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排序方式: 共有772条查询结果,搜索用时 15 毫秒
1.
Wireless Networks - In this paper, we analyze the performance of wireless networks subject to random loss. In this regard, we revisit our TCP Congestion Control Enhancement for Random Loss (CERL)... 相似文献
2.
Kamar M. S. Shalan A. S. Youssef W. M. Hussein A. E. M. Khawassek Y. M. Taha M. H. 《Radiochemistry》2022,64(2):244-256
Radiochemistry - Ferrugination, sericitization, desulfitization, chloritization, and kaolinitization of hydrothermal origin are the main wall rock alterations occurring within the NNW shear zones... 相似文献
3.
Enas Taha Sayed Hussain Alawadhi A.G. Olabi Aisha Jamal Menna Salah Almahdi Juiaria Khalid Mohammad Ali Abdelkareem 《International Journal of Hydrogen Energy》2021,46(8):5975-5983
Microbial fuel cell (MFC) is a promising technology for simultaneous wastewater treatment and energy harvesting. The properties of the anode material play a critical role in the performance of the MFC. In this study, graphene oxide was prepared by a modified hummer's method. A thin layer of graphene oxide was incorporated on the carbon brush using an electrophoretic technique. The deoxygenated graphene oxide formed on the surface of the carbon brush (RGO-CB) was investigated as a bio-anode in MFC operated with real wastewater. The performance of the MFC using the RGO-CB was compared with that using plain carbon brush anode (PCB). Results showed that electrophoretic deposition of graphene oxide on the surface of carbon brush significantly enhanced the performance of the MFC, where the power density increased more than 10 times (from 33 mWm?2 to 381 mWm?2). Although the COD removal was nearly similar for the two MFCs, i.e., with PCB and RGO-CB; the columbic efficiency significantly increased in the case of RGO-CB anode. The improved performance in the case of the modified electrode was related to the role of the graphene in improving the electron transfer from the microorganism to the anode surface, as confirmed from the electrochemical impedance spectroscopy measurements. 相似文献
4.
Enhancement of the dissolution rate of the poorly water-soluble hypoglycemic agent, gliclazide, by the aid of lyophilization was investigated. Mannitol, sodium lauryl sulfate (SLS) and polyvinyl pyrrolidone (PVP-k-30) were employed in different weight ratios (43%, 56% and 64% w/w, respectively) as water-soluble excipients in the formulation. Lyophilized systems were found to exhibit extremely higher in vitro dissolution rate compared to the unprocessed drug powder. Solid state characterization of the lyophilized systems using X-ray powder diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry techniques revealed that dissolution enhancement was attributable to transformation of gliclazide from the crystalline to an amorphous state in the solid dispersion formed during the lyophilization process. The gastrointestinal absorption and hypoglycemic effect of the lyophilized gliclazide/SLS system were investigated following oral administration to Albino rabbits. Cmax and area under the plasma concentration–time curve of gliclazide (AUC0–12) after administration of the lyophilized formulations were significantly higher than those obtained after administration of the unprocessed gliclazide. 相似文献
5.
Amer Ibrahim Al-Omari Ibrahim M. Almanjahie Amal S. Hassan Heba F. Nagy 《计算机、材料和连续体(英文)》2020,64(2):835-857
In reliability analysis, the stress-strength model is often used to describe the life of
a component which has a random strength (X) and is subjected to a random stress (Y). In this
paper, we considered the problem of estimating the reliability R=P [Y<X] when the
distributions of both stress and strength are independent and follow exponentiated Pareto
distribution. The maximum likelihood estimator of the stress strength reliability is calculated
under simple random sample, ranked set sampling and median ranked set sampling methods.
Four different reliability estimators under median ranked set sampling are derived. Two
estimators are obtained when both strength and stress have an odd or an even set size. The
two other estimators are obtained when the strength has an odd size and the stress has an
even set size and vice versa. The performances of the suggested estimators are compared
with their competitors under simple random sample via a simulation study. The simulation
study revealed that the stress strength reliability estimates based on ranked set sampling and
median ranked set sampling are more efficient than their competitors via simple random
sample. In general, the stress strength reliability estimates based on median ranked set
sampling are smaller than the corresponding estimates under ranked set sampling and simple
random sample methods. 相似文献
6.
Su M.F. Reda Taha M.M. Christodoulou C.G. El Kady I. 《Photonics Technology Letters, IEEE》2008,20(10):761-763
Processing methods used in photonics and nanotechnology possess many limitations restricting their application areas such as high cost, inability to produce fine details, problems with scalability, and long processing time. Proximity field nanopatterning is a lithography method which surpasses these limitations. By using interference patterns produced by a two-dimensional phase mask, the technique is able to generate a submicron detailed exposure on a millimeter-size slab of light sensitive photopolymer, which is then developed like a photographic plate to reveal three-dimensional interference patterns from the phase mask. While it is possible to use simulations to obtain the interference patterns produced by a phase mask, realizing the mask dimensions necessary for producing a desired interference pattern is analytically challenging due to the intricacies of light interactions involved in producing the final interference pattern. An alternative method is to iteratively optimize the phase mask until the interference patterns obtained converge to the desired pattern. However, depending on the optimization technique used, one either risks a significant probability of failure or requires a prohibitive number of iterations. We argue that an optimization technique that is to take advantage of the physics of the problem using machine learning methods (here fuzzy learning) can lead to competent mask design. This technique is described in this letter. 相似文献
7.
Exchange and oxidation of C16O were investigated at 450°C on 18O-predosed Rh and Pt catalysts supported on A12O3, CeO2 and CeO2-Al2O3. In all cases, a rapid exchange of C16O with the surface can be observed. CO oxidation leads to C16O2, C16O18O and C18O2. Significant formation of C16O2 is due to the relatively high 16O coverage in reaction resulting from the C16O exchange and from an exchange between O surface species and 16O internal atoms. Hydrogen is also formed via a water-gas shift reaction (CO + surface OH) in higher proportion on CeO2-containing catalysts than on A12O3. Chlorine inhibits all the reactions (exchange, oxidation and WGS) and particularly the internal exchange. 相似文献
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10.
The solar cooking process has been investigated to develop safe, simple, portable, and reliable solar cookers. The concept of insulated and vapor-tight pots has been introduced and applied to oven, point-focus and heat-pipe cookers. A new, flat-plate cooker with heat pipes has been developed. It requires no tracking and allows cooking to be done in the shade or indoors. Also, a novel-portable cooker, the Mina Oven, featuring a vapor-tight pot and an integral collector with reflector flaps, has been constructed and tested. A second portable cooker that has been developed is the Arafa Cooker, which comprises a parabolic dish focused at a glazed and insulated receiver. Experiments indicated that all cookers yielded satisfactory performance, with cooking times of 25–45 min per kg of food per m2 of solar collection area while operating from 10 a.m. to 4 p.m. 相似文献