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<b>Synthesis and characterization of soybean oil derivatives for metalworking lubricants and gear oils</b>Elena A Robles Molina (9751112) 02 August 2024 (has links)
<p dir="ltr">Vegetable oils are a fundamental part of human civilization. Beyond their nutritional value and functional implementation in food applications, their triglyceride structure facilitates their implementation as industrial inputs. Furthermore, applications such as metal gear fluids and gear oil represent a valuable market due to their environmental impact and widespread application. Soybean oil is one of the most produced oilseeds in the U.S., and recently, novel oil varieties such as high oleic soybean oil (HOSBO) tackle drawbacks in the use of vegetable oil such as the heterogeneous fatty acid composition by increasing the concentration of oleic acid. This dissertation evaluates the successful implementation of HOSBO and SBO as lubricant and gear oils through epoxy ring opening reactions for synthesizing polyols and estolides. Epoxidation of double bonds in unsaturated fatty acids creates reaction sites for the branching of fatty acids in estolides or hydroxylated moieties in the case of polyols. The difference in fatty acid composition is shown in terms of thermomechanical characteristics. HOSBO polyols and estolides are solid to semi-solid greases with high viscosities and SAE grades as gear oils from 85W up. In contrast, SBO-derived oils have lower viscosities and a larger viscosity index.</p><p dir="ltr">The second part of this research focuses on the kinetics of the hydroxylation defined by distinctive fatty acid compositions. The sites of reaction in the double bonds can be, in part, sterically hindered by the glycerol backbone. Thus, this chapter focuses on the influence of the reaction rates given the fatty acid composition of the oil. Consumption of epoxide groups in HOSBO and SBO was modeled under pseudo-first-order kinetics. The results highlight the benefit of using HOSBO with reaction rates at least 30% faster than SBO. Furthermore, the progress of the reaction was monitored by FTIR, which highlighted the formation of ether groups corresponding to the addition of 1-propanol branches. However, further optimization steps must focus on the controlled removal of water in order to prevent the esterification of the oil and the resulting increase of free fatty <a href="" target="_blank">acids</a><a href="#_msocom_1" target="_blank">[EAS1]</a> .</p><p dir="ltr"><a href="#_msoanchor_1" target="_blank">[EAS1]</a>Seems to end abruptly</p><p><br></p>
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Chemische und physikalische Verfahren zur Inaktivierung von pathogenen Mikroorganismen in allogenen KnochentransplantatenPruß, Axel 12 November 2004 (has links)
In allogeneic bone transplantation, the transmission of viral and non-viral infectious pathogens is the most severe undesirable concomitant phenomenon. The investigations published were examined regarding the inactivating capacity of inactivation procedures that are presently performed in bone banks (peracetic acid/ethanol, gamma irradiation, moist heat) against clinically relevant pathogens (aiming at a virus titer reduction of at least 4 log10 TCID50/ml or titer reduction of non-viral micro-organisms of at least 5 log10 cfu/ml). In the suspension experiments, treatment with peracetic acid/ethanol (peracetic acid 2%, ethanol 96%, aqua ad iniectabilia 2:1:1, 4 hours, 200 mbar, agitation) achieved a titer reduction of > 4 log10 already after 5 minutes for a number of viruses (PSR, PV, BVDV). HIV-2 was also inactivated within 5 minutes below the level of detection ( 4 log10 TCID50/ml was only reached after 4 hours. The results mentioned could be confirmed in the carrier test (contaminated spongiosa cuboids used as ‘worst case’ scenario). In the suspension experiment as well as in the carrier test, the HAV titer was reduced after 4 hours by only 3.7 log10 and 2.87 log10, respectively. The preceding step of defatting the spongiosa tissue by chloroform/ethanol was validated using cell-associated HAV and showed an HAV titer reduction of 7 log10. In the investigations regarding non-viral pathogens, all test organisms were completely inactivated by more than 5 log 10 steps (cfu/ml). Gamma irradiation was the second procedure examined. D10 values (irradiation dose required to reduce 90% of the pathogen titers by one log10 step) that were determined in inactivation kinetics experiments (irradiation conditions: –30°C, 60Co source) corresponded to data published so far. In order to provide for maximal safety, an irradiation dose of 34 kGy was recommended for allogeneic bone transplants using BPV and a diaphysis model from human femurs. The ‘Marburg bone bank system’ was the third procedure examined (thermal disinfection, guaranteed temperature of at least 82.5°C for a minimum of 15 min) using centrally contaminated human femoral heads. All viruses were completely inactivated and their titer reduced by more than 4 log10 steps. Vegetative bacteria and fungi were also completely inactivated (>= 6 log10 in the supernatant). As expected, spores and spore-forming pathogens were not sufficiently inactivated and not inactivated, respectively (titer reduction of less than 2 log10 cfu/ml). However, the latter group can be disregarded, since femoral heads are procured in the operation room under sterile conditions and the following production process rules out a secondary contamination with spores. It could be shown in the investigations presented that all three procedures examined guarantee an inactivation of the viruses investigated according to the recommendations by the senior federal authorities. The three treatment procedures offer additional biosafety by a comprehensive inactivation of non-viral pathogens.
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O impacto de reúso de dialisadores nos marcadores de estresse oxidativo e inflamatórios em pacientes em hemodiálise / Evaluation of oxidative stress and inflamatory markers on hemodialysis patients with and without dialysers reuseFurlan, Carla Barbosa Muraro 27 March 2014 (has links)
A morbimortalidade dos pacientes em hemodiálise permanece alta apesar da evolução tecnológica do procedimento, sendo que os eventos cardiovasculares são a sua principal causa. Estes desencadeados pela alta prevalência de fatores de risco tradicionais, fatores relacionados ao procedimento dialítico e estresse oxidativo. Considerando o procedimento dialítico e o estresse oxidativo, foi avaliado o quanto a habitual prática de reuso de dialisadores/RD (difundida nas Américas e amparada principalmente por questões econômicas) e uso único de dialisadores, influenciam nos marcadores inflamatórios e de estresse oxidativo. Para isto, foram utilizados como marcadores laboratoriais as medidas de PCR ultrassensível (u PCR), interleucina 6 (IL6), a determinação de substâncias reativas ao ácido tiobarbitúrico (TBARS), superóxido dismutase (SOD), glutationa (GSH) e albumina, em 29 pacientes em tratamento de hemodiálise. Estes pacientes encontravam-se em tratamento com dialisadores de alto fluxo do tipo polieterssulfona e reuso manual, e ao iniciar este estudo foram programados 3 ciclos sequenciais com duração de 6 semanas com as seguintes características: primeiro ciclo (uso único de dialisadores;); segundo ciclo (reuso de dialisadores); terceiro ciclo (reuso de dialisadores e administração de N-acetilcisteína/NAC, na dose de 1200 mg/dia). Foram coletadas amostras de sangue de cada paciente no início e final da última sessão de hemodiálise anteriormente ao início dos ciclos (denominado Período 1) e no início e final da última sessão de hemodiálise de cada ciclo (denominados Períodos 2, 3 e 4 respectivamente). O TBARS aumentou no período de uso único. Todas as demais variáveis não apresentaram diferença significativa. Os resultados indicaram que o RD pode proporcionar uma melhora no estresse oxidativo. O uso único foi associado com maior estresse oxidativo. Não foi encontrado nenhum benefício adicional com NAC / The morbidity and mortality of patients undergoing hemodialysis remains high despite the technological development of this procedure, and cardiovascular events are the main causes of morbidity and mortality. These cardiovascular events are triggered by the high prevalence of traditional risk factors, factors associated with dialysis procedures, and oxidative stress. Considering the factors associated with dialysis procedures and oxidative stress, we assessed how dialyzer reuse (DR; widespread in the Americas, especially because of economic issues) and use of single-use dialyzers influence oxidative stress and inflammatory markers. We used ultrasensitive PCR (u-PCR) to measure levels of the laboratory markers interleukin-6 (IL6), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), glutathione (GSH), and albumin in 29 patients undergoing hemodialysis treatment. These patients were receiving treatment with polyethersulfone high-flux dialyzers and manual reuse. In the initial phase of this study, the 3 following sequential cycles, each lasting 6 weeks, were scheduled: first cycle (single-use dialyzers); second cycle (DR); and third cycle (DR and administration of N-acetylcysteine [NAC] at a dose of 1200 mg/day). Blood samples were collected from each patient at the beginning and end of the last hemodialysis session that preceded the start of the cycles (termed Period 1), and at the beginning and end of the last hemodialysis session of each cycle (termed Periods 2, 3, and 4, respectively). The levels of TBARS increased during the single-use period. The remaining variables did not show significant differences. The results indicated that DR may ameliorate oxidative stress. Single-use dialyzers were associated with higher oxidative stress. No additional benefit was found with use of NAC
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Eliminación del Biofouling en intercambiadores de calor-condensadores que minimicen el impacto ambiental en el medio marinoRío Calonge, Belén 28 September 1999 (has links)
La presente tesis doctoral tiene por objeto tratar de eliminar el fenómeno no deseable de formación de biofouling en diferentes superficies tubulares de intercambiadores de calor, mediante tratamientos físicos y químicos, intentando minimizar el impacto ambiental creado en los efluentes de las instalaciones industriales.El equipo experimental está compuesto por una planta piloto de intercambiadores de calor condensadores dotada de ocho tubos que funcionan como sistemas independientes, donde se controlan los parámetros de presión, temperatura y caudal, que define indirectamente el biofouling depositado en el interior de dichos tubos a través de los valores de resistencia friccional al flujo y resistencia a la transferencia de calor.También ha sido diseñado y construido otra planta piloto o monitor "MCMDID" (monitor combinado de medición directa e indirecta del biofouling) donde se mide en continuo el espesor del biofouling adherido a la superficie de un tubo del mismo material que los ensayados en la planta descrita anteriormente.
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EFEITO DA IMERSÃO PERIÓDICA EM SOLUÇÕES LIMPADORAS NA RUGOSIDADE SUPERFICIAL, PORCENTAGEM DE VARIAÇÃO DE MASSA E RESISTÊNCIA FLEXURAL DE LIGAS DE COBALTO-CROMO / Co-Cr ALLOY IMMERSION IN CLEANING SOLUTIONS: EFFECTS ON FLEXURAL STRENGTH, SURFACE ROUGHNESS AND PERCENTUAL OF VARIATION OF MASSBorsa, Pedro Carlos Cortiana 22 August 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to evaluate the flexural strength, elastic modulus,
mass changes and surface roughness of two cobalt-chromium alloys, before and
after immersions in four cleaning solutions and distilled water (as control). Co-Cr
alloys (Co-Cr®, Dentsply-DeguDent Industria e Comércio, São Paulo, Brasil; and GM
800+®, Dentaurum GmbH & Co KG, Ispringen, Alemanha) were investigated. Fifty
bar specimens (25 x 3 x 0,5 mm) for the flexural test, 50 quadrangular specimens
(10 x 10 x 1 mm) for mass changes evaluation and 35 cylindrical specimens (10 x 1
mm) for surface roughness measurements were obtained by casting. They were
polished by abrasive paper (#240 to #2500) and diamond polishing paste (3μm).
Specimens were randomly divided into 5 groups according the following cleaning,
solutions: pure white vinegar, 0.2% peracetic acid, sodium perborate - Corega
Tabs®, 0.37% sodium hypochlorite and the control, distilled water. Surface
roughness (Ra parameter) was analyzed using a profilometer (Mitutoyo SJ 410,
Mitutoyo Corp, Kanagawa, Japan) before and after 5, 20 e 90 immersions (10 min
each). Ra changes (ΔRa5, ΔRa20 e ΔRa90) were calculated for the different
intervals. Qualitative surface analyses were performed by Scanning Electron
Microscope (JSM 6360 SEM, JEOL). Both alloys, immersed in pure white vinegar,
0.2% peracetic acid, sodium perborate - Corega Tabs®, 0.37% sodium hypochlorite
had similar roughness changes after 90 immersions (ΔRa from -0,012 to 0,022 μm).
There was a significant surface roughening in hypochlorite (ΔRa90= 0,064 μm for
CoCr®; and ΔRa90 = 0,592 μm for GM 800+). The number of immersions influenced
on the roughness changes only in hypochlorite and there were greater changes in
the GM 800+ alloy. After 90 immersions, GM 800+ alloy showed mass lost in the
hypochlorite solution (-0,3%). This alloy presented higher flexural strength after 90
immersions in SH (σF= 1516 MPa in hypochlorite; 1366 MPa in control). However,
there were no elastic modulus changes. CoCr® alloy did not present differences in
the σF or in elastic modulus in any solution. The only solution that damaged the alloy
surface was 0.37% sodium hypochlorite. / O objetivo deste trabalho foi avaliar a rugosidade superficial,o percentual de variação
de massa, a resistência flexural e o módulo de elasticidade de duas ligas de Cobalto-Cromo
após submetidas à imersões em quatro soluções limpadoras e água (controle). Foram
utilizadas as ligas Co-Cr® DeguDent (Dentsply-DeguDent Industria e Comércio, São
Paulo, Brasil) e Remanium® GM 800+ (Dentaurum GmbH & Co KG, Ispringen, Alemanha).
De cada liga fundiu-se cinquenta corpos de prova, 50 cilíndricos (10 x 1 mm) para a análise
da rugosidade, 50 quadrangulares (10 x 10 x 1 mm) para avaliação da variação de massa e
em formato retangular (25 x 2,5 x 0,75 mm) para o teste flexão 3 pontos. O polimento se deu
por seqüencia de lixas (#400 a 2500) e pasta diamantada (3μm). A distribuição aleatória foi
em 5 grupos, conforme os agentes de limpeza: vinagre branco puro, ácido peracético 0,2% ,
perborato de sódio (Corega Tabs®), hipoclorito de sódio 0,37% e o controle: água destilada.
Foram realizadas avaliações da rugosidade superficial (Parâmetro Ra) através de
rugosímetro (Mitutoyo SJ 410, Mitutoyo Corp, Kanagawa, Japan) antes e após 5, 20 e 90
ciclos de imersão de 10 minutos. As alterações de Ra (ΔRa5, ΔRa20 e ΔRa90) foram
calculadas entre os diferentes interrupções. Análise complementar da superfície foi realizada
em imagens obtidas por microscopia eletrônica de varredura (JSM 6360 SEM, JEOL Ltd.,
Tokyo, Japan). A pesagens dos corpos de prova para cálculo da variação de massa se deu
após 5 e 90 imersões, utilizando-se de balança eletrônica analítica com sensibilidade de
0,0001 g (FA 2004, Coleman E. P. L. Com. e Imp. Ltda. Santo André, São Paulo). Os
ensaios de flexão a 3 pontos para determinação da resistência flexural (σF) e do módulo de
elasticidade foram realizados após 90 imersões. Os dados obtitos foram analisados quanto
a normalidade e testes de comparação entre médias foram aplicados conforme o tipo de
distribuição. As duas ligas, imersas nas soluções vinagre puro, ácido peracético, corega
tabs® apresentaram comportamento semelhante em relação as alterações de rugosidade
superficial (Ra), quando comparadas ao controle, após 90 imersões (ΔRa entre -0,012 e
0,022 μm). Aumento da rugosidade significativo ocorreu na solução de hipoclorito (ΔRa90=
0,064 μm (CoCr®) e 0,592 μm (GM 800+). O número de imersões influenciou na variação de
rugosidade, apenas para a solução de hipoclorito, sendo que as maiores variações
ocorreram na liga GM 800+. Após 90 imersões a liga GM 800+ demonstrou perda de massa
na solução de hipoclorito (-0,3%). Ocorrendo para essa liga aumento da resistência flexural
(σF= 1516 MPa em hipoclorito; 1366 MPa no controle) após 90 imersões, sem modificação
de seu módulo de elasticidade. A liga CoCr® não apresentou diferenças na σF ou no
módulo de elasticidade nas diferentes soluções. A única solução que causou dano à
superfície das ligas foi o hipoclorito de sódio 0,37%.
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O impacto de reúso de dialisadores nos marcadores de estresse oxidativo e inflamatórios em pacientes em hemodiálise / Evaluation of oxidative stress and inflamatory markers on hemodialysis patients with and without dialysers reuseCarla Barbosa Muraro Furlan 27 March 2014 (has links)
A morbimortalidade dos pacientes em hemodiálise permanece alta apesar da evolução tecnológica do procedimento, sendo que os eventos cardiovasculares são a sua principal causa. Estes desencadeados pela alta prevalência de fatores de risco tradicionais, fatores relacionados ao procedimento dialítico e estresse oxidativo. Considerando o procedimento dialítico e o estresse oxidativo, foi avaliado o quanto a habitual prática de reuso de dialisadores/RD (difundida nas Américas e amparada principalmente por questões econômicas) e uso único de dialisadores, influenciam nos marcadores inflamatórios e de estresse oxidativo. Para isto, foram utilizados como marcadores laboratoriais as medidas de PCR ultrassensível (u PCR), interleucina 6 (IL6), a determinação de substâncias reativas ao ácido tiobarbitúrico (TBARS), superóxido dismutase (SOD), glutationa (GSH) e albumina, em 29 pacientes em tratamento de hemodiálise. Estes pacientes encontravam-se em tratamento com dialisadores de alto fluxo do tipo polieterssulfona e reuso manual, e ao iniciar este estudo foram programados 3 ciclos sequenciais com duração de 6 semanas com as seguintes características: primeiro ciclo (uso único de dialisadores;); segundo ciclo (reuso de dialisadores); terceiro ciclo (reuso de dialisadores e administração de N-acetilcisteína/NAC, na dose de 1200 mg/dia). Foram coletadas amostras de sangue de cada paciente no início e final da última sessão de hemodiálise anteriormente ao início dos ciclos (denominado Período 1) e no início e final da última sessão de hemodiálise de cada ciclo (denominados Períodos 2, 3 e 4 respectivamente). O TBARS aumentou no período de uso único. Todas as demais variáveis não apresentaram diferença significativa. Os resultados indicaram que o RD pode proporcionar uma melhora no estresse oxidativo. O uso único foi associado com maior estresse oxidativo. Não foi encontrado nenhum benefício adicional com NAC / The morbidity and mortality of patients undergoing hemodialysis remains high despite the technological development of this procedure, and cardiovascular events are the main causes of morbidity and mortality. These cardiovascular events are triggered by the high prevalence of traditional risk factors, factors associated with dialysis procedures, and oxidative stress. Considering the factors associated with dialysis procedures and oxidative stress, we assessed how dialyzer reuse (DR; widespread in the Americas, especially because of economic issues) and use of single-use dialyzers influence oxidative stress and inflammatory markers. We used ultrasensitive PCR (u-PCR) to measure levels of the laboratory markers interleukin-6 (IL6), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), glutathione (GSH), and albumin in 29 patients undergoing hemodialysis treatment. These patients were receiving treatment with polyethersulfone high-flux dialyzers and manual reuse. In the initial phase of this study, the 3 following sequential cycles, each lasting 6 weeks, were scheduled: first cycle (single-use dialyzers); second cycle (DR); and third cycle (DR and administration of N-acetylcysteine [NAC] at a dose of 1200 mg/day). Blood samples were collected from each patient at the beginning and end of the last hemodialysis session that preceded the start of the cycles (termed Period 1), and at the beginning and end of the last hemodialysis session of each cycle (termed Periods 2, 3, and 4, respectively). The levels of TBARS increased during the single-use period. The remaining variables did not show significant differences. The results indicated that DR may ameliorate oxidative stress. Single-use dialyzers were associated with higher oxidative stress. No additional benefit was found with use of NAC
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New adsorption and oxidation-based approaches for water and wastewater treatment:studies regarding organic peracids, boiler-water treatment, and geopolymersLuukkonen, T. (Tero) 12 January 2016 (has links)
Abstract
This thesis examines three different areas of water treatment technology: the application of organic peracids in wastewater treatment; the removal of organic residues from boiler make-up water; and the use of geopolymers as sorbents.
The main advantages of peracids as alternative wastewater disinfectants are their effective antimicrobial properties and high oxidation power, as well the absence of harmful disinfection by-products after their use. Performic, peracetic and perpropionic acids were compared in laboratory-scale disinfection, oxidation and corrosion experiments. From the techno-economical point of view, performic acid proved to be the most effective disinfectant against E. coli and fecal enterococci. However, in the bisphenol-A oxidation experiments, no advantages compared to hydrogen peroxide use were observed. It was also determined that corrosion rates on stainless steel 316L were negligible, while carbon steel seemed unsuitable in terms of corrosion for use with peracids even in low concentrations.
Organic compounds in the boiler plant water-steam cycle thermally decompose and form potentially corrosive species. Activated carbon filtration was confirmed to be a suitable method for the removal of organic residue from deionized boiler make-up water. No significant differences in terms of treatment efficiency between commercial activated carbons were observed. However, acid washing as a pre-treatment reduced the leaching of impurities from new carbon beds. Nevertheless, a mixed-bed ion exchanger was required to remove leached impurities, such as silica and sodium.
Geopolymers, or amorphous analogues of zeolites, can be used as sorbents in the treatment of wastewater. Metakaolin and blast-furnace-slag geopolymers showed positive potential in the treatment of landfill leachate (NH4+ ) and mine effluent (Ni, As, Sb). / Tiivistelmä
Tämä väitöskirja käsittelee kolmea erillistä vedenkäsittelyteknologian osa-aluetta: orgaanisten perhappojen käyttöä jäteveden käsittelyssä, orgaanisten jäämien poistoa suolavapaasta kattilalaitoksen lisävedestä ja geopolymeerien sovelluksia vedenkäsittelysorbentteina.
Orgaanisten perhappojen pääasialliset edut verrattuna kilpaileviin tekniikoihin ovat hyvä desinfiointiteho, korkea hapetuspotentiaali ja desinfioinnin sivutuotteiden muodostumattomuus. Permuurahais-, peretikka- ja perpropaanihapon vertailu osoitti permuurahaishapon olevan kemikaaleista tehokkain E. coli - ja enterokokkibakteerien inaktivoinnissa kustannus- ja teknisistä näkökulmista. Hapetuksessa, jossa käytettiin bisfenoli-A:ta malliaineena, ei kuitenkaan havaittu etua verrattuna edullisempaan vetyperoksidiin. Ruostumattoman teräksen (316L) pinnalla ei havaittu merkittävää korroosiota, kun taas hiiliteräs ei sovellu käytettäväksi perhappojen kanssa.
Orgaaniset jäämät kattilalaitoksen vesi-höyrykierrossa hajoavat termisesti pienen moolimassan hapoiksi ja aiheuttavat korroosioriskin. Aktiivihiilisuodatuksen todettiin olevan soveltuva menetelmä orgaanisten jäämien poistoon lisävedestä. Aktiivihiililaatujen välillä ei havaittu merkittäviä eroja, mutta happopesu aktiivihiilen esikäsittelynä vähensi hiilestä liukenevien epäpuhtauksien määrää.
Geopolymeerit ovat zeoliittien amorfisia analogeja ja niiden ioninvaihtokykyä voidaan hyödyntää vedenkäsittelysovelluksissa. Metakaoliini- ja masuunikuonapohjaisten geopolymeerien todettiin olevan lupaavia materiaaleja malliliuosten, kaatopaikan suotoveden ja kaivoksen purkuveden käsittelyssä poistettaessa ammoniumia, nikkeliä, arseenia ja antimonia.
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