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排序方式: 共有1628条查询结果,搜索用时 15 毫秒
1.
Caio Felippe Curitiba Marcellos Camila M. Senna Figueiredo Frederico W. Tavares Maurício Bezerra de Souza Jr. Paulo Laranjeira da Cunha Lage João Francisco Cajaiba da Silva Argimiro R. Secchi Amaro G. Barreto Jr. 《加拿大化工杂志》2020,98(11):2435-2450
An experimental methodology for inferring brine dissolution rate in monoethylene glycol (MEG) solutions at different temperatures using a webcam combined with a mathematical model is presented. The measurement system is designed to track the RGB (red, green, and blue) colour variations during the dissolution process. A dynamic model augmented with the population balance equation is applied to describe the dissolution process. Moreover, the dissolution rate is consistently related to the temperature and MEG concentration through the driving force based on the Gibbs energy and chemical affinity. The applied low-cost measurement apparatus proved to be a useful resource for tracking the dissolution dynamics in a wide range of undersaturation. 相似文献
2.
Cyclo 3 Fort is used in the treatment of chronic venous insufficiency. In this study, the effects of Cyclo 3 Fort, 2, 10 and 50 mg/kg, were studied in cheek pouch preparations from diabetic hamsters. The mean arteriolar diameter in animals receiving Cyclo 3 Fort, 10 and 50 mg/kg, was significantly greater than in control animals (p < 0.05), and the mean venule diameter was significantly lower in animals receiving the 50 mg/kg dose than in the control group. This suggests that Cyclo 3 Fort, 50 mg/kg/day, has a venotonic effect in diabetic animals. The venoarteriolar reflex was studied by measuring the internal diameter of arterioles during venular occlusion. The reflex was impaired in animals treated with either placebo or 2 mg/kg, but this was reversed by treatment with Cyclo 3 Fort, 10 and 50 mg/kg. 相似文献
3.
Alexandre Szklo Giovani Machado Roberto Schaeffer Jacqueline Mariano Janaí na Sala Marina Tavares 《Catalysis Today》2005,106(1-4):123-128
This paper assesses the impacts of a GTL plant on the expansion of Brazil's oil refining segment. The GTL plant (50,000 bpd) was sized to start up operations in 2015, producing diesel and naphtha through the indirect route (FT-synthesis). This plant will consume the non-associated natural gas production from the recent discoveries at the Santos Basin (around 419 Bm3), and the associated gas production from the Campos Basin. Both basins are located in the Southeast of Brazil, the most populated, rich and industrialized region of the country. Two different criteria for refinery expansion were simulated in order to meet oil product demand scenarios. Findings show that depending on the refinery expansion criteria considered GTL will play a fundamental hole to meet the oil product demand forecast to Brazil in the next 10 years. 相似文献
4.
Turner S.E. Elder R.B. Jr. Jansen D.S. Kotecki D.E. 《Microwave and Wireless Components Letters, IEEE》2005,15(3):144-146
A 41-GHz 4-b adder-accumulator test circuit implemented in InP double heterojunction bipolar transistor (DHBT) technology using 624 transistors is reported. High clock rates are obtained by combining the logic functions into pipelined latches. The adder-accumulator contains a single-level parallel-gated carry circuit that is used as a step toward reduced power consumption. The carry circuit has a maximum clock frequency of 55 GHz. The accumulator architecture employs modular, pipelined 2-b adders and is cascadable to 2 N-bits. The test circuit includes a 4-b digital to analog converter (DAC) that facilitates demonstration of high-speed operation. 相似文献
5.
A new CMOS VLSI implementation of an asymmetric programmable sigmoid neural activation function, as well as of its derivative, is presented. It consists of two coupled PMOS and NMOS differential pairs with different programmable bias currents that set the upper and lower limits of the sigmoid. The circuit works in the weak inversion region, for low power consumption and exponential envelope, or in strong inversion to achieve higher speeds. The results obtained from the theoretical transfer function, and from the simulations of the circuit implemented in AMI's 0.35 /spl mu/m technology, show a very good match. 相似文献
6.
Ana MRB Xavier Ana Paula M Tavares Margarida SM Agapito Dmitry V Evtuguin 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(12):1602-1608
BACKGROUND: A sequential batch reactor (SBR) was used for eucalypt kraft pulp effluent treatment with Trametes versicolor. A 23 full factorial design and response surface methodology were applied to optimise the batch fermentation conditions. Effluent concentration, culture medium and inoculum age were the factors selected for this study in order to optimise the reduction of chemical oxygen demand (COD). RESULTS: The presence of Trametes Defined Medium (TDM) in the fermentation was required to obtain a significant COD reduction. Experiments in the batch reactor confirmed, in general, the predicted results of optimisation developed from Erlenmeyer batch assays. The T. versicolor culture remained active during 42 days of study in the SBR, providing approximately 80% of COD reduction. CONCLUSION: Trametes versicolor may be considered as very promising for the biological treatment of effluents from kraft pulp mills in an SBR system instead of the activated sludge mixed cultures traditionally used. Copyright © 2008 Society of Chemical Industry 相似文献
7.
E Persson M Ljunggren J la Cour Jansen R Strube L J?nsson 《Water science and technology》2006,53(12):139-147
A Discfilter with 10 and 18 microm filter openings, respectively, was placed in parallel to a flotation plant for separation of biological flocs from a post-denitrifying Kaldnes Moving Bed Process, the last treatment step at the municipal wastewater treatment plant at Sj?unda, Malm?, Sweden. The effluent concentrations from the 10 and 18 microm filter were 2-5 and 2-8 mg SS L(-1), respectively, which is comparable to, or better than, the flotation plant. Comparison with experiences from activated sludge plants shows that the Discfilter works especially well after the Kaldnes process. Particle size distribution (PSD) studies show that particles larger than the filter openings of 10 and 18 microm are separated with approximately 90% efficiency, whereas most of the smaller particles pass the filter. This fact indicates that the major particle separation mechanism is physical blocking. These findings point to the possibility of improving the prediction of the separation efficiency by combining measurements of turbidity and suspended solids with particle size analysis. 相似文献
8.
能源成本上涨速度高于纱线价格上涨速度,Autocoro纺纱厂每年的能耗成本约占每年营业额的5%,主要能耗是电能. 相似文献
9.
J. E. G. Hulshoff K. Van Dijk J. P. C. M. Van Der Waerden W. Kalk J. A. Jansen 《Journal of materials science. Materials in medicine》1996,7(10):603-609
The bone response to different calcium phosphate (Ca-P) coated implants was evaluated in a goat animal model. Two types of plasma spray coatings were applied to a commercially pure titanium (cpTi) tapered, conical screw-design implant (BioComp®); hydroxyapatite (HA-PS) and a dual coating, consisting of FA and HA (FA/HA-PS). In addition an amorphous RF magnetron sputter coating (Ca-P-a) and uncoated implants were investigated. Forty-eight implants were inserted in the maxilla of 12 adult female goats. After implantation periods of 3 and 6 months, the bone implant interface was evaluated histologically and histomorphometrically. After both implantation periods all plasma spray coated implants were maintained. On the other hand three Ca-P-a and two cpTi implants were lost. Histological examination revealed a better bone response to both plasma spray coated implants. Histomorphometrical evaluation confirmed this finding. At 3 and 6 months significantly higher percentages of bone contact (p<0.001, ANOVA) were measured for both plasma spray coated implants than for the cpTi and Ca-P-a implants, while no significant difference (p<0.05) existed between both implantation periods. Degradation of both plasma spray coatings was observed. Supported by the results, it is concluded that, although Ca-P coatings can improve the performance of dental implants, the presence of a Ca-P coating is not the only important factor for bone healing around implants placed in low density trabecular bone. 相似文献
10.
MC Ocké D Kromhout A Menotti C Aravanis H Blackburn R Buzina F Fidanza A Jansen S Nedeljkovic A Nissienen 《Canadian Metallurgical Quarterly》1995,61(4):480-484
This ecologic study aimed to investigate whether differences in population mortality from lung, stomach and colorectal cancer among the 16 cohorts of the Seven Countries Study could be explained by differences in the average intake of anti-oxidant (pro)vitamins. In the 1960s, detailed dietary information was collected in small sub-samples of the cohorts by the dietary record method. In 1987, food-equivalent composites representing the average food intake of each cohort at baseline were collected locally and analyzed in a central laboratory. The vital status of all participants was verified after 25 years of follow-up. The average intake of vitamin C was strongly inversely related to the 25-year stomach-cancer mortality (r = -0.66, p = 0.01), also after adjustment for smoking and intake of salt or nitrate. The average intake of alpha-carotene, beta-carotene, and alpha-tocopherol were not independently related to mortality from lung, stomach or colorectal cancer, nor was vitamin C related to lung and colorectal cancer. 相似文献