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71.
Linus Hammar Jimmy Ehnberg Alberto Mavume Boaventura C. Cuamba Sverker Molander 《Renewable & Sustainable Energy Reviews》2012,16(7):4938-4950
Several African countries in the Western Indian Ocean (WIO) endure insufficiencies in the power sector, including both generation and distribution. One important step towards increasing energy security and availability is to intensify the use of renewable energy sources. The access to cost-efficient hydropower is low in coastal and island regions and combinations of different renewable energy sources will play an increasingly important role. In this study the physical preconditions for renewable ocean energy are investigated, considering the specific context of the WIO countries. Global-level resource assessments and oceanographic literature and data have been compiled in an analysis of the match between technology-specific requirements for ocean energy technologies (wave power, ocean thermal energy conversion (OTEC), tidal barrages, tidal current turbines, and ocean current power) and the physical resources in 13 WIO regions Kenya, Seychelles, Northern Tanzania and Zanzibar, Southern Tanzania, Comoros and Mayotte, Northern-, Central-, and Southern Mozambique, Western-, Eastern-, and Southern Madagascar, Réunion, and Mauritius. The results show high potential for wave power over vast coastal stretches in southern parts of the WIO and high potential for OTEC at specific locations in Mozambique, Comoros, Réunion, and Mauritius. The potential for tidal power and ocean current power is more restricted but may be of interest at some locations. The findings are discussed in relation to currently used electricity sources and the potential for solar photovoltaic and wind power. Temporal variations in resource intensity as well as the differences between small-scale and large-scale applications are considered. 相似文献
72.
Despite the small or near-zero Seebeck coefficient of metallic nanotubes, a nanotube film can be readily scaled up in length. Thus so can its thermoelectric power. In this work, we inserted a nanomesh pattern into a carbon nanotube film by using an anodized aluminum oxide membrane as an etching mask. We found that by patterning densely packed nanoscale holes into the nanotube film, its total thermoelectric power can be further increased, by as much as 30% (from 29 to 39 μV K(-1)). We present this finding, attributed to electron localization due to nanopatterning, as indicative of the potential of a new degree of freedom. 相似文献
73.
Jimmy Xu 《哈尔滨工业大学学报(英文版)》2021,28(1):1-11
Physical coloration stimulated the development of a new era of science and technology some hundred years earlier. It is now again presenting us new opportunities and challenges on multiple fronts. This article focuses on a selectively few of them that are more directional in nature: scalable nanomanufacturing of physical coloration, physical amplification of colorimetric sensing, and provision of biophilic lighting with real-time full-spectrum physical coloration. Physical coloration is a rather large multi-dimensional field that is open and awaiting for creative minds and hands. Its impact has been broad and profound to the well-being of humankind. This article attempts to complement the reviews of broad scopes available in literature by one with a narrower focus on the more recent advances on the three fronts. 相似文献
74.
Experimental and numerical investigation of laminated steel sheet in V-bending process considering nonlinear visco-elasticity of polymer layer 总被引:1,自引:0,他引:1
Laminated steel sheet consists of two steel sheets and a polymer layer which bonds them. During forming process, mechanical properties of polymer layer significantly influence the shape of final product. In this study, a continuum model in which nonlinear visco-elasticity is taken into account has been developed for polymer layer of laminated steel sheet and implemented in a commercial finite element program by material subroutines. Lap-shear test and T-peel test have been conducted to obtain parameters of this continuum model. Two different methods are compared to establish a better method for modeling the polymer layer deformation in lap-shear test simulation. One is cohesive zone element and the other is contact method. In order to assess calculation efficiency, both explicit and implicit procedures are used to simulate lap-shear test, and T-peel test is simulated by implicit procedure to evaluate accuracy. The result indicates that cohesive element is easier to solve convergence problem and implicit procedure may save much simulation time. T-peel test data can be used to describe the normal mechanical behavior of polymer layer in an acceptable range. Finally, V-bending forming process has been studied to investigate the effect of polymer layer on the springback and final deformation shape through experiment and numerical simulation. The result indicates that the comparison between numerical simulation and experiment is in good agreement. The finite element model can accurately predict the final shape after bending and springback. 相似文献
75.
Yin Liang Katherine Song Leo Shaw Michael Zhu Alex Tait Nicole Businelli Jane Yang Ryan Soussan Haonan Zhou Jimmy Lu Thomas Mbise 《International Journal of Hydrogen Energy》2011,36(21):13880-13887
As a highly reactive gas, hydrogen presents significant challenges for its acquisition and safe storage. Consequently, the viability of a sustainable hydrogen economy greatly depends on the development of an efficient, cost-effective method of hydrogen production. One model for addressing this challenge is to deploy portable hydrogen generators for the home. The Princeton University Chapter of the International Association for Hydrogen Energy (IAHE-PU) has designed and created a generator that produces hydrogen through water electrolysis and optimizes cost effectiveness and portability while maximizing hydrogen output.For our proof-of-concept, the system utilizes simple household items with a Sharp ND130UJF 130W solar panel. In our design, Ni electrodes submerged in 8 M KOH solution in six glass containers were utilized to power an external circuit. Over 1 h, our system produced 8.61 L of hydrogen gas at an estimated cost of $8.58 per kilogram of hydrogen gas over the 25-year lifetime of the solar panel. 相似文献
76.
77.
Direct encapsulation of water-soluble drug into silica microcapsules was facilely achieved by a sol-gel process of tetraethoxysilane (TEOS) in W/O emulsion with hydrochloric acid (HCl) aqueous solution containing Tween 80 and drug as well as cyclohexane solution containing Span 80. Two water-soluble drugs of gentamicin sulphate (GS) and salbutamol sulphate (SS) were chosen as model drugs. The characterization of drug encapsulated silica microcapsules by scanning electronic microscopy (SEM), FTIR, thermogravimetry (TG) and N2 adsorption-desorption analyses indicated that drug was successfully entrapped into silica microcapsules. The as-prepared silica microcapsules were uniform spherical particles with hollow structure, good dispersion and a size of 5-10 μm, and had a specific surface area of about 306 m2/g. UV-vis and thermogravimetry (TG) analyses were performed to determine the amount of drug encapsulated in the microcapsules. The BJH pore size distribution (PSD) of silica microcapsules before and after removing drug was examined. In vitro release behavior of drug in simulated body fluid (SBF) revealed that such system exhibited excellent sustained release properties. 相似文献
78.
Atomistic and coarse-grained (CG) models of cross-linked sulfonated Poly (1, 3-cyclohexadiene) (xsPCHD) were developed and implemented in Molecular Dynamics (MD) simulations of PCHD chains with different architectures. In the atomistic model, PCHD chains are cross linked by a sulfur–sulfur bond. Sulfonic acid groups are evenly distributed along the chain. The architecture is specifically aimed for application as a proton exchange membrane used in fuel cells. An atomistic force field for this architecture was tested and applied in the atomistic MD simulation of xsPCHD for the first time. The atomistic simulations generate the density and cross-linker separation distribution. To further study the structural properties of longer chain systems, a CG model was proposed. The bonded structural probability distribution functions (PDFs) and non-bonded pair correlation function (PCF) of the CG beads were obtained from the atomistic simulation results. The bonded CG potentials are obtained by simple inversion of the corresponding PDFs. The CG non-bonded potential is parameterized to the PCF using the Iterative Boltzmann Inversion (IBI) method. The CGMD simulations of xsPCHD chains using potentials from above method satisfactorily reproduce the structural properties from atomistic MD simulation of the same system. The transferability of the CG potentials has been further tested through CGMD simulation of xsPCHD homopolymer with different architectures. 相似文献
79.
介绍了含磁液磁路系统中音圈的力学特性,一般讨论中该范畴内容常分两大部分:即静力学特性和动力学特性.着重讨论的是含磁液磁路系统音圈的动力学特性并对之进行了分析. 相似文献
80.
Johanna Mårtensson Markus Nilsson Freddy Ståhlberg Pia C. Sundgren Christer Nilsson Danielle van Westen Elna-Marie Larsson Jimmy Lätt 《Magma (New York, N.Y.)》2013,26(6):527-537