排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
2.
3.
Roychoudhuri Lopamudra Al-Shaer Ehab S. 《Network and Service Management, IEEE Transactions on》2005,2(1):29-38
The effect of packet loss on the quality of real-time audio is significant. Nevertheless, Internet measurement experiments continue to show a considerable variation of packet loss, which makes audio error recovery and concealment challenging. We propose a novel framework to predict packet loss and congestion, based on measurements of end-to-end delay variation and trend, enabling proactive error recovery and congestion avoidance. Our preliminary simulation and experimentation results with various sites on the Internet show the effectiveness and the accuracy of the Loss Predictor technique. 相似文献
4.
A highly crosslinked composite dextran-based scaffold (named DexFoam) was tailored to overcome specific deficiencies of polymeric and ceramic bone scaffolds and to guarantee a bone-mimicking microenvironment for the proliferation of human mesenchymal stem cells in vitro. The creep resistance for up to 90% compressive stain, the capability to regain the original shape after deformation, and the good thermal stability in both physiological and “body limit” conditions make DexFoam a valid alternative to the currently available bone scaffolds. Histopathological evaluation for host reaction and tissue colonization of DexFoam scaffold, implanted subcutaneously in mice, demonstrated its in vivo biocompatibility and biodegradability. 相似文献
5.
Pattanaik Lopa Padhi Susant Kumar Hariprasad P. Naik Satya Narayan 《Clean Technologies and Environmental Policy》2020,22(8):1639-1654
Clean Technologies and Environmental Policy - The emerging demand of natural indigo dye due to the environmental and sociological concerns imparted by the synthetic dye helps in leveraging the... 相似文献
6.
Eva Bergerová Zuzana Hrnčírová Monika Stankovská Miroslava Lopašovská Peter Siekel 《Food Analytical Methods》2010,3(3):211-218
Processing of raw plant materials causes occurrence of degraded DNA in foods. The effect of DNA degradation on amplification
and quantification of transgenic and non-transgenic DNA in raw and experimentally thermally processed foods was studied. The
degree of DNA degradation was checked by agarose gel electrophoresis and polymerase chain reaction (PCR). Cetyl trimethyl
ammonium bromide method yielded DNA of a better quality, while Genespin and Wizard were less appropriate. Baking at 220 °C
considerably reduced the size of DNA fragments. In order to measure the length of amplifiable DNA, primers for soybean and
maize genes were used. Small DNA fragments ranging from 100 to 200 bp were amplified in all samples. DNA fragments over 1 kbp
were amplified only if heating at 220 °C lasted less than 30 min. Baking of flour (220 °C) reduced the size of extracted DNA
fragments so that 1,100 bp amplicon was no longer amplifiable, while the amplicons of 913 and 1,100 bp were obtained from
the baked bread. When PCR assays targeting maize high mobility group and zein genes were used under the same conditions, analogous
results were achieved. Quantification of genetically modified organism content was not influenced by baking. 相似文献
7.
S.K. Roychoudhuri Nupur Bandyopadhyay 《Computers & Mathematics with Applications》2007,54(11-12):1341-1352
The generalized thermo-elasticity theory III is employed to study thermo-elastic interactions in a homogeneous isotropic unbounded solid due to distributed continuous and instantaneous body forces. The solutions are derived by using a Laplace transform on time and then a Fourier transform on space. It is found that the interactions consist of a wave part traveling with the speed of the dilatational wave and a diffusive part. For continuous body forces, both temperature and deformation are continuous at the elastic dilatational wave front, while the stress suffers finite discontinuity at this location. For instantaneous body forces, both deformation and temperature suffer finite discontinuities at the elastic wave front, while stress exhibits delta function discontinuity resulting from the Dirac delta function at this location. All the fields suffer exponential attenuation at the elastic wave front and the attenuation is influenced by thermo-elastic coupling and thermal diffusivity of the medium. The results achieved in the present analysis are compared to those obtained by using generalized thermo-elasticity theory II without energy dissipation and other generalized theories. Lastly, numerical results applicable to a copper-like material are presented in order to illustrate the analytical result. 相似文献
8.
Jana Minarovi?ov?? Janka Lopa?ovsk?? ?ubom??r Val??k Tom??? Kuchta 《Food Analytical Methods》2011,4(1):116-120
A method for the detection of Cryptosporidium parvum oocysts in milk was developed on the basis of optimizing microfiltration and elution of the material from the filter, and
using a previously developed highly sensitive downstream detection by real-time polymerase chain reaction. The method involves
heating of milk to 40°C, microfiltration through a membrane microfilter made of a mixture of cellulose acetate and cellulose
nitrate (pore size, 3.0 μm), elution of the material from the filter by a solution containing sodium pyrophosphate and Tween
80 in a shaker, rapid DNA extraction using a Chelex-based agent, and single-tube nested real-time PCR. The detection limit
of the method is 10 C. parvum oocysts per 100 ml of milk. The developed method may be useful for specific and sensitive control of contamination of milk
by C. parvum oocysts. 相似文献
9.
Taewook Ryu Faiz Ahmed Sabuj Chandra Sutradhar Nasrin Siraj Lopa Hanmo Yang Soojin Yoon Seungchan Lee Inhwan Choi Whangi Kim 《International Journal of Hydrogen Energy》2018,43(26):11862-11871
The grafted block copolymer based polymer electrolyte membrane (PEM) was successfully synthesized by the superacid-catalyzed polyhydroxyalkylation reaction from biphenyl, 2,2′-biphenol and isatin and the performance of the block copolymer were compared in conjunction with the random copolymer. These polymers have all carbon-carbon structure on polymer backbone without ether linkage. The bromoalkylsulfone potassium salt was prepared from 1,3-propane sultone and potassium bromide. Particularly, the attached alkyl sulfone groups were afforded better stability due to less reactivity towards nucleophilic substitution reaction. Moreover, the block copolymer exhibited better proton conductivity (76.84 mS/cm under 90% relative humidity at 80 °C), water resistivity, chemical, and thermal stability compared to the random copolymer, because block copolymer membranes showed good hydrophilic/hydrophobic phase separation and wide ionic channels. The structures of the resultant PEMs were confirmed by 1H NMR spectroscopy and thermogravimetric analysis (TGA). These membranes were studied by proton conductivity, water uptake (WU), and ion exchange capacity (IEC). Fenton test was attended by Fenton's reagent (4 ppm Fe2+, 3% H2O2) for confirmation of the polymer degradation and the surface morphology of membranes was also analyzed by atomic force microscope. 相似文献
10.
Taewook Ryu Hohyoun Jang Faiz Ahmed Nasrin Siraj Lopa Hanmo Yang Sujin Yoon Inhwan Choi Whangi Kim 《International Journal of Hydrogen Energy》2018,43(10):5398-5404
High molecular weight polymer containing N-methylisatin was synthesized by superacid-catalyzed polyhydroxyalkylation reactions. Their functionality with sulfonic acid groups and the measurement of apposite parameters for proton exchange membranes (PEMs) were described. Sulfonic acid groups were introduced into the polymer through sulfonation reaction with chlorosulfonic acid. The membranes were casted from the solution of sulfonated polymer in dimethylsulfoxide (DMSO). The structural properties of the synthesized polymers were investigated by 1H NMR spectroscopy. The membranes were studied by thermogravimetric analysis (TGA), ion exchange capacity (IEC), water uptake, dimensional stability and proton conductivity assessment. Different levels of sulfonation and ion exchange were tested; the resulting membranes exhibited high proton conductivities of up to 88.63 mS/cm. The sulfonated membranes showed good dimensional stability owing to having all carbon-carbon linkages on polymers' backbone. 相似文献