Ce travail porte sur la synthèse et la caractérisation de fluorures divisés obtenus par voiesolvothermale assistée par chauffage micro-ondes pour la réduction des impuretés dans lecycle du combustible nucléaire. / This work deals with the synthesis and characterization of divided fluorides obtained bysolvothermal process assisted by microwave heating to reduce impurities in the nuclear fuelcycle.

A kinetic study of the pyrolysis of municipal solid waste (MSW) was carried out bythermogravimetric analysis (TGA). Different runs were performed at heating rates of 5, 10and 150C/min. The effect of the N2, CO2 and O2 gas with different combination in theprocess was also evaluated. The results show that the most weight loss was obtained whenthe MSW was treated at a temperature interval of (20-750)0C which led to a weigh loss of95%. The kinetic study of the pyrolysis process showed also the gas mixture used in theprocess effect also the activation energy of the process and the presence of the CO2 in theincreased the activation energy (Ea) to 56 kJ/mol. Higher concentration of CO2 in the processlead to increase in the activation energy which is not optimal for the reaction. The treated andthe untreated samples were incubated and the biological activity was observed. The resultsshow that the pretreated samples did not have any biological activity. From these results itcould be concluded that the thermal pretreatment could be an alternative way for of waste forlong period of time, which could have significant impact in i.e. for transportation anddurability during storage. / Program: Högskoleingenjörsutbildning i kemiteknik

Plants respond to and defend themselves against a wide range of disease-causing microbes. In order to do so, massive reprogramming of cellular protein expression patterns, which underpin various defense pathways, must occur. A family of basic leucine zipper transcription factors, called TGA factors, has been implicated in mediating this response. The TGA factors themselves are subject to complex regulation; of note, TGA1 and TGA4 are regulated via a reduction of conserved cysteines after treatment with the phenolic signaling molecular salicylic acid, which accumulates following pathogen challenge. Previous studies indicate that TGA factors physically interact in the yeast two-hybrid system with the plant-specific CC-type of glutaredoxin (Grx)-like proteins. Grx are a family of oxidoreductases that are important for maintaining the cellular redox status and often are required to modulate protein activity. The goal of this study was to ascertain the role of these Grx-like proteins in regulating TGA1 redox state. To this end, the expression patterns of several Grx genes were analyzed.<p> Quantitative-reverse-transcriptase PCR (q-RT-PCR) experiments indicated that TGA1 and TGA4 may be involved in down-regulating levels Grx-like gene transcripts after exposure to pathogens or salicylic acid (SA). Furthermore, qRT-PCR experiments also indicated that expression of some Grx-like genes is induced by SA, jasmonic acid (JA), and <i>Pseudomonas syringae</i>. Overexpression of the Grx-like protein, CXXC9, in <i>Arabidopsis thaliana</i> revealed that it is a regulatory factor in the cross-talk between vi theSA/JA pathways as it is able to suppress expression of PDF1.2, a marker for the JA defense pathway, as determined by qRT-PCR. The â-hydroxy ethyl disulfide (HED) assay was utilized to determine if the CC-type of Grx-like proteins have oxidoreductase activity <i>in vitro</i>. These studies revealed that that the Grx-like proteins do not exhibit oxidoreductase activity in this assay.

Mesoporous silica materials containing microporous cavities provided by covalently bound ¦Â-cyclodextrin (CD ICS) were synthesized by co-condensation of a ¦Â-CD functionalized triethoxy silane (CD ICL) with tetraethyl orthosilicate (TEOS) by using neutral amine surfactants as structure directing agents (SDA). CD ICL was prepared by reacting ¦Â-CD with 3-isocyanatopropyltriethoxysilane. IR spectroscopy of CD ICL showed complete disappearance of isocyanato group at 2270 cm-1. 1H NMR results indicate an average of four isocyanate linkers covalently attached to random hydroxyl substituents of each molecule of ¦Â-CD. <p> Nine different CD ICS materials were synthesized using dodecylamine, tetradecylamine or hexadecylamine with ¦Â-CD (2, 4, and 6 mol %) with respect to TEOS. The incorporation of ¦Â-CD within the mesoporous framework was supported by IR, Raman, MALDI TOF MS, solid state 13C NMR CP-MAS and TGA results. Small angle X-ray diffraction results showed a peak at 2¦È ¡Ö 2.20, supporting the presence of an ordered silica mesostructure framework. For materials with same CD loading, the surface area and pore volume doubled as the surfactant from dodecylamine to hexadecylamine. However, as the CD loading increased from 2% to 6%, the surface area decreases by a factor of ~ 1.5. <p>MALDI TOF mass spectrometry showed two peaks at m/z 1157 a.m.u. and 1173 a.m.u. for [¦Â-CD + Na]+ and [¦Â-CD + K]+ respectively due to desorption of ¦Â-CD from the walls of the silica matrix. The 13C NMR CP MAS results showed 13C signals in the region ¦Ä=60-110 ppm due to the nuclei of ¦Â-CD. CD ICS materials were found to be effective as a sorbent in both gas and aqueous phases, respectively. The sorption capacity (mmol/g) of p-nitrophenol increased from 61% to 84% with an increase of CD loading from 2% to 6% and as the alkyl chain length of the SDA increases from dodecylamine to hexadecylamine. The adsorption isotherm of CH3Cl in the gas phase and that of p-nitrophenol in the aqueous phase at ambient temperature adopts a multilayer model of adsorption.

Mesoporous silica materials containing microporous cavities provided by covalently bound ¦Â-cyclodextrin (CD ICS) were synthesized by co-condensation of a ¦Â-CD functionalized triethoxy silane (CD ICL) with tetraethyl orthosilicate (TEOS) by using neutral amine surfactants as structure directing agents (SDA). CD ICL was prepared by reacting ¦Â-CD with 3-isocyanatopropyltriethoxysilane. IR spectroscopy of CD ICL showed complete disappearance of isocyanato group at 2270 cm-1. 1H NMR results indicate an average of four isocyanate linkers covalently attached to random hydroxyl substituents of each molecule of ¦Â-CD. <p> Nine different CD ICS materials were synthesized using dodecylamine, tetradecylamine or hexadecylamine with ¦Â-CD (2, 4, and 6 mol %) with respect to TEOS. The incorporation of ¦Â-CD within the mesoporous framework was supported by IR, Raman, MALDI TOF MS, solid state 13C NMR CP-MAS and TGA results. Small angle X-ray diffraction results showed a peak at 2¦È ¡Ö 2.20, supporting the presence of an ordered silica mesostructure framework. For materials with same CD loading, the surface area and pore volume doubled as the surfactant from dodecylamine to hexadecylamine. However, as the CD loading increased from 2% to 6%, the surface area decreases by a factor of ~ 1.5. <p>MALDI TOF mass spectrometry showed two peaks at m/z 1157 a.m.u. and 1173 a.m.u. for [¦Â-CD + Na]+ and [¦Â-CD + K]+ respectively due to desorption of ¦Â-CD from the walls of the silica matrix. The 13C NMR CP MAS results showed 13C signals in the region ¦Ä=60-110 ppm due to the nuclei of ¦Â-CD. CD ICS materials were found to be effective as a sorbent in both gas and aqueous phases, respectively. The sorption capacity (mmol/g) of p-nitrophenol increased from 61% to 84% with an increase of CD loading from 2% to 6% and as the alkyl chain length of the SDA increases from dodecylamine to hexadecylamine. The adsorption isotherm of CH3Cl in the gas phase and that of p-nitrophenol in the aqueous phase at ambient temperature adopts a multilayer model of adsorption.

Plants respond to and defend themselves against a wide range of disease-causing microbes. In order to do so, massive reprogramming of cellular protein expression patterns, which underpin various defense pathways, must occur. A family of basic leucine zipper transcription factors, called TGA factors, has been implicated in mediating this response. The TGA factors themselves are subject to complex regulation; of note, TGA1 and TGA4 are regulated via a reduction of conserved cysteines after treatment with the phenolic signaling molecular salicylic acid, which accumulates following pathogen challenge. Previous studies indicate that TGA factors physically interact in the yeast two-hybrid system with the plant-specific CC-type of glutaredoxin (Grx)-like proteins. Grx are a family of oxidoreductases that are important for maintaining the cellular redox status and often are required to modulate protein activity. The goal of this study was to ascertain the role of these Grx-like proteins in regulating TGA1 redox state. To this end, the expression patterns of several Grx genes were analyzed.<p> Quantitative-reverse-transcriptase PCR (q-RT-PCR) experiments indicated that TGA1 and TGA4 may be involved in down-regulating levels Grx-like gene transcripts after exposure to pathogens or salicylic acid (SA). Furthermore, qRT-PCR experiments also indicated that expression of some Grx-like genes is induced by SA, jasmonic acid (JA), and <i>Pseudomonas syringae</i>. Overexpression of the Grx-like protein, CXXC9, in <i>Arabidopsis thaliana</i> revealed that it is a regulatory factor in the cross-talk between vi theSA/JA pathways as it is able to suppress expression of PDF1.2, a marker for the JA defense pathway, as determined by qRT-PCR. The â-hydroxy ethyl disulfide (HED) assay was utilized to determine if the CC-type of Grx-like proteins have oxidoreductase activity <i>in vitro</i>. These studies revealed that that the Grx-like proteins do not exhibit oxidoreductase activity in this assay.

Hydroxyl terminated polybutadiene (HTPB) based polyurethanes (PUs) are low modulus materials and degrade easily at low temperature. Polycarbodiimide (PCDI) and polysiloxane (PSi) are reactive-type fillers when formed by carbodimidzation and sol-gel process, respectively. During the combustion, PCDI and PSi give off non-toxic, non-corrosive volatile gases, and finally form carbonaceous and siliceous chars. In this study, modified PUs were prepared by incorporating PCDI or PSi into PUs to give high carbon, nitrogen and silicon materials. These modified PUs are kinds of organic-inorganic hybrids with higher modulus and higher thermal stability than HTPB-based PUs. In addition, new silicone based insulation materials were prepared by mixing two silicone rubber materials LSR-2670 and RTV-627 from GE Silicones, in order to improve the heat insulation and to reduce the ablation rate. These inhibitors can keep the rocket motor from the high temperature ablation for a long time, especially castable silicone based heat insulations for the case of the ramjet engines. The mechanical properties at room temperature and the thermal stability of these modified PUs and silicone rubbers were investigated using a tensile tester and a thermogravimetric analyzer (TGA). ATR/FTIR (Attenuated total reflectance / Fourier transform infrared) technique is applied to monitor the synthesis process of PCDI and to examine the change of surface chemistry of insulator before and after thermal degradation via TGA. TGA coupled with FTIR (TGA/FTIR) was used to analyze the kinetics and the mechanism of thermal degradation under nitrogen and/or air. The Friedman and Kissinger methods of analysis were used for calculating the activation energy of degradation from dynamic TGA. The modified PUs (HIPTD-40%Psi¤ÎHIPTD-30%PMPS-PSi) with average activation energy of 88 and 112 kcal/mole (0.5¡Õ£\¡Õ0.9, under N2) and the modified silicone rubber (LR-5%HTB) with activation energy of 46.2~67.0 kcal/mole (0.1¡Õ£\¡Õ0.9, under N2) and 34.0~59.1 kcal/mole (0.1¡Õ£\¡Õ0.9, under air).The maximum degradation temperature (Tmax) and char yield (CY) of thermal degradation were estimated from a series of experiments with heating rates of 1, 3, 5, 10, 20, 30, 40 and 50 ¢J/min, under nitrogen or air. It is apparent that the maximum degradation temperature is dependent on heating rate. By assuming the heating rate for the insulator used in a rocket operating environment is about 5000¢J/min, Tmax calculated for the modified PUs (HIPTD-40%PSi and HIPTD-30%PMPS-PSi under N2) are found as 538 and 562¢J and for the modified silicone rubber (LR-5%HTB under N2 and air) are found as 576 and 562¢J, respectively. CY calculated for the modified silicone rubber (LR-5%HTB under N2 and air) is found as 71.5% and 66.2%. The morphology of modified PUs and silicone rubbers before and after thermal degradation via TGA was observed by optical and scanning electron microscope (SEM).

This study investigated the adsorptive capacity and isotherm of HgCl2 onto spherical activated carbons (SAC) via thermogravimetric analysis (TGA). Activated carbon injection (ACI) is thought as the best available control technology (BACT) for mercury removal from flue gas. There are two major forms of vapor-phase mercury, Hgo and Hg2+, of which HgCl2 accounts for 60-95% of total mercury. Mercury emitted from the incineration of municipal solid wastes (MSW) could cause severely adverse effects on human health and ecosystem since it exists mainly in vapor phase due to high vapor pressure. Although the adsorptive capacity of HgCl2 onto activated carbon has been studied in previous adsorption column tests, only a few studies have thoroughly investigated the adsorption isotherms of HgCl2 onto SAC. Equilibrium and kinetic studies are important towards obtaining a better understanding of mercury adsorption. Many investigations have addressed the relationship between sorption kinetics and equilibrium for different adsorbent/adsorbate combinations. For the removal of vapor-phase mercury, several bench-pilot, and full-scale tests have be proceeded to examine the influence of carbon types, carbon structures, carbon surface characteristics, injection methods (dry or wet), amount of carbon injected, and flue gas temperature on mercury removal. In addition, the dynamics of spherical activated carbons (SAC) adsorbers for the uptake of gas-phase mercury was evaluated as a function of temperature, influent concentration of mercury, and empty-bed residence time. However, only a few studies investigated the adsorption isotherms of HgCl2 onto activated carbons. In this study, TGA was applied to obtain the adsorptive capacity of HgCl2 onto SAC with adsorption temperature (30~150oC) and influent HgCl2 concentration (50~1,000£gg/m3). Experimental results indicated that the adsorptive capacity of HgCl2 onto SAC was 0.67and 0.20 mg/gC at 30¡B70 and 150oC, respectively. This study investigated the adsorptive capacity of HgCl2 vapor onto SAC via TGA analysis. Experimental results indicated that the adsorptive capacity of SAC decreased with the increase of the adsorption temperature. Furthermore, the results suggested that that the adsorption of SAC on HgCl2 vapor was favorable equilibrium at 30 and 70¢J and unfavorable equilibrium at 150¢J. In comparison of the experimental data with isotherm equations, Freundlich isotherm fitted the experimental results better than Langmuir isotherm. The model simulations were found to fit very well to the high concentration experimental kinetic data for both adsorption and desorptionusing two adjust parameter, effective diffusivity, and the Freundlich isothermexponent.¡@The extracted model parameter, effective diffusivity and n, were then used to predict the experimental kinetic data for the same combination at other concentrations.

In this study the catalytic pyrolysis and combustion characteristics of Turkish coal samples in O2/N2 and O2/CO2 (oxy-fuel conditions) ambient conditions were explored and the evolution of emissions during these tests was investigated using non-isothermal Thermo-gravimetric Analysis (TGA) technique combined with Fourier Transform Infrared (FTIR) spectroscopy. Potassium carbonate (K2CO3), calcium hydroxide (Ca(OH)2), iron (III) oxide (Fe2O3) and iron (III) chloride (FeCl3) were employed as precursors of catalysts to investigate the effects of potassium (K), calcium (Ca) and iron (Fe). Furthermore the effects of these catalysts on calorimetric tests of Turkish coal samples were investigated. TGA-FTIR pyrolysis tests were carried out in 100 % N2 and 100 % CO2 ambient conditions which are the main diluting gases in air and oxy-fuel conditions. Lignite pyrolysis tests revealed that the major difference between pyrolysis in these two ambient conditions was observed beyond 720

This study investigated the adsorptive and desorption capacity of HgCl2 onto powdered activated carbon derived from carbon black of pyrolyzed waste tires (CPBAC) via thermogravimetric analysis (TGA). Due to incomplete classification and recycling of municipal solid wastes (MSW), they still mix with a lot of hazardous materials, which unfortunately can not be removed by incinerators and air pollution control devices(APCDs). Among them, mercury and its pollutants attract more attention by people. Mercury and its pollutants emitted from the incineration of municipal solid wastes could cause severely adverse effects on human health and ecosystem since they exist mainly in vapor phase due to high vapor pressure. If they can not be remove by the air pollution control devices, they will be emitted to the atmosphere and cause serious effects on environmental ecology via various routes. Activated carbon has been widely applied to the treatment of organic compounds and heavy metals in wastewater and waste gas stream. However, the adsorptive capacity of activated carbon decreases with adsorption temperature. The low adsorptive capacity of activated carbon at high temperature (>150 oC) can be overcome by impregnated activated carbons. Previous study reported that sulfur impregnated powdered activated carbons could effectively remove the vapor-phase elemental mercury (Hgo) emitted from MSW incinerators and utility power plants. However, the impregnated typically used is sulfur (S) which is solely applied for the adsorption of elemental mercury (Hgo). Besides, these studies seldom investigate the distribution of impregnated sulfur in the inner pores of activated carbon and its effects on the specific surface area and pore size distribution. Thus, this study was to investigate the fundamental mechanisms for the adsorption/desorption of HgCl2 by/from sulfur impregnated PAC. Experimental results indicated that the sulfur content of sulfur impregnated CBPAC decreased with increasing impregnation temperatures form 400 to 650 oC; while the surface area of sulfur impregnated CBPAC increased with impregnation temperatures. In this study, TGA was applied to obtain the adsorptive capacity of HgCl2 onto CBPAC with adsorption temperature (150oC) and influent HgCl2 concentration (100~500 £gg/m3). Experimental results indicated that the adsorptive capacity of CBPAC increased with the increase of influent HgCl2 concentration and surface area of the activated carbon. This study revealed that the impregnation of sulfur on CBPAC could increase its adsorption capacity at high temperatures. Desorption experimental parameters included desorption temperature (400, 500, and 600 oC), heating rate (10, 15, and 20 oC /min) and regeneration cycle (1~7 cycles). In probing into the regeneration efficiency of CBPAC, experiments were conducted at the desorption times of 60 and 30 min. The results suggested the regeneration efficiency of carbon under 30 min was generally highter than that under 60 min. Because the desorption time was more longer and the sulfur content was lesser. Therefore, the regeneration times was reduce. Experimental results indicated that the mechanism of HgCl2 desorption from the spent CPBAC was strongly affected by desorption temperature. Both the desorption efficiency and the desorption rate of HgCl2 increased dramatically with desorption temperature. The desorption heat of HgCl2 (823 KJ/mole) was much higher than the vaporization heat of HgCl2 (59.2 KJ/mole), indicating that the adsorption of HgCl2 on sulfur impregnated CBPAC was chemical adsorption. Consequently, raising desorption temperature could enhance the desorption of HgCl2 and shorten the duration for HgCl2 desorption. Moreover, the formation of HgS during the desorption of HgCl2 from activated carbons can be proved by the surface characteristics of sulfur impregnated activated carbons. Results obtained from the regeneration of sulfur impregnated activated carbons indicated that the regeneration cycles decreased as the desorption duration increased. It was attributed to the potential desorption of sulfur from actived carbons, which thus decreased the adsorptive capacity and the regeneration cycles.