as biological tissues with relation to electroporation. This thesis presents an attempt at constructing a theoretical mathematical description – a model, for studying mass (and heat) transfer in electroporated tissue. The model was developed employing conservation and transport laws and enables coupling effects of electroporation to the membrane of individual cells with the resulting mass transport or heat transfer in tissue. An analytical solution has been found though the model can be extended with additional dependencies to account for the phenomenon of electroporation, and solved numerically. Thesis comprises five peer-reviewed papers describing electroporation in the food industry, model creation for the problem of diffusion, translation of the model to the mathematically-related case of juice expression, model validation, as well as suggestions for possible future development, extension, and generalization. An additional chapter is dedicated to transfer of heat in tissue

碩士
東海大學
食品科學系
107
Due to the globalization of the industry and people's awareness of health benefits, the consumption of blueberries has increased steadily over the past decade. Due to the seasonality of blueberries, jams, juices or fruits are usually made through various processing techniques. Mud, heat treatment (such as pasteurization) is effective for the deactivation of microorganisms and enzymes, but heat treatment may have adverse effects on heat-sensitive polyphenols, so some non-traditional non-heat treatment techniques are under development. Among them, plasma has been proven to be effective in microbial inactivation and enzyme inactivation, while plasma treatment has a low temperature (usually < 70 ° C), so there is no damage to food nutrition due to heat. Ingredients, the purpose of this study was to compare the effects of different heat treatment conditions and plasma operating conditions on the nutritional value of blueberry peel extracts. The heat treatment conditions were 65 °C, 30 minutes, 80 °C, 2 minutes, 90 °C, 15 minutes; the plasma operating conditions were at a frequency of 20 kHz, a gas flow rate of 12 L/min and an electrode spacing of 1 cm. , 3, 6 and 9 minutes; voltages of 120 V, 140 V, 160 V and 180 V; working gas is the treatment conditions of nitrogen and argon, on the nutrient composition and nutritional value of blueberry peel extract. The experimental results show that 90 ° C, 15 minutes will cause a significant reduction in anthocyanins, while 65 ° C, 30 minutes and 80 ° C, 2 minutes will not have a significant effect on anthocyanins, and compared to nitrogen Plasma, argon plasma has better anthocyanin retention. None of the three heat treatments had a significant effect on the total phenolic content, and the longer the argon plasma and nitrogen plasma treatment time, the greater the total phenolic content. 90 ° C, 15 minutes will significantly increase the percentage of polymer color, 80 ° C, 2 minutes and 65 ° C, 30 minutes will not significantly increase the percentage of polymer color, and with argon plasma and nitrogen plasma treatment time Increasing, the polymer color percentage will increase significantly. The three heat treatments did not significantly reduce the DPPH inhibition rate, and the DPPH inhibition rate of the argon plasma treated blueberry peel hot water extract was better than that obtained by the nitrogen plasma treatment. The conclusion is that the longer the heat treatment and plasma treatment time, the greater the influence on the Antioxidant properties of blueberry.

Thermal sprayed coatings are frequently used in corrosive environments, even when their major purpose is to provide wear or thermal resistance, rather than corrosion resistance. This includes Thermal Barrier Coatings (TBC), where high porosity is a desired feature to give good thermal protection. Porosity also provides increased strain tolerance of the coating. However, as this proves to be a limiting factor in the corrosion protection, a trade off is involved. This is because the interconnected porosity in TBCs allows the corrosive media to reach the coating-substrate interface, which eventually leads to delamination of the coatings. The current techniques to reduce coating permeability include polymer impregnation and laser glazing. Polymer impregnation into the pores is difficult and it severely limits the high temperature properties of the parent coating. Laser glazing produces segmented cracks in the coating which are useful in providing strain tolerance, but accelerate the rate of bond coat oxidation. This work addresses the problem of permeability of TBCs which is responsible for the poor corrosion protection offered by these coatings. The coatings studied included yttriastabilized zirconia and alumina TBCs. A simple infiltration technique has been proposed using sol-gel ceramic precursors. The precursors included metal alkoxides which decompose at relatively low temperatures to their respective oxides. It has been proven that these precursors effectively penetrate into the pores and are beneficial in drastically reducing the coating permeability to gases. Electrochemical tests were carried out in 3.0 wt.% NaCl solution to study the effectiveness of the sealant in reducing the coating permeability. These potentiodynamic tests as well as gas permeability tests show a considerable decrease in interconnected porosity with sol-gel modification of the coatings. Burner rig tests show an increase in sealed coating life time under thermo-mechanical fatigue conditions. The peel adhesion tests confirm an increase in the adhesion values with such a post deposition treatment. It is concluded that the advantages of sol-gel route to ceramics have been successfully utilized to post-treat porous thermal sprayed coatings in an attempt to reduce their permeability and to increase the life expectancy under corrosive and/or thermo-mechanical fatigue conditions.

碩士
東海大學
環境科學系
89
This study investigates the effect of heating temperature and type of additive on chromium leaching. The final goal is to enable the immobzlization and reutilization of chromium- containing sludge. Chromium leaching can be more effectively reduced with increased heating temperature. The XRD results indicate that ZnFe2O4 and ZnCr2O4 are the main products to immobilize chromium. When mixed with clay, the chromium can be better immobilized only after heating at 1100℃, compared with the raw sludge. The addition of fly ash that contains great amount of calcium compounds tend to mobilize chromium, as indicated by the CaCrO4 formation. The addition of NaCl or NaOH into the sludge will cause an increase of chromium leaching due to the increased pH or/and formation of Na2CrO4.

博士
國立臺灣大學
環境工程學研究所
89
Oil sludge, if unused, is one of the major industrial wastes requiring treatment from petroleum refinery plants or the petrochemical industry. It contains a large amount of combustibles with high heating values. The oil sludge waste investigated in this study is obtained from the oil storage tank of a typical petroleum refinery plant located in the northern Taiwan. By using the methods of sole pyrolysis, oxidative thermal decomposition, thermal degradation in the presence of carbon dioxide, adding inexpensive additives in pyrolysis and mutilstage thermal operation in the thermal treatment of oil sludge, one can not only solve the disposal problems but also have the appeal of resource utilization. Therefore, one can finally propose a practical thermal treatment process of oil sludge. In the kinetics of sole pyrolysis, oxidative thermal decomposition and thermal degradation with the presence of carbon dioxide of oil sludge, a temperature-programmed dynamic thermogravimetric analysis ( TGA ) is used for studying the phenomena of reactions with different carrier gases. In the sole pyrolysis and thermal degradation of oil sludge with the presence of carbon dioxide, three - parallel - reaction models are proposed to describe the results and give the best fit. Including the sole pyrolysis reactions, the overall oxidative thermal decomposition of oil sludge can be adequately described by a five — parallel — reaction model. In the major products obtained from the sole pyrolysis, the major gaseous products ( noncondensable gases at 298 K ) excluding N2 are CO2 ( 50.88 wt. % ), HCs ( hydrocarbons, 25.23 wt. % ), H2O ( 17.78 wt. % ) and CO ( 6.11 wt. % ). The HCs mainly consist of low molecular paraffins and olefins ( C1 ~ C2, 51.61 wt. % of HCs ). The distillation characteristics of liquid product ( condensate of gas at 298 K ) from the pyrolysis of oil sludge is close to diesel oil. However, it contains a significant amount of vacuum residue of about 9.57 wt. %. In the major products obtained from the oxidative thermal decomposition of oil sludge, the higher O2 concentration would enhance the oxidative thermal decomposition reactions and reduce the residual mass. The major emitted gases ( noncondensable gases at 298 K ) excluding N2 are CO, CO2, hydrocarbons ( HCs ), H2O and H2. The HCs mainly consist of low molecular paraffins, especially C1. The distillation characteristics of the oil portion of liquid products ( condensates of gas at 298 K ) from the oxidative thermal treatment of oil sludge at T of 378 ~ 873 K, low oxygen conditions ( ie. 1.09 vol. % O2 ) not only accelerate the thermal reaction of oil sludge, but also at the same time avoid or reduce the production of water. In the use of inexpensive and non-harmful additives on the possible improvement of the sole pyrolysis of oil sludge, the dynamic thermogravimetric analysis ( TGA ) is used again. It appears that the above additives enhance the conversions ( X ) when the temperatures ( T ) are in 650 ~ 740 K. At 720 K, the largest differences of conversion ( ΔX ) are adding K2CO3, fly ash and KOH. The additives achieve the largest improvement of the quality ( q ) of pyrolysis oil ( as sum of light and heavy naphtha and light gas oil ) are adding CaO, KOH and fly ash. The largest ratios of instantaneous reaction rates ( r = dX/dt ) in the presence and absence of additives with the deductions of additives in the pyrolysis of oil sludge are about 1.47 for adding NaOH and 1.4 for adding fly ash at 680 K. In the multistage thermal operation of treating oil sludge, one can propose a 3 - stage thermal operation process by combing the best and effective additives, sole pyrolysis and oxidative thermal decomposition of oil sludge. The distillation characteristics of the 1 - stage oil ( condensates of gas at 298 K ) from the pyrolysis of oil sludge at T of 378 K and retaining 4 hours give the best results and the 1 - stage oil is very close to diesel oil. In the 2 - stage, the 2 - stage oil with adding 10 wt. % CaO and 100 vol. % N2 at 378 to 653 K and retaining 10 minutes gives the best distillation results. Therefore, among the 3-stage oils, the oil without additives and of 20.95 vol. % O2 at 653 to 743 K and retaining 30 minutes ( with 2 - stage of 100 vol. % N2 and without additives ) gives the best distillation results and that is better than gasoline. However, it needs to be separated from water before use. Meanwhile, with 20.95 vol. % O2 and without additives, the amounts of residue of thermal treatment of oil sludge will achieve minimum. Among the waterless 3 - stage oils, the oil with adding 10 wt. % CaO and 1.09 vol. % O2 gives the best distillation results. Finally, according the results, one can propose a practical thermal treatment process of oil sludge and provide for the commercial designs and runs of thermal treatment of oil sludge.

碩士
國立臺北科技大學
材料及資源工程系研究所
101
Different GN ratios CuCrO2 nanopowder were prepared by glycine nitrate combustion method. Our study can divide two parts. Part one：GN = 1.5 CuCrO2 nanopowder annealed in air and nitrogen at 300 ~ 900°C for 1 h, exploring thermal behavior of CuCrO2 and variation of a-axis and c-axis length of CuCrO2 annealed in nitrogen and air at 300°C ~ 900°C and variation of surface area after acid-washing process, demonstrate that CuCrO2 can reserve original phase in nitrogen. CuCrO2 can reserve original phase in air before 300°C and temperature goes up to 400°C, it starts to produce CuO phase. When temperature up to 500 ~ 800°C , CuCrO2 phase oxidizes and reacts to CuCr2O4 + CuO phase , and temperature up to 900°C , CuCr2O4 + CuO phase transfers into CuCrO2 phase. In addition, CuCrO2 nanopowder annealed in air at 400°C for 2-4 h and at 500°C for 1 h, it makes CuCrO2 oxide react into CuCr2O4 + CuO phase. The powder after acid-washing process ,it not only can eliminate CuO phase but also appear cloud shape. Surface area of 26.4 m2/g for CuCrO2 powder annealed in air at 400˚C is higher than that of annealed in air at 500˚C.(22.36 m2/g).Part two: Preparation of CuCrO2 nanopowder GN ratios are 1.2 ~ 2.5, exploration different GN ratios CuCrO2 nanopowder are influence to composition phase and variation of surface area after acid-washing process. Experiment show that GN = 1.2 ~ 1.8 CuCrO2 nanopowder can reserve original phase. When GN = 1.9 it start produce Cu and Cr2O3 phase. When GN=2.0 ~ 2.5 it makes CuCrO2 nanopowder go back to Cu and Cr2O3 phase completely. Furthermore, Original GN = 1.2, 1.4, and 1.6 powder surface area 50, 49, and 36 m2/g will go up to 57, 61, and 41m2/g after acid-washing process.

碩士
國立臺灣大學
環境工程學研究所
96
Bioenergy is a renewable energy which is friendly towards the earth. In general energy conversion process of vegetal biomass, huge amount of waste was produced though still had reusable worth. In this study, application of thermal process for the utilization of sunflower seed residue was investigate. Multi-stage temperature program was employed. Effects of controlling parameters such as heating rate, goal temperature, holding time, sample size, relative humidity of the system, carrier gas, and flow rate were examined. 　The instantaneous decomposition rate of sunflower residue reaches its maximum at about 375 ℃. Compared with those high-temperature reaction, to hold the furnace stay at lower temperature such as 375 ℃ will not only consume less energy but also keep the reactants in a state with maximum reaction rate. 　Combustible species in the products of pyrolysis of sunflower residue arise apparently after 300 ℃. The major product is methane, its content reaches up to 95.8% at 340 ℃when the multi-stage temperature program was as follows: first, sunflower residue was heated from 25 to 105 ℃ and hold at 105 ℃ for 2 h; then the temperature was raised to 800 ℃ with heating rate of 20 ℃/min. The carrier gas was helium, with flow rate of 50 mL/min. As thermal process goes on, the proportion of combustible long chain species in gaseous product increase. The high heating value of gaseous hydrocarbon products of 53.9 kJ/g close to 60.8 kJ/g of natural gas and the total yield of methane reaches 10.94 wt.% (relative to the initial input sample). The total gas yield was elevated when the relative humidity (RH) of the system is increased, it attained to 55.86% when RH = 84.9%.

碩士
東海大學
環境科學系
82
The lead (Pb) contamination of farm soil and drainage sludge around leaden storage battery manufacturing factories is of considerable concem to public health. Concentration as high as 40,373 ppm in drainage sludge and 2,093 ppm in farm soil was literally reported. Potential predicament to human health and environment of these sludge and soil is no less severe than that hazardous wastes. It was thus the purpose of this research study to raise more concern by visualizing the contaminated soil as hazardous wastes, and upon them TCLP criterion was imposed. The "hazardous" soil will be under mild thermal treatment with the addition of coal fly ash, scrap brick power, cement and kaolin in a fixed bed incinerator within the temperature range from 200℃ to 500℃ for various durations, in a hope to transform the hazardous characteristic into non-hazardous one. The TCLP threshold value of 5mg/L for lead was closely ckecked for both treated and untreated 　　samples. 　　The study parameter was as follows: 　　　　‧temperature of fluidized bed 　　　　‧duration of thermal treatment 　　　　‧type of sorbents 　　　　．lead concentration in samples 　　　　．air velocities 　　　　．thermal treatment types 　　The results of this reseach showed that: for the fixed-bed incinerator, coal fly ash gave the lowest degree of stabilization capability among these sorbents and the TCLP leaching concentration of Pb was up to 3.59 mg/L for artificial Pb-spiked soils thermally treated at a mild temperature of 300℃ and a treating time of 30 minutes; however, which still met criteria of 5 mg/L. The stabilization capability of cement was the best and that had 0.03 mg Pb/L from TCLP test after treated ca. 200℃ for half an hour. The leaching value 0.03mg/L is not to one hundredth of EPA temporary TCLP standards. Generally speaking, the higher temperature (200-500℃), the better the effeciency, that was, the lower leaching value from TCLP test cauld be achieved. 　　Changing Pb concentrations of samples had apparent effect on LP% for the fixed-bed incinerator, compared with other parameters such as air velocity, sorbent type and treating time. Under the same operating condition, the degree of increasment of LP% for bottem ash was as same as that of Pb concentration. 　　From the-saving point of view, a fluidized-bed incinerator was better than a fixed-bed one. For example, the TCLP leaching concentration of bottem ash was 2.89 mg/L for the minutes and the effeciency was good enough to a compare with with that for the fixed-bed incinerator at a treating time of 30 minutes (TCLP leaching concentration 3.02 mg/L).

碩士
國立屏東科技大學
環境工程與科學系
94
In this study, we use the thermal molten system to treat the swarf. Samples were collected in flue gas and then analyzed the levels of concentration of Polycyclic Aromatic Hydrocarbons (PAHs) and BTEX by GC/MS and GC/FID. The results are as following: 1.The gas-phase concentration of PAHs with applying the second combustion chamber was 1347 times higher than those of without applying second combustion chamber. 2.For gas-phase, the decomposition efficiency reached 99.93%, and the particulate-phase PAHs was up to 105% with using the second combustion chamber. When using the first combustion chamber only, the low molecular weight PAHs was the main production for gas-phase PAHs. 3.The total toxicity of the particulate-PAHs, BaA, BbF, BaP, IND were high (all were over 90% of the total BaPeq). (with applying the second combustion chamber, it is 90.89%; without applying the second combustion chamber, it is 97.41%). 4.With applying the second combustion chamber or without it, the particle-bound PAHs composition reached 243604.91 μg/g and 9936.63 μg/g. 5.The decomposition efficiency of the concentrations of toulene and ethybenzene reached 56.36±0.05% and -0.01±0.12%,respectively, with applying the second combustion chamber.

碩士
國立高雄第一科技大學
機械與自動化工程所
92
Hardening treatment is a necessary process for precision part. The process is often taken place off line from production, which usually leads to the increases of production cost. If part hardening can be made during machining, the efficiency can be affectively increased. Grinding process is often applied for precision machining of steel component to reach the required accuracy. However, extremely high surface temperature rise might be induced during grinding. Due to the reason, grinding heat treatment was ever proposed to utilize the grinding heat as the heat source for part surface hardening. Currently, the proposed idea has been proven to be feasible if the appropriate grinding parameter is applied. While heating and cooling conditions for grinding heat treatment are still no fully discussed though, this process by no means is a controllable technique. This paper started from thermal point of view to observe the relationship among grinding heat flux, grinding zone temperature rise, and equivalent grinding parameters, and thus the possibility of surface hardening after grinding. The process, renamed as “thermal scanning hardening treatment of grinding”, was proven to be feasible by a designated grinding experiments in this paper. In the work, under different velocity rate lead to different result between q, and . Temperature of grinding zone could be controlled by manufacture parameter. After experiment, it has found that between and depth hardened layers of material exist. To summary, grinding heat behavior will influence harden of surface material, if it can build various grinding quantification model. The thermal scanning hardening treatment of grinding will be maturity

碩士
東海大學
環境科學系
88
Thermal treatment at 500,700,900, and 1100℃ is carried out on Ni-Plating sludge that has been mixed with equal weight of fly ash or clay, or 5 wt % Nacl or NaOH .A flame atomic absorbance spectroscope is used to measure the concentration of various metals, while an ion chromatograph is employed to determine CrO42- concentration in the leachates. An X-ray diffraction（XRD）technique is used to measure the reaction products in samples that have been heated at 105,900, and 1100℃. The experimental parameters include type of additive, heating temperature, speciation detected by XRD, and leaching concentrations. The results indicate that addition of additive and thermal treatments do not reduce the leaching of CrO42- . The XRD results show that thermal treatment produces some crystal compounds that are made of Ca, Ca, Ni, Si , etc. CrO4 is dertermined to be the key compound that leach CrO42- .

Tese de Doutoramento em Química e Engenharia Biológica
This manuscript intends to address “non-thermal” effects associated with using electricity during a thermal process. Being so, a wide range of research areas were focused with the main objective of obtaining results which will be used to develop new research topics related to the use of moderate electric fields. The main themes were approached from a practical point of view and grouped into five main chapters. The first chapter reviews the main research studies related to ohmic heating technology highlighting the most important vantages and disadvantages of the technology itself, mathematical modeling for process description and available equipments and configurations. Furthermore, the economical viability depending on the specific application is also addressed and actual applications of this technology to the food industry are described in detail. The following chapter deals with the “non-thermal” effects of electricity in food enzymes, namely the inactivation kinetics of the enzymes when an electric field is present. Several food relevant enzymes were chosen, namely lipoxygenase (LOX), alkaline phosphatase (ALP), polyphenol oxidase (PPO), pectinase (PEC) and β-galactosidase (β-gal). Some of these enzyes are used as TTI’s (time temperature integrators) in the food sector. The experimental results indicate that some of the enzymes (LOX and PPO) are significantly affected by the presence of electric fields while the others (PEC, ALP and β-gal) do not seem to be clearly affected. The third chapter has the main goal of assessing the “electricity effect” on target microorganisms. Being so, microorganisms relevant to food safety (due to high thermal resistance or probability of occurrence) were chosen: Byssochlamys fulva ascospores, Escherichia coli vegetative cells and spores of Bacillus licheniformis and their inactivation kinetics determined in real food matrices, respectively strawberry pulp, goat milk and cloudberry jam. For all the microorganisms tested the ohmic decimal reduction times (D-values) were lower than the ones obtained when using conventional heating. It was possible to conclude that the presence of a moderate electric field during a thermal process reduces the time needed to achieve microbial inactivation (in the conditions and for the microorganisms tested). Care should be taken when extrapolating the results to other food matrices or different microorganisms because food safety can be jeopardized. The application of moderate electric fields to fermentative processes is the topic under research in the fourth chapter. A recombinant yeast strain with high yields of ethanol production and the ability to ferment lactose and excreting β-Gal was used. Moderate electric fields, ranging from 0 to 2 V/cm, were applied continuously or in specific stages of the fermentation. Aerobic and anaerobic conditions were tested. The results point out to a clear effect of the electric field under aerobic conditions namely in terms of reduction of the lag phase and the increase of biomass yields (which increases linearly with the electric field) thus considerably reducing the total fermentation time. However under anaerobic conditions the “electric” effect was not evident. On the other hand, plasmid stability was affected by the increase of the electric field value when using it continuously but if an electric field was used only during a limited time the results were quite encouraging. The results obtained in this section open a wide range of potential new applications of moderate electric fields technology (ohmic heating). Furthermore, the temperature and pH profiles of the excreted enzyme were studied and it has been concluded that there were no effects of the electric field on the enzyme characteristics. In the last chapter, the hydrodynamic behavior of a lab scale ohmic heater was determined and the results compared with the ones obtained from CFD (computational fluid dynamic) computer modelling. Summing up, the themes addressed were quite wide and aimed at gathering data for the validation of the ohmic heating technology as an alternative processing technology. Moreover, news topics for further research were raised during this work.
Este trabalho pretende explorar os efeitos não térmicos relacionados com a tecnologia de aquecimento óhmico. Desta forma, foram abordados diversos temas na tentativa de obter resultados que conduzam, posteriormente, a diversas linhas de investigação relacionadas com a tecnologia de aquecimento óhmico (ou aplicação de campos eléctricos moderados). Os assuntos foram abordados de um ponto de vista essencialmente prático e agrupados em cinco capítulos principais. No primeiro capítulo é feita uma revisão bibliográfica genérica sobre a tecnologia de aquecimento óhmico indicando as suas vantagens e desvantagens, modelos matemáticos usados e tipos de equipamentos existentes. Adicionalmente, aborda-se a questão da viabilidade económica desta tecnologia consoante as suas potenciais aplicações e são descritas, com algum detalhe, as actuais aplicações na indústria alimentar já implementadas (ou em fase de teste). No segundo capítulo, pretendeu-se determinar se existiam efeitos “não térmicos”, relacionados com a presença de campos eléctricos moderados, que alterem as cinéticas de inactivação térmica de diversas enzimas. Para tal, foram escolhidas algumas enzimas relevantes na indústria alimentar quer por serem utilizadas como TTI’s (time temperature integrators) quer por serem necessárias para a produção de alguns alimentos. Estudaram-se as cinéticas de inactivação da lipoxigenase (LOX), polifenoloxidase (PPO), fosfatase alcalina (ALP), pectinase (PEC) e β-galactosidase (β-Gal). Os resultados obtidos indicam que algumas das enzimas (LOX e PPO) são bastante afectadas pela presença de campos elétricos moderados enquanto que as restantes (ALP, PEC e β-Gal) apresentam um efeito menos significativo. Na terceira secção deste trabalho foi realizado um estudo semelhante aos referido no segundo capítulo mas usando microrganismos alvo. Para tal foram seleccionados microrganismos representativos na indústria alimentar quer pela sua resistência térmica quer pela sua elevada probabilidade de aparecimento em alimentos: ascosporos de Byssochlamys fulva, células de Escherichia coli e esporos de Bacillus licheniformis em matrizes de alimentos, respectivamente, polpa de morango, leita de cabra e compota de cloudberry. Em todos os microrganismos estudados a presença de um campo eléctrico tem um efeito adicional na perda de viabilidade microbiana, consequentemente, os valores do tempo de redução decimal obtidos (valores D) foram, em geral, inferiores quando existia um campo eléctrico. Em suma, a presença de um campo eléctrico diminui o tempo de processamento térmico necessário à inactivação microbiana, nos alimentos e condições testadas. A extrapolação dos resultados obtidos para outras matrizes ou microrganismos deverá ser realizada com precaução para que a segurança alimentar não seja posta em causa. A aplicação de campos eléctricos moderados a processos fermentativos constitui o tema sob investigação no quarto capitulo desta tese. Utilizou-se uma estirpe recombinante de levedura produtora de β-Gal extra-celular e com elevado rendimento de produção de etanol e aplicaram-se campos eléctricos (0 a 2 V/cm) continuos ou descontinuos em condições de aerobiose ou anaerobiose. Os resultados experimentais apontam para um efeito pouco significativo quando se trata de condições de anaerobiose mas, na presença de arejamento, obteve-se uma redução considerável da fase de latência (reduzindo o tempo total da fermentação) e um aumento do rendimento em biomassa (cujo aumento varia linearmente com o aumento do campo eléctrico). Por outro lado, e dado que se trata de uma estirpe recombinante, verificou-se uma perda de estabilidade plasmídica aquando do uso de campos eléctricos contínuos. Tal não se verificou quando o campo eléctrico era apenas aplicado na fase inicial da fermentação abrindo novas perspectivas para optimização de processos fermentativos usandos campos eléctricos contínuos ou descontínuos consoante a aplicação pretendida. A avaliação do perfil óptimo de actividade da enzima excretada durante as fermentações foi igualmente estudado, conluindo-se que a presença do campo eléctrico não altera o perfil óptimo da enzima. No quinto e último capítulo deste documento efectua-se a determinação do comportamento hidrodinâmico de um aquecedor óhmico à escala piloto e comparam-se os resultados obtidos usando a ferramenta de CFD (computational fluid dynamics) com os dados obtidos experimentalmente. Conluindo, os temas abordados apesar de diversos, destinaram-se a reunir dados para a validação da tecnologia de processamento óhmico com alternativa processual aos tratamentos térmicos convencionais e abrem horizontes para novas aplicações desta tecnologia.
Fundação para a Ciência e a Tecnologia (FCT).

碩士
長庚大學
半導體研究所
90
In this thesis, we have systematically studied the self-organized InAs quantum dots, including 3, 4, and 5 monloayers grown by solid sources molecular beam epitaxy (MBE) in heterosystems strain effect by rapid thermal annealing (RTA) and temperature dependent photoluminescence system. As-grown InAs QDs samples, the photoluminescence emission peak energy shift dominated effected by both the hydrostatic and the shear strain in the smaller InAs quantum dots. However, the characteristics of the PL peak energy in the larger InAs quantum dots are predominantly attributed to the hydrostatic effect. On the other hand, due to the elastic stiffness constants, the GaAs matrix-dependent characteristics are examined in the smaller quantum dots, while the InAs-like properties are observed in the larger ones. By the thermal treatment samples（300℃、400℃、500℃）, we can find some PL spectrum changes and due to the result of strain relaxation. All the results obtained in this work indicate that the strain effect plays a key role in the InAs quantum dot systems.

碩士
國立臺灣大學
機械工程學研究所
106
In this study, the PEDOT:PSS (CLEVIOS™ HIL-E 100 from Heraeuse) films coated on glass substrate was treated by CO2 pulsed laser in the air. The property of the PEDOT:PSS was investigated by in-line four-point probe array, spectrophotometry, AFM, SEM, and XPS. Through manipulating the fluence and the scan speed of the laser, the change in PEDOT:PSS property induced by CO2 pulsed laser was analyzed. The conductivity of the film was enhanced from 2.83E-02 S/cm to 59.4 S/cm in 181 seconds as a result of the remove of the residual water. Meanwhile, the average transmittance decreased from 89.1219 % to 88.4766 %, and the RMS roughness increased from 2.27 nm to 2.49 nm. The conductivity enhancement might be caused by the reunion between PEDOT:PSS moleculars, and the rise in the surface PEDOT/PSS ratio as investigated by SEM and XPS. However, when the laser power excess the durability of PEDOT:PSS, some significant decrease in conductivity and transmittance was observed. Compared with the hotplate thermal traetment in the air, which can not significantly increase the conductivity of PEDOT:PSS, it is found that CO2 pulsed laser thermal treatment have advantages in PEDOT:PSS thermal treatment in small area without air controled. In this study, a promising method of heat treatment for PEDOT:PSS is investigated. The conductivity of PEDOT:PSS is enhanced to 59.4 S/cm in air by CO2 Laser, which is much better than hotplate. With the advantage of selective treatment, the heat can be controled for more complicated electrical stucture in the future.

碩士
國立中山大學
電機工程學系研究所
97
In this study, 1/2 λ mode SMR filters on Si substrates by reactive RF magnetron sputtering method were fabricated. In addition, the thermal annealing process was adopted to improve the insertion loss of SMR filter. The Bragg reflector in SMR is alternately mounted by high and low acoustic impedance materials, with low acoustic impedance material of SiO2 and high acoustic impedance material of W. We could obtained three kinds of crystal structures of W, α - phase W、β - phase W and α & β - mixed phase W, respectively, it could be obtained by modulating the sputtering recipe. α - phase W possesses higher acoustic impedance and is suitable for high acoustic impedance material in bragg reflector. The piezoelectric layer of ZnO is sputtered by a 2-step deposition method on Si substrates with different temperature. The ZnO film with stronger C-axis (002) orientation and lower surface roughness value could be obtained at substrate temperature of 200 ℃, which is suitable for fabricating SMR device. After the SMR filter had completed, the device is thermal annealed with CTA、RTA and RTA in O2 ambient. After thermal treatment, the properties of filters are improved. The properties could be optimized with RTA in O2 ambient condition. The insertion loss was improved from -12.03 dB to -6.96 dB. The film characteristics of ZnO changes after the SMR processed thermal treatment. The strongest C-axis (002) intensity with the lowest surface roughness value at 400 ℃ annealing temperature could be obtained, in that, approximate equal Zn:O ratio could be achieved by XPS examination. The central frequency of SMR filter drifted to higher value as the temperature of thermal treatment increased, which is attributed to the changes of the ZnO acoustic velocity(υ) after thermal treatment.