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61.
62.
Claire Fortenberry Michael Walker Audrey Dang Arun Loka Gauri Date Karolina Cysneiros de Carvalho Glenn Morrison Brent Williams 《Indoor air》2019,29(5):761-779
The air composition and reactivity from outdoor and indoor mixing field campaign was conducted to investigate the impacts of natural ventilation (ie, window opening and closing) on indoor air quality. In this study, a thermal desorption aerosol gas chromatograph (TAG) obtained measurements of indoor particle‐ and gas‐phase semi‐ and intermediately volatile organic compounds both inside and outside a single‐family test home. Together with measurements from a suite of instruments, we use TAG data to evaluate changes in indoor particles and gases at three natural ventilation periods. Positive matrix factorization was performed on TAG and adsorbent tube data to explore five distinct chemical and physical processes occurring in the indoor environment. Outdoor‐to‐indoor transport is observed for sulfate, isoprene epoxydiols, polycyclic aromatic hydrocarbons, and heavy alkanes. Dilution of indoor species is observed for volatile, non‐reactive species including methylcyclohexane and decamethylcyclopentasiloxane. Window opening drives enhanced emissions of semi‐ and intermediately volatile species including TXIB, DEET, diethyl phthalate, and carvone from indoor surfaces. Formation via enhanced oxidation was observed for nonanal and 2‐decanone when outdoor oxidants entered the home. Finally, oxidative depletion of gas‐phase terpenes (eg, limonene and α‐pinene) was anticipated but not observed due to limited measurement resolution and dynamically changing conditions. 相似文献
63.
Valéria T. Crexi Micheli L. Monte Maurício L. Monte Luiz A. A. Pinto 《Journal of the American Oil Chemists' Society》2012,89(2):329-334
The aims of this study were to compare three treatments in the chemical hydrolysis reaction of bleached oil from carp (Cyprinus carpio) heads and to obtain polyunsaturated fatty acid concentrates by urea complexation. The three treatments were carried out
with different oil:ethanol molar ratios. In the treatment with a 1:39 molar ratio, a higher yield of free fatty acids was
found. These fatty acids were submitted to urea complexation (−10 °C for 20 h, and urea–fatty acid ratio of 4.5–1). There
was a 31.4% increase in monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) content and a 75% decrease in saturated
fatty acids (SAF) content. An increase of 85.4% in the EPA + DHA content was found. The non-urea complexing fraction can be
considered a rich source of MUFA and PUFA with a total amount of 88.9%. 相似文献
64.
65.
Cybele Lotti Rogério M.B. Moreno Paulo de S. Gonçalves Satinath Bhattacharya Luiz H.C. Mattoso 《Polymer Engineering and Science》2012,52(1):139-148
Natural rubber (NR) is a biopolymer whose properties depend on the molecular structure of the 1,4‐cis polyisoprene chains, nonrubber constituents, environmental conditions, etc. NR has been characterized by Mooney viscosity, Wallace plasticity, nitrogen content (%N). However, these cannot effectively account for clone's differences. The aim of this work is to use extensional rheology to characterize and differentiate NR samples as for clone type and the season of the year in comparison to the traditional characterizations. Three IAC 300 series and RRIM 600 clones of Hevea brasiliensis tapped between October 2006 (Oct_06) and August 2008 (Aug_08) were investigated. IAC 329 clones showed the least susceptibility to seasonal changes, whereas RRIM 600 was the most influenced. An opposite trend between extensional viscosity (ηE) and %N was established. The former was very sensitive to changes in the molecular structure of NR, being fundamental for monitoring purposes and strategic development of new rubber tree clones. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers 相似文献
66.
Fuzzy frequency response: definition and analysis for uncertain dynamic systems is proposed in this paper. In terms of transfer function, the uncertain dynamic system is partitioned into several linear sub‐models and organized according to Takagi–Sugeno fuzzy representation. The main contribution of this paper is to demonstrate through the proposal of a Theorem that fuzzy frequency response is a boundary in the magnitude and phase Bode plots. Low‐ and high‐frequency analysis of fuzzy dynamic model is obtained by varying the frequency ω from zero to infinity. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
67.
Marcio Schmiele Leandra Zafalon Jaekel Stella Maris Cardoso Patricio Caroline Joy Steel Yoon Kil Chang 《International Journal of Food Science & Technology》2012,47(10):2141-2150
The use of bran and whole grain flour changes dough rheology and causes difficulties in manufacturing bakery products. The aim of this study was to analyse the influence of substituting refined wheat flour (WF) by wheat bran (WB; 5%, 10%, 20%, 30% and 40%) or whole grain wheat flour (WGWF; 10%, 20%, 30%, 40% and 50%) on dough rheological properties and pan bread quality characteristics. The addition of WB and WGWF increased water absorption and resistance to extension and decreased stability, extensibility and peak viscosity. Effects with WB were more pronounced. The presence of WB or WGWF increased crumb moisture content, firmness and hardness and decreased specific volume of pan bread. It is important to set new farinographic and extensographic standards when using WB and WGWF, allowing for a correct correlation between rheology and quality characteristics of bakery products, as the same standards used for WF are not valid. 相似文献
68.
Paula Rúbia Ferreira Rosa Samantha Christine Santos Edson Luiz Silva 《International Journal of Hydrogen Energy》2014
The fermentation of glucose, cheese whey and the mixture of glucose and cheese whey were evaluated in this study from two inocula sources (sludge from a UASB reactor for swine wastewater treatment and poultry slaughterhouse) for hydrogen production in continuous anaerobic fluidized bed reactors (AFBR). For all fermentations, a hydraulic retention time (HRT) of 6 h and a substrate concentration of 5 g COD L−1 were used. In glucose fermentation, the maximum hydrogen yield (HY) was 1.37 mmol H2 g−1 COD. The co-fermentation of the cheese whey and glucose mixture was favorable for the concomitant production of hydrogen and ethanol, with yields of up to 1.7 mmol H2 g−1 COD and 3.45 mol EtOH g−1 COD in AFBR2. The utilization of cheese whey as a sole substrate resulted in an HY of 1.9 mmol H2 g−1 COD. Throughout the study, ethanol fermentation was evident. 相似文献
69.
Ane H. Medeiros Fabiana B. Mingossi Renata O. Dias Flávia P. Franco Renato Vicentini Marcia O. Mello Daniel S. Moura Marcio C. Silva-Filho 《International journal of molecular sciences》2016,17(9)
Sugarcane’s (Saccharum spp.) response to Diatraea saccharalis (F.) (Lepidoptera: (Crambidae) herbivory was investigated using a macroarray spotted with 248 sugarcane Expressed Sequence Tags (ESTs) encoding serine peptidase inhibitors, serine peptidases. and Clp protease system subunits. Our results showed that after nine hours of herbivory, 13 sugarcane genes were upregulated and nine were downregulated. Among the upregulated genes, nine were similar to serine peptidase inhibitors and four were similar to Bowman-Birk Inhibitors (BBIs). Phylogenetic analysis revealed that these sequences belong to a phylogenetic group of sugarcane BBIs that are potentially involved in plant defense against insect predation. The remaining four upregulated genes included serine peptidases and one homolog to the Arabidopsis AAA+ chaperone subunit ClpD, which is a member of the Clp protease system. Among the downregulated genes, five were homologous to serine peptidases and four were homologous to Arabidopsis Clp subunits (three homologous to Clp AAA+ chaperones and one to a ClpP-related ClpR subunit). Although the roles of serine peptidase inhibitors in plant defenses against herbivory have been extensively investigated, the roles of plant serine peptidases and the Clp protease system represent a new and underexplored field of study. The up- and downregulated D. saccharalis genes presented in this study may be candidate genes for the further investigation of the sugarcane response to herbivory. 相似文献
70.
Steferson Luiz Stares Alina Kirilenko Márcio Celso Fredel Peter Greil Lothar Wondraczek Nahum Travitzky 《Advanced Engineering Materials》2013,15(4):230-237
Porous bioactive glass (BaG) structures were manufactured applying novel preceramic paper process. Preceramic papers were produced for aqueous suspensions loaded with different contents of pulp fiber and BaG filler. Pressure loading was applied in order to increase the packing density in the paper sheets. The paper sheets were sintered at 630 °C for 1 h. The porous glass–ceramic specimens were characterized for density, porosity, composition, microstructure, and mechanical properties. A pronounced volumetric shrinkage was observed, but no surface flaws or inhomogeneous areas were detected. The mechanical strength using the ball on three balls test and elastic modulus of sintered specimens vary between 21 and 33 MPa and 0.30–0.85 GPa, respectively. 相似文献