Average Efficiency Research Articles

Coordinated self-assembly of ultraporous 3D aramid nanofibrous separators with a poly(vinyl alcohol) sheath for lithium-metal batteries

Li-metal batteries with a low negative/positive electrode capacity ratio require significant improvement to ensure their practical implementation as high-energy-density batteries. In the present study, ultraporous aramid nanofiber (ANF) separators with a poly(vinyl alcohol) (PVA) sheath were fabricated using a coordinated self-assembly process to produce an ultrahigh bulk (>95 %) and surface (>48.6 %) porosity and a high ion affinity. In this process, sol films consisting of an optimized mixture of aramid nanoseed sols and PVA were sequentially immersed in ethanol and water to induce the formation of a 3D aramid network and the phase separation of PVA by their rate differences, followed by swelling-induced pore formation. The resulting separators exhibited an excellent ion conductivity and Li+ ion transference number of up to 2.73 mS cm−1 and 0.78, respectively, with the effective suppression of Li dendritic growth and the formation of a stable fluorine-rich solid electrolyte interphase (SEI) layer on the Li-metal surface. Li/Li half cells exhibited stable operation for up to 1500 cycles with a high current density of 10 mA cm–2 and an areal capacity of 1 mAh cm–2, with Li/Cu half cells operating for over 244 cycles even with a lithiophobic Cu current collector. LFP/Li full cells with a low N/P ratio (∼2.03) exhibited stable operation for 172 cycles with an average Coulombic efficiency of 99.6 %. NCM/Li full cell with extremely low N/P ratio (0.96) and lean electrolyte condition (4 g Ah–1) stably operated for 55 cycles with projected energy density of 350.7 Wh kg–1.

Performance enhancement of photovoltaic system using composite phase change materials

Solar photovoltaic (PV) systems are becoming a more feasible energy source. Energy storage devices can increase Photovoltaic (PV) system performance when PV module temperature rises and electrical efficiency declines. This work uses Lauric and Palmitic acid composite phase change material to evaluate polycrystalline solar panels in real-time. The best Lauric and Palmitic acid ratio was 3:1 in experiments. Three other solar panels were fabricated using 7, 10, and 14 composite-filled Al pipes at the bottom, apart from the reference panel. Compared to panels with 7 and 10 Al-pipes, the L + P CPCM 14 Al-pipes panel had the greatest mean electrical output of 38.56 W, a peak average efficiency of 15.23 % while the average temperature was 43.74 °C. The highest temperature reduction of the CPCM was 26.2 % and the energy stored was 28.78 kJ. The CPCM exhibited a maximum power improvement of 39.9 % and an efficiency improvement of 31.1 %. However, the reference panel had the maximum mean electrical output of 27.56W and peak mean efficiency of 12.78 % only if all days of experimentation were considered.

Assessing the Efficiency of Wheat Producers in Dihdadi District

Given the strategic importance of wheat production for the country's food security, this study aimed to analyze the efficiency of wheat producers in the Dihdadi district of Balkh province, Afghanistan, using the Data Envelopment Analysis (DEA) approach. The required data were classified using a random sampling method, and 295 questionnaires were collected in 2022. The results show that the average technical, allocative, economic, pure technical (management), and scale efficiencies are 0.858, 0.632, 0.541, 0.964, and 0.893, respectively. Based on these results, increasing the efficiency of wheat producers in this district can improve technical, allocative, economic, management, and scale efficiencies by 14.2%, 36.8%, 45.9%, 3.6%, and 43.6%, respectively. 16.95% of wheat producers operate with decreasing returns relative to the scale, 72.2% use with increasing returns relative to the scale, and only 10.85% operate at the optimal scale (constant returns to scale). Therefore, increasing the production scale is suggested to enhance rational efficiency. Recommendations, management, and policy contexts related to improving the efficiency of wheat producers can contribute to local economic and social conditions.

Theoretical analysis on temperature-lifting cycle for ocean thermal energy conversion

A significant obstacle to the widespread large-scale utilization of ocean thermal energy is the low temperature of the heat source, which restricts the turbine inlet to saturated steam conditions and results in notably reduced turbine efficiency. In this paper, a novel temperature-lifting based Ocean Thermal Energy Conversion cycle (OTEC) is proposed. The cycle combines the second-type absorption heat pump and the Rankine power cycle to overheat the working fluid at the turbine inlet using both surface and deep seawater, thereby mitigating the adverse effects of low surface seawater temperatures on energy conversion. The thermodynamic model is developed for this proposed cycle, 22 wet working fluids are selected for the Rankine sub-cycle. A comparative analysis with the traditional Rankine cycles is conducted to evaluate the cycle performance. The results show that the overheated temperature at the turbine inlet reaches up to 44.7 °C relying on the ocean thermal energy. In contrast to the traditional Rankine cycle, the proposed cycle achieved an average thermal efficiency improvement of 40 % and a substantial increase in exergy efficiency, ranging from 17.99–57.58 % to 32.83–68.88 %. The economic analysis reveals that the optimal cost is reduced by 38 % compared to the Rankine cycle, leading to a lower levelized cost of energy, down from 0.18 $/kWh to 0.13 $/kWh. This novel cycle offers an economically efficient and easily implementable approach to enhance low-grade thermal energy conversion.

Nutrients removal by high-rate activated sludge and its effects on the mainstream wastewater treatment

Conventional wastewater treatment technologies often involve energy-intensive processes, creating a need for more sustainable and efficient solutions. The high-rate activated sludge (HRAS) process, characterized by short sludge and hydraulic retention times, demonstrates proficient chemical oxygen demand (COD) removal with minimal oxidation and energy expenditure, positioning it as a promising approach for achieving energy-efficient wastewater treatment.This study addresses the nutrient removal efficiency of a demonstration-scale pilot plant (35 m3·d-1) operating for 497 days. It investigates the correlation between nutrient removal efficiencies, COD fractions, and suspended solids removal in real wastewater, without primary clarification.The process consistently achieves average removal efficiencies: 23% for total Kjeldahl Nitrogen (TKN), 7.3% for N-NH4+, 56% for total phosphorus (TP), and 11% for P-PO43-. The superior TP removal is attributed to the high particulate influent fractions (81%), underscoring the pivotal role of settling efficiency. The HRAS process effectively controls TP peak values, although its influence on TKN peaks is somewhat limited. This underscores HRAS's proficiency in mitigating phosphorus spikes in influent wastewater. In contrast, the lower TKN removal is associated with diminished particulate inlet fractions (46%).Nutrient removal mechanisms in HRAS mirror those of COD, primarily revolving around adsorption and entrapment processes, as opposed to conventional biological pathways. It also highlights the independence of oxidized COD, nitrogen, and phosphorus removal. Furthermore, a comprehensive analysis of the COD/TKN within HRAS effluent unveils the presence of a short-cut nitrification/denitrification process, supplemented by Anammox in the sidestream, as the most suitable pathway for downstream nitrogen removal. This revelation signifies a substantial advancement and positions HRAS as a potential initial stage of a partial nitritation/Anammox (PN/A) process within mainstream wastewater treatment.

Cascading latent heat thermal energy storage in parabolic trough solar collector as a promising solution: An experimental investigation

Solar energy system can be considered as a reliable energy source if it connects to a latent heat thermal energy storage (LHTES) system using phase change materials (PCMs). To tackle the low thermal conductivity coefficient of PCMs, the cascaded latent heat storage (CLHS) configuration is a promising solution. This study aims to illustrate the improvement of CLHS setup comparing with non-cascaded arrangement, performing a whole-scale experimental investigation. A compact parabolic trough collector (PTC) unit equipped with a LHTES module is designed and constructed for a residential purpose. Experimental results reveal that the average thermal efficiency of PTC is 73.5 %. Three paraffin waxes with melting ranges of (64–68 ℃), (57–60 ℃) and (46–48 ℃) are injected in three same series of shell-tube heat exchangers. For comparing cascaded and non-cascaded PCM performance, three experimental series, namely (Exp.1, Exp.2 and Exp.3) are performed. The experimental findings show that the deployment of the CLHS configuration improves the latent heat storage of non-CLHS-Exps.1, 2, and 3 by more than 10, 47, and 5 %, respectively. In addition, CLHS system has a potential to increase the exergy storage of non-CLHS setup by up to 27.4 %. Furthermore, impact of increasing heat transfer fluid (HTF) flow rate is examined and it is observed that the melting process is shortened by almost 39 %. Accordingly, increasing flow rate improves energy stored in PCMs1, 2, and 3 by 60 %, 59.62 %, and 72.04 %, respectively. Consequently, the latent thermal exergy storage of the PCM experiences a twofold increase. Conducting an experimental evaluation of thermal performance of the storage module integrated with PTC setup can be valuable, particularly in the realm of residential applications.

Lyophilization enhances the stability of Panax notoginseng total saponins-loaded transfersomes without adverse effects on ex vivo/in vivo skin permeation

Transfersomes (TFSs) have been extensively investigated to enhance transdermal drug delivery. As a colloidal dispersion system, TFSs are prone to problems such as particle aggregation and sedimentation, oxidation and decomposition of phospholipids. To enhance the stability of panax notoginseng saponins (PNS)-loaded transfersomes (PNS-TFSs) without adverse influences on their skin permeation, we prepared lyophilized PNS-loaded transfersomes (PNS-FD-TFSs), clarified their physicochemical characteristics and investigated their in vitro drug release, ex vivo skin permeation/deposition and in vivo pharmacokinetics. In this study, a simple, fast and controllable process was developed for preparing lyophilized PNS-TFSs. In the optimized PNS-FD-TFS formulation, sucrose and trehalose were added to the PNS-TFS dispersion with a mass ratio of trehalose, sucrose, and phospholipid of 3:2:1, and the mixture was frozen at −80 °C for 12 h followed by lyophilization at −45 °C and 5 Pa for 24 h. The optimized formulation of PNS-FD-TFSs was screened based on the appearance and reconstitution time of the lyophilized products, vesicle size, and PDI of the freshly reconstituted dispersions. It maintained stable physicochemical properties for at least 6 months at 4 °C. The vesicle size of PNS-FD-TFSs was below 100 nm and homogenous with a polydispersity index of 0.2 after reconstitution. The average encapsulation efficiencies of the five index saponins notoginsenoside R1 (NGR1), ginsenoside Rg1 (GRg1), ginsenoside Re (GRe), ginsenoside Rb1 (GRb1) and ginsenoside Rd (GRd) in PNS-FD-TFSs were 68.41 ± 5.77%, 68.95 ± 6.08%, 65.46 ± 10.95%, 91.50 ± 5.62% and 95.78 ± 1.70%, respectively. The reconstituted dispersions of PNS-FD-TFSs were similar to PNS-TFSs in in vitro release, ex vivo skin permeation, and deposition. The pharmacokinetic studies showed that, compared with the PNS liposomes (PNS-LPS), the PNS-FD-TFS-loaded drug could permeate through the skin and enter the blood rapidly. It can be concluded that the lyophilization process can effectively improve the stability of PNS-TFSs without compromising their transdermal absorption properties.

An Improved Optimal Tracking Rotor Algorithm of Wind Turbine Based on Dynamic Adjustment of Compensation Coefficient

The Optimal Tracking Rotor method, as one of the control methods for MPPT, increases the compensation coefficient to achieve an improvement in average wind energy capture efficiency, but it causes a significant increase in wind turbine load. There are differences in the energy contained between the high-wind-speed areas and the low-wind-speed areas. This paper proposes an improved optimal tracking rotor method by dynamically adjusting the compensation coefficient, to enhance the capture of wind energy in high wind speed areas and slow down the capture of wind energy in low wind speed areas. After research, it was found that the adjustment of the compensation coefficient varies with changes in wind speed and wind wheel acceleration. In response to this problem, the optimal change curve between the compensation coefficient and related parameters was determined. Fuzzy control was used to achieve dynamic adjustment of the compensation coefficient. Finally, the effectiveness of the proposed method was verified based on simulation results in Matlab/Simulink.

3D structure of box-and-grid electron multiplier with higher electron collection efficiency

In this paper, the electron collection efficiency of dynodes in different electron multiplier (EM) structures is analyzed using Computer Simulation Technology. Three main factors that lead to low efficiency in electronic collection have been identified as crossing, trapped, and blocked electrons. The proportions of these three types of electrons are investigated to illustrate the characteristics of EMs with different structures. It is observed that the optimized 3D structure outperforms all 2D structures, and the reasons for this improvement are also discussed. The spiral EM is designed to achieve an average collection efficiency of 98.9% at the optimal parameters. By adopting the proposed structure, not only the size of the EM can be reduced, but also the gain of the EM can be significantly improved. Consequently, this will allow for a reduction in the operating voltage of the EM and prolong its lifetime.

Inorganic Hybrid Interfacial Layer for a Stable Zinc Metal Anode.

In aqueous zinc-ion batteries (AZIBs), the zinc metal anode faces serious problems such as dendrite growth, interface corrosion, and byproduct accumulation, which hinder the commercialization process of AZIBs. Herein, an inorganic hybrid interfacial layer ZnF2/ZnSe (ZnFS) including the insulating interfacial phase (ZnF2) and conductive interfacial phase (ZnSe) has been manufactured. ZnF2 provides excellent corrosion resistance, inhibiting the corrosion and passivation of the zinc metal anode to enhance interfacial stability. The conductive ZnSe can reduce the interfacial resistance and induce the rapid migration of Zn2+, leading to the uniform deposition of Zn to inhibit the dendrite growth. Consequently, the Zn/ZnFS//Zn/ZnFS symmetrical batteries can run stably for more than 2200 h at 1 mA cm-2/1 mAh cm-2 and over 700 h at 5 mA cm-2/5 mAh cm-2. At the same time, the average Coulombic efficiency of the Zn/ZnFS//Ti half batteries reaches 98.3% after 600 cycles (1 mA cm-2/1 h), indicating that the reversibility of zinc was greatly improved. The full batteries based on the Zn/ZnFS anode and (NH4)2V10O25·8H2O cathode perform a high capacity ratio of 73.4% after 620 cycles at 1 A g-1. The concept of hybrid interface layer design can provide inspiration for the modification of metal anode.

Ionic surfactants of different dipole moments as anti-solvent additives for air-processing MAPbI3−xClx perovskite thin films

Three ionic surfactants, didodecyldimethylammonium bromide (DDABr), sodium lauryl ether sulfate (NaLES) and sodium lauryl sulfate (NaLS), with different dipole moment values: 0.907, 17 and 212 Debye, respectively, have been used as anti-solvent additives to remove the moisture from perovskite precursor solutions. The three additives impact in different ways on the crystallinity, wettability and morphology of perovskite thin films, as well as on the stability and efficiency of air-processed perovskite solar cells (PSCs). The hydrophobic groups of the additives at the surface of perovskite thin films help to increase the stability of PSCs, especially DDABr of the lowest dipole moment. On the other hand, NaLES, of the highest dipole moment, is the most efficient to extract moisture from the perovskite precursor coatings, increasing the average power conversion efficiency (PCE) of NaLES-based PSCs from 16.16 ± 0.94% to 17.21 ± 0.32% in comparison with that of the reference. Furthermore, the synergy between NaLES and the perovskite precursor additive, KI, achieves the best photovoltaic performance of the PSCs, leading to an average PCE of 17.42% and the best PCE of 18.75%. It is concluded that ionic surfactants of different dipole moments are good candidates as anti-solvent additives to improve the efficiency and stability of air-processed PSCs.

A new approach to solve the problem of partial shading in a photovoltaic system

<p>This paper introduces a novel global maximum power point (GMPP) tracking method that addresses the challenges of efficiency and power quality degradation in photovoltaic (PV) systems caused by inadequate tracking of the GMPP. The proposed approach employs a cuckoo search algorithm with proportional, integral, and derivative (CSPID). A bio-inspired optimization technique, to effectively track the GMPP under varying weather conditions. To demonstrate its effectiveness, the CSPID algorithm is comprehensively evaluated against two well-established methods, particle swarm optimization (PSO), and cuckoo search algorithm traditional (CSA). The evaluation includes three different scenarios with gradual changes in irradiance and temperature, these tests show the ability of the algorithm to handle the condition of partial shading. The results reveal that the CSPID method achieves an average tracking time of 0.098s and an average tracking efficiency of 99.62%, thereby significantly improving the efficiency and quality of photovoltaic energy production.</p>

Estimating the Sustainable Efficiency and Economic Efficiency of Vegetable Crop Growers in Baghdad Governorate

The research aims to measure the sustainability value and efficiency of sustainable for vegetable crops in the Baghdad governorate. Additionally, it aims to assess the economic efficiency for the agricultural season of 2022-2023. The research sample includes 182 farmers from the studied province, analyzed using the Data Envelopment Analysis (DEA) method. The explanatory variables for sustainability value include factors such as cultivated area, working hours, capital excluding land rent, household consumption of vegetable crops, fuel, and nitrogen fertilizer. The dependent variable is agricultural production value. The variables for sustainable efficiency encompass cultivated area, seed quantity, fertilizer quantity, pesticide quantity, number of workers, and irrigation frequency. The results indicate that there is a sustainable value for the utilized resources, reaching approximately 1.6. Moreover, the sustainability efficiency reaches about (1.2). This implies that despite resource wastage, farmers have positive and satisfactory productivity. However, the average economic efficiency is around 70.81%, revealing that vegetable crop farmers in Baghdad’s province have not achieved full economic efficiency of 100%. There is a notable variation in achieving these levels, necessitating changes in the utilization of production inputs to enhance productivity. The research recommends that farmers should redistribute resources to minimize waste, aiming to reach the optimal combination that maximizes profits while minimizing costs. This could be achieved by seeking guidance from experienced farmers and experts or by providing training on modern technology usage and mechanization of production resources. Furthermore, the research suggests the importance of conducting further studies on cost-return variation and resource utilization to evaluate sustainability.

A rapid and highly efficient sorghum transformation strategy using GRF4-GIF1/ternary vector system.

Sorghum is an important crop for food, forage, wine and biofuel production. To enhance its transformation efficiency without negative developmental by-effects, we investigated the impact of GRF4-GIF1 chimaera and GRF5 on sorghum transformation. Both GRF4-GIF1 and GRF5 effectively improved the transformation efficiency of sorghum and accelerated the transformation process of sorghum to less than 2 months which was not observed when using BBM-WUS. As agrobacterium effectors increase the ability of T-DNA transfer into plant cells, we checked whether ternary vector system can additively enhance sorghum transformation. The combination of GRF4-GIF1 with helper plasmid pVS1-VIR2 achieved the highest transformation efficiency, reaching 38.28%, which is 7.71-fold of the original method. Compared with BBM-WUS, overexpressing GRF4-GIF1 caused no noticeable growth defects in sorghum. We further developed a sorghum CRISPR/Cas9 gene-editing tool based on this GRF4-GIF1/ternary vector system, which achieved an average gene mutation efficiency of 41.36%, and null mutants were created in the T0 generation.

РАЗРАБОТКА ДИНАМИЧЕСКОЙ МОДЕЛИ ДЛЯ РАСЧЕТА КИНЕМАТИЧЕСКОЙ ПОГРЕШНОСТИ И ОЦЕНКИ ЕЕ ВЛИЯНИЯ НА КПД ПЛАНЕТАРНЫХ МЕХАНИЗМОВ С ТЕЛАМИ КАЧЕНИЯ

When studying the characteristics of the mechanisms of small-sized drives, an important task is to develop ways to increase the efficiency of the mechanism. The article discusses theoretical issues related to the influence assessment of kinematic error on the efficiency of gears with rolling bodies. As a result of the research, a generalized dynamic model of planetary ball and roller mechanisms is obtained, taking into account kinematic errors, linking manufacturing errors or elastic deformations and kinematic transmission error. Mathematical dependences of the dynamic model of mechanisms with rolling bodies are derived. The model was tested on the example of calculating the kinematic error of a single-stage planetary ball transmission. Polynomial equations with constant coefficients are obtained for determining kinematic errors from the influence of manufacturing errors of transmission links. It is established that for different kinematic schemes, gear ratios and angular velocities of planetary mechanisms with rolling bodies, the transmission efficiency can vary significantly depending on its kinematic error. For gear ratios from 1.5 to 5, drive shaft rotation speeds from 1,500 to 3,000 rpm, depending on the highest values of the kinematic error from 0.00175 to 0.0349 radians, the transmission efficiency within the driven shaft rotation can decrease from 0.93 to 11 %. At the same time, transmissions constructed according to the sixth kinematic scheme have the highest efficiency values. The average efficiency value per revolution of the driven shaft from the influence of kinematic errors can decrease up to 5 %. Graphs of the dependences of transmission efficiency on their kinematic errors are given.

Environmental and Economic Assessment of the Italian Energy Transition Scenarios

The aim of this work is to assess the environmental and economic impact of the Energy Transition of the Italian Electrical Sector, as planned by the PNIEC (Integrated National Energy and Climate Plan), published in December 2019, and by the scenarios, developed by Terna and Snam, updated to reach the Fit-for-55 objectives. The analysis of the historical trends related to RES (Renewable Energy Sources) capacity increase, allows comparing the historical effort with the one expected to reach the 2030 goals. In particular wind off-shore production is expected to have a larger impact than envisaged before. On the technical side, some scenarios assumptions are going to be revised to more realistic values. The technological and economic efforts, besides an estimation of the expected global environmental benefit, are assessed taking into account: i) the revised RES capacity increase, ii) the grid infrastructure enhancement, and iii) the envisaged installation of new storage and electrolyzer capacity. With flexibility items, ii) and iii), requiring a similar level of capital cost as the new RES capacity. The reduction in natural gas consumption in the different scenarios is expected to reduce both the Green House Gas emissions and the operating cost with a large impact on the average efficiency of the natural gas-fed power plants.

SPATIAL EFFICIENCY OF ROMANIAʼS DEVELOPMENT REGIONS FROM THE PERSPECTIVE OF SUSTAINABLE DEVELOPMENT

The study assesses the spatial efficiency of Romaniaʼs counties and development regions from the perspective of sustainable development. Data Envelopment Analysis (DEA) was used to calculate spatial efficiency, and A-P model (Andersen and Petersen) was used to rank efficient units (those with a score of 1.000) to assess superefficiency. The results of the study are graphically translated into four maps. The average efficiency of Romaniaʼs counties is 0.945 and the average efficiency of development regions is 0.986. Almost all development regions are efficient, with the only inefficient region being the Sud-Est region (0.887). The development regions with the highest superefficiency scores are located in the western part of Romania. The highest score of superefficiency is registered by the București-Ilfov region (30.997), the capital of the country and its surroundings, the economic engine of Romania.

Study and Verify the Performance Evaluation and Percentage Removal Efficiency of the Plant

Domestic, commercial, and industrial wastewater all belong to the category of urban wastewater. There are various treatment technologies available to treat the waste water from simple oxidation ponds to advanced MBBR systems. The present study is to verify the performance evaluation and percentage removal efficiency of the plant. The various water quality parameters like COD, BOD, TSS, TDS, Oil & Grease , Nitrates, pH, EC, DO, Turbidity and Phosphates of the waste water were being analyzed for the which were collected. Water samples were collected at different stages of treatment plant such as (raw water inlet, Aeration tank, Clarisettler and Treated water outlet) in the weekly basis for a period of 6 weeks before disposal into water body streams. After treatment, the average percentage removal efficiency for the parameters COD, BOD, TSS, TDS, Oil & Grease, and Phosphates was found to be 89%, 88%, 85%, 68%, 69% and 75%. After the analysis the result were finalized by comparing data with CPCB and IS standard values and ultimately, the performance and removal efficiency of the waste water treatment facility was found to be under good condition and the treated water are being used for flush-outs and gardening.

Dual-polarized 8-port sub 6 GHz 5G MIMO diamond-ring slot antenna for smart phone and portable wireless applications.

This manuscript presents high performance dual polarized eight-element multiple input multiple output (MIMO) fifth generation (5G) smartphone antenna. The design consists of four dual-polarized microstrip diamond-ring slot antennas, positioned at corners of printed circuit board (PCB). Cheap Fr-4 dielectric with permittivity 4.3 and thickness of 1.6mm is used as substrate with overall dimension of 150 × 75 × 1.6 mm3. In mobile system due to limited space mutual coupling between nearby antenna elements is an issue that distort MIMO antenna performance. Defected ground structure is used to control coupling. The defected ground structure has advantages like ease of fabrication, compact size and high efficiency as compare to other techniques. Less than 30dB coupling is achieved for adjacent elements. The -10 dB impedance bandwidth of 700 MHz is achieved for all radiating elements ranging from 3.3 GHz to 4.1 GHz. The value is about 900MHz for -6dB. The proposed antenna offers good results in terms of fundamental antenna parameters like reflection coefficient, transmission coefficient, maximum gain, total efficiency. The antenna achieved average gain more than 3.8dBi and average radiation efficiency more than 80% for single dual polarized element. The antenna provides sufficient radiation coverage in all sides. The MIMO antenna characteristics like diversity gain (DG), envelope correlation coefficient (ECC), total active reflection coefficient (TARC) and channel capacity are calculated and found according to standards. Furthermore, effect of user on antenna performance in data-mode and talk-mode are studied. Proposed design is fabricated and tested in real time. The measured results shows that proposed design can be used in future smartphones applications. The design is compared with some of the existing work and found to be the best one in many parameters and can be used for commercial use.

Multi-Objective Genetic Algorithm-Based Technique for Achieving Low-Power VLSI Circuit Partition

Minimizing the power consumption of electronic systems is one of the most critical concerns in the design of integrated circuits for very large-scale integration (VLSI). Despite the reality that VLSI design is known for its compact size, low power, low price, excellent dependability, and high functionality, the design stage remains difficult to improve in terms of time and power. Several optimization algorithms have been designed to tackle the present issues in VLSI design. This study discusses a bi-objective optimization technique for circuit partitioning based on a genetic algorithm. The motivation for the proposed research is derived from the basic concept that, if some portions of a circuit's system are deactivated during the processor's idle time, the circuit's power consumption is automatically reduced. To reduce the overall system's power consumption, maximization of sleep time and minimization of net cuts are required. To achieve these, an effective fitness function has been constructed in such a way that the balance criteria are also maintained. The approach has been tested on a set of net lists from the ISPD'98 benchmark suite, each containing 10 to 30 nodes. The experimental results are compared with two existing methods that clearly indicate the acceptability of the suggested method. The suggested strategy achieves an average reduction of 24.69% and 31.46% for net cut, whereas average extensions of 15.20% and 12.31% are observed in sleep time when compared with two existing methods. The proposed method also achieves an average power efficiency of 14.98% and 12.09% with respect to these two state-of-the-art methods.