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81.
    
Recently, an authentication scheme was presented for health-care in IoT for WBANs by Fotouhi et al. Authors asserted their scheme to be free from a number of attacks. Here, we find that Fotouhi et al.'s scheme suffers from insider attack, fails to provide proper authentication and bears inefficient password update phase. Therefore their scheme has security pitfalls that can lead to further security breaches. We remove the weaknesses of Fotouhi et al.'s scheme and hence propose a user authentication scheme for patient care. Our scheme is suitable for providing special care to patients in the healthcare industry. The proposed scheme facilitates health professionals to access the real-time data of patients under treatment for some diseases. It also safeguards the medical staff from catching an infection from the patients by minimizing the need to come in direct contact with the patients. We justify the security of our proposed scheme by applying the random oracle model to it. The proposed scheme is compared with some related works to judge its efficacy over the compared counterparts.  相似文献   
82.
    
The mechanical and electrical properties were investigated for nanocomposites based on carbon nanotubes (CNTs) and conductive carbon black (CB). Solution room‐temperature‐vulcanized silicone rubber was used as a matrix. Vulcanizates based on CNTs and CB was prepared by solution mixing. With the addition of 2 phr of CNTs to the rubber matrix, the Young's modulus increased by 272% and reached as high as ~706% at 8 phr, whereas the modulus increased only 125% for CB specimens at 10 phr. Similarly, the electrical properties at 5 phr content of CNT were ~0.7 kΩ against ~0.9 kΩ at 20 phr CB. The Kraus plot from equilibrium swelling tests shows that the high properties for CNT specimens are due to high polymer–filler interfacial interactions, the small particle size that improves the distribution of the filler in a highly exfoliated state, and high electrical connective networks among the filler particles. These improvements can especially influence medical products such as feeding tubes, seals and gaskets, catheters, respiratory masks and artificial muscles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44407.  相似文献   
83.
84.
    
In India, little attention has been paid on antimicrobial resistance (AMR) in the context of developing “One Health” approach. Hence, utilizing multi-disciplinary approach, we assess the AMR level and dynamics/pattern of multi-drug resistance (MDR) in Escherichia coli, Salmonella spp., and Staphylococcus aureus circulating over the different stages of poultry in India. A total of 342 isolates including E. coli (n = 143), Salmonella spp. (n = 104), and S. aureus (n = 95) were recovered from fecal (n = 80) and cecal (n = 80) samples of chicken, collected across the different poultry-retail shops and poultry-farms located at urban and rural areas of Rajasthan, India, respectively. High rates of AMR to drugs that are critically/highly important both in human and veterinary medicine were observed among all the isolates. Upward trends in AMR prevalence was observed in poultry-retail shops than in poultry-farms. Notably, >90% of all the isolates were MDR, of particular, pattern/prevalence of MDR was substantially varied across the poultry-farms vs. poultry-retail shops. Our results indicate AMR including MDR to be common in E. coli, Salmonella spp., and S. aureus distributed frequently in poultry. The study encourages the formulation of national policy, programmes and further research with a “One Health” approach that can benefits to the human/animal and the environment.  相似文献   
85.
    
The Michael addition of amines with enones for synthesizing β‐amino carbonyls constitutes a valuable transformation in organic chemistry. While various catalyst have been made available for catalyzing the Michael addition of aromatic amines to enones but there is no report of using α‐amylase enzyme to catalyze this transformation. The α‐amylase from Aspergillus oryzae was found to catalyze the Michael addition of various aryl (hetero) amines to methyl vinyl ketone with high catalytic efficiency (63–83% yield). A hybrid of α‐amylase with copper nanoparticle (α‐amylase@CuNPs) has been prepared and used to catalyze this transformation as a reusable catalyst. Further, an application of α‐amylase catalyzed aza‐Michael addition in the cascade reactions has been exhibited by synthesizing biologically important 3‐acetyl quinoline. In addition, molecular docking and molecular dynamics (MD) simulation studies are carried out to get insight into the key interactions of the substrates with the amino acid residues near the active site and the probable reaction mechanism, which reveals Glu230 and Asn295 play a crucial role in the substrate activation process.

  相似文献   

86.
    
In this work, polyethylene glycol (PEG) as a phase change material (PCM) was incorporated with palygorskite (Pal) clay to develop a novel form-stable composite PCM (F-SCPCM). The Pal/PEG(40 wt%) composite was defined as F-SCPCM and characterized using SEM/EDS, FT-IR, XRD, DSC, and TGA techniques. The DSC results revealed that the F-SCPCM has a melting temperature of 32.5°C and latent heat capacity of 64.3 J/g for thermal energy storage (TES) applications. Thermal cycling test showed that the F-SCPCM had good cycling thermal/chemical stability after 500 cycles. The TGA data proved that that both cycled and non-cycled F-SCPCMs had considerable high thermal durability. Consequently, the created F-SCPCM could be considered as an additive material for production of green construction components with TES capability. POLYM. ENG. SCI., 60:909–916, 2020. © 2020 Society of Plastics Engineers  相似文献   
87.
    
MXenes exhibit excellent capacitance at high scan rates in sulfuric acid aqueous electrolytes, but the narrow potential window of aqueous electrolytes limits the energy density. Organic electrolytes and room-temperature ionic liquids (RTILs) can provide higher potential windows, leading to higher energy density. The large cation size of RTIL hinders its intercalation in-between the layers of MXene limiting the specific capacitance in comparison to aqueous electrolytes. In this work, different chain lengths alkylammonium (AA) cations are intercalated into Ti3C2Tx, producing variation of MXene interlayer spacings (d-spacing). AA-cation-intercalated Ti3C2Tx (AA-Ti3C2), exhibits higher specific capacitances, and cycling stabilities than pristine Ti3C2Tx in 1 m 1-ethly-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMIMTFSI) in acetonitrile and neat EMIMTFSI RTIL electrolytes. Pre-intercalated MXene with an interlayer spacing of ≈2.2 nm, can deliver a large specific capacitance of 257 F g−1 (1428 mF cm−2 and 492 F cm−3) in neat EMIMTFSI electrolyte leading to high energy density. Quasi elastic neutron scattering and electrochemical impedance spectroscopy are used to study the dynamics of confined RTIL in pre-intercalated MXene. Molecular dynamics simulations suggest significant differences in the structures of RTIL ions and AA cations inside the Ti3C2Tx interlayer, providing insights into the differences in the observed electrochemical behavior.  相似文献   
88.
    
An alternate option for improving the performance of the thermoelectric heat pump (TEHP) is the variation in thermoelectric leg configuration. In this paper, the thermodynamic model based on first and second law of thermodynamics for an exoreversible TEHP including influence of Thomson effect as well as leg geometry on the coefficient of performance and heating load of the device has been developed and optimized. Modified expressions have been derived analytically for dimensionless heating load, irreversibilities, figure of merit, energy, and exergy efficiency. The effects of operating and geometry parameters such as shape parameter (Ac/Ah), temperature ratio (Tc/Th), Thomson effect, thermal and electrical contact resistances on the coefficient of performance, and heating load of the TEHP have been analysed. The results indicate that the Thomson effect has adverse effect on heating load of the system. The optimal parameters obtained through GA optimization process have been compared with the optimal parameters obtained through analytical method which proved the validity of GA optimization method for optimization of TEHP. After the testing, the GA optimization has been performed to determine the optimum parameters corresponding to maximum energy efficiency and maximum heating load. It was found that the GA population converges quickly after 20 runs only which proved the GA as time and cost‐effective optimization tool. This study will be useful for designing of practical TEHP systems of different leg geometries.  相似文献   
89.
    
This study investigated the role of flaxseed meal (FSM), a rich terrestrial source of ω-3 fatty acids, in the alteration of the fatty acid profile and metabolism, health indices, physicochemical properties, and sensory quality of broiler chicken meat. The broiler chickens were fed 100 g FSM kg−1 diet for different time periods (1, 2, 3, 4, and 5 weeks). The results revealed that 100 g FSM feeding in broiler chickens for at least 3 weeks increased (P < 0.01) the EPA, DHA, MUFA, PUFA, ω-3 PUFA, and ω-6 PUFA of broiler chicken meat with the corresponding decrease in palmitic acid, stearic acid, and SFA content. 100 g FSM feeding up to 3 weeks has increased the Δ9-desaturases (P < 0.05), thioesterase index (P < 0.01), and Δ5-desaturase + Δ6-desaturase activity (P < 0.01) along with an improvement in health indices (P < 0.01) of chicken meat. Similarly, a reduction in meat cholesterol and fat content of thigh meat (P < 0.01) was observed by feeding 100 g FSM for at least 3 weeks with no effect on the pH, color scores, and sensory evaluation of broiler chicken meat. The water-holding capacity (WHC) and extract release volume (ERV) decreased, whereas, drip loss of meat increased (P < 0.01) due to the feeding of 100 g FSM beyond 3 weeks. Thus, this study concluded that 100 g FSM feeding for 3 weeks in broiler chickens significantly improves the fatty acid profile, lipid metabolism, and health indices of meat, without compromising the physicochemical properties of broiler chicken meat.  相似文献   
90.
    
Rubber nanocomposites were prepared by mixing room‐temperature‐vulcanized (RTV) silicone rubber and nanofillers such as graphitic nanofillers (GRs), carbon nanotubes (CNTs), and carbon black (CB) for industrial applications. The possible correlations were examined between the properties and morphology of the fillers. The vulcanizates based on the CNT hybrid showed higher reinforcement with as an elastic modulus of ∼5.3 MPa compared to ∼3.2 MPa for GR flakes and ∼3.1 MPa for the CB hybrid at 8 phr. Similarly, lower resistances of 17 kΩ at 4 phr and 0.7 kΩ at 12 phr were obtained for the CNT hybrid. A correlation was determined between the mechanical and electrical properties in enhancing the displacements of the nanocomposites when used in actuators. Such improvements might be useful for flexible electrodes, energy harvesting, or actuators. POLYM. COMPOS., 40:E373–E382, 2019. © 2017 Society of Plastics Engineers  相似文献   
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