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1.
A. Demoz C. Khulbe C. Fairbridge S. Petrovic 《Journal of Applied Electrochemistry》2008,38(6):845-851
Hydrogen is among the emerging energy vectors that are being developed to replace nonrenewable hydrocarbon energy sources.
The preferred method to produce hydrogen without generating greenhouse gases is the electrolysis of water using renewable
energy. The reduction of energy during the water electrolysis process is a desirable goal regardless of the source of electric
power. Similar to ferrous/ferric mediation, iodide can be used as a mediator in the electrolysis of an acidic suspension of
coke or coal. The iodide ion is oxidized at a far lower anodic potential than the alternative oxygen evolution reaction. This
reduces the cell electrolysis voltage and, consequently, reduces electricity use. The iodide consumed at the anode is continuously
regenerated by chemical reaction with the coke/coal in suspension. 相似文献
2.
C Isidoro M Demoz D De Stefanis F Mainferme R Wattiaux FM Baccino 《Canadian Metallurgical Quarterly》1995,60(1):61-64
Using immunomagnetic cell separation and fluorescent in situ hybridization (FISH), we studied nine patients who had chronic granulocytic leukemia (CGL) for the proportion of interphase nuclei with Mbcr/abl fusion in a direct preparation of the bone marrow and also in the mononuclear cell (MNC), neutrophil, and B- and T-cell fractions of the peripheral blood. In five untreated patients, conventional cytogenetics revealed 97% to 100% Philadelphia chromosome (Ph)+ metaphases. In three of these five patients, FISH studies on bone marrow direct preparations and peripheral blood MNCs indicated that an Mbcr/abl fusion occurred in 62% to 69% of the cells. We observed 69% to 88% of nuclei with Mbcr/abl fusion within the neutrophil fractions. In contrast, the values were 12% to 39% within the T-cell fractions in the four patients we studied. B-cell fractions were studied in three patients, and only one had an abnormal value (58%). In the four patients receiving alpha-interferon therapy, the degree of conventional cytogenetic remission correlated best with the degree of FISH remission observed in the peripheral blood neutrophil fraction. Our results are in agreement with earlier studies in that both B and T lymphocytes may be involved with the clonal process in CGL. The FISH-based detection of Mbcr/abl fusion in the peripheral blood neutrophil compartment provided the best estimate for the proportion of Ph metaphases determined by conventional cytogenetics. 相似文献
3.
Alebachew Demoz 《American Institute of Chemical Engineers》2015,61(12):4402-4411
Operations to reclaim mature fine tailings (MFT) ponds involve flocculation using high‐molecular‐weight polymers, for which inline static mixers are suited. Three different commercial static mixers were utilized to determine mixing parameters corresponding to optimal dewatering performance of flocculated MFT. MFT was treated with polymer solution under different mixing conditions. The dewatering rates passed through a peak with increasing mean velocity, V and Reynolds number, Re of the fluid. The greater the number of mixer elements, the lower the V and Re at which the peak dewatering rate occurred. Mixing parameters such as G‐value, residence time, and mixing energy dissipation rate of the most rapidly dewatering flocculated MFT were dependent on mixer type and setup. In contrast, peak dewatering rates converged when scaled with respect to specific mixing energy, E, demonstrating that E is a suitable scale‐up parameter for inline static mixing to produce optimally dewatering MFT. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4402–4411, 2015 相似文献
4.
Numerical simulation of light backscattering by spheres with off-center inclusion. Application to the lidar case 总被引:1,自引:0,他引:1
A Mie backscattering model for spherical particles with off-center inclusion has been developed and tested. The program is capable of dealing with size parameter values up to approximately 1000, thus allowing one to simulate the optical behavior of a large variety of atmospheric aerosols, as well as cloud and precipitation particles. On the basis of this model, we simulated the optical properties of polydisperse composite atmospheric particles as observed by ground-based and airborne lidar systems. We have characterized optical properties in terms of host and inclusion radii, considering water particles with different composition inclusions. The performed modeling provides some insight into the so-called lidar bright- and dark-band phenomenon. 相似文献
5.
M G?ttlicher A Demoz D Svensson P Tollet RK Berge JA Gustafsson 《Canadian Metallurgical Quarterly》1993,46(12):2177-2184
Fatty acids have recently been demonstrated to activate peroxisome proliferator-activated receptors (PPARs) but specific structural requirements of fatty acids to produce this response have not yet been determined. Importantly, it has hitherto not been possible to show specific binding of these compounds to PPAR. To test whether a common PPAR binding metabolite might be formed, we tested the effects of long-chain omega-3 polyunsaturated fatty acids, differentially beta-oxidizable fatty acids and inhibitors of fatty acid metabolism. We determined the activation of a reporter gene by a chimaeric receptor encompassing the DNA binding domain of the glucocorticoid receptor and the ligand binding domain of PPAR. The omega-3 unsaturated fatty acids were slightly more potent PPAR activators in vitro than saturated fatty acids. The peroxisomal proliferation-inducing, non-beta-oxidizable, tetradecylthioacetic acid activated PPAR to the same extent as the strong peroxisomal proliferator WY 14,643, whereas the homologous beta-oxidizable tetradecylthiopropionic acid was only as potent as a non-substituted fatty acid. Cyclooxygenase inhibitors, radical scavengers or cytochrome P450 inhibitors did not affect activation of PPAR. In conclusion, beta-oxidation is apparently not required for the formation of the PPAR-activating molecule and this moiety might be a fatty acid, its ester with CoA, or a further derivative of the activated fatty acid prior to beta-oxidation of the acyl-CoA ester. These data should aid understanding of signal transduction via PPAR and the identification of a receptor ligand. 相似文献
6.
Alebachew Demoz 《加拿大化工杂志》2018,96(1):265-273
Industrial scroll decanter centrifuge (SDC) separation of the solids in fluid fine tailings (FFT) which have particles 10 μm and smaller in size require flocculant addition. Accordingly, the mechanism in the centrifuge is flocculation of the fine solid particles followed by sedimentation. Thus, feeding preflocculated material obviates the flocculation step inside the SDC resulting in improved process efficiency by reducing the power consumption and increasing the throughput capacity of each SDC. This work evaluated the separation performance of the SDC using inline static mixers to preflocculate oil sands FFT containing solids, 90 mass% of which are < 9 μm in size. The minimum G‐forces required to achieve the industry benchmarks of < 1 mass% solids in the centrate water and > 97 % fines capture rate were 750 G without preflocculation and 400 G with preflocculation. Since power consumption by the SDC, as expected, was directly proportional to the G‐force, the savings in power due to preflocculation amounted to 47 %. Preflocculation increased SDC throughput capacity by up to 50 %. Operating at lower G‐force has the additional benefits of protecting the high‐capital‐cost SDC machine and reducing ambient noise levels. 相似文献
7.
Demoz Gebre-Egziabher Gabriel H. Elkaim J. David Powell Bradford W. Parkinson 《Canadian Metallurgical Quarterly》2006,19(2):87-102
This paper presents an algorithm for calibrating strapdown magnetometers in the magnetic field domain. In contrast to the traditional method of compass swinging, which computes a series of heading correction parameters and thus is limited to use with two-axis systems, this algorithm estimates magnetometer output errors directly. Therefore, this new algorithm can be used to calibrate a full three-axis magnetometer triad. The calibration algorithm uses an iterated, batch least-squares estimator that is initialized using a two-step nonlinear estimator. The algorithm is simulated to validate convergence characteristics and further validated on experimental data collected using a magnetometer triad. It is shown that the postcalibration residuals are small and result in a system with heading errors on the order of 1?to?2?degrees. 相似文献
8.
Translocation of long-chain acyl-coenzyme A hydrolase from the microsomal fraction to the cytosolic fraction was promoted
in cell-free extracts of rat liver by palmitic acid, oleic acid, tetradecylthioacetic acid, and tetradecylthiopropionic acid,
and by their CoA esters. The CoA esters were more effective than the non-esterified acids in the translocation of the enzyme.
Treatment of normolipidemic rats with sulfur-substituted non-β-oxidizable fatty acid analogues resulted in a transitory increase
in hepatic concentration of long-chain acyl-CoA. Longer feeding times almost normalized the hepatic long-chain acyl-CoA content.
Microsomal long-chain acyl-CoA hydrolase activity was inhibited, whereas the activity of the cytosolic form was stimulated.
The rise in enzyme activity coincided with a reduction in liver content of triglyceride and an increase in hepatic phospholipid
content. The results suggest that the activity of long-chain acyl-CoA hydrolase in the cytosol may control the amount of acyl-CoA
thioesters in the liver. Esterified and non-esterified fatty acids causedin vitro translocation of phosphatidate phosphohydrolase and cytidine 5′-triphosphate (CTP):phosphocholine cytidylyltransferase from
the cytosolic fraction to the microsomal fraction. However, the translocation of these two enzyme systems was not obtainedin vivo. The activity of phosphatidate phosphohydrolase decreased in microsomal and cytosolic fractions while the activity of cytidylyltransferase
in these fractions increased. The activities of soluble phosphatidate phosphohydrolase and long-chain acyl-CoA hydrolase appeared
to be inversely correlated. The results imply that in cytoplasm, long-chain acyl-CoA hydrolase may compete with the biosynthetic
enzymes for the acyl-CoA substrate, thus influencing the rate of lipid synthesis. The reduced hepatic triglyceride content
observed in tetradecylthioacetic acid-treated rats is probably due to reduced triglyceride synthesis, which is mediated by
an inhibition of phosphatidate phosphohydrolase accompanied with translocation and stimulation of long-chain acyl-CoA hydrolase.
Development of fatty liver as an effect of tetradecylthiopropionic acid is probably due to accelerated triglyceride biosynthesis,
which is mediated by a stimulation of phosphatidate phosphohydrolase and a decrease in cytosolic palmitoyl-CoA hydrolase activity. 相似文献
9.
To calculate aerosol extinction from Raman lidar data, it is necessary to evaluate the derivative of a molecular Raman signal with respect to range. The typical approach taken in the lidar community is to make an a priori assumption about the functional behavior of the data to calculate the derivative. It has previously been shown that the use of the chi-squared technique to determine the most likely functional behavior of the data prior to actually calculating the derivative eliminates the need for making a priori assumptions. Here that technique is validated through numerical simulation and by application to a significant body of Raman lidar measurements. In general, we show that the chi-squared approach for evaluating extinction yields lower extinction uncertainty than traditional techniques. We also use the technique to study the feasibility of developing a general characterization of the extinction uncertainty that could permit the uncertainty in Raman lidar aerosol extinction measurements to be estimated accurately without the need of the chi-squared technique. 相似文献
10.
An electronic sensor was evaluated as an instrument for early detection of mastitis. This method involved measuring the conductivity of milk continuously throughout the milking process and then establishing a conductivity ratio. The lowest conductivity measurement of the four quarters was a basis for assessing the degree of mastitis in the other quarters. This assumed that at least one of the quarters was normal at examination and the lowest reading was normal conductivity. The conductivity ratio was evaluated by comparison with the leukocyte concentration and combined leukocyte concentrations and cultural examiniations of milk samples from 1028 quarters. In healthy cows conductivities of milk from each of the quarters were similar. If, however, one or more quarters were infected, this milk showed higher conductivity compared to the noninfected quarter of the same cow. The conductivity ratio correctly identified 69% of the established cases of mastitis. For the Wisconsin Mastitis Test, 93.2% of the normal quarters were detected correctly by the conductivity ratio. Leukocyte counts were frequently high when there was no other evidence of mastitis. We believe the conductivity ratio is effective in detecting mastitis at an early stage of infection caused by most of the pathogenic microorganisms. 相似文献