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61.
Smart-Grid Security Issues 总被引:3,自引:0,他引:3
Although researchers have spent considerable time on smart-grid cybersecurity issues, major problems remain unsolved. This article presents a high-level review of authentication and encryption solutions for smart-grid architectures. 相似文献
62.
A channel configuration for the elimination of end effects in field-flow fractionation (FFF) channels is simulated and demonstrated for a microfabricated FFF system. In field-flow fractionation, the carrier liquid and sample particles are transferred from a point injection to the full breadth of the rectangular channel using a triangular end piece at the inlet. The nonuniformity in streamline length generated by this end piece results in an increased instrument-related plate height. An additional contribution from the end piece at the outlet of the channel further increases the total band broadening. This paper presents a novel approach to minimize end-effect contributions to plate height by fabricating microstructures in the channel end sections to redistribute the flow streams and force streamline lengths to be more uniform. Numerical analysis of the flow profile and sample dispersion (including spreading of particles due to diffusion and advection) is carried out to investigate the optimized microstructure column size, shape, and placement in the end pieces. The configuration obtained from the numerical simulation results is used to design a prototype device. Experimental measurement of the plate heights for this prototype with an on-chip impedance-based detector shows marked improvement in performance due to the presence of the microstructures in comparison to conventional FFF channel geometry with an average 50% reduction in plate height. The redesigned inlet triangle results in a uniform transition of the point-injected sample into a thin and straight band across the width of the channel at the start of the rectangular section of the fractionation channel. 相似文献
63.
Salim Amena Vishnoi Ritu Dixit Himanshu Chaudhary Vikesh Bhardwaj Jyotsna Gupta Divya Aggarwal Sanjeev Dwivedi Umesh Kumar Kumar Pushpendra Bishnoi Sunita Sharma Ganesh D. Singhal Rahul 《Journal of Materials Science: Materials in Electronics》2022,33(19):15533-15545
Journal of Materials Science: Materials in Electronics - Au nanoparticles are synthesized in a fullerene C60 matrix using the thermal co-evaporation technique. Fullerene C60 is chosen due to its... 相似文献
64.
Sustainability is hinged on innovation. The importance of sustainable innovation management in sustainable supply chain management (SSCM) cannot be underestimated. Studies on SSCM have emphasised the need for sustainable innovation in achieving sustainability but none provide deep insights into sustainable innovation management in SSCM implementation. This lack of research depth stimulates this study to identify and investigate criteria for sustainable supply chain management innovation advancement. This paper proposes a sustainable innovation criteria framework for investigating sustainable supply chains in manufacturing companies. To exemplify the applicability and efficiency of the proposed framework, a sample of five Indian manufacturing companies are used to evaluate and prioritise the sustainable innovation management criteria, using the ‘best–worst’ multi-criteria decision-making (BW-MCDM) model. The criteria weights for all companies from BWM are aggregated, averaged and used for ranking. The respondent managers viewed ‘financial availability for innovation’ as the most important sustainable innovation sub-criteria. The results of the study will inform industrial managers, practitioners and decision-makers on which criteria to focus on during the implementation stage, to increase sustainability in manufacturing supply chains, and further advance corporate and supply chain sustainable development. The framework may also serve as a theoretical construct for a future empirical study on sustainable supply chain innovation in the manufacturing sector. This paper sets the stage for further research in sustainable innovation practices in the manufacturing sector and its supply chains. 相似文献
65.
A perfect antireflection (AR) coating would remove completely the reflection from an interface between two media for all wavelengths, polarizations, and angles of incidence. The degree to which this can be achieved is investigated numerically. It is shown that wideband solutions can be found provided that layers can be deposited with refractive indices that are close to that of the low-index medium. Thus realistic solutions exist for interfaces between two solid media. Narrow-band high-angle AR solutions are also possible for polarized light and for unpolarized light in the vicinity of certain reststrahlen bands. 相似文献
66.
67.
Himanshu Sharma karthikeyan Rajagopal G. Gugapriya Rajneesh Pareek Arun Kumar Haya Mesfer Alshahrani Mohamed K. Nour Hany Mahgoub Mohamed Mousa Anwer Mustafa Hilal 《计算机系统科学与工程》2023,45(2):1199-1210
Multicarrier Waveform (MCW) has several advantages and plays a very important role in cellular systems. Fifth generation (5G) MCW such as Non-Orthogonal Multiple Access (NOMA) and Filter Bank Multicarrier (FBMC) are thought to be important in 5G implementation. High Peak to Average Power Ratio (PAPR) is seen as a serious concern in MCW since it reduces the efficiency of amplifier use in the user devices. The paper presents a novel Divergence Selective Mapping (DSLM) and Divergence Partial Transmission Sequence (D-PTS) for 5G waveforms. It is seen that the proposed D-SLM and PTS lower PAPR with low computational complexity. The work highlighted a combination of multi-data block partial transmit schemes along with tone reservation. In this, an overlapping factor is used to determine the number of data blocks for every group. Here, considering only those data blocks that have minimum signal power, the use of DSLM and DPTS are required to eliminate the segment’s peaks. Simulation results reveal that the suggested hybrid technique proves to be better than the conventional PTS scheme. Furthermore, the power saving performance of FBMC and NOMA is compared with the Orthogonal Frequency Division Multiplexing (OFDM) waveform. 相似文献
68.
In the current research work, performance enhancement of stepped solar still (SSS) having an external reflector (ER) and glass cover cooling (GCC) arrangements is presented. The individual and combined effects of ER and GCC on the performance of SSS have been evaluated and compared with simple SSS. The GCC reduces the glazing temperature significantly and results in increased distillate. The ER reflected the solar radiation inside the basin that increases the water temperature, consequently increasing distillate. The SSS having ER and GCC (SSS-ER-GCC) gave a maximum distillate of 4.340 kg/m2 which was observed, respectively, 12.43%, 3.21%, and 1.36% higher than that of simple SSS, SSS with ER (SSS-ER) and SSS with GCC (SSS-GCC). The average energy efficiency of SSS-ER-GCC was evaluated as 40.78%, which was found to be 14.36%, 7.84%, and 10.64%, respectively, higher than that of simple SSS, SSS-ER, and SSS-GCC. The carbon credits earned and CO2 mitigation were found the maximum for SSS-ER-GCC having values $65.96 and 4.40 tons, respectively. The economic payback period was found the minimum (490 days) for SSS-ER-GCC. 相似文献
69.
This study investigates the individual and cumulative effects of phase change material (PCM) and evacuated tube collector (ETC) on the performance of a stepped solar still (SSS). Experiments have been performed on SSS, SSS loaded with PCM (SSS-PCM), SSS coupled with ETC (SSS-ETC), and SSS loaded with PCM and coupled with ETC (SSS-PCM-ETC). An innovative way of loading paraffin wax as PCM is introduced to utilize solar energy efficiently for the distillation process during off-sunshine hours. ETC is used to provide pre-heated RO wastewater to the distillation unit. The distillate output was observed maximum for SSS-PCM-ETC (4.97 kg/m2 day) which is 99% more than that of the SSS unit. The PCM and ETC individually with SSS unit increases the distillate output by 31% and 24%, respectively. The working time of the distillation unit was observed to be increased by 3 h by the use of PCM. The total heat transfer coefficient was evaluated at the maximum for SSS-PCM-ETC and was observed in the range of 16.94–167.04 W/m2 °C. The thermal energy efficiencies of SSS, SSS-ETC, SSS-PCM, and SSS-PCM-ETC were evaluated as 28.65%, 35.59%, 43.88%, and 44.04%, respectively. SSS-PCM-ETC is found to be the most economic with the best environmental conservation having maximum values of daily productive cost ($0.69) and carbon credits earned ($184.8). 相似文献
70.
This research is part of a project whose scope was to develop high strength ternary alloys based on Cu-Ti system with the
primary aim of substituting them for toxic and expensive Cu-Be alloys. In this pursuit, age hardening behaviour of Cu-4Ti-1Cd
alloy has already been investigated and the present paper reports the investigations on the influence of prior cold work by
rolling of 50, 75 and 90% on the age hardening of a Cu-4Ti-1Cd alloy using hardness and tensile tests and optical as well
as transmission electron microscopy. As a result of cold work followed by aging, hardness of the alloy increased from 237 Hv
in solution treated condition to 425 Hv on 90% cold work and peak aging. Similarly, yield and tensile strengths of the alloy
reached maxima of 1037 and 1252 MPa respectively on 90% deformation and peak aging. The microstructure of the deformed alloy
exhibited elongated grains and deformation bands. The maximum strength on peak aging was obtained due to precipitation of
ordered, metastable and coherent βl, Cu4Ti phase in addition to high dislocation density and deformation twins. Both hardness and strength of the alloy decreased
on overaging due to the formation of incoherent and equilibrium β, Cu3Ti phase. However, the morphology of the discontinuous precipitation was changed to globular shape due to large deformations
and overaging. 相似文献