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排序方式: 共有1369条查询结果,搜索用时 15 毫秒
1.
Thakur Divyansh Kumar Yugal Kumar Arvind Singh Pradeep Kumar 《Wireless Personal Communications》2019,104(1):471-489
Wireless Personal Communications - Data security is currently become a serious concern in wireless communication system for both the users and providers. Without a secure medium, the data... 相似文献
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High‐performance thermosets with tailored properties derived from methacrylated eugenol and epoxy‐based vinyl ester 下载免费PDF全文
Yuehong Zhang Yuzhan Li Vijay Kumar Thakur Zhenhua Gao Jiyou Gu Michael R Kessler 《Polymer International》2018,67(5):544-549
A renewable chemical, eugenol, is methacrylated to produce methacrylated eugenol (ME) employing the Steglich esterification reaction without any solvent. The resulting ME is used as a low‐viscosity co‐monomer to replace styrene in a commercial epoxy‐based vinyl ester resin (VE). The volatility and viscosity of ME and styrene are compared. The effect of ME loading and temperature on the viscosity of the VE–ME resin is investigated. Moreover, the thermomechanical properties, curing extent and thermal stability of the fully cured VE–ME thermosets are systematically examined. The results indicate that ME is a monomer with low volatility and low viscosity, and therefore the incorporation of ME monomer in VE resins allows significant reduction of viscosity. Moreover, the viscosity of the VE–ME resin can be tailored by adjusting the ME loadings and processing temperature to meet commercial liquid molding technology requirements. The glass transition temperatures of VE–ME thermosets range from 139 to 199 °C. In addition, more than 95% of the monomer is incorporated and fixed in the crosslinked network structure of VE–ME thermosets. Overall, the developed ME monomer exhibits promising potential for replacing styrene as an effective low‐viscosity co‐monomer. The VE–ME resins show great advantages for use in polymer matrices for high‐performance fiber‐reinforced composites. This work is of great significance to the vinyl ester industry by providing detailed experimental support. © 2018 Society of Chemical Industry 相似文献
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Ajay Jaryal Suresh Thakur Joginder Singh Pathania Sanjay Vikrant Dinesh Kumar Lokesh Verma 《Hemodialysis international. International Symposium on Home Hemodialysis》2020,24(1):E10-E12
Neurological complications are common in patients with acute or chronic renal failure, especially when there is marked reduction in the glomerular filtration rate (GFR). One such clinical syndrome, uremic encephalopathy (UE), occurs due to widespread dysfunction of central nervous system (CNS). It manifests with myriad clinical features and usually is suggested by bedside elicitation of asterixis (flapping tremor). Symptomatic involvement of the basal ganglia manifesting as choreoathetosis and clinical and radiological resolution with hemodialysis has been reported in the medical literature, but only rarely. The present report details such a case. 相似文献
5.
Chatterjee Tanmoy Essien Aniekan Ganguli Ranjan Friswell Michael I. 《Neural computing & applications》2021,33(23):16809-16828
Neural Computing and Applications - This paper addresses the influence of manufacturing variability of a helicopter rotor blade on its aeroelastic responses. An aeroelastic analysis using finite... 相似文献
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Maurya Ranjan Kumar Kaur Rajvinder Kumar Ramesh Agarwal Ajay 《Microsystem Technologies》2019,25(10):3933-3941
Microsystem Technologies - This paper reports the development of a novel electronic micro-viscometer capable of measuring viscosity of different Newtonian fluids using less than 100 µl which... 相似文献
7.
Das Swarup Chattopadhyay Krishnendu Bhadra Chaudhuri Sekhar Ranjan 《Wireless Personal Communications》2020,110(2):677-698
Wireless Personal Communications - In this paper a combination of rectangular and elliptical fractal geometry is applied on a regular hexagonal wide slot antenna fabricated using a FR4 substrate to... 相似文献
8.
Moges Abebe Barik Chitta Ranjan Purohit Sukumar Goud Vaibhav V. 《Food science and biotechnology》2021,30(12):1555-1569
Food Science and Biotechnology - The physico-chemical, polyphenols, antioxidant and antibacterial properties of berries and mixture of male and female leaves of Hippophae salicifolia were... 相似文献
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In the current study, a combination of acrylic polyol (AP) and ester polyol (EP) were synthesized and reacted at variable ratios with hexamethylene diisocyanates and isophorone diisocyanates to prepare a transparent two-component polyurethane (PU) coating formulation. The formations of the polyol system, isocyanate system, and the PU systems were confirmed by 1H nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Transparency of the coatings was examined using haze, and gloss measurement, which showed acrylic-ester-polyurethane (aePU-5 and aePU-6) have 91.5% and 91.8% transparency and gloss of 90.3 and 90.7 GU respectively. The thermal properties like Tg and the thermal stability of the coatings were verified using differential scanning calorimetry, and thermogravimetric analysis respectively which was found to increase with increasing EP content and decreasing AP content which may be ascribed to improved compatibility of copolymers, and homogeneity in PU along with enhanced crosslinking density. The degree of adhesion of coating with the substrate was validated from lap-shear, and cross-cut tape test which showed improved performance at AP:EP ratio of 60:40. The coatings were found to exhibit resistance toward pencil hardness with aePU-5 and aePU-6 having the optimum resistance of 9H. The surface morphology and topography were observed under scanning electron microscopy, and atomic force microscopy, respectively. The outcome confirms the higher smoothness of the surfaces subjected to the increase in EP content. The PU system with 40 wt% AP content and 60 wt% EP designated as aePU-5 was found to exhibit optimum performance. 相似文献
10.
Gold nanoparticles (AuNPs) of about 5 nm in diameter were biosynthesized at room temperature (300 K). The PVA/2.5 wt% KH2PO4 or KDP composite film and PVA/2.5 wt% KDP/AuNPs nanocomposite films with different concentrations of AuNPs were prepared. Interestingly, addition of 0.05 wt% of AuNPs to the PVA/2.5 wt% KDP percolative composite film destroys percolative behavior of this composite film. Furthermore, the PVA/2.5 wt% KDP/0.05 wt% AuNPs nanocomposite film exhibited high room temperature dielectric permittivity (ε′ ∼ 590 at 1 kHz). The behavior of AC conductivity (σac) of the nanocomposite films indicated correlated barrier hopping type of conduction mechanism. The Cole–Davidson dielectric response becomes evident as the interfacial polarization process acquires a more symmetric form, tending to Debye relaxation. High value of ε′ promises direct application in capacitors. Moreover, the novel feature of destroying the percolative behavior by AuNPs may be applied even in other systems. 相似文献