Evaluating sustainable energy harvesting systems for human implantable sensors

Achieving most appropriate energy-harvesting technique for human implantable sensors is still challenging for the industry where keen decisions have to be performed. Moreover, the available polymeric-based composite materials are offering plentiful renewable applications that can help sustainable development as being useful for the energy-harvesting systems such as photovoltaic, piezoelectric, thermoelectric devices as well as other energy storage systems. This work presents an expert-based model capable of better evaluating and examining various available renewable energy-harvesting techniques in urban surroundings subject to various technical and economic, often conflicting, criteria. Wide evaluation criteria have been adopted in the proposed model after examining their suitability as well as ensuring the expediency and reliability of the model by worldwide experts’ feedback. The model includes establishing an analytic hierarchy structure with simultaneous 12 conflicting factors to establish a systematic road map for designers to better assess such techniques for human implantable medical sensors. The energy-harvesting techniques considered were limited to Wireless, Thermoelectric, Infrared Radiator, Piezoelectric, Magnetic Induction and Electrostatic Energy Harvesters. Results have demonstrated that the best decision was in favour of wireless-harvesting technology for the medical sensors as it is preferable by most of the considered evaluation criteria in the model.     

超临界压力状态氟利昂泄压实验研究

超临界状态的流体从超临界状态向次临界状态的泄压过程,对超临界水冷堆（SCWR）的安全有非常重要的影响。本文通过相似性原理及模化方法,利用临界点较低的氟利昂（R134a）代替水对超临界水冷堆的泄压过程进行了实验研究。泄压过程分别从容器顶部和底部进行,实验集中观测了超临界态流体泄压过程中压力和温度的瞬态变化。实验分析了流体初始状态、泄压孔直径对泄压过程的影响。在等熵泄压过程中观测到工质从超临界状态进入次临界状态时,两相开始产生的压力和温度主要取决于初始状态及泄压的速率。在等熵泄压过程实验中未观测到容器内工质中形成明显的轴向温度分布。     

Lattice Boltzmann Simulation of Convective Heat Transfer from Heated Blocks in a Horizontal Channel

This article presents the application of the multiple-relaxation-time (MRT) lattice Boltzmann equation (LBE) method with nine-velocity model to the numerical prediction of a laminar and convective-heated transfer through a two-dimensional obstructed channel flow. The obstruction is carried out by three obstacles including two located on the upper wall and the other on the lower wall of the channel. The calculations are validated against results available in literature. Various physical arrangements are regarded as the size of the obstacles and the distance between the two upper obstacles to investigate their effects on thermal and flow characteristics. Results, presented for a Prandtl number equal to 0.71 and a Reynolds number ranging from 100 to 1200, showed that the heat transfer and the air flow depend both on the Reynolds number and geometric data of the configuration.     

Impact of irrigation water quality and envelope materials around drip line on emitter performance in subsurface drip irrigation

A field experiment was conducted to study the effect of water quality types of fresh water (FW) and treated wastewater (TWW) and envelope materials of coarse sand (CS), fine sand (FS), and control (CO) on emitter performance, dry matter yield (DMY), and water use efficiency (WUE) under subsurface drip irrigation.The main interaction effect of water quality type and envelope material on coefficient of variation, Christiansen uniformity coefficient, and emission uniformity was not significant (P < 0.05), but they have a significant effect on the average emitter discharge (Q_avg), DMY, and WUE. The means of Q_avg for FW with CS, FS, and CO were 7.13, 6.94, 2.65 L/h, and for TWW, they were 6.78, 6.84, and 2.35 L/h, respectively. The DMY under FW with CS, FS, and CO was 3083.87, 1367.95, and 417.45 kg/ha, and under the TWW, it was 2409.5, 1347.4, and 417 kg/ha, respectively.     

New SRAM design using body bias technique for low‐power and high‐speed applications

In this paper, a new SRAM cell with body‐bias actively controlled by a control circuit and word line is introduced to realize low‐power and high‐speed applications. The cell uses two word lines, which vary between positive and negative voltage levels to control the body bias of cell's transistors. In this design, using a peripheral control circuit with the least possible number of transistors, the access time is decreased and also a trade‐off between static and dynamic power consumption is provided. Compared to a conventional SRAM cell, the proposed cell reduces the static power consumption by 82% and improves the read performance by 40% and the write performance by 27%. Copyright © 2013 John Wiley & Sons, Ltd.     

Chance-Constrained Optimization of Pumping in Coastal Aquifers by Stochastic Boundary Element Method and Genetic Algorithm

In this paper the optimization of groundwater pumping in coastal aquifers under the threat of saltwater intrusion is investigated. The aquifer is inhomogeneous and contains several hydraulic conductivities zones. The aquifer data such as the hydraulic conductivities are uncertain, but with their expected mean and standard deviation values given. A stochastic boundary element method based on the perturbation technique is employed as the simulation tool. The stochastic optimization is handled by the chance-constrained programming. Genetic algorithm is selected as the optimization tool. Numerical examples of deterministic and stochastic problems are provided to demonstrate the feasibility of the proposed schemes.     

Electrodeposition of functionalized Pyrrole (N-[3-(dimethylpyridyl-2-yl)aminopropyl], N-(3-aminopropyl), N-(3-acetamidopropyl) and N-(2-cyanoethyl)) on Stainless Steel gauze for membrane preparation

The preparation of dense membranes for ion separation by the electropolymerization of functionalized pyrrole has been carried out using pyrrole monomers with complexing groups such as amino and bis pyridine. The synthesis conditions of polymer films depend mainly on the applied potential and electrolyte composition; for polymer films derived from pyrrole monomers bearing amino groups, the film synthesis has been achieved only in acid solution. The main results obtained for the electropolymerization of N-(2-cyanoethyl)pyrrole, N-(3-aminopropyl)pyrrole, N-(3-acetamidopropyl)pyrrole and N-[3-(dimethylpyridyl-2-yl)aminopropyl]pyrrole are compared and the experimental conditions for membrane preparation discussed. The thickness and the morphology of the supported conducting polymer membrane prepared at a constant potential depend on the precursor monomer used. The duration of electrolysis should be sufficient to cover the metallic support, particularly for the N-[3-(dimethylpyridyl-2-yl)aminopropyl]pyrrole polymer membrane.     

Resilient modulus–moisture content relationships for pavement engineering applications

In recent years, there has been an increased interest in determining the influence of moisture changes on the resilient modulus (M_R) of subgrade soils beneath pavement structures. Efforts have also been made to develop mathematical models that predict the change in M_R values with moisture. These models are expected to account for seasonal variations in subgrade moisture content. This study evaluates the variation of resilient modulus with post-compaction moisture content of soils in the State of Oklahoma and the State of Pennsylvania. A series of specimens was compacted at optimum moisture content and then tested for resilient modulus; other series of specimens were prepared at optimum moisture content and then either wetted or dried prior to M_R testing. Employed wetting and drying procedures are time-efficient in developing the M_R–moisture relationships. Results showed that M_R–moisture content relationships varied with soil types and M_R values varied inversely with changes of moisture content. In addition, an M_R–moisture model predicting the variation of resilient modulus with moisture contents is proposed. This model can be used to predict changes in the bearing capacity of pavements due to seasonal variations of moisture content.     

Effect of acidic products from degradation of N-methyldiethanolamine amine on CO2/H2S capturing from natural gas

Clean Technologies and Environmental Policy - To evaluate the impact of heat-stable salts on the CO2/H2S separation from natural gas using 45&nbsp;wt% of MDEA amine, we comprehensively and...