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111.
Lo?c Petigny Sandrine Périno Matteo Minuti Francesco Visinoni Jo?l Wajsman Farid Chemat 《International journal of molecular sciences》2014,15(5):7183-7198
Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant. 相似文献
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Jian-Yu Shih Yen-Chi Chen Chih-Hung Chiu Chung-Lun Lo Chi-Chung Chang Kuan-Neng Chen 《Nanoscale research letters》2014,9(1):541
This paper presents one wafer level packaging approach of quartz resonator based on through-silicon via (TSV) interposer with metal or polymer bonding sealing of frequency components. The proposed silicon-based package of quartz resonator adopts several three-dimensional (3D) core technologies, such as Cu TSVs, sealing bonding, and wafer thinning. It is different from conventional quartz resonator using ceramic-based package. With evaluation of mechanical structure design and package performances, this quartz resonator with advanced silicon-based package shows great manufacturability and excellent performance to replace traditional metal lid with ceramic-based interposer fabrication approach. 相似文献
114.
Nawfal Blal Lo?c Daridon Yann Monerie Stéphane Pagano 《International Journal of Fracture》2012,178(1-2):71-83
In this study, criteria on the artificial compliance due to intrinsic cohesive zone models are presented. The approach is based on a micromechanical model for a collection of cohesive zone models embedded between each mesh of a finite element-type discretization. The overall elastic behaviour of this cohesive volumetric medium is obtained using homogenization techniques and is given in a closed-form as function of bulk properties of the relevant material and mesh parameters (the mesh type and size). Practical criteria are obtained for the calibration of the cohesive stiffnesses bounding the additional compliance inherent to intrinsic cohesive zone models by lower value. For isotropic planar discretizations (e.g. Delaunay mesh), a rigorous bound is derived whereas convenient estimates are given for non-isotropic discretizations (e.g. regular mesh). 相似文献
115.
Feifei Li Haoqiang Ai Changmin Shi Kin Ho Lo Hui Pan 《International Journal of Hydrogen Energy》2021,46(24):12886-12896
Electrochemical CO2 reduction reaction (CO2RR) is an efficient way in the utilization of CO2. In this work, single transition-metal (TM) atom (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) anchored on two-dimensional (2D) Ti2CN2 are designed for CO2RR using density-functional-theory (DFT) calculation. We show that Ti2CN2 serves as an excellent substrate to support single atom catalysts (SACs), compared to Ti2CO2 and Ti2CF2. We find that the Sc, Ti and V supported on Ti2CN2 show high catalytic activities to produce CO with a low overpotential of 0.37, 0.27, and 0.23 eV, respectively. Differently, the Mn and Fe on Ti2CN2 are catalytically active for the production of HCOOH with a low overpotential of 0.32 and 0.43 eV, respectively. We further show that the negatively charged TM-Ti2CN2 can capture and activate CO2 more effectively, and the catalytic activity and selectivity can be significantly tuned by injecting extra electrons. 相似文献
116.
Thomas L. Bougher Luke Yates Chien-Fong Lo Wayne Johnson 《Nanoscale and Microscale Thermophysical Engineering》2016,20(1):22-32
In this work, we investigate the thermal boundary resistance and thermal conductivity of GaN layers grown on Si with 100 nm AlN transition layers using time domain thermoreflectance (TDTR). The GaN layers ranged from 0.31 to 1.27 μm. Due to the challenges in determining the thermal boundary resistance of the buried interfaces found in this architecture, a new data reduction scheme for TDTR that utilizes a Monte Carlo fitting method is introduced and found to dramatically reduce the uncertainty in certain model parameters. The results show that the GaN thermal conductivity does not change significantly with layer thickness, whereas the resistance of the AlN layer decreases slightly with GaN thickness. 相似文献
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118.
Yen-Jen Wang Teng-Yuan Lo Chieh-Hsi Wu Dean-Mo Liu 《Journal of the Royal Society Interface》2013,10(86)
In this communication, we report a facile nanotopographical control over a stainless steel surface via an electrophoretic deposition of colloidal amphiphilic chitosan for preferential growth, proliferation or migration of vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atomic force microscopy revealed that the colloidal surface exhibited a deposition time-dependent nanotopographical evolution, wherein two different nanotopographic textures indexed by ‘kurtosis’ (Rkur) value were easily designed, which were termed as ‘sharp’ (i.e. high peak-to-valley texture) surface and ‘flat’ (i.e. low peak-to-valley texture) surface. Cellular behaviour of VSMCs and HUVECs on both surfaces demonstrated topographically dependent morphogenesis, adherent responses and biochemical properties in comparison with bare stainless steel. The formation of a biofunctionalized surface upon a facile colloidal chitosan deposition envisions the potential application towards numerous biomedical devices, and this is especially promising for cardiovascular stents wherein a new surface with optimized texture can be designed and is expected to create an advantageous environment to stimulate HUVEC growth for improved healing performance. 相似文献
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This work builds on papers published in Transactions during 2015 and 2018 reporting research into low-cost commercial methods for the prevention of nickel release from decorative nickel plated articles, rendering them suitable for placement on the European market in accordance with the requirements of REACH. ‘Nickel Allergy’ sometimes occurs when nickel-containing articles are in direct and prolonged contact with the skin, leading to corrosion of elemental nickel by sweat, liberating sufficient nickel ions to be absorbed through the skin and initiate an allergenic effect. The EU ‘Nickel Restrictions’ impose limits on the amount of nickel released from articles intended for use in this application, but permits a non-nickel surface coating that can ensure the rate of nickel release does not exceed 0.5?µg?cm?2 week?1 after 2 years of normal use. The official tests for coated items are simulated wear and corrosion under EN 12472 followed by determination of nickel release under EN 1811. Earlier work concluded that suitable barrier coatings over bright electrodeposited nickel are regular chromium deposited from a hexavalent electrolyte, microporous trivalent chromium from a chloride electrolyte and UV cured PU electrophoretic coatings. Further tests reported here focused on nickel release from examples of wearable articles such as costume jewellery and watch cases. A typical flash coating of gold over bright nickel is thin and porous and being more noble, causes the rate of nickel release to be accelerated; but this can be prevented by an intermediate barrier coating of electrodeposited palladium. To round out the relevance of this study on wearable articles, nickel release tests were also conducted on nickel-containing Grades 304 (UNS S30400) and 316 (UNS S31600) austenitic stainless steels, plus a typical gold alloy containing nickel. All passed the nickel release tests satisfactorily. 相似文献