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191.
The modelling of the nitrification process of high-strength ammonium wastewater must be designed to consider it as a two-step reaction with substrate inhibition. Consequently, kinetic and stoichiometric parameters of both steps are required. In this work, the second step in the nitrification process was studied: a biological nitrite oxidation model was formulated, calibrated and validated using only oxygen uptake rate (OUR) measurements. The model included biomass growth and substrate inhibition. First, the biomass yield coefficient for nitrite-oxidising biomass was determined. Then, a respirometric experiment with one nitrite pulse of 500 mg N-NO2− L−1 was performed to estimate the rest of the model parameters. The practical identifiability study showed that the parameters were strongly correlated. Hence, a new experimental design consisting of two consecutive pulses and a delayed third one was designed to improve the parameter identifiability. Both experimental designs were compared using contour plots of the objective function and optimal experimental design criteria for parameter estimation. It was concluded that the parameter identifiability was improved with the new experimental design. Finally, the estimated parameters were validated and the pH effect on the inhibition coefficient was evaluated. 相似文献
192.
Superior thermal conductivity of single-layer graphene 总被引:42,自引:0,他引:42
We report the measurement of the thermal conductivity of a suspended single-layer graphene. The room temperature values of the thermal conductivity in the range approximately (4.84+/-0.44)x10(3) to (5.30+/-0.48)x10(3) W/mK were extracted for a single-layer graphene from the dependence of the Raman G peak frequency on the excitation laser power and independently measured G peak temperature coefficient. The extremely high value of the thermal conductivity suggests that graphene can outperform carbon nanotubes in heat conduction. The superb thermal conduction property of graphene is beneficial for the proposed electronic applications and establishes graphene as an excellent material for thermal management. 相似文献
193.
LeBlanc Vicki R.; Regehr Cheryl; Jelley R. Blake; Barath Irene 《Canadian Metallurgical Quarterly》2008,15(1):76
This study investigated the relationship between coping styles and police recruits' stress responses and performance during a stressful event and the relationship between coping styles and traumatic symptoms. Recruits participated in a simulated stressful policing situation and were scored by expert raters. Distress measures included biological and psychological indicators of stress. Coping styles were associated with subjective and physiological distress but not with performance. Different coping styles were associated with different patterns of traumatic symptoms in the participants. Police recruits appear to rely on their training and skill sets in stressful situations regardless of how they manage their emotional response. Furthermore, the results suggest that different posttraumatic stress disorder manifestations may represent different pathologies, each associated with a different style of coping. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
194.
Comparative B‐mode and Doppler renal ultrasonography with histopathological findings in dogs positive for canine visceral leishmaniasis 下载免费PDF全文
Pollyana Irene Baltazar Laecio Da Silva Moura Gerson Tavares Pessoa Renan Paraguassu De Sá Rodrigues Marina Pinto Sanches Anaemilia Das Neves Diniz Francisco Das Chagas Araújo Sousa Porfírio Candanedo Guerra Willams Costa Neves Robson Fortes Giglio Jacyara De Jesus Rosa Pereira Alves Francisco De Assis Leite Souza Juliana Fortes Vilarinho Braga Flávio Ribeiro Alves 《Microscopy research and technique》2016,79(7):637-645
Morphological parameters and renal flow were assessed and measured in six clinically healthy dogs with negative serological and parasitological examinations for canine visceral leishmaniasis (CVL) and six dogs with CVL‐positive serological and parasitological tests and asymptomatic condition of the disease. Kidney length and diameter were measured and compared with the aorta/kidney ratio. Alterations in flow were measured using the flow velocity (cm/s) and resistance index (RI). Renal function was assessed by serum biochemical examination (urea, creatine, total proteins, albumin, and globulin) and urinalysis. CVL‐positive animals presented heterogeneous kidney echotexture, reduced vascular flow, hypoperfusion, lesser visualization of the arcuate arteries, high RI values (1.06 ± 0.28 for the right kidney and 1.10 ± 0.30 for the left kidney), reduced diastolic flow, and high systolic peak. They also presented positive creatine/RI correlation and between the renal artery vascular flow and kidney diameter. Histopathological analysis of CVL‐positive animals was compatible and confirmed hemodynamic changes observed by Doppler ultrasound. The findings in the present study showed that Doppler ultrasonography is a valid method to assess and detect alterations in flow in renal pathological processes with kidney vascular damage, as in the case of leishmaniasis, and can help in the diagnosis of animals with this infection. Microsc. Res. Tech. 79:637–645, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
195.
Pork forelegs were used for manufacturing fresh sausages, treated with different natural antioxidants (rosemary, ascorbic acid and black pepper), packaged in 80% O2 + 20% CO2 atmosphere and displayed at 2 ± 1 °C under different lightings (darkness, standard fluorescent, low-UV colour-balanced lamp and standard fluorescent plus a UV-filter). Two packs for each treatment were opened every 4 days for subsequent analysis of colour CIE L∗, a∗, b∗, TBARS, microbial psychrotrophic aerobes and sensory discolouration and off-odour. Lighting with standard fluorescent was highly deleterious for sausage display life, which fell from 12 to 8 days due mainly to early discolouration. Inserting a UV-filter extended display life to 12 days, while the use of a low-UV lamp was not effective in protecting from discolouration. Addition of rosemary plus ascorbic acid, in the absence of black pepper, retarded discolouration only in sausages illuminated with the UV-filter, reaching a display life of 16 days, equal to that of sausages maintained in the dark. 相似文献
196.
Single-source molecular precursors were found to produce iron phosphide materials. In a surfactant system of trioctylamine and oleic acid, H2Fe3(CO)9PtBu reacted to form Fe4(CO)12(PtBu)2, which decomposed to give Fe2P nanorods and "bundles." Control of the morphology obtained was possible by varying the surfactant system; addition of increasing amounts of oleic acid resulted in crystal splitting, while the addition of microliter amounts of an alkane enhanced the crystal splitting to give sheaflike structures. The different morphologies seen were attributed to imperfect crystal growth mechanisms. 相似文献
197.
198.
Shaw Brian F.; Elkin Irene; Yamaguchi Jane; Olmsted Marion; Vallis T. Michael; Dobson Keith S.; Lowery Alice; Sotsky Stuart M.; Watkins John T.; Imber Stanley D. 《Canadian Metallurgical Quarterly》1999,67(6):837
This study reports on the relationship of therapist competence to the outcome of cognitive-behavioral treatment in the National Institute of Mental Health Treatment of Depression Collaborative Research Program. Outpatients suffering from major depressive disorder were treated by cognitive-behavioral therapists at each of 3 U.S. sites using a format of 20 sessions in 16 weeks. Findings provide some support for the relationship of therapist competence (as measured by the Cognitive Therapy Scale) to reduction of depressive symptomatology when controlling for therapist adherence and facilitative conditions. The results are, however, not as strong or consistent as expected. The component of competence that was most highly related to outcome is a factor that reflects the therapist's ability to structure the treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
199.
The paper presents the results of an empirical study of the Danish and Nordic Publication behaviour and international impact
in Clinical and Social Medicine covering the period 1988–96. As indicators are applied the international visibility of Scandinavian
research output, the publication activity per capita in SCI journals, the development over time of the national citation impact
in an OECD and World context, and the ratio of cited papers relative to the World. Compared toMay's analysis (1997), covering 1981–94, the analysis shows that a certain reshuffle of national positions among the OECD countries
in citation impact has occurred. UK and New Zealand as well as Denmark and Sweden have lost in ranking to Finland and Belgium,
both countries coming up from behind. The most interesting results concern the opposite research policy strategies displayed
by Finland and Denmark which result in similar impact patterns relative to the World impact. The implications are discussed. 相似文献
200.
Irene Zorraquín Eva Sánchez-Hernández Begoña Ayuda-Durán Mariana Silva Ana M González-Paramás Celestino Santos-Buelga Maria V Moreno-Arribas Begoña Bartolomé 《Journal of the science of food and agriculture》2020,100(10):3789-3802
Interactions between polyphenols and gut microbiota are indeed a major issue of current interest in food science research. Knowledge in this subject is progressing as the experimental procedures and analysis techniques do. The aim of this article is to critically review the more leading-edge approaches that have been applied so far in the study of the interactions between grape/wine polyphenols and gut microbiota. This is the case of in vitro dynamic gastrointestinal simulation models that try to mitigate the limitations of simple static models (batch culture fermentations). More complex approaches include the experimentation with animals (mice, rats, pigs, lambs and chicks) and nutritional intervention studies in humans. Main advantages and limitations as well as the most relevant findings achieved by each approach in the study of how grape/wine polyphenols can modulate the composition and/or functionality of gut microbiota, are detailed. Also, common findings obtained by the three approaches (in vitro, animal models and human nutritional interventions) such as the fact that the Firmicutes/Bacteroidetes ratio tends to decrease after the feed/intake/consumption of grape/wine polyphenols are highlighted. Additionally, a nematode (Caenorhabditis elegans) model, previously used for investigating the mechanisms of processes such as aging, neurodegeneration, oxidative stress and inflammation, is presented as an emerging approach for the study of polyphenols interacting gut microbiota. © 2020 Society of Chemical Industry 相似文献