Bioelectricity: a new approach to provide the electrical power from vegetative and fruits at off-grid region

In this research, we studied the performance of different vegetative and fruits electrochemical cells namely PKL, Aloe Vera, Tomato and Lemon juice electrochemical cells with load condition for 2:1 Zn/Cu based electrodes. It was also studied the variation of Load Voltage (V_L), Load Current (I_L), and Load Power (P_L), with the variation of time for PKL, Aloe Vera, Tomato and Lemon juice electrochemical Cells. Among those cells the PKL electrochemical Cell was more efficient than the other three types of Cells regarding the load Current (I_L), Load Voltage (V_L), and Load Power (P_L). However, we investigated the performance of different types of Cells without load condition for 1:1 Zn/Cu based electrodes. Moreover, the variation of open circuit voltage (V_oc), short circuit current (I_sc) and maximum power (P_max) with the variation of time for those cells were explored. The discharge characteristic of the PKL electrochemical cell was more effective than the other three electrochemical Cells as the Open circuit voltage (V_oc), Short circuit current (I_sc) and Maximum Power (P_max) are more stable and steady in comparison with others. Heat treatment temperature was a new approach by which we can enhance the performance of these electrochemical cells. Most of the results have been tabulated and graphically discussed.

     

An improved power conditioning system for grid integration of solar power using ANFIS based FOPID controller

Power loss become common while integrating with common grid and in specific when power produced through Solar. This is the very lacking area which this proposal implements an Adaptive Neuro Fuzzy Inference System (ANFIS) based controller of Fractional Order Proportional Integral Derivative (FOPID) used for Tracking of Maximum PP of Grid Integrated Solar Power Conditioning System. The proposed work advances with different ambient light conditions for maximum power point traction. In this work a clear-cut Photo Voltaic (PV Cell) model has been developed and an intensive and operative training data have been extracted from the developed controller. This produced dataset have been the feeder input for the ANFIS structure in turn to locate the Tracking of Maximum PP (MPPT). Traction of MPPT is done, the FOPID controller is enforced by matching the voltage from the array of Photo Voltaic cell with attained or reference voltage produced by the ANFIS structure. In the meantime driving this PV array, DC to DC converter's duty cycle is controlled for producing maximum power from the structure. The duty cycle in FOPID controller is generated through calculating the error within the reference voltage and PV voltage. Those values are then simulated through Math Lab and the Simulation results show that this proposed work efficiency is better than the regularly employed controllers in the solar power production and conditioning system     

基于Stacking模型融合的光伏发电功率预测

为了提高光伏发电输出功率的预测精度和可靠性,本文提出一种基于Stacking模型融合的光伏发电功率预测方法.选取某光伏电站温度、湿度、辐照度等历史实测数据为研究对象,在将光伏发电功率数据进行特征交叉以及基于模型的递归特征消除法进行预处理和特征选择的基础上,以XGBoost、LightGBM、RandomForest 3种机器学习算法作为Stacking集成学习的第一层基学习器,以LinearRegression作为第二层元学习器,构建了多个机器学习算法嵌入的Stacking模型融合的光伏发电功率预测模型.预测结果表明,该方法的R²、MSE分别达到了0.9874和0.1056,相较于单一的机器学习模型,预测精度显著提升.     

管式SOFC数学模型及系统性能分析

固体氧化物燃料电池(SOFC)是一种高效低污染的新型能源。该文基于物质和能量守恒并耦合流体流动、热量产生和传递以及电化学知识建立了以天然气为燃料的管式固体氧化物燃料电池的数学模型,对模型进行求解,并分析系统参数(电流密度、工作压力、燃料的摩尔流量等)对系统性能(发电量、发电效率等)的影响。结果表明:SOFC系统的发电效率可以达到50.73%。通过增加单电池个数来减小电流密度可以增加系统发电量和发电效率,但是会增加系统投资;增大燃料电池的工作压力可以改善系统的性能;而增加燃料的摩尔流量(燃料利用率不变)会使系统的发电效率降低。     

SGTE data for pure elements

Thermodynamic data for the condensed phases of 78 elements as currently used by SGTE (Scientific Group Thermodata Europe) are tabulated. SGTE is a consortium of seven organisations in Western Europe engaged in the compilation of a comprehensive, self consistent and authoritative thermochemical database for inorganic and metallurgical systems. The data are being published here in the hope that they will become widely adopted within the international community as a sound basis for the critical assessment of thermodynamic data, thereby, perhaps, limiting unnecessary duplication of effort. The data for each phase of each element considered aie presented as expressions showing, as a function of temperature, the variation of (a) G-H_SER, the Gibbs energy relative to the enthalpy of the “Standard Element Reference” ie the reference phase for the element at 298.15 K and (b) the difference in Gibbs energy between each phase and this reference phase (ie lattice stability). The variation of the heat capacity of the various phases and the Gibbs energy difference between phases are also shown graphically. For certain elements the thermodynamic data have been assessed as a function of pressure as well as temperature. Where appropriate a temperature— pressure phase diagram is also shown.

Throughout this paper the thermodynamic data are expressed in terms of J mol⁻¹. The temperatures of transition between phases have been assessed to be consistent with the 1990 International Temperature Scale (ITS90).     

光伏发电系统中改进型MPPT控制技术研究

对光伏发电系统提出了一种新的最大功率点跟踪（MPPT）控制方法。对固定电压法、电导增量法以及所提的两者的结合方法分别进行仿真,结果表明,所提方法能够快速、准确地跟踪光伏阵列的最大功率点,减少了在最大功率点振荡的能量损失,提高了光伏发电系统的能量转换效率。     

Vibration of triangular plates of variable thickness

The problem of the natural frequencies and mode shapes of cantilevered triangular plates with variable thickness and arbitrary planform is solved using the finite element technique. This is done for various combinations of four non-dimensional geometric parameters, namely, the aspect ratio, the two thickness ratios along the two coordinate directions and the sweepback angle. The frequencies for the various cases are tabulated and a few typical mode shapes have been presented graphically.     

Magnetohydrodynamic three-dimensional flow of nanofluids with slip and thermal radiation over a nonlinear stretching sheet: a numerical study

A numerical simulation for mixed convective three-dimensional slip flow of water-based nanofluids with temperature jump boundary condition is presented. The flow is caused by nonlinear stretching surface. Conservation of energy equation involves the radiation heat flux term. Applied transverse magnetic effect of variable kind is also incorporated. Suitable nonlinear similarity transformations are used to reduce the governing equations into a set of self-similar equations. The subsequent equations are solved numerically by using shooting method. The solutions for the velocity and temperature distributions are computed for several values of flow pertinent parameters. Further, the numerical values for skin-friction coefficients and Nusselt number in respect of different nanoparticles are tabulated. A comparison between our numerical and already existing results has also been made. It is found that the velocity and thermal slip boundary condition showed a significant effect on momentum and thermal boundary layer thickness at the wall. The presence of nanoparticles stabilizes the thermal boundary layer growth.

     

Time‐averaged spatial profile of Xe excitation efficiency in PDPs

Abstract— The Xe excitation efficiency for various Xe content was analyzed by monitoring the panel luminance and IR emission intensity. It was found that dependences of the Xe excitation efficiency and luminous efficacy on the sustain voltage show almost the same tendency. A decrease for increasing sustaining voltage was found in a low‐Xe‐content panel and an increase was found in a high‐Xe‐content panel. A reduction in the effective electron temperature and a reduction in plasma saturation contribute to the efficacy improvement. The time‐averaged spatial profile of the Xe excitation efficiency in PDPs was investigated by measuring the distribution of IR and blue‐phosphor emissions. The results show that the Xe excitation efficiency is similar in the cathode and anode regions even though the spatial and time development of the discharge in these regions is very different. An extended theory that takes into account not only the radiative transition process but also the collisional de‐excitation process from Xe** to Xe* is proposed for investigating the pressure dependence of the Xe excitation efficiency. By using the proposed theory, it was found that Xe excitation efficiency increases, attains a maximum value at 30% Xe, then decreases as the Xe content is increased, when the rate coefficient of the collisional de‐excitation process is less than 1.0 × 10^?10 cm³/sec.     

Global sensitivity analysis of an energy–economy model of the residential building sector

In this paper, we discuss the results of a sensitivity analysis of Res-IRF, an energy–economy model of the demand for space heating in French dwellings. Res-IRF has been developed for the purpose of increasing behavioral detail in the modeling of energy demand. The different drivers of energy demand, namely the extensive margin of energy efficiency investment, the intensive one and building occupants, behavior are disaggregated and determined endogenously. The model also represents the established barriers to the diffusion of energy efficiency: heterogeneity of consumer preferences, landlord–tenant split incentives and slow diffusion of information. The relevance of these modeling assumptions is assessed through the Morris method of sensitivity analysis, which allows for the exploration of uncertainty over the whole input space. We find that the Res-IRF model is most sensitive to energy prices. It is also found to be quite sensitive to the factors parameterizing the different drivers of energy demand. In contrast, inputs mimicking barriers to energy efficiency have been found to have little influence. These conclusions build confidence in the accuracy of the model and highlight occupants' behavior as a priority area for future empirical research.     

Walking in visually handicapped children and its energy cost

Walking is a basic activity in visually handicapped subjects, and often it is used as a general means of improving physical fitness. The level of adaptation to walking may be assessed by means of energy cost, c. The variable c was studied during walking on a treadmill in two groups of visually handicapped children (international classification of vision of 5/200 or less). The two groups were comprised of 15 boys (mean age= 11.8± 2.1 years) and 13 girls (mean age = 11.6±3.1 years). The mean energy cost in boys was found to be 3.79±0.31 J kg^?1 m^?1 and in girls it was 3.77±0.36 J kg^?1 m^?1. Both these values were not significantly higher than the energy cost in untrained nonhandicapped children of the same age. There was a U-shaped dependence of c on increased speed of walking. The minimum was about 3.6 km h^?1 in both groups of handicapped children, which was similar to that for non-handicapped subjects. It is concluded that in visually handicapped children the energy cost of walking, and thus adaptation to walking, is the same as in the healthy children. The visually handicapped individuals show a ‘normal’ response to exercise, to which they are adapted, with increases in both cardiovascular and muscular fitness.     

High performance nanocomparator: a quantum dot cellular automata-based approach

Quantum dot cellular automata (QCA) are emerging nanotechnology that offers few significant advantages like faster speed, higher circuit density, and lower power dissipation. Comparator is a fundamental and essential block in QCA logic circuit family. In this article, a single-layered and straightforward design of a QCA-based one-bit magnitude comparator has been proposed. The proposed design is 6.38%, 6.67% and?~?10% more efficient in cell complexity, cell area and total area measurement, respectively, in comparison to prior reported designs. Furthermore, the energy dissipation of the proposed circuit has been calculated using QCADesigner-E and QCAPro tools to check the energy efficiency of the proposed circuit. The total energy dissipation of the reported magnitude comparator is 19.50 meV when measured using the QCADesigner-E tool. Similarly, according to the QCAPro tool, it has?~?71% less energy dissipation than the existing designs.

     

Simulation of lazer light propagation and thermal processes in red blood cells exposed to infrared laser tweezers (λ = 1064 nm)

Continuous-wave laser micro-beams are generally used as diagnostic tools in laser scanning microscopes or, in the case of near-infrared micro-beams, as optical traps for cell manipulation and force characterization. Because single beam traps are created with objectives of high numerical aperture, typical trapping intensities and photon flux densities are in the order of 10⁶ W/cm² and 10³ cm⁻² s⁻¹, respectively. These extremely high fields may induce two-photon absorption processes and anomalous biological effects. We studied effects occurring in red blood cells (RBCs) radiated by near-infrared laser tweezers λ = 1064 nm). The main idea of our study was to investigate the thermal reaction of RBCs irradiated by laser micro-beam. It is supported by the fact that many experiments have been carried out on RBCs using laser near infrared tweezers. Usually they are relatively long lasting and the thermal aspects of such experiments are not examined. In the present work it has been identified that the laser affects a RBC with a density of absorbed energy at approximately 10⁷ J/cm³, which causes a temperature rise in the cell of about 10–15°C.     

Isolation and elution of Hep3B circulating tumor cells using a dual-functional herringbone chip

Circulating tumor cells (CTCs), which are derived from primary tumor and circulate to secondary site, are regarded as the cause of metastasis. Many methods have been applied for CTC isolation and enumeration so far. However, it remains a challenge to effectively elute the captured cells from the device for further cellular and biomolecular analyses. In this paper, we fabricate a dual-functional herringbone chip to achieve both CTC capture and elution based on the immunoassay of epithelial cell adhesion molecule antigen expressed on the surface of human liver cancer cell line Hep3B. The results show that the capture limit of Hep3B cells can reach as low as 3 cells per ml with capture efficiency over 50 % on average. On the other hand, the elution rate of more than 50 % of the captured Hep3B cells can be achieved for cell density ranging from 5 to 2 × 10³/ml. It demonstrates that this herringbone chip exhibits excellent dual functions with high capture efficiency and considerable elution rate, indicating its promising capability for clinical assay in cancer diagnosis.     

Energy‐transfer dynamics of blue‐phosphorescent iridium and rhodium complexes doped in fluorescent molecules

Abstract— The temperature‐dependent photoluminescence features of polycarbonate thin films doped with blue‐phosphorescent molecules, either bis[(4,6‐difluorophenyl)‐pyridinato‐N,C^2′] (picolinate) iridium (Flrpic) or bis(2‐phenylpyridinato‐N,C^2′) (acetylacetonate) rhodium [(ppy)²Rh(acac)], which have an equivalent triplet energy of 2.64 eV, have been studied. The photoluminescence intensity of the Flrpic‐doped polycarbonate thin film did not show any dependence on temperature. On the other hand, as for the (ppy)²Rh(acac)‐doped polycarbonate thin film, decreasing photoluminescence intensity with increasing temperature (especially above 100K) was clearly visible. These results reflect that the internal heavy‐atom effect of (ppy)²Rh(acac) is weaker than that of Flrpic. Furthermore, the steady‐state and time‐resolved photoluminescence spectra of tris(8‐hydroxyquinoline) aluminum (Alq₃) thin films heavily doped with Flrpic or (ppy)²Rh(acac) (50 wt.%) at 8K was studied. It was found that the enhanced phosphorescence from Alq₃ is mainly due not to the external heavy‐atom effect by doping with the phosphorescent molecule but to the exothermic triplet energy transfer from the phosphorescent molecule to Alq₃.     

Extended Comparative Analysis of Flip-Flop Architectures for Subthreshold Applications in 28 nm FD-SOI

Nine D-type Flip-Flop (DFF) architectures were implemented in 28 nm FDSOI at a target, subthreshold, supply voltage of 200 mV. The goal was to identify promising DFFs for ultra low power applications. The single-transistor pass gate DFF, the PowerPC 603 DFF and the C²MOS DFF are considered to be the overall best candidates of the nine. The pass gate DFF had the lowest energy consumption per cycle for frequencies lower than 500 kHz and for supply voltages below 400 mV. It was implemented with the smallest physical footprint and it proved to be functional down to the lowest operating voltage of 65 mV in the typical process corner. During Monte Carlo (MC) process and mismatch simulations it was also found that the pass gate DFF is least prone to variations in both minimal setup- and minimal hold-time. Race conditions, during mismatch variations, occurred for the flip-flop that is constructed from NAND and inverter based multiplexers. The pass gate DFF is outperformed slightly when it comes to D-Q-based power-delay product and more significantly when it comes to the maximum clock frequency. The flip-flops having the shortest D-Q delays were the PowerPC 603 and the transmission gate D flip-flop, these also had the lowest D-Q-based power-delay of 26% and 30% respectively of that of the worst-case S²CFF power-delay product.     

Energy cost and mechanical efficiency of riding a human-powered recumbent bicycle

When dealing with human-powered vehicles, it is important to quantify the capability of converting metabolic energy in useful mechanical work by measuring mechanical efficiency. In this study, net mechanical efficiency (η) of riding a recumbent bicycle on flat terrain and at constant speeds (v, 5.1–10.0 m/s) was calculated dividing mechanical work (w, J/m) by the corresponding energy cost (C_c, J/m). w and C_c increased linearly with the speed squared: w = 9.41 + 0.156 · v²; C_c = 39.40 + 0.563 · v². η was equal to 0.257 ± 0.0245, i.e. identical to that of concentric muscular contraction. Hence, i) η seems unaffected by the biomechanical arrangement of the human–vehicle system; ii) the efficiency of transmission seems to be close to 100%, suggesting that the particular biomechanical arrangement does not impair the transformation of metabolic energy in mechanical work. When dealing with human-powered vehicles, it is important to quantify mechanical efficiency (η) of locomotion. η of riding a recumbent bicycle was calculated dividing the mechanical work to the corresponding energy cost of locomotion; it was practically identical to that of concentric muscular contraction (0.257 ± 0.0245), suggesting that the power transmission from muscles to pedals is unaffected by the biomechanical arrangement of the vehicle.     

A method for solving nonlinear time-dependent drainage model

The purpose of this paper is to present a method for solving nonlinear time-dependent drainage model. This method is based on the perturbation theory and Laplace transformation. The proposed technique allows us to obtain an approximate solution in a series form. The computed results are in good agreement with the results of Adomian decomposition method. Results are presented graphically and in tabulated forms to study the efficiency and accuracy of method. The present approach provides a reliable technique, which avoids the tedious work needed by classical techniques and existing numerical methods. The nonlinear time-dependent drainage model is solved without linearizing or discretizing the nonlinear terms of the equation. The method does not require physically unrealistic assumptions, linearization or discretization in order to find the solutions of the given problems.     

Design and realization of an ultra‐low power sensing RF energy harvesting module with its RF and DC sub‐components

Herein, design, development, and analysis of ultra‐low power sensing energy harvesting modules and their subcomponents for ISM band applications have been studied with a holistic approach in an effort to achieve a feasible and high efficient RF energy harvesting performance. The complete harvester system designed and developed here consists of a zero‐bias RF energy rectifying antenna (rectenna), DC boost converters and energy storage super‐capacitors. Compared with the counterpart energy sources, the surrounding or transmitted wireless energy has low intensity which requires designs with high efficiency. To achieve a successful harvester performance, rectifier circuits with high sensitivity Schottky diodes and proper impedance matching circuits are designed. Dedicated RF signals at various levels from nanowatts to miliwatts are applied at the input of the rectenna and the measured input power versus the scavenged DC output voltage are tabulated. Furthermore, by connecting the rectifier to a high gain antenna and using a RF signal transmitter, the wireless RF power harvesting performance at 2.4 GHz was tested up to 5 m. The performance of the rectenna is analyzed for both low‐power detection and efficiencies. Impedance matching network is implemented to reduce the reflected input RF power, DC to DC converters are evaluated for their compatibility to the rectifiers, and super‐capacitor behaviors are investigated for their charging and storage capabilities. The measured results indicate that a wide operating power range with an ultra‐low power sensing and conversion performance have been achieved by optimizing the efficiency of the Schottky rectifier as low as ?50 dBm. The system can be used for battery free applications or expanding battery life for ultra‐low power electronics, such as; RFID, LoRa, Bluetooth, ZigBee, and low power remote sensor systems.     

Microfluidic chips for cells capture using 3-D hydrodynamic structure array

Microfluidic chips were designed and fabricated to capture cells in a relative small volume to generate the desired concentration needed for analysis. The microfluidic chips comprise three-dimensional (3-D) cell capture structures array fabricated in PDMS. The capture structure includes two layers. The first layer consists of spacers to create small gap between the upper layer and glass. The second layer is a sharp corner U-shaped compartment with sharp corners at the fore-end. And another type capture structure with Y-shaped fluidic guide has been designed. It was demonstrated that the structures can capture cells in theory, using Darcy–Weisbach equation and COMSOL Multiphysics. Then yeast cell was chosen to test the performance of the chips. The chip without fluid guides captured ~1.44 × 10⁵ cells and the capture efficiency was up to 71 %. And the chip with fluid guides captured ~5.0 × 10⁴ cells and the capture efficiency was ~25 %. The chip without fluid guides can capture more cells because the yeast cells in the chip without fluid guides are subject to larger hydrodynamic drag force.