A viscoelasticidade do pulmão do mamífero é determinada principalmente pelas propriedades mecânicas, estrutura e regulação do músculo liso das vias aéreas. A exposição ao ar poluído pode deteriorar essas propriedades com consequências danosas à saúde individual. O formaldeído é um importante poluente presente em ambientes internos que adentra o músculo liso formando ligações covalentes entre proteínas da matriz extracelular e da estrutura intracelular deteriorando algumas funções do músculo liso das vias aéreas, alterando propriedades mecânicas e induzindo a hiperresponsividade. O primeiro objetivo desse trabalho foi desenvolver um modelo de rede viscoelástica bidimensional baseada na tesselação de Voronoi para reproduzir algumas propriedades mecânicas do músculo liso de via aérea a nível de tecido. O segundo objetivo foi comparar os resultados obtidos com o nosso modelo com aqueles previamente observados em experimentos com tiras de tecido após a exposição ao formaldeído. Nosso modelo simula as propriedades mecânicas do músculo liso de via aérea usando um conjunto de molas e amortecedores. Esse conjunto de molas e amortecedores não somente mimetiza as propriedades viscoeláticas do músculo liso mas também o aparato contrátil das células. Nós hipotetizamos que a formação de ligações covalentes, devido à ação do formaldeído, pode ser representada no modelo por uma alteração simples na constante elástica das molas, enquanto que a ação da metacolina reduz o tamanho da mola. Nosso modelo é hábil para reproduzir uma medida de força isométrica onde o músculo liso é sujeito a um agente contrátil, com e sem exposição in vitro ao formaldeído. Assim, a nossa nova abordagem mecanicista incorpora diversas propriedades bem conhecidas do sistema contrátil das células em um tecido a nível de modelo. O modelo pode também ser usado em diferentes escalas biológicas / The viscoelastic properties of the mammalian lung is mainly determined by the mechanical properties, structure and regulation of the airways smooth muscle. The exposure to polluted air may deteriorate these properties with harmful consequences to individual health. Formaldehyde is an important indoor pollutant that permeate through the smooth muscle tissue forming covalent bonds between proteins in the extracellular matrix and intracellular protein structure deteriorating some of the airways smooth muscle functions, changing mechanical properties, and inducing hyperresponsiveness. The first objectives of this work was to develop a two-dimensional viscoelastic network model based on Voronoi tessellation to reproduce some of the mechanical properties of airway smooth muscle at the tissue level. The second objective was to compare the results obtained with our model with those previously observed in tissue strip experiments after the tissue exposure to formaldehyde. Our model simulates the mechanical properties of airway smooth muscle using a set of springs and dashpot. This set of springs and dashpot not only mimic the viscoelastic properties of the smooth muscle but also the cells contractile apparatus. We hypothesize that the formation of covalent bonds, due to the action formaldehyde, can be represented in the model by a simple change in the elastic constant of the springs, while the action of methacholine reduce the size of the spring. Our model is able to reproduce an isometric force measurement, where the smooth muscle is subjected to a titration of a contractile agent, with and without an in vitro exposure to formaldehyde. Thus, our new mechanistic approaches incorporates several well know features of the contractile system of the cells in a tissue level model. The model can also be used in different biological scales

Resíduos de formaldeído são descarregados de diversas formas no ambiente, resultantes de muitos processos industriais, e de seu uso como conservantes. A pesquisa por tecnologias adequadas para o tratamento de formaldeído aponta processos físico-químicos e biológicos, com atenção especial para os processos anaeróbios por constituírem sistemas compactos e de baixo consumo energético. No entanto, algumas lacunas presentes na pesquisa sobre tratamento anaeróbio de formaldeído e alguns pontos de discordância devem ser esclarecidos. Em muitos casos, esses resíduos são descartados de forma intermitente, motivando a opção por processos em batelada. Nesse contexto, o presente estudo avaliou a degradação de formaldeído em reator anaeróbio operado em bateladas seqüenciais, contendo biomassa imobilizada em espuma de poliuretano. O desempenho do reator foi monitorado para várias concentrações afluentes de formaldeído, variando de 31,6 a 1104,4 mg/L. Os resultados obtidos indicaram excelente estabilidade do reator e eficiência de remoção de formaldeído acima de 99%. Entretanto foi constatado acúmulo de matéria orgânica no efluente devido à presença de ácidos orgânicos, principalmente acético e propiônico. Essa constatação levanta um questionamento importante sobre a rota anaeróbia de degradação do formaldeído, que pode diferir substancialmente do que foi registrado na literatura. Os ácidos gerados não foram degradados pela biomassa exposta ao formaldeído, contudo poderiam ser facilmente removidos com a utilização de um reator em série com inoculo adaptado à remoção de ácidos orgânicos. / Formaldehyde residues are discharged into the environment in several different ways, as a result of several industrial processes, as well as its use as a preservative. Research for suitable technologies for treatment of formaldehyde points to physical-chemical and biological processes, with special attention to anaerobic processes, once they represent compact systems with low energy requirements. Nevertheless, some blank spaces still remaining in the research regarding anaerobic treatment of formaldehyde must be filled, and some points of disagreement must be clarified. In several cases, formaldehyde residues are discharged intermittently, favoring the choice of batch processes. In this context, the present study evaluated the degradation of formaldehyde in an anaerobic sequencing batch reactor, containing biomass immobilized in polyurethane foam matrices. Reactor performance was monitored for different influent formaldehyde concentrations, ranging from 31.6 to 1104.4 mg/L. Results obtained indicate excellent reactor stability and efficiency in formaldehyde removal above 99%. However, accumulation of organic matter was observed in the effluent, due to presence of non-degraded organic acids, especially acetic and propionic. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in literature. The degradation of the generated products could occur in another reactor in serie containing biomass adapted to organic acids removal.

Orientador: Wagner dos Santos Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T09:30:52Z (GMT). No. of bitstreams: 1 Lucchini_CarlosEduardo_M.pdf: 5504371 bytes, checksum: d489cf9f3064f2f4afae8674e395758a (MD5) Previous issue date: 2008 / Resumo: Neste trabalho analisa-se de modo particular a resina fenol formaldeído para se obter uma redução do tempo de processamento nas condições de processo, além de melhorar as características de aplicação da resina em estudo. O trabalho se concentra principalmente na etapa de refluxo, onde ocorre a metilação do polímero. Faz-se a comparação da condução da reação da resina fenólica na etapa de refluxo, logo após a etapa exotérmica. Para o estudo considerou-se uma primeira fase, estando o reator aberto para a atmosfera, através do condensador e numa segunda etapa, mantendo reator fechado, obtendo a pressão de equilíbrio em 3 x104 N/m2. Os resultados mostram que é possível uma redução de aproximadamente meia hora estando o reator fechado durante a fase de refluxo, mantendo a pressão em 3 x104 N/m2. / Abstract: This study analyzes a phenol formaldehyde resin and to develop it in order to reach a time reduction in the cycle time and, in second plane, to evaluate if it improves the resin characteristics in the application. The study concentrated on the condensation step, where the formation of the chain of polymer occurs. The comparison between the reaction of the phenolic resin with the reactor opened to the atmosphere through the condenser during the reflux step and that same reaction with the vent closed to the atmosphere right after the exothermal phase, also in the reflux step. The results show that a reduction of approximately half an hour is possible when the reactor is closed during the reflux step, keeping the pressure in 3x104N/m2. / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química

Orientadores: Edson Aparecido Abdul Nour, Angela dos Santos Barretto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-18T23:01:38Z (GMT). No. of bitstreams: 1 Santos_EloisaMariadosReisdos_M.pdf: 6258003 bytes, checksum: b7f23780de2803fe78e2f875075800dd (MD5) Previous issue date: 2011 / Resumo: O presente estudo teve como objetivo avaliar a eficiência na redução da concentração de formaldeído do efluente de um sistema de tratamento combinado: filtro anaeróbio (FA), seguido de biofiltro aerado submerso (BAS) e decantador, por meio de testes de toxicidade utilizando as espécies Pseudokirchneriella subcapitata, Daphnia similis, Poecilia reticulata e Girardia tigrina. O experimento foi desenvolvido nas dependências do Laboratório de Saneamento da FEC/UNICAMP. Os 3 pontos de coleta foram: efluente bruto mais formaldeído, saída do FA e saída do decantador, correspondendo ao efluente tratado pelo sistema. O estudo foi dividido em quatro fases diferenciadas pela concentração teórica de formaldeído aplicada: Fase 1 (F1) - 100 mg L-1, Fase 2 (F2) - 200 mg L-1, Fase 3 (F3) - 400 mg L-1 e Fase 4 (F4) - 500 mg L-1. A água residuária que foi utilizada neste estudo apresentava características condizentes às de um esgoto sanitário de média concentração em termos de matéria orgânica. Em cada fase de operação, a concentração média e a porcentagem de redução do formaldeído no efluente tratado pelo sistema foram de 0,1 mg L-1 e 99,9% (F1); 0,1 mg L-1 e 100% (F2); 0,7 mg L-1 e 99,8% (F3) e 3,8 e 99,2% (F4). O valor médio da concentração e da porcentagem de remoção de DQO total para o efluente tratado pelo sistema, durante o período de estudo foi de 53 mg L-1 e 87% (F1), 41 mg L-1 e 93% (F2), 62 mg L-1 e 93% (F3) e 131 mg L-1 e 90% (F4). O efluente do sistema combinado não apresentou toxicidade aguda para D. similis em todas as concentrações teóricas afluentes aplicadas. Na F1 o efluente do sistema apresentou toxicidade aguda pouco significativa para P. subcapitata e P. reticulata; na F2 para G. tigrina e P. reticulata, na F3 para P. subcapitata, P. reticulata; e G. tigrina. Na F4 o efluente foi significativamente tóxico aos organismos: P. subcapitata, P. reticulata e G. tigrina. As espécies estudadas indicaram serem organismos-teste adequados a estudos de toxicidade de esgoto sanitário contendo formaldeído tratado pelo sistema combinado alvo do estudo. Pelos resultados obtidos, o sistema combinado, na configuração utilizada neste estudo, foi considerado adequado à redução da toxicidade para as concentrações de formaldeído presentes, exceto para a concentração de 500 mg L-1, tóxica a três organismos-teste, sendo necessário um período maior de monitoramento para garantir a adaptação da biomassa a fim de reduzir a toxicidade do efluente / Abstract: This study aimed to evaluate the efficiency in reducing formaldehyde concentration in the effluent of a system of combined treatment: anaerobic filter (AF), followed by aerated submerged biofilter (BAS) and decanter through toxicity tests using species Pseudokirchneriella subcapitata, Daphnia similis, Poecilia reticulata and Girardia tigrina. The experiment was developed in the Sanitation Laboratory FEC / UNICAMP. The three collection points were raw effluent more formaldehyde, AF output and output of the decanter, corresponding to the effluent treated by the system. The study was divided into four phases distinguished by the theoretical concentration of formaldehyde applied: Phase 1 (F1) - 100 mg L-1, Phase 2 (F2) - 200 mg L-1, Phase 3 (F3) - 400 mg L-1 and Phase 4 (F4) - 500 mg L-1. The wastewater which was used in this study had characteristics consistent with those of an average concentration of sewage in terms of organic matter. At each stage of operation, the average concentration and percentage reduction of formaldehyde in the effluent treated by the system was 0.1 mg L-1 and 99.9% (F1), 0.1 mg L-1 and 100% (F2) 0 , 7 mg L-1 and 99.8% (F3) and 3.8 and 99.2% (F4). The average concentration and percentage of total COD removal for the treated effluent through the system, Section 3, during the study period was 53 mg L-1 and 87% (F1), 41 mg L-1 and 93% (F2), 62 mg L-1 and 93% (F3) and 131 mg L-1 and 90% (F4). The effluent of the combined system showed no acute toxicity to D. similis in all concentrations applied theoretical tributaries. In F1, F2 and F3, the effluent of the system showed little significant acute toxicity to P. subcapitata, P. reticulata, and G. tigrina. F4 in the effluent was significantly toxic to organisms: P. subcapitata, P. reticulata and G. tigrina. The species indicated that the test organisms suitable for toxicity studies of formaldehyde containing wastewater treated by the combined system of the target study. From the results, the combined system, the configuration used in this study was considered appropriate to reduce the toxicity of formaldehyde concentrations present, except for the concentration of 500 mg L-1, toxic to three test organisms, requiring a longer period of adaptation of the system to reduce effluent toxicity / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Two different research projects were investigated for this thesis, which has consequently been presented in two parts. PART 1 An attempt has been made to improve the high temperature performance of phenol-formaldehyde thermosets by modification of their structure with inorganic phosphate groups. Transesterification of tri-phenyl phosphate with resorcinol has given a resorcinol phosphate resin, which cured with hexamethylenetetramine. A pilot scale batch of this resin has been made and used in high temperature stability studies. Post-cured resorcinol phosphate resin-chrysotile asbestos (30: 70) moulded bars retained 59.5% of their flexural strength after ageing at 523K for 1000 hr in air. Similar phenol-formaldehyde composite bars aged under identical conditions retained only 5.3% of their initial flexural strength. The utility of the resorcinol phosphate resin composite as a commercial product is limited, since the bars had a much lower initial flexural strength (30.85 MNm-2) than the phenol-formaldehyde resin composite bars (108.5 MNm-2). Thermogravimetry and isothermal heating studies have indicated that the degradation of resorcinol phosphate resin was greatly accelerated by chrysotile asbestos, which may catalyse a bond re-organisation process that has been tentatively proposed as a mechanism for the fragmentation of the resin. PART 2 Recently an ionomer dental cement (ASPA), prepared from aqueous poly(acrylic acid) and an ion-leachable aluminosilicate glass, has been developed. The system has been extended by studying other aqueous polymers. The factors influencing the gelation and the properties of the set cements have been examined. Poly(carboxylic acids) with hydrophobic, or no pendant substituents were found to be the most satisfactory polymers for preparing water stable cements. To study the influence of the nature of the cation and polymer structure on the gelation and water stability of ionomer cements, a wide range of metal oxide-polyacid products have been studied. The formation of water stable cements depended markedly on the type of oxide and polyacid employed and appeared to involve factors such as the co-ordination geometry and radius of the cation and the nature of the cation-polyanion bonding in the matrix. A comparison between the water stabilities of ASPA cement and poly(acrylic acid)-CaO, Al2O3, or Al(OH)3 cements has shown that the chemistry of ASPA cement is more complex than has been hitherto reported. Stability constants have been determined for Ca 2+ and Cd 2+ with poly(acrylic acid) and ethyl ethylene-maleic acid copolymer by a potentiometric titration method developed by Gregor and modified by Mandel and Leyte. The stability constants obtained in 1.0M NaNO3 at 298.2 ± 0.2K were: for poly(acrylic acid), with Cat2+, log b1 Ca2+ PAA ~ -3.35 with Cd2+, log Bav Cd2+ PAA = -2.30 for ethylene-maleic acid copolymer, with Cat2+, log b1 CA2+ EMA ~ -4.05 with Cd2+, log Bav Cd2+ EMA = -1.95 The log b1 values probably had little precise meaning, although to a first approximation, log b1 Ca2+ PAA > log b1 Ca2+ EMA The determined stability constants have been used with limited success in predicting the water stabilities of the corresponding metal oxide-polyacid cements.

Formaldehyde is a colorless gas that is found naturally in the environment. It is a popular additive in many consumer products including composite wood products. Composite wood products are engineered wood panels produced from pressing pieces, chips, particles, or fibers of wood together at high temperatures held together with a bonding agent. This bonding agent is often formaldehyde-containing resins that are known to release formaldehyde over time. This is concerning because of the carcinogenic classification of formaldehyde, the wide spread application of composite wood products, and the increasing amount of time spent in the indoor environment. In a controlled 0.53 m3 chamber, a panel of medium density fiberboard (MDF) with a surface area of 4.49 m2 was subjected to multiple temperatures to measure formaldehyde emissions. The panels were allowed to acclimate for 48 hours followed by a 72 hour sample period using passive diffusive monitors at temperatures: 26.1, 29.3, 34.1, and 38.9 °C. The results of the study found a strong relationship (R2 = 0.9954) between the emission rate of formaldehyde from MDF and temperature. The emission rate increased 192% between 26.1 °C and 38.9 °C. The results of the study indicate that as temperature increases, the amount of formaldehyde emitted from a panel of MDF also increases. This results in higher airborne concentrations of formaldehyde in environments where the panels are present.

This thesis studies the development of a new method for photochemical overall water splitting using a small organic shuttle. In Section 2, BiVO4, was studied to determine the CO2 reduction mechanism and how catalytic activity decays. BiVO4 catalysts were capable of producing a maximum of 200 μmol of methanol per gram of catalyst from CO2 in basic media, and later decomposed by BiVO4. The decay of BiVO4¬ was studied by x-ray diffraction and scanning electron microscopy, demonstrating reversible decomposition of BiVO4. BiVO4 is etched, leeching vanadium into solution, while nanoparticles of bismuth oxide are deposited on the surface of BiVO4. In Section 3, ferrocyanide salts, an aqueous, cheap, and abundant photocatalyst was used for the first time to dehydrogenate aqueous formaldehyde selectively into formate and hydrogen. The catalyst is capable of record turnovers and turnover frequencies for formaldehyde dehydrogenation catalysts. A preliminary mechanism was proposed from experimental and computational data.

Dans l’air intérieur, de nombreux composés organiques volatils sont présents, parmi lesquels le formaldéhyde, composé cancérogène. Sa présence dans l’air intérieur s’explique par son utilisation abondante dans les matériaux d’ameublement et de décoration. L’objectif est de concevoir un procédé d’épuration, propre, sûr et capable d’éliminer le formaldéhyde de l’air intérieur. Le choix s’est tourné vers un épurateur d’air autonome. Afin de protéger les utilisateurs, le dispositif doit piéger et dégrader complètement les polluants de l’air sans émettre de sous-produits. L’absorption a été choisie comme méthode de piégeage et la photocatalyse comme technique de dégradation. L’épurateur pilote couplant absorption et photocatalyse a été testé en laboratoire et un modèle a été construit pour prédire son efficacité à dégrader en continu le formaldéhyde. L’épurateur dimensionné pour une situation réelle se révèle avoir un encombrement réduit, compatible avec son installation dans un bureau / In indoor air, many volatile organic compounds are present, including formaldehyde. The presence of this carcinogenic compound in indoor air is due to its abundant use in furniture and decoration materials. The objective of this work is to design a purification device, clean, safe and capable of removing formaldehyde from indoor air. The choice turned to a stand-alone air purifier. To protect users, the device must trap and completely degrade air pollutants without emitting by-products. Absorption was chosen as trapping method and photocatalysis as degradation technique. The cleaner coupling absorption and photocatalysis has been tested in the laboratory and a model was built to predict its efficiency to continuously degrade formaldehyde. The purifier designed for a real situation appears to have a small volume. An efficient, compact, quiet and attractively designed device is an advantage for this air purification solution is accepted and adopted by users

Content: Developing novel tanning agents from renewable biomass is regarded as an effective strategy for sustainable leather industry. In this study, a series of dialdehyde carboxymethyl cellulose (DCMC) were prepared by periodate oxidation of carboxymethyl cellulose (CMC) with varying degrees of substitution (DS: 0.7, 0.9 and 1.2). The structural properties of DCMC were characterized. Size Exclusive Chromatography measurements showed that CMC underwent severe degradation during periodate oxidation, resulting in the decline of weight-average molecular weight from 250,000 g/mol to around 13,000 g/mol. FT-IR analysis illustrated that aldehyde group was successfully introduced into DCMC. The aldehyde group content of DCMC decreased from 8.38 mmol/g to 2.95 mmol/g as the DS rose from 0.7 to 1.2. Interestingly, formaldehyde was found to be produced in DCMC, and its content was 159.4, 151.7 and 38.4 mg/L, respectively when the DS of CMC was 0.7, 0.9 and 1.2, respectively. Further analysis by HPLC found that fructose was formed during oxidative degradation, and was subsequently oxidized to generate formaldehyde. This was in accordance with the fact that higher DS resulted in lower formaldehyde content in DCMC. The whole reaction mechanism is still under investigation at the moment. Tanning trials showed that the shrinkage temperature and thickening rate of DCMC tanned leather decreased as the DS increased. This should be due to the difference in aldehyde content of DCMC. Leather tanned by DCMC-0.7 (DS of CMC was 0.7) had the highest shrinkage temperature of 81°C and thickening rate of 76%. It was noteworthy that the formaldehyde content in DCMC tanned leather was only 0.11-0.40 mg/kg even though DCMC contained a small amount of formaldehyde. In general, we hope the work on dialdehyde tanning agent derived from CMC could provide some essential data for the development of sustainable tanning material and process. Take-Away: 1. Higher degree of substitution (DS) of CMC resulted in lower aldehyde group content of DCMC. 2. The formaldehyde content of DCMC was negatively correlated with DS. 3. The tanning performance of DCMC with lower DS was better.

Thousand of new substances with unknown environmental effect are produced and used daily. Many of them are deliberately or by negligence released and deposited into the environment where they could undergo different transport and degradation mechanisms. They are able to affect different types of organisms, as well as humans. For this reason, the awareness of the problems, associated with pollution of all environmental compartments is growing. The environmental impact of monomer formaldehyde resins, which are produced for commercial use, on the environment were studied in this research. For the purposes of ecotoxicological evaluation samples of melamine-formaldehyde and urea-formaldehyde resin were chosen and three toxicity tests were run: acute test with measurement of inhibition of the mobility of Daphnia magna, the acute test with luminescent bacteria Vibrio fischeri and acute test with measurement of inhibition of oxygen consumption by activated sludge. For more comprehensive assessment of the impact of these substances on the environment, biodegradability was also determined. Both tested substances showed minor hazardous impact to testing organisms and it can be concluded, that these substances should not present a significant risk to the environment.