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Synthèse de résines phénoliques bio-sourcées sans formaldéhyde pour l’industrie aérospatiale / Synthesis of biobased phenolic resins without formaldehyde for the aerospatial industryFoyer, Gabriel 04 December 2015 (has links)
Les résines phénoliques de type résole présentent des propriétés applicatives et thermiques adaptées à l'élaboration de matériaux composites pour l'industrie aérospatiale. En particulier, ces résines peuvent être polymérisées en plusieurs étapes et présentent des propriétés de charbonnement très élevées. Seulement, ces résines sont principalement synthétisées à partir de formaldéhyde et de phénol. Ces précurseurs sont classés Cancérigène Mutagène Reprotoxique (CMR) respectivement de catégorie 1B et 2 et sont issus de ressources pétrolières. Du fait de cette classification CMR et de la raréfaction des ressources pétrolières, la société SAFRAN-Herakles souhaite substituer le formaldéhyde par des précurseurs non classés CMR et d'origine renouvelable. Les précurseurs aldéhyde aromatiques issus des lignines, 4-hydroxybenzaldéhyde, vanilline et syringaldéhyde, ne sont pas toxiques et peuvent être issus d'une ressource renouvelable abondante et bon marché, les lignines. Néanmoins, nous avons montré que ces trois précurseurs bio-sourcés ne sont pas réactifs en synthèse de résines résole. Nous avons également montré que le formaldéhyde doit être substitué par des précurseurs dialdéhyde aromatiques réactifs pour synthétiser des résines phénoliques avec d'excellentes propriétés de charbonnement. Ainsi, nous avons mis au point deux méthodes de fonctionnalisation pour transformer ces composés aldéhyde aromatiques bio-sourcés en de tels précurseurs dialdéhyde aromatiques réactifs. Les précurseurs obtenus ont ensuite été utilisés en synthèses de résines résole sans formaldéhyde et bio-sourcées. Après caractérisation de ces résines, nous avons enfin identifié des précurseurs donnant accès à des résines résole bio-sourcées avec des propriétés de charbonnement supérieures aux résines formophénoliques actuelles. En résumé, ces nouveaux précurseurs aldéhyde bio-sourcés représentent des alternatives prometteuses à l'usage de formaldéhyde pour la synthèse de résines résole avec des propriétés cibles pour des applications dans l'industrie aéropatiale. / Resol-type phenolic resins present applicative and thermal properties suitable for applications such as composite manufacture in aeropatial industry. Especially, resols can be polymerized stage-wise and present after curing high char yield properties. However, those resins are typically synthesized from formaldehyde and phenol. Those precursors are both classified as Carcinogenic Mutagenic Reprotoxic (CMR), respectively 1B and 2, and are petrobased. Because of this classification and of the fossil feedstock depletion, SAFRAN-Herakles wants to substitute formaldehyde by non-toxic and biobased aldehyde precursors. Aromatic aldehyde precursors such as 4-hydroxybenzaldehyde, vanillin and syringaldehyde are interestingly non-toxic and can be produced from the cheap and abundant lignins. Nevertheless, we have shown that those precursors are not reactive in resol synthesis conditions. Also, we have shown that difunctional and reactive aromatic aldehyde precursors are suitable for the synthesis of high char yield resins. Then, we have designed two functionalization methods to turn the biobased aldehyde precursors into difunctional and reactive ones. Finally, those precursors have been used for the synthesis of biobased resols without formaldehyde. Those new resins can be polymerized stage-wise and present higher char yield properties than the current formophenolic resins. Hence, those new biobased aldehyde precursors represent promising alternatives to formaldehyde for the synthesis of resols with target properties for aerospatial industry applications.
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Resíduo sólido de depilação como adsorvente de corantes para tingimento de couroMella, Bianca January 2017 (has links)
Nas etapas de processamento do couro, de limpeza da pele, de recortes e ajuste da espessura do couro, diferentes tipos de resíduos sólidos são gerados. Dentre esses resíduos, os pelos provenientes da etapa de depilação são descartados. Além disso, nas etapas finais do acabamento molhado do couro, em especial no tingimento, são adicionados corantes e outros produtos químicos com o objetivo de dar ao couro características superficiais, como cor e textura, gerando, consequentemente, efluentes de difícil tratamento devido ao potencial recalcitrante dos produtos químicos. O objetivo deste trabalho é apresentar uma alternativa ao uso do pelo proveniente da etapa de depilação, possibilitando assim uma extensão no ciclo de vida deste resíduo como um adsorvente alternativo para remoção de corantes empregados na indústria do couro. O pelo (CHW) foi caracterizado através de microscopia eletrônica de varredura (MEV), espectroscopia de raios X dispersiva de energia (EDS), espectroscopia de infravermelho (FTIR), bem como sua área superficial específica e distribuição de tamanho de poro por análises de BET/BJH. A capacidade de remoção dos corantes Azul Ácido 161 (AB-161) e Preto Ácido 210 (AB-210) em soluções aquosas foi estudada emfaixas de pH de 1,0 a 10,0 e também a dosagem ótima de adsorvente. Nas isotermas de adsorção,o modelo de Liu foi o que melhor apresentou resultados para os dois corantes estudados em todas as temperaturas analisadas (30, 40 e 50ºC) No estudo cinético, o modelo de ordem-geral apresentou o melhor ajuste dos dados, com menor tempo de contato para remoção do corante AB-161 de 600 min com o pelo (CHW) e 90 min com o carvão ativado comercial (CAC), nos valores de pH 3,0 e pH 4,0, respectivamente. Para o corante AB-210 o menor tempo de contato para atingir o equilíbrio foi de 120 min e 90 min para CHW e o CAC, nos valores ótimos de pH de 2,0 e 4,0, respectivamente. O carvão produzido (AC-CHW) a partir do pelo residual foi ativado com H3PO4, caracterizado e testado em efluentes reais para remoção dos corantes Laranja Ácido 142 (AO-142) e Marrom Ácido 414 (AB-414). O carvão produzido apresentou um elevado diâmetro de poro (140,70 A), o que favoreceu a adsorção de moléculas maiores e mais complexas, como as presentes nos efluentes reais. Através do MEV e do FTIR observou-se a presença dos compostos estudados no AC-CHW após aadsorção, onde os resultados indicaram que os grupos funcionais de -CH=CH- participaram ativamente do processo de remoção. O pHzero obtido do AC-CHWfoi de 3,65, o que favoreceu a remoção desses compostos já que o efluente real apresenta um pH inferior a 4,0. Os percentuais de remoção obtidos de área sob as curvas de adsorção indicam uma remoção de 51,94% e 49,73% dos efluentes contendo AB-414 e AO-142, respectivamente. / In the stages of leather processing, skin cleansing, trimming and leather thickness adjustment, different types of solid waste are generated. Among these residues, hairs from the depilation stage are discarded. In addition, in the final stages of the wet finishing of leather, in particular in dyeing, dyes and other chemical products are added with the aim of giving the leather surface characteristics, such as color and texture, thus generating effluents that are difficult to treat due to the potential recalcitrant of chemicals. The objective of this work is to present an alternative to the use of hair from the depilation stage, thus allowing an extension in the life cycle of this residue as an alternative adsorbent for the removal of dyes used in the leather industry. The hair (CHW) was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), infrared spectroscopy (FTIR), as well as its specific surface area and pore size distribution by analysis of BET/BJH. The ability to remove Acid Blue 161 (AB-161) and Acid Black 210 (AB-210) dyes in aqueous solutions was studied in pH ranges from 1 to 10 and also the optimum dosage of adsorbent. In the adsorption isotherms, Liu model presented the best results for the two dyes studied at all temperatures (30, 40 and 50ºC). In the kinetic study, the general-order model presented the best fit of the data, with a lowest contact time to remove the AB-161 dye of 600 min with the hair (CHW) and 90 min with the commercial activated charcoal (CAC) at pH 3.0 and pH 4.0, respectively For the dye AB-210, the lowest contact time to reach equilibrium was 120 min and 90 min for CHW and CAC, at the optimum pH values of 2.0 and 4.0, respectively. The charcoal produced (AC-CHW) from the residual was activated with H3PO4, characterized and tested in actual effluents to remove the Acid Orange 142 (AO-142) and Acid Brown 414 (AB-414) dyes. The carbon produced had a high pore diameter (140,70 A), which favored the adsorption of larger and more complex molecules, such as those present in the actual effluents. The presence of the compounds studied in the AC-CHW after adsorption was observed through the SEM and the FTIR, where the results indicated that the functional groups of -CH = CH- actively participated in the removal process. The obtained pHzero of AC-CHW was 3.65, which favored the removal of these compounds since the actual effluent had a pH lower than 4.0. The percentages of removal obtained from area under the adsorption curves indicate a 51.94% and 49.73% removal of the effluents containing AB-414 and AO-142, respectively.
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Analyse des différentes formes sociales de pratiques physiques et sportives sur sable : Regard singulier sur quatre pratiques et leurs pratiquants : le beach volley, le beach tennis, le beach rugby et le char à voile / Analysis of different forms of social practice physical and sand sports : Unique perspective on four practices and practitioners : beach volleyball, beach tennis, beach rugby and yachtingDebeauquesne, Diane 19 October 2012 (has links)
Les cultures sportives s’expriment à travers des formes sans cesse renouvelées, soumises à des lectures, relectures, tensions, préemptions, propres à l’existence-même d’un phénomène social.Au sein de ce foisonnement, les pratiques physiques et sportives sur sable méritent une attention particulière. Nous avons choisi de les observer et donner à voir comme des productions et produits humains de l’instant présent, dans un environnement social où l’humain agit et interagit. Après avoir procédé à leur recension et classement, nous avons sélectionné quatre d’entre elles ‒ le beach volley, le beach tennis, le beach rugby et le char à voile ‒ afin de les analyser sous l’angle de ce que font et disent les pratiquants, au sein d’un système complexe, interdépendant, qui met en jeu pratiques, pratiquants et espaces de pratique. À cet effet, les observations, les entretiens, ainsi que les questionnaires que nous avons menés ont permis de montrer que les pratiquants des activités sur sable présentent des caractéristiques communes et des représentations partagées. Cependant, nous constatons que ces activités, le plus souvent saisonnières, drainent, non pas de nouveaux pratiquants, mais bien un public de sportifs qui s’adonne majoritairement à la version beach de son sport de référence, sans les contraintes calendaires des compétitions fédérales (continuité, rupture).Si les espaces de pratique sont décrits comme des territoires d’activités humaines où se créent du lien social, des découvertes, des loisirs et de la dépense physique, il n’en demeure pas moins qu’ils s’avèrent plus domestiqués que sauvages et que la quête de l’autrement et de l’ailleurs reste continûment à l’ordre du jour. / Pas de résumé en anglais
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Developing Formaldehyde Free Flame Retardant for CelluloseHannan, MD.Abdul January 2011 (has links)
Two organophosphorus compounds, namely diethyloxymethyl-9-oxa-10- phosphaphenanthrene-10-oxide (DOPAC) and diethyl (2,2-diethoxyethyl) phosphonate (DPAC) were applied on cotton cellulose to impart non-carcinogenic and durable (in alkaline washing) flame retardant property to it. Some acidic catalysts, sodium dihydrogen phosphate (NaH2PO4), ammonium dihydrogen phosphate (NH4H2PO4) and phosphoric acid (H3PO4), were successfully used to settle acetal linkage between cellulose and flame retardant (FR) compound. Appreciable limiting oxygen index (LOI) values of 24% and 23.9% were achieved in case of the samples treated with FR compound DPAC along with the combined acidic catalyzing effect of NaH2PO4+H3PO4 and NaH2PO4+NH4H2PO4. A distinguishing outcome of total heat of combustion (THC) 3.27 KJ/g was revealed during pyrolysis combustion flow calorimetry (PCFC) test of the treated sample. In respect of thermal degradation, low temperature dehydration in conjugation with sufficient amount of char residue (30.5%) was obtained in case of DOPAC treated sample. Consistently, the temperature of peak heat release rate (TPHRR) (325°C) of DPAC treated sample supported the expected low temperature pyrolysis in condensed phase mechanism. Subsequent thermogravimetric analysis (TGA) also reported inspiring weight retention% of the treated samples. Furthermore, for both of the flame retardant compounds, effect of different catalysts, considering both individual and combined, effect of solvents, and overall the optimization of the process parameters were studied in detail. / Program: Magisterutbildning i textilteknologi
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Product evaluation and reaction modelling for the devolatilization of large coal particles / Barend Burgert HattinghHattingh, Barend Burgert January 2012 (has links)
A fundamental understanding of the process of devolatilization requires extensive knowledge of
not only the intrinsic properties of the parent coal and its subsequent formed products (tars,
gases and chars), but also its characteristic reaction rate behaviour. Devolatilization behaviour
has been extensively addressed in literature with the use of powdered coal samples, which
normally do not adhere to particle size constraints of coal conversion processes utilizing lump
coal. The aim of this investigation was therefore to assess the devolatilization behaviour (with
respect to product yield and -quality; and reaction rate modelling) of four typical South African
coals (UMZ, INY, G#5 and TSH) confined to the large particle regime. All four coals were found
to be bituminous in rank, with vitrinite contents ranging between 24.4 vol.% and 69.2 vol.%
(mineral matter free basis). Two were inertinite-rich coals (UMZ and INY) and the other two
were vitrinite-rich coals (G#5 and TSH). From thermoplasticity measurements it was evident that
only coal TSH displayed extensive thermoplastic behaviour, while a comparison between
molecular properties confirmed the higher abundance of poly-condensed aromatic structures
(aromaticity of 81%) present in this coal.
Product evolution was evaluated under atmospheric conditions in a self-constructed, large
particle, fixed-bed reactor, on two particle sizes (5 mm and 20 mm) at two isothermal reactor
temperatures (450°C and 750°C) using a combination of both GC and MS techniques for gas
species measurement, while standard gravimetric methods were used to quantify tar- and char
yield respectively. Elucidation of tar- and char structural features involved the use of both
conventional- and advanced analytical techniques. From the results it could be concluded that
temperature was the dominating factor controlling product yield- and quality, with significant
increases in both volatile- and gas yield observed for an increase in temperature. Tar yields
ranged between 3.6 wt.% and 10.1 wt.% and increased in the order UMZ < INY < TSH < G#5,
with higher tar yields obtained for coal G#5, being ascribed to larger abundances of vitrinite and
liptinite present in this coal. For coal TSH, lower tar yields could mainly be attributed to the
higher aromaticity and extensive swelling nature of this coal. Evolved gases were found to be
mainly composed of H2, CH4, CO and CO2, low molecular weight olefins and paraffins; and
some C4 homologues. Advanced analytical techniques (NMR, SEC, GC-MS, XRD, etc.)
revealed the progressive increase of the aromatic nature of both tars and chars with increasing
temperature; as well as subsequent differences in tar composition between the different parent coals. In all cases, an increase in devolatilization temperature led to the evolution of larger
amounts of aromatic compounds such as alkyl-naphthalenes and PAHs, while significant
decreases in the amount of aliphatics and mixed compounds could be observed. From 13C
NMR, HRTEM and XRD carbon crystallite results it was clear that an increase in temperature
led to the formation of progressively larger, more aromatic and structurally orientated polycondensed
carbon structures.
Reaction rate studies involved the use of non-isothermal (5-40 K/min) and isothermal (350-
900°C) thermogravimetry of both powdered (-200 μm) and large particle samples (20 mm) in
order to assess intrinsic kinetics and large particle rate behaviour, respectively. Evaluation of
the intrinsic kinetic parameters of each coal involved the numerical regression of non-isothermal
rate data in MATLAB® 7.1.1 according to a pseudo-component modelling philosophy. Modelling
results indicated that the intrinsic devolatilization behaviour of each coal could be adequately
described by using a total number of eight pseudo-components, while reported activation
energies were found to range between 22.3 kJ/mol and 244.3 kJ/mol. Description of the rate of
large particle devolatilization involved the evaluation of a novel, comprehensive rate model
accounting for derived kinetics, heat and mass transport effects, as well as physical changes
due to particle swelling/shrinkage. Evaluation of the proposed model with the aid of the
COMSOL Multiphysics 4.3 simulation software provided a suitable fit to the experimental data of
all four coals, while simulation studies highlighted the relevant importance of not only the effect
of particle size, but also the importance of including terms affecting for heat losses due to
particle swelling/shrinkage, transport of volatile products through the porous char structure, heat
of reaction and heat of vaporization of water. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013
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Product evaluation and reaction modelling for the devolatilization of large coal particles / Barend Burgert HattinghHattingh, Barend Burgert January 2012 (has links)
A fundamental understanding of the process of devolatilization requires extensive knowledge of
not only the intrinsic properties of the parent coal and its subsequent formed products (tars,
gases and chars), but also its characteristic reaction rate behaviour. Devolatilization behaviour
has been extensively addressed in literature with the use of powdered coal samples, which
normally do not adhere to particle size constraints of coal conversion processes utilizing lump
coal. The aim of this investigation was therefore to assess the devolatilization behaviour (with
respect to product yield and -quality; and reaction rate modelling) of four typical South African
coals (UMZ, INY, G#5 and TSH) confined to the large particle regime. All four coals were found
to be bituminous in rank, with vitrinite contents ranging between 24.4 vol.% and 69.2 vol.%
(mineral matter free basis). Two were inertinite-rich coals (UMZ and INY) and the other two
were vitrinite-rich coals (G#5 and TSH). From thermoplasticity measurements it was evident that
only coal TSH displayed extensive thermoplastic behaviour, while a comparison between
molecular properties confirmed the higher abundance of poly-condensed aromatic structures
(aromaticity of 81%) present in this coal.
Product evolution was evaluated under atmospheric conditions in a self-constructed, large
particle, fixed-bed reactor, on two particle sizes (5 mm and 20 mm) at two isothermal reactor
temperatures (450°C and 750°C) using a combination of both GC and MS techniques for gas
species measurement, while standard gravimetric methods were used to quantify tar- and char
yield respectively. Elucidation of tar- and char structural features involved the use of both
conventional- and advanced analytical techniques. From the results it could be concluded that
temperature was the dominating factor controlling product yield- and quality, with significant
increases in both volatile- and gas yield observed for an increase in temperature. Tar yields
ranged between 3.6 wt.% and 10.1 wt.% and increased in the order UMZ < INY < TSH < G#5,
with higher tar yields obtained for coal G#5, being ascribed to larger abundances of vitrinite and
liptinite present in this coal. For coal TSH, lower tar yields could mainly be attributed to the
higher aromaticity and extensive swelling nature of this coal. Evolved gases were found to be
mainly composed of H2, CH4, CO and CO2, low molecular weight olefins and paraffins; and
some C4 homologues. Advanced analytical techniques (NMR, SEC, GC-MS, XRD, etc.)
revealed the progressive increase of the aromatic nature of both tars and chars with increasing
temperature; as well as subsequent differences in tar composition between the different parent coals. In all cases, an increase in devolatilization temperature led to the evolution of larger
amounts of aromatic compounds such as alkyl-naphthalenes and PAHs, while significant
decreases in the amount of aliphatics and mixed compounds could be observed. From 13C
NMR, HRTEM and XRD carbon crystallite results it was clear that an increase in temperature
led to the formation of progressively larger, more aromatic and structurally orientated polycondensed
carbon structures.
Reaction rate studies involved the use of non-isothermal (5-40 K/min) and isothermal (350-
900°C) thermogravimetry of both powdered (-200 μm) and large particle samples (20 mm) in
order to assess intrinsic kinetics and large particle rate behaviour, respectively. Evaluation of
the intrinsic kinetic parameters of each coal involved the numerical regression of non-isothermal
rate data in MATLAB® 7.1.1 according to a pseudo-component modelling philosophy. Modelling
results indicated that the intrinsic devolatilization behaviour of each coal could be adequately
described by using a total number of eight pseudo-components, while reported activation
energies were found to range between 22.3 kJ/mol and 244.3 kJ/mol. Description of the rate of
large particle devolatilization involved the evaluation of a novel, comprehensive rate model
accounting for derived kinetics, heat and mass transport effects, as well as physical changes
due to particle swelling/shrinkage. Evaluation of the proposed model with the aid of the
COMSOL Multiphysics 4.3 simulation software provided a suitable fit to the experimental data of
all four coals, while simulation studies highlighted the relevant importance of not only the effect
of particle size, but also the importance of including terms affecting for heat losses due to
particle swelling/shrinkage, transport of volatile products through the porous char structure, heat
of reaction and heat of vaporization of water. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013
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Reconfiguring spaceThomas, Paul Unknown Date (has links)
The starting point of my dissertation is the question: What would be needed of a device to culturally reconfigure the way that we see? The question has been addressed through a theoretical examination of spatial theories in modern times and a creative exploration of new spatialities in new media technologies, both visual and aural. Central to my thesis are three claims: 1. the paradigmatic mathematical theory of single-point perspective is fundamental to the imagining and construction of space in modern times; 2. perspective is a seductive space because its virtualisations seem more authentic than phenomenological experience; 3. the structure of perspective space prefigures the computer screen, hence any attempt to reconfigure the spatial imaginary through the devices of new media technologies must first confront the historical ubiquity of perspective. The specific focus of my written research is a comparative study of Filippo Brunelleschi's perspective device and the virtual reality work of Char Davies. This comparative study focuses on the ingredients of both devices as well as the similarities between the environments in which they were demonstrated. Brunelleschi's Peephole device, according to his biographer Manetti, first demonstrated perspective theory in the early fifteenth century. Brunelleschi's device, with its three main components, the mirror, the burnished silver and the painted panel, are examined in regards to the environment it was demonstrated in. The dissertation explores these elements as the essential conceptual ingredients for the reconfiguration of space in modern times. Aspects of Brunelleschi's device are also examined creatively in my practical work. Today emergent technologies are being used to explore the potential of a new spatial world order. However, these new technologies are generally based on an Old World order perspective. Even the cubist reconfiguration of space did not change, in any fundamental way, the dominant perspectival model of perception because it did not have the same ideological and psychological power as perspective, which seduced the viewer into believing that the gap (or loss) between the technology and reality had been compensated. Arguably, the same claims can be made for virtual reality devices. Hence, important to the dissertation is a comparative study of Brunelleschi's perspective device and the virtual reality work of Char Davies. The creative work investigates the effects and work of perspectival spatiality by examining (through digital video, photographically and sonically) residual spaces in the environment. To me these residual spaces provide potential resistances to the perspectival space from which they evolved, and thus show new ways of exploring the virtual reality of cyberspace that, while acknowledging the pervasive presence of perspective systems, also deconstruct or even map new post-perspective spatialities.
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Resíduo sólido de depilação como adsorvente de corantes para tingimento de couroMella, Bianca January 2017 (has links)
Nas etapas de processamento do couro, de limpeza da pele, de recortes e ajuste da espessura do couro, diferentes tipos de resíduos sólidos são gerados. Dentre esses resíduos, os pelos provenientes da etapa de depilação são descartados. Além disso, nas etapas finais do acabamento molhado do couro, em especial no tingimento, são adicionados corantes e outros produtos químicos com o objetivo de dar ao couro características superficiais, como cor e textura, gerando, consequentemente, efluentes de difícil tratamento devido ao potencial recalcitrante dos produtos químicos. O objetivo deste trabalho é apresentar uma alternativa ao uso do pelo proveniente da etapa de depilação, possibilitando assim uma extensão no ciclo de vida deste resíduo como um adsorvente alternativo para remoção de corantes empregados na indústria do couro. O pelo (CHW) foi caracterizado através de microscopia eletrônica de varredura (MEV), espectroscopia de raios X dispersiva de energia (EDS), espectroscopia de infravermelho (FTIR), bem como sua área superficial específica e distribuição de tamanho de poro por análises de BET/BJH. A capacidade de remoção dos corantes Azul Ácido 161 (AB-161) e Preto Ácido 210 (AB-210) em soluções aquosas foi estudada emfaixas de pH de 1,0 a 10,0 e também a dosagem ótima de adsorvente. Nas isotermas de adsorção,o modelo de Liu foi o que melhor apresentou resultados para os dois corantes estudados em todas as temperaturas analisadas (30, 40 e 50ºC) No estudo cinético, o modelo de ordem-geral apresentou o melhor ajuste dos dados, com menor tempo de contato para remoção do corante AB-161 de 600 min com o pelo (CHW) e 90 min com o carvão ativado comercial (CAC), nos valores de pH 3,0 e pH 4,0, respectivamente. Para o corante AB-210 o menor tempo de contato para atingir o equilíbrio foi de 120 min e 90 min para CHW e o CAC, nos valores ótimos de pH de 2,0 e 4,0, respectivamente. O carvão produzido (AC-CHW) a partir do pelo residual foi ativado com H3PO4, caracterizado e testado em efluentes reais para remoção dos corantes Laranja Ácido 142 (AO-142) e Marrom Ácido 414 (AB-414). O carvão produzido apresentou um elevado diâmetro de poro (140,70 A), o que favoreceu a adsorção de moléculas maiores e mais complexas, como as presentes nos efluentes reais. Através do MEV e do FTIR observou-se a presença dos compostos estudados no AC-CHW após aadsorção, onde os resultados indicaram que os grupos funcionais de -CH=CH- participaram ativamente do processo de remoção. O pHzero obtido do AC-CHWfoi de 3,65, o que favoreceu a remoção desses compostos já que o efluente real apresenta um pH inferior a 4,0. Os percentuais de remoção obtidos de área sob as curvas de adsorção indicam uma remoção de 51,94% e 49,73% dos efluentes contendo AB-414 e AO-142, respectivamente. / In the stages of leather processing, skin cleansing, trimming and leather thickness adjustment, different types of solid waste are generated. Among these residues, hairs from the depilation stage are discarded. In addition, in the final stages of the wet finishing of leather, in particular in dyeing, dyes and other chemical products are added with the aim of giving the leather surface characteristics, such as color and texture, thus generating effluents that are difficult to treat due to the potential recalcitrant of chemicals. The objective of this work is to present an alternative to the use of hair from the depilation stage, thus allowing an extension in the life cycle of this residue as an alternative adsorbent for the removal of dyes used in the leather industry. The hair (CHW) was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), infrared spectroscopy (FTIR), as well as its specific surface area and pore size distribution by analysis of BET/BJH. The ability to remove Acid Blue 161 (AB-161) and Acid Black 210 (AB-210) dyes in aqueous solutions was studied in pH ranges from 1 to 10 and also the optimum dosage of adsorbent. In the adsorption isotherms, Liu model presented the best results for the two dyes studied at all temperatures (30, 40 and 50ºC). In the kinetic study, the general-order model presented the best fit of the data, with a lowest contact time to remove the AB-161 dye of 600 min with the hair (CHW) and 90 min with the commercial activated charcoal (CAC) at pH 3.0 and pH 4.0, respectively For the dye AB-210, the lowest contact time to reach equilibrium was 120 min and 90 min for CHW and CAC, at the optimum pH values of 2.0 and 4.0, respectively. The charcoal produced (AC-CHW) from the residual was activated with H3PO4, characterized and tested in actual effluents to remove the Acid Orange 142 (AO-142) and Acid Brown 414 (AB-414) dyes. The carbon produced had a high pore diameter (140,70 A), which favored the adsorption of larger and more complex molecules, such as those present in the actual effluents. The presence of the compounds studied in the AC-CHW after adsorption was observed through the SEM and the FTIR, where the results indicated that the functional groups of -CH = CH- actively participated in the removal process. The obtained pHzero of AC-CHW was 3.65, which favored the removal of these compounds since the actual effluent had a pH lower than 4.0. The percentages of removal obtained from area under the adsorption curves indicate a 51.94% and 49.73% removal of the effluents containing AB-414 and AO-142, respectively.
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Quantificação do teor de char e finos de coque no pó de balão do alto-forno por difração de raios-XMachado, André da Silveira January 2011 (has links)
A injeção de carvão pulverizado (PCI — pulverized coal injection) nos altos-fornos (AFs) é uma tecnologia utilizada pelas usinas siderúrgicas para aumentar a produtividade e diminuir o consumo de coque no AF. Nas últimas décadas as taxas de injeção de carvão pulverizado aumentaram na maior parte dos AFs. O principal problema associado à utilização de altas taxas de PCI é a geração de char (carvão incombusto) na zona de combustão. Este material percorre um caminho ascendente junto ao fluxo gasoso, podendo acumular-se e assim prejudicar a permeabilidade do AF. A presença, nas amostras sólidas recolhidas do gás de saída do AF, de altos teores de char pode ser o resultado da injeção de um carvão pulverizado com uma combustibilidade inadequada e de uma operação instável do AF. Portanto, conhecer a proporção de char que sai do AF contribuirá na seleção do tipo de carvão utilizado e na otimização da prática de PCI. Análises químicas das amostras de pó do AF revelam, sem distinguir, a presença de materiais carbonosos. A microscopia ótica foi utilizada para estudar estas amostras sólidas, mas apresenta certas limitações. A difração de raios-X (DRX) é uma técnica padrão para caracterizar a estrutura cristalina dos materiais. Ela também pode ser utilizada para quantificar as dimensões dos cristalitos (Lc, La, etc.) dos materiais carbonosos. Uma vez que a estrutura do coque é mais ordenada que a do char, seria possível quantificar a proporção destes materiais nas amostras de pó do AF através da DRX combinada a análises químicas. O objetivo principal deste trabalho foi identificar e quantificar os componentes carbonosos (char e finos de coque) presentes no pó de balão (PB) do AF, por DRX e análise elementar de carbono. O efeito da temperatura sobre a grafitização do coque também foi avaliado, a fim de identificar a possível origem dos finos de coque gerados no AF. Três amostras de PB coletadas de um AF, uma em operação a coque e duas a PCI, foram selecionadas. Os pós foram fracionados e analisados quimicamente. Após, as frações destas amostras foram moídas, desmineralizadas e analisadas por DRX e análise elementar de carbono. Amostras de char produzidas em laboratório e respectivos carvões foram utilizados como padrões para a quantificação. Amostras de coque foram tratadas termicamente a diferentes temperaturas, sendo posteriormente analisadas por DRX. Este estudo mostrou que a DRX pode ser usada como técnica padrão para identificar as estruturas do char e do coque podendo ser utilizada para quantificar a proporção destes materiais carbonosos no pó de balão do AF. Além disto, observou-se que quanto maior a temperatura de tratamento térmico mais ordenada fica a estrutura cristalina do coque. / In a Blast Furnace (BF), Pulverized coal injection (PCI) is the most popular injection technology used worldwide to reduce coke consumption and to increase the productivity. In the last decades the PCI injection rates raised in the most of BFs. One of the problems during the PCI operation in BF is the unburnt char formation. Higher char levels in the BF stack could impact burden permeability. The off gas BF solid samples contain char, coke fines, metallic oxides, etc. The quantification of the carbonaceous materials content in these samples could be used to improve the PCI performance in operating BF. Chemical analysis in the BF dust samples reveal without differentiates some carbonaceous material. The optical microscopy was used to study these solid samples but with some restrictions. XRD (X-ray diffraction) is a standard means of characterizing the structure of materials. This technique has been utilized to determine the crystallite sizes (Lc, La, etc.), in carbonaceous materials. Since the coke structure is more ordered than the char structure, it would be possible to quantify the proportion of these materials in the off-gas BF samples by chemical analysis in combination with XRD. The aim of this work is to identify and quantify carbonaceous components (coal, char and coke fines) in the flue dust BF samples through the use of the XRD technique and ultimate analysis. Besides, the effect of temperature on coke graphitization will be studied aiming to identify the possible origin of coke fines in the BF dust. Four dusts collected in the off-gas BF, two at all coke and two at PCI operations, were selected for this investigation. The dusts were fractioned and chemically analyzed. After the fractions were grounded, demineralized and analyzed by ultimate analysis and XRD. Besides, were investigated the atomic structure of raw coals and its laboratory char, and raw coke and its laboratory heattreated samples. This study has shown that the XRD technique could be used as a standard procedure to identify the char and coke structures and could be used to quantify the fines proportions of these carbonaceous materials in the BF flue dust. It was concluded that the bigger the annealing temperature the more ordered becomes the atomic coke structure.
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A palavra arbitrária: estudo e tradução de Fenêtres dormantes et porte sur le toit, de René CharAlselmi, André Luiz [UNESP] 17 March 2008 (has links) (PDF)
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alselmi_al_me_arafcl.pdf: 284676 bytes, checksum: 9d9251477b103be2a6f980c465fffe58 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / René Char (1907-1988) deu início à sua vida literária no momento de uma estreita ligação com o movimento surrealista, no início da década de 30. No entanto, logo o poeta desligou-se do grupo liderado por Breton, engajou-se na Resistência Francesa e trilhou um caminho próprio que o levou a produzir uma poesia única, marcada pela associação de técnicas surrealistas a um certo rigor formal, dois elementos aparentemente opostos, mas cuja união produziu textos de intenso efeito poético. Char deixou uma vasta produção poética, ainda pouco estudada (sobretudo no Brasil), fato que se deve à difícil compreensão da obra do poeta, considerada muito hermética. Entretanto, ela tem despertado cada vez mais o interesse da crítica e, pouco a pouco, vem conquistando o espaço merecido: começa a transpor os limites territoriais e lingüísticos, fazendo-se conhecida e acolhida pelos espíritos agraciados pela receptividade e empenho na decifração de mensagens poéticas. Esta pesquisa tem como objetivo o estudo da estética de René Char acompanhado da tradução comentada de Fenêtres dormantes et porte sur le toit e da análise das dificuldades encontradas durante a prática tradutória. A análise da obra centra-se no estudo de questões estilísticas, formais, bem como na herança surrealista presente na obra do poeta. A pesquisa desenvolveu-se em duas grandes frentes de estudo que deram os subsídios para o trabalho de tradução. A primeira delas centrou-se no estudo de textos sobre teoria da poesia, sobre história literária do século XX e sobre a obra de René Char. A segunda etapa centrou-se no estudo teórico da tradução, possibilitando um aprofundamento das principais questões envolvidas no ato de traduzir tanto no seu aspecto teórico quanto prático. / René Char (1907-1988) began his literary life at the time of close liaison with the surrealist movement at the beginning of the 30’s. However, once the poet is disconnected from the group led by Breton, engaged in the French Resistance and decided to work by his own, which made him produce a singular poetry, marked by the association of surrealistic techniques and formal traces – two opposite elements, whose mixture produced texts of intense poetic effect. Char left a huge poetic work, yet little studied (especially in Brazil) a fact which is due to the difficulty of understanding his work, considered very hermetic. Neverthless, his work has increasingly aroused the interest of the critical and, little by little, has been conquering the space deserved: it begins to cross the boundaries and language, making itself known and accepted by the spirits given by the receptiveness and commitment to the deciphering of the poetic messages. This research aims at studying the esthetics of René Char by the commented translation of Fenêtres dormantes et porte sur le toit and analysis of the difficulties faced during the translation work. The analysis of this book focuses on the study of the esthetic and formal issues and on the surreal legacy in the poet’s work. The survey was developed in two main fronts of study that allowed the translation work. The first one focused on the study of texts on the theory of poetry, literary history in the twentieth century and René Char’s work. The second one focused on the translation theory, what made possible a deeper knowledge about the main questions concerned with the translation act, both theoretical and practical. At the end of this work, we not only demonstrate the importance of Char as one of the most significant poets of the twentieth century, but also open the possibility of presenting to the Brazilian reader an author still little known and poorly translated.
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