In this study, an electrolytic micro-machining tester is employed to investigate the effects of the supply voltage, the immerse depth of tungsten rod, and the machining time on the current waveform, the material removal rate, and the geometry of the tungsten needle. The tungsten rod to be electrolyzed is dipped in an aqueous electrolyte of 10 wt% sodium hydroxide as the anode, and the stainless steel ring as the cathode. The spindle rotating speed and the stirring rotating speed are set to be 100 rpm and 200rpm, respectively. According to analyze the topography of the tungsten needle, four machined regimes have been identified as:¡]1¡^non-machined regime,¡]2¡^incomplete machined regime,¡]3¡^complete machined regime,¡]4¡^over machined regime. In order to obtain the perfect tungsten needle, the experiments are conducted in the complete machined regime. Results show that the tungsten rod becomes a short cone for the immerse depth of 5 mm, and a long cone for the depth of 10mm. When the immerse depth of 10 mm and the supply voltage of 3V, the surface of tungsten needle becomes rough slightly and the tip radius of tungsten needle is about 2£gm. With increasing the supply voltage to 4.5 V, the surface of tungsten needle is uniform with a downward trend in material removal rate, and the tip radius can achieve a submicron. For the supply voltage of 6V, because the material removal rate varies violently, it becomes very difficult to control the diameter of tungsten needle. During the machining time between 0 to 10 min for the supply voltage of 4.5V, the diameter of tungsten rod is decreased from 1000 to 200£gm, but during the machining time between 10 to 12.5 min, the tungsten rod gradually transforms into the needle due to a downward trend in current, and the tip radius is decreased from 200£gm to submicron. Hence, the machining time must be controlled accurately to manufacture the needle in a submicron radius.

Dans le cadre du développement des réacteurs nucléaires à neutrons rapides refroidis au sodium, des études sont menées sur les conséquences d’un feu de sodium, et sur l'impact toxicologique de rejets éventuels d’aérosols vers l’atmosphère. La carbonatation des aérosols issus d’un feu de sodium entraîne une diminution de leur toxicité, à partir de leur rejet sous forme d'hydroxyde de sodium (NaOH). L’objectif est de développer et de valider expérimentalement un modèle cinétique de carbonatation des aérosols de NaOH. L’adaptation d’un modèle cinétique basé sur l'absorption réactive du CO2 atmosphérique et par la théorie du double film permet de décrire la carbonatation des aérosols de NaOH, initialement sous forme de gouttelettes de soude. Ce modèle définit les caractéristiques initiales des aérosols de soude en équilibre avec l'atmosphère. Il a été appliqué en considérant l'absorption du CO2 à la surface externe des particules. L’ensemble des variables du modèle ont été décrites et leurs équations explicitées. La validation du modèle cinétique a motivé la mise en place d’un dispositif expérimental dédié au suivi du comportement chimique d’aérosols issus d’un feu de sodium, dans des conditions contrôlées d’atmosphère réactive et de prélèvement d’aérosols. L’exploitation des nouvelles données expérimentales montre la compétition entre l’influence de la température, de la pression partielle en eau et en CO2. La confrontation des résultats expérimentaux avec le modèle développé a permis de le valider pour des humidités relatives supérieures à 30%. Enfin, le modèle cinétique a été explicité sous la forme d’une expression analytique pour une utilisation associée aux calculs de dispersion atmosphérique. / As part of the development of 4th generation Sodium cooled Fast Reactors, studies are conducted on the consequences of a sodium fire, including the toxicological impact of possible releases of aerosols into the atmosphere. The carbonation of aerosols from a sodium fire results in a decreased toxicity, from their release point in sodium hydroxide (NaOH). The objective is to develop and experimentally validate a kinetics model of NaOH aerosols carbonation. The kinetic model based on the reactive absorption of atmospheric CO2 and using the double film theory enables to describe the carbonation of NaOH aerosols, initially formed as soda droplets. This model defines the initial aerosol characteristics of soda in equilibrium with the atmosphere. It is applied by considering the absorption of CO2 at the particle’s external surface. All the model variables are described and their equations explained. The validation of this kinetic model has motivated the development of an experimental device dedicated to the monitoring of physicochemical behavior of aerosols from a sodium fire with a better control of conditions of reactive atmosphere and of aerosols sampling. The new experimental data show the competition between the influence of temperature, partial pressure of water and of CO2. The comparison between the experimental results validates the kinetic model based on reactive absorption for relative humidity over 30%. Finally, the kinetic model was adapted into the form of an analytic expression for its use in association with the atmospheric dispersion calculation.

Ethylene oxide (EO) is a very versatile compound with considerable energy in its ring structure. Its reactions proceed mainly via ring opening and are highly exothermic. Under some conditions, it is known to undergo a variety of reactions, such as isomerization, polymerization, hydrolysis, combustion and decomposition Due to its very reactive characteristic and widely industrial applications, EO has been involved in a number of serious incidents such as Doe Run 1962, Freeport 1974, Deer Park 1988 and Union Carbide Corporation’s Seadrift 1991. The impacts can be severe in terms of death and injury to people, damage to physical property and effects on the environment. For instance, the Union Carbide incident in 1991 caused one fatality and extensive damage to the plant with the property damage of up to 80 million dollars. Contamination has a considerable impact on EO reactivity by accelerating substantially its decomposition and playing a key role on EO incidents. In this work, the reactivity of EO with contaminants such as KOH, NaOH, NH4OH, and EDTA is evaluated. Useful information that is critical to the design and operation of safer chemical plant processes was generated such as safe storage temperatures (onset temperature), maximum temperature, maximum pressure, temperature vs. time, heat and pressure generation rates as a function of temperature and time to maximum rate using adiabatic calorimetry. A special arrangement for the filling-up of the cell was constructed due to the gaseous nature and toxicity of EO. A comparison of their thermal behavior is also presented since several contaminants are studied.

This research enthusiastically highlights the bio-adsorption of methylene blue (MB) by local, poultry, NaOH and citric acid modified ubiquitous eggshell (LES, NLES, CLES, PES, NPES and CPES) adsorbents. The microstructures of these adsorbents indicated that they had some surface functional moieties that were responsible for the adsorption of MB. The Langmuir isotherm and PSO model best fit the experiment data. The largest Langmuir monolayer adsorption capacity qmax, was 242.47mg/g, with the largest MB initial concentration of 400mg/L. This was a clear indication and a confirmation that MB adsorption by the powdered eggshells was chemisorptive. Moreover, the values of F $F$, the thickness of the boundary layer/film were >0, showing that the rate limiting step for the adsorption process was controlled by more than one diffusion mechanism. The values of ΔG° for the adsorption of MB by the adsorbents indicated that the adsorption reactions were all non-feasible and non-spontaneous. The values for ΔS° (J/K/mol) for LES, NLES and CPES for the uptake of MB showed decrease in the chaos or degree of randomness of the adsorption reactions, and the reverse was the case for PES, NPES and CLES for the uptake of MB, which showed increase in the chaos or degree of randomness of the adsorption. The adsorption of MB by LES, NLES and CPES gave ΔH°(kJ/mol) values which were indicative of endothermic nature of the adsorption systems, and the reverse was the case for the uptake of MB by PES, NPES and CLES, which was indicative of the exothermic nature of the adsorption systems.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-22T11:49:48Z No. of bitstreams: 2 Dissertação - Andressa Pasini Herranz de Carvalho - 2013.pdf: 4440445 bytes, checksum: 9c8760635007ecd17af9fe33a5ee57e1 (MD5) license_rdf: 21267 bytes, checksum: 73e23c2acaaf13389e092bd813e3223d (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-22T11:51:56Z (GMT) No. of bitstreams: 2 Dissertação - Andressa Pasini Herranz de Carvalho - 2013.pdf: 4440445 bytes, checksum: 9c8760635007ecd17af9fe33a5ee57e1 (MD5) license_rdf: 21267 bytes, checksum: 73e23c2acaaf13389e092bd813e3223d (MD5) / Made available in DSpace on 2015-05-22T11:51:56Z (GMT). No. of bitstreams: 2 Dissertação - Andressa Pasini Herranz de Carvalho - 2013.pdf: 4440445 bytes, checksum: 9c8760635007ecd17af9fe33a5ee57e1 (MD5) license_rdf: 21267 bytes, checksum: 73e23c2acaaf13389e092bd813e3223d (MD5) Previous issue date: 2013-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The residual oils obtained from the process of frying food are considered hazardous waste by the ministry of environment, due to their degradative nature when improperly discarded in soil and groundwater. Thousands of tons of this waste are produced daily across the country, and more than half are discarded improperly, because no public policies that encourage proper disposal and even recycling of these oils. Soaps are carboxylic salts can be made from these wastes, becoming an alternative to the recycling of frying oils, promoting sustainable development. Liquid soaps are widely used either as cleaning products or toiletries, however the use of frying oils in these products, delimits the knowledge still popular, with little initiative industries in marketing these products. Therefore, this work was developed with the aim to formulate liquid soaps with residual oil in a frying food industry, different pHs (8, 10, 12 and 14) and saponified by different bases (KOH / NaOH). The soaps were evaluated for their technological qualities, divided into physical (foaming ability, solubility, viscosity and cleaning), chemical properties (acidity and alkalinity free) and microbiological (minimal inhibitory concentration for E. coli and S. aureus). The two tests with liquid soaps KOH or NaOH, were processed under mechanical stirring and soaps obtained at pH 8, 10, 12 and 14 using KOH or HCL / NaOH to correct pH. Liquid soaps with KOH showed characteristics less viscous than treatments with NaOH (propensity for solidification) confirming the better employment of this base in the production of liquid soaps. The cleaning power of soaps with KOH and NaOH was similar (yield around 93% of the ability to clean greasy surfaces to soiling 87% with low levels of fats), increasing with an increase in pH of the formulations. Liquid soaps with KOH and NaOH, showed good ability of foaming, however the best solubilization capacity (water, ethanol, methanol, acetone and petroleum ether), was acquired with soaps with KOH (pH 10, 12 and 14), soaps pH 8 were sparingly soluble in both assays (KOH / NaOH). The antibacterial analysis, through minimum inhibitory concentration showed that soaps with NaOH able to inhibit the cultivation of S. aureus and E. coli, a smaller amount (6.25 and 25%, respectively) than the soap with KOH (at least 50% of soap and 100). The kinetic model that best fit the values obtained for pH was processing the first order. Both trials evaluated had technological characteristics favorable for their marketing, with soaps with more alkaline pH may be intended for industrial use, since its high pH does not allow it to be handled by untrained people. Soaps with lower pHs (8, 10), may be destined for domestic or commercial, allowing a good efficiency of their application. / Os óleos residuais obtidos do processo de frituras de alimentos são considerados resíduos perigosos pelo ministério do meio ambiente, devido a sua natureza degradativa quando descartados incorretamente, nos solos e águas. Milhares de toneladas deste resíduo são produzidos diariamente em todo o país, sendo que mais da metade é descartada de maneira incorreta, por não haver políticas públicas que incentivem o descarte correto e até mesmo a reciclagem destes óleos. Os sabões são sais carboxílicos que podem ser produzidos a partir destes resíduos, tornando-se uma alternativa para a reutilização dos óleos de frituras, favorecendo o desenvolvimento sustentável. Os sabões líquidos, são amplamente utilizados, seja como produtos de limpeza ou de higiene pessoal, entretanto a utilização dos óleos de frituras nestes produtos, ainda se delimita à conhecimentos populares, com pouca iniciativa das indústrias em comercializar estes produtos. Neste contexto este trabalho foi desenvolvido, com o objetivo de formular sabões líquidos com óleo residual de fritura de uma indústria alimentícia, de diferentes pHs (8, 10, 12 e 14) e saponificados por diferentes bases (KOH/ NaOH). Os sabões foram avaliados quanto às suas qualidades tecnológicas, dividas em físicas (capacidade de formação de espuma, de solubilidade, de limpar e viscosidade), químicas (alcalinidade e acidez livre) e microbiológicas (concentração inibitória mínima para E. coli e S. aureus). Os dois ensaios de sabões líquidos com KOH ou NaOH, foram processados sob agitação mecânica e obtidos sabões com pH 8, 10, 12 e 14 utilizando-se HCL ou KOH/ NaOH para corrigir os pHs. Os sabões líquidos com KOH apresentaram características menos viscosas do que os tratamentos com NaOH (propensão à solidificação) confirmando a melhor empregabilidade desta base na produção de sabões líquidos. O poder de limpeza dos sabões com KOH e NaOH foi similar (obtendo ao redor de 93% de capacidade de limpar superfícies gordurosas 87% para sujidades com baixos teores de gorduras), aumentando conforme houve um aumento do pH das formulações. Os sabões líquidos com KOH e NaOH, apresentaram boa capacidade de formação de espuma, entretanto a melhor capacidade de solubilização (água, etanol, metanol acetona e éter de petróleo), foi adquirida com os sabões com KOH (pH 10, 12 e 14), os sabões de pH 8 foram limitadamente solúvel nos dois ensaios (KOH / NaOH). A análise antimicrobiana, por meio da concentração inibitória mínima, mostrou que os sabões com NaOH conseguiram inibir as culturas de S. aureus e E. coli, em quantidade menores (6,25 e 25% respectivamente) do sabão do que os com KOH (mínima de 50 e 100% do sabão). O modelo cinético que melhor se ajustou aos valores obtidos para o pH do processamento foi o de primeira ordem. Os dois ensaios avaliados apresentaram características tecnológicas favoráveis para a sua comercialização, sendo que os sabões com pHs mais alcalinos podem ser destinados para uso industrial, já que seu pH elevado não permite que seja manipulado por pessoas não treinadas. Os sabões com pHs menores (8 e 10), podem ser destinados para o uso doméstico ou comercial, permitindo uma boa eficiência de sua aplicação.

Filmes foram preparados com êxito dissolvendo e misturando quitosana com celulose de sisal no sistema de solvente NaOH/tiouréia. Nenhum solvente residual foi encontrado nos filmes preparados, conforme mostrado por análise elementar (S) e absorção atômica (Na). Os filmes foram caracterizados por técnicas como espectroscopia na região do infravermelho com transformada Fourier, difração de raios-X e análise térmica (TG, DSC e DMTA). A compatibilidade de ambos biopolímeros foi avaliada por microscopia eletrônica de varredura, em cujas imagens o filme de biocompósito mostrou uma organização intermediária entre a rede de fibra de celulose e a homogeneidade do filme de quitosana. Interações com água foram estudadas por medida de ângulos de contatos de uma gota d\'água com a superfície do filme, isoterma de absorção de umidade e relaxometria de RMN T2. A análise de ângulo de contato mostrou uma deformação que pode ocorrer na superfície devido a alta afinidade destes materiais com a gota d\'água. O sistema de solvente NaOH/tiouréia levou a despolimerização de ambos biopolímeros, mas sem provocar perda da capacidade de formação de filme dos mesmos. Resultados de índice de cristalinidade sugeriram que as interações entre quitosana e o solvente foram mais intensas do que as interações entre celulose e o solvente. Os resultados de relaxometria de RMN T2 do biocompósitos mostrou que as características da quitosana prevaleceram sobre as da celulose no que se refere as interações com água. Acetatos de celulose de sisal com diferentes graus de substituição foram preparados em meio homogêneo (DMAc/LiCl como sistema de solvente) e caracterizados por RMN 1H (determinação do grau de substituição), cromatografia de exclusão por tamanho (determinação da massa molar média) e análise térmica (TG e DSC). Filmes deste acetato de celulose de sisal com diferentes graus de substituição, com e sem reforço de celulose de sisal, foram preparados com êxito a partir de soluções de DMAc/LiCl. Nenhum solvente residual foi encontrado nos filmes preparados, conforme evidenciado por análise elementar (Na) e absorção atômica (Li). Na caracterização dos filmes, foram utilizadas técnicas de análise térmica (DSC, TG e DMTA) e ensaio de tração que mostraram que os filmes de acetatos de celulose mais substituídos apresentam decomposição térmica em temperaturas mais elevada e são menos resistentes a tração que os filmes de acetatos de celulose menos substituídos. A partir da análise de isoterma de absorção de umidade, foi possível constatar que os filmes de acetatos de celulose mais substituídos são consideravelmente menos higroscópicos que os filmes de acetatos de celulose menos substituídos. As imagens de microscopia eletrônica de varredura mostraram que os filmes de acetato com diferentes graus de substituição apresentam morfologia distinta. Tanto a associação de celulose de sisal com quitosana quanto com acetato de celulose, obtido de celulose de sisal, mostrou melhoras nas propriedades dos filmes, gerando um interesse em novas pesquisas e aplicações destes materiais. / Films were successfully prepared by dissolving and mixing chitosan and sisal cellulose in NaOH/thiourea solvent system. No residual solvent was found in the prepared films, as shown by elemental analysis (S) and atomic absorption (NA). They were characterized by conventional techniques such as Fourier Transformed Infrared spectroscopy, X-ray diffractometry and thermal analysis (DSC, TG, DMTA). The compatibility of both biopolymers was evaluated by scanning electron microscopic, in which the biocomposite film showed an organization interposed between the cellulose fiber mesh and chitosan films homogeneity. Water interactions were studied by measuring contact angles, humidity absorption isotherms and NMR T2 relaxometry. Contact angle analysis pointed out the deformation that can occur at the surface due to the high affinity of these materials with the drop of water. The solvent system, NaOH/thiourea, led to depolymerization of both biopolymers, without causing loss of film forming capacities. Results about crystalline-properties index suggested that the interactions between chitosan and solvent were more intense than the interactions between cellulose and solvent. The behavior of the T2 NMR relaxometry of biocomposites showed more evident interaction between chitosan and water compared to cellulose-water interaction. Sisal cellulose acetates with different degrees of substitution (DS) were prepared in homogeneous environment (DMAc/LiCl as solvent) and characterized by NMR 1H (determining the degree of substitution), size exclusion chromatography (determination of molar mass average) and thermal analysis (TG and DSC). Sisal cellulose acetate films of varying degrees of substitution (DS), were successfully prepared using DMAc/LiCl as solvent system, with and without sisal cellulose strengthening. No residual solvent was found in the prepared films, as verified by elemental analysis (Na) and atomic absorption (Li). The characterization of the films were carried out by thermal analysis techniques (DSC, TG and DMTA) and traction test which showed that the cellulose acetate films with bigger DS present thermal decomposition at higher temperatures and are less resistant to traction than cellulose acetate films with smaller DS. From humidity absorption analysis, it was found that the cellulose acetate films with higher DS are considerably less hygroscopic than cellulose acetate films with lower DS. From scanning electron microscopic analysis it was possible to evaluate that acetate films with different DS have distinct morphology. Sisal cellulose association with both chitosan and cellulose acetate obtained from sisal cellulose, showed improvements in the properties of films, generating an interest in new research and applications of these materials.

Filmes foram preparados com êxito dissolvendo e misturando quitosana com celulose de sisal no sistema de solvente NaOH/tiouréia. Nenhum solvente residual foi encontrado nos filmes preparados, conforme mostrado por análise elementar (S) e absorção atômica (Na). Os filmes foram caracterizados por técnicas como espectroscopia na região do infravermelho com transformada Fourier, difração de raios-X e análise térmica (TG, DSC e DMTA). A compatibilidade de ambos biopolímeros foi avaliada por microscopia eletrônica de varredura, em cujas imagens o filme de biocompósito mostrou uma organização intermediária entre a rede de fibra de celulose e a homogeneidade do filme de quitosana. Interações com água foram estudadas por medida de ângulos de contatos de uma gota d\'água com a superfície do filme, isoterma de absorção de umidade e relaxometria de RMN T2. A análise de ângulo de contato mostrou uma deformação que pode ocorrer na superfície devido a alta afinidade destes materiais com a gota d\'água. O sistema de solvente NaOH/tiouréia levou a despolimerização de ambos biopolímeros, mas sem provocar perda da capacidade de formação de filme dos mesmos. Resultados de índice de cristalinidade sugeriram que as interações entre quitosana e o solvente foram mais intensas do que as interações entre celulose e o solvente. Os resultados de relaxometria de RMN T2 do biocompósitos mostrou que as características da quitosana prevaleceram sobre as da celulose no que se refere as interações com água. Acetatos de celulose de sisal com diferentes graus de substituição foram preparados em meio homogêneo (DMAc/LiCl como sistema de solvente) e caracterizados por RMN 1H (determinação do grau de substituição), cromatografia de exclusão por tamanho (determinação da massa molar média) e análise térmica (TG e DSC). Filmes deste acetato de celulose de sisal com diferentes graus de substituição, com e sem reforço de celulose de sisal, foram preparados com êxito a partir de soluções de DMAc/LiCl. Nenhum solvente residual foi encontrado nos filmes preparados, conforme evidenciado por análise elementar (Na) e absorção atômica (Li). Na caracterização dos filmes, foram utilizadas técnicas de análise térmica (DSC, TG e DMTA) e ensaio de tração que mostraram que os filmes de acetatos de celulose mais substituídos apresentam decomposição térmica em temperaturas mais elevada e são menos resistentes a tração que os filmes de acetatos de celulose menos substituídos. A partir da análise de isoterma de absorção de umidade, foi possível constatar que os filmes de acetatos de celulose mais substituídos são consideravelmente menos higroscópicos que os filmes de acetatos de celulose menos substituídos. As imagens de microscopia eletrônica de varredura mostraram que os filmes de acetato com diferentes graus de substituição apresentam morfologia distinta. Tanto a associação de celulose de sisal com quitosana quanto com acetato de celulose, obtido de celulose de sisal, mostrou melhoras nas propriedades dos filmes, gerando um interesse em novas pesquisas e aplicações destes materiais. / Films were successfully prepared by dissolving and mixing chitosan and sisal cellulose in NaOH/thiourea solvent system. No residual solvent was found in the prepared films, as shown by elemental analysis (S) and atomic absorption (NA). They were characterized by conventional techniques such as Fourier Transformed Infrared spectroscopy, X-ray diffractometry and thermal analysis (DSC, TG, DMTA). The compatibility of both biopolymers was evaluated by scanning electron microscopic, in which the biocomposite film showed an organization interposed between the cellulose fiber mesh and chitosan films homogeneity. Water interactions were studied by measuring contact angles, humidity absorption isotherms and NMR T2 relaxometry. Contact angle analysis pointed out the deformation that can occur at the surface due to the high affinity of these materials with the drop of water. The solvent system, NaOH/thiourea, led to depolymerization of both biopolymers, without causing loss of film forming capacities. Results about crystalline-properties index suggested that the interactions between chitosan and solvent were more intense than the interactions between cellulose and solvent. The behavior of the T2 NMR relaxometry of biocomposites showed more evident interaction between chitosan and water compared to cellulose-water interaction. Sisal cellulose acetates with different degrees of substitution (DS) were prepared in homogeneous environment (DMAc/LiCl as solvent) and characterized by NMR 1H (determining the degree of substitution), size exclusion chromatography (determination of molar mass average) and thermal analysis (TG and DSC). Sisal cellulose acetate films of varying degrees of substitution (DS), were successfully prepared using DMAc/LiCl as solvent system, with and without sisal cellulose strengthening. No residual solvent was found in the prepared films, as verified by elemental analysis (Na) and atomic absorption (Li). The characterization of the films were carried out by thermal analysis techniques (DSC, TG and DMTA) and traction test which showed that the cellulose acetate films with bigger DS present thermal decomposition at higher temperatures and are less resistant to traction than cellulose acetate films with smaller DS. From humidity absorption analysis, it was found that the cellulose acetate films with higher DS are considerably less hygroscopic than cellulose acetate films with lower DS. From scanning electron microscopic analysis it was possible to evaluate that acetate films with different DS have distinct morphology. Sisal cellulose association with both chitosan and cellulose acetate obtained from sisal cellulose, showed improvements in the properties of films, generating an interest in new research and applications of these materials.

Barley spent grain, the main residue of the brewing industry, is a lignocellulosic material, which could be considered a potential raw material for ethanol production. In this work, spent grains generated in a microbrewery were fractionated by acid hydrolysis and delignification. The investigated sort of barley spent grains had high carbohydrate content, accounting for 60% of the dry matter, while its lignin content was lower than that reported for other sorts of spent grains. Since the used spent grains contained residual starch different treatment approaches were used for separating their main components without affecting the sugars generated by starch hydrolysis. Two kinds of acid hydrolysis processes, namely single-step and two-step hydrolysis, were used for solubilising the carbohydrate fraction. Single-step hydrolysis was performed either at 100oC or at 121oC. In the two-step approach, a second hydrolysis, at 121oC, was performed after the first hydrolysis step. The dilute-acid hydrolysis at 100oC removed all the starch, whereas the hydrolysis at 121oC removed also a part of the hemicelluloses in addition to starch. During the second hydrolysis step, the content of easily hydrolysable polysaccharides decreased from 32.5 to 7.6% in the material pre-hydrolyzed at 100oC and from 20.3 to 10.6% in the material pre-hydrolyzed at 121oC. The amount of easily hydrolysable polysaccharides removed in the second step corresponded to 83% and 81.5% of the total removed matter in the materials pre-hydrolyzed at 100 and 121oC, respectively. In the next step, acetosolv and alkaline delignification, either alone or combined with acid hydrolysis, were used for dissolving the lignin fraction. A higher solubilisation occurred after alkaline delignification, where 83% of the initial material was removed. Only 34% of the initial lignin was removed by direct acetosolv, while the combined acid hydrolysis/acetosolv approach resulted in lignin removal between 70 and 75%. However, the resulted pulp still contained important amount of lignin. The acid prehydrolysis was also beneficial for alkaline delignification, but the effect was less noticeable than for acetosolv. Lignin removal increased from 95% in direct alkaline delignification to nearly 100% in the acid hydrolysis-assisted alkaline treatment. Two different methods were carried out for lignin precipitation. In the liquid fraction obtained by acetosolv, lignin was precipitated by water addition after concentration of the liquors to 75% of the initial volume. Although the visual inspection of the liquors after water addition revealed a relatively good lignin precipitation, the separation by filtration of the precipitated material was difficult, apparently due to the small particle size of precipitated lignin molecules. Some improvement was observed for the combined treatments, especially for those including two-step acid hydrolysis. The best recovery, 54% of the precipitated lignin, occurred for the process including consecutive acid hydrolyses at 100 and then at 121oC before acetosolv. In the alkaline liquors, lignin was precipitated by pH adjustment to 2.0 by HCl. Around 40.5% of the solubilised lignin was precipitated, and it increased to 85-100% when combined treatments were applied. The best results were achieved upon the treatment including acid prehydrolysis at 121oC before alkaline process.

Development of a simple, specific, sensitive and rapid RNA microchip for detection of Head and Neck Cancer (HNC) mRNA, pathogenic bacteria and dengue virus (DENV) RNA is reported. By use of nucleases and polymerases specific RNAs are selectively labeled and detected without separation, reverse transcription and or polymerase chain reaction. This is accomplished by designing specific Hybrid probes consisting of DNA-2’-O-Me-RNA-DNA regions to target the RNA of interest. Upon hybridization with the target RNA, RNase H digestion is used to remove the 3’- RNA sequences which exposes the template for Klenow extension with reporter molecules such as hapten or fluorophore labels. This novel RNA microchip is fast (ca. 1 h detection time), selective as individual RNAs are detected in a synthetic mixture and total RNA mixtures, specific for single nucleotide polymorphisms (SNPs) discrimination and sensitive up to attomole level for chemiluminescence detection and lower femtomole for gold nanoparticles (AuNPs) and silver staining method. Using chemiluminescence, HNC biomarkers, VCAM1 and IL8 are specifically labeled and detected in the presence of thousands of other mRNAs in cancer cell lines and human colon cancer total RNA without interference. Furthermore, the method is highly specific as shown with DENV SNPs discrimination. Moreover, we report rapid (ca 1hour), selective, specific multi-marker detection of pathogenic mRNAs and HNC mRNAs using AuNPs-silver staining on the RNA microchip. Streptavidin gold nanoparticles technology has a potential in the analysis of specific mRNAs in a wide array of field including infectious diseases diagnosis, viral infections, food safety, gene expression profiling and cancer detection. A simple and rapid NaOH RNA extraction procedure was developed for E. coli total RNA extraction with specific results on the RNA microchip using both chemiluminescence and AuNPs silver staining. This extraction avoids the use of commercial RNA purification kits thus reducing the cost. Furthermore, visual detection on the RNA microchip is simple, does not require electricity or special equipment, and therefore is a good candidate for field diagnostics with minimum resources.

In the study, micro-PEM fuel cells are designed and fabricated in-house through a deep UV lithography SU-8 process and a wet etching technique for perforated holes plates (diameter is 750 £gm) of 50 £gm thickness of pure copper. Measurements of cell performance are performed using the low percentage of the weight concentration (1-10 wt. %) of NaOH solution, Al paper as the source material for hydrogen production, and different open ratios of the perforated plates to determine which best improves cell power density. Experimental results are presented in the form of polarization VI and PI curves under the above operating conditions. The experimental results show cell performance is enhanced by the self-heating, humidifying of hydrogen production, hydrogen internal circulation and accumulated pressure. Finally, the micro-PEM fuel cell system with DC/DC boost converter can generate 4.99 V for use in cellular phone accumulators charging.