Average Efficiency Research Articles

A comprehensive 4E (energy, exergy, economic, environmental) analysis of novel pyramid solar still coupled with pulsating heat pipe: An experimental study

Remote regions and poor communities often suffer the most from the shortage of fresh water. Providing a sustainable supply of fresh water and improving the quality of life for millions of people worldwide is crucial.In the present study, two experimental setups, namely (i) a modified pyramid solar still (MPSS) coupled with pulsating heat pipe and (ii) the conventional pyramid solar still (CPSS), were designed, constructed, and investigated under the same ambient conditions of Surat City, India. The MPSS and CPSS were compared for freshwater yield, energy, exergy, and economic analysis at four different depths. The experimental results demonstrate that the accumulated distillate yield for the MPSS was higher than that of the CPSS. The maximum freshwater yield obtained for MPSS and CPSS was approximately 4.10 L/m2-day and 3.05 L/m2-day at 2 cm depth. During the experiment, improvement in the yield of MPSS due to the attachment of PHP was 34.42%, 37.13%, 31.87%, and 29.62 % as compared to CPSS for 2 cm, 3 cm, 4 cm, and 5 cm, respectively. Moreover, the energy and exergy efficiency of MPSS was higher than CPSS. The maximum enhancement for average energy and average exergy efficiency obtained in MPSS was 25.51% and 29.31% compared to CPSS at 2 cm water depth. The economic analysis exhibits that the cost per liter of fresh water was decreased by up to 13.33% compared with CPSS at 2 cm depth. Based on the environmental assessment, the MPSS's most significant environmental parameter (CO2 mitigation) at 2 cm of water depth was 18.79 tons. The present study's advantage is using a pulsating heat pipe and passively transferring the additional heat energy into the basin.

UJI KINERJA OVEN PENGERING SPESIMEN CAT TIPE TERTUTUP DENGAN PENAMBAHAN ISOLATOR ALUMINIUM FOIL

UJI KINERJA OVEN PENGERING SPESIMEN CAT TIPE TERTUTUP DENGAN PENAMBAHAN ISOLATOR ALUMINIUM FOIL

NERONE: The Fast Way to Efficiently Execute Your Deep Learning Algorithm at the Edge.

Semantic segmentation and classification are pivotal in many clinical applications, such as radiation dose quantification and surgery planning. While manually labeling images is highly time-consuming, the advent of Deep Learning (DL) has introduced a valuable alternative. Nowadays, DL models inference is run on Graphics Processing Units (GPUs), which are power-hungry devices, and, therefore, are not the most suited solution in constrained environments where Field Programmable Gate Arrays (FPGAs) become an appealing alternative given their remarkable performance per watt ratio. Unfortunately, FPGAs are hard to use for non-experts, and the creation of tools to open their employment to the computer vision community is still limited. For these reasons, we propose NERONE, which allows end users to seamlessly benefit from FPGA acceleration and energy efficiency without modifying their DL development flows. To prove the capability of NERONE to cover different network architectures, we have developed four models, one for each of the chosen datasets (three for segmentation and one for classification), and we deployed them, thanks to NERONE, on three different embedded FPGA-powered boards achieving top average energy efficiency improvements of 3.4× and 1.9× against a mobile and a datacenter GPU devices, respectively.

Effects of shift work on sleep quality and cardiovascular function in Taiwanese police officers

ABSTRACT This study aimed to investigate the effects of shift work on sleep quality, cardiovascular function, and physical activity (PA) levels in Taiwanese police officers. Twenty-one male police officers aged 26.9 ± 4.1 years old located in Taipei voluntarily participated in this study. The participants completed the resting heart rate (HR) and hemodynamic variables (e.g. blood pressure, BP) before and after day-time (DTW) and night-time (NTW) shift work phases (5 working days and 2 resting days for each phase). Additionally, an actigraphy was administered to measure PA and sleep patterns in the last 3 working days. The average total sleep time and sleep efficiency were 278.5 ± 79. 6 min and 72.9 ± 10%, respectively, in the NTW phases, which were significantly lower than that in the DTW phases. A comparison of the PA characteristics between the two phases revealed that a lower proportion of moderate-vigorous PA (1.2 ± 0.8%) and a greater proportion of sedentary behaviour PA (74.8 ± 6.4%) was found in the NTW phases. The results of hemodynamic measures demonstrated that the police officers have significantly elevated systolic BP by 3.3% and diastolic BP by 3.9% after the NTW phases. Furthermore, the NTW phases exhibited a significantly higher percentage change ratio of systolic BP and diastolic BP compared to the DTW phases. Compared with the DTW phases, the NTW phase was significantly more likely to report higher decreasing parasympathetic-related HR variability with a range of −5.9% to −7.8%. In conclusion, night-time shift work resulted in negative physiological changes leading to adverse effects on the health and well-being of Taiwanese police officers.

Biochar inoculated with Rhodococcus biphenylivorans altered microecological regulation by promoting quorum sensing and electron transfer: Up-regulation of related genes and enhancement of phenol and ammonia degradation

Bioaugmentation is an efficient method for improving the efficiency of coking wastewater removal. Nevertheless, how different immobilization approaches affect the efficiency of bioaugmentation remains unclear, as does the corresponding mechanism. With the assistance of immobilized bioaugmentation strain Rhodococcus biphenylivorans B403, the removal of synthetic coking wastewater was investigated (drying agent, alginate agent, and absorption agent). The reactor containing the absorption agent exhibited the highest average removal efficiency of phenol (99.74 %), chemical oxygen demand (93.09 %), and NH4+–N (98.18 %). Compared to other agents, the covered extracellular polymeric substance on the absorption agent surface enhanced electron transfer and quorum sensing, and the promoted quorum sensing benefited the activated sludge stability and microbial regulation. The phytotoxicity test revealed that the wastewater's toxicity was greatly decreased in the reactor with the absorption agent, especially under high phenol concentrations. These findings showed that the absorption agent was the most suitable for wastewater treatment bioaugmentation.

Development and Economical Analysis of Innovative Parabolic Trough Collector Integrated Solar Still

Experimental setup of the integrated parabolic trough collector (PTC) with solar still was developed. PTC was designed considering the solar geometry and the physical laws of parabolic shape and the concentrators. Test were conducted at the location with latitude 19.9975ON and longitude 73.7898OE. Theoretical analysis was done using ray tracing and engineering equation solver (EES) software while designing the system. PTC system was developed with dimensions of 1.5 m length, 1 m width and a concentration ratio (CR) of 21.22. Theoretical thermal efficiency was predicted as 48.1% whereas experimental average thermal efficiency is observed as 42.76%. The observed temperature difference between the vapor and the glass cover is about 17 °C and between ambient air and vapor is about 24.4 °C. Maximum water temperature in the conventional solar still was 64.6 °C where as for the PTC coupled solar still was 74.4 °C. PTC coupled solar still is having averagely 37% higher production rate. This has definitely added an advantage because of the higher energy absorption rate compared with the conventional solar still. PTC coupled solar still system has nearly 35% more heat absorption. Total embodied energy of the system is around 896.875 kWh. Total capital cost of the system is Rs. 41300/-. Total annual output of pure water is around 3 L/Day. Estimated energy payback period is around 2.29 years and the total carbon credit earned is Rs. 2165.38 per year.

Natural convective solar dryer powered by stepped fin plate integrated trough array solar air heater for agricultural produce preservations

In this work, heat energy analysis and economic feasibility of natural convection mixed mode solar dryer under three different methods viz., normal flat plate collector solar dryer (NFPSD), step fin plate integrated trough array collector solar dryer (SFPTSD) and SFPTSD with latent heat storage (LHS) are experimentally investigated. The drying time in SFPTSD – LHS (setup 3) to reach its safe moisture content for paddy, wheat, green chilli are 5.5 h, 6 h and 7 h respectively and it is significantly lowered to a maximum of 47 % as compared with NFPSD (setup 1). Also, the average maximum heat efficiency of 62.19 % for collector and 38.32 % for drying cabinet is obtained in setup 3. The specific heat energy consumption is lowered by 20.65 % and specific moisture extraction rate increases to 21.73 % for this proposed setup in comparison with setup 1. The improvement potential is reduced to a substantial margin of 136.5 W and yields an exergetic efficiency increase of 12.38 % than setup 1. An average annual saving increase of 193.08$ with its present value 94.33$ is achieved for setup 3 as compared with setup 1. We recommend this setup can dry edible produce at low cost and affordable to economically weak farming communities.

Suspended sediment load modeling using Hydro-Climate variables and Machine learning

Machine learning (ML) models have the potential to improve the accuracy of Suspended Sediment Load (SSL) predictions. However, their ability to incorporate climate data to enhance SSL predictions remains underexplored. This study investigates the efficacy of ML models in modeling sediment transport using hydro-climate variables as input data. Boosted decision tree models, including Xgboost, LightGBM, and Catboost, were employed to estimate SSL using hydro-climate variables such as streamflow and precipitation, as well as maximum and minimum temperatures. The models were trained, optimized, and evaluated using either climate/streamflow data or a combination of both, encompassing 47 gauges across the contiguous United States (CONUS) between 1950 and 2022. The results demonstrate that streamflow data alone is insufficient for accurate SSL estimation in all rivers. Consequently, integrating climate data and streamflow data proved effective in predicting SSL at the daily scale across diverse climate zones with commendable accuracy. The models achieved an average Nash-Sutcliffe Efficiency (NSE) of > 0.66, Kling-Gupta Efficiency (KGE) of > 0.67, and Willmott Index (WI) of > 0.83 during the unseen (test) phase. These findings highlight the potential of ML models, particularly when combining climate data with streamflow, to enhance SSL predictions and improve our understanding of sediment transport dynamics.

Intelligent Application of Digital Shared Management System in Journal Resource Integration

In this paper, a journal resource integration system under digital sharing was designed to assess the symmetry of the journal resource matrix using the shared resource matrix analysis method, so that the journal resources can transmit information covertly among the subjects. Subsequently, the collected journal resource data were processed to improve the accuracy of information categorization and integration to form a perfect resource management system. The nature of journal resources was deeply understood by calculating the characteristic observable vectors of journal resources. Finally, with the help of ant colony particle optimization algorithm, the sharing sequence and time of journal resources were calculated, and the metadata format of all journals was unified and standardized to complete the design of journal resource integration system. The results show that the whole average integration efficiency of journal resources is 92.8%. Compared with the traditional integration system, the integration efficiency is improved by 28.3%, which fully confirms the significant performance improvement of the designed digital system in the integration of shared journal resources.

Multiobjective Design and Benchmark of Wide Voltage Range Phase Shift Full-Bridge DC/DC Converters for EV Charging Application

This paper presents an analysis, multi-objective design, and benchmark of three modified Phase-Shift Full-Bridge (PSFB) converters that are well-suited for Electric Vehicle (EV) battery charging applications, covering both typical battery voltage classes (400V and 800V). These three modified PSFB converters, denoted as the t-PSFB, r-PSFB, and i-PSFB converters, have the ability to reconfigure and provide better efficiency performance in the wide voltage range necessary for public EV battery charging applications. In this paper, the characteristics and design considerations of these reconfigurable PSFB converters are discussed in detail. A multi-objective converter design process is proposed to optimize the average efficiency, normalized cost, and power density of the magnetic components and heat sinks. This design process employs the correlations between the cost and performance indexes of the key components derived based on open and accessible components data to estimate the design objectives. In this way, the design process is not constrained by certain component choices, making it easier to identify the most advantageous design. A benchmark study is conducted among the re-configurable PSFB topologies and the conventional PSFB circuit using the proposed multi-objective design process. To validate the analysis, a close-to-Pareto-front 11kW, 45kHz r-PSFB converter prototype with 640-840V input voltage and 250-1000V output voltage ranges is developed and tested.

Improving the hydraulic performance of a high-speed submersible axial flow pump based on CFD technology

The hydraulic performance of a high-speed submersible axial flow pump is investigated to reduce its energy consumption. A more efficient and stable optimization method that combines parametric design, computational fluid dynamics, and a computer algorithm is proposed. The main aim is to broaden the high-efficiency operating zone, so the average efficiency under multiple conditions is optimized while considering rotor–stator matching. The design-of-experiments method and a radial-basis-function neural network are combined to form the optimization platform, and automatic optimization of the pump design is realized through repeated execution of design and simulation. The flow loss mechanism inside the pump is studied in depth via the entropy generation rate, and regression analysis shows that the pump efficiency is influenced mainly by the blade angles. After optimization, the target efficiency is increased by 8.34%, and the flow field distribution shows that the channel vortex and hydraulic loss are controlled effectively. Finally, the results are validated by experiment. The proposed optimization approach has advantages in saving manpower and obtaining globally optimal solutions.

Experimental investigation of hybrid vacuum tube solar water heater/parabolic concentrator integrated with phase change material and nanofluid as HTF simultaneously; energy and exergy assessments

ABSTRACT Solar water heaters suffer from fluctuating hot water production due to unpredictable weather changes throughout the day. In this study, the hybrid configuration of a vacuum tube solar water heater with a parabolic solar concentrator, in conjunction with the application of paraffin as a phase change material, is employed as a novel approach to address this problem. Furthermore, the study investigates the utilisation of a nanofluid (0.05%, 0.1%, and 0.2% mass) containing Al2O3 and ZnO nanoparticles dispersed in water-ethylene glycol (base fluid) as the medium fluid to enhance thermal performance. The experimental results revealed that the utilisation of 0.2% mass ZnO and Al2O3 nanofluids led to a considerable increase of 10.74% and 7.25%, respectively, in the maximum reservoir temperature. This resulted in a respective average thermal efficiency improvement of 41.6% and 33.9% compared to the base fluid. Furthermore, the maximum exergy efficiency of the system exhibited a significant increment of 54% and 40.1% compared to the base fluid. Moreover, the incorporation of phase change material in the system effectively minimised temperature fluctuations.

Understanding energy performance in drinking water treatment plants using the efficiency analysis tree approach

Water treatment processes are known to consume substantial amounts of energy, making it crucial to understand their efficiency, drivers, and potential energy savings. In this study, we apply Efficiency Analysis Tree (EAT), which combines machine learning and linear programming techniques to assess the energy performance of 146 Chilean drinking water treatment plants (DWTPs) for 2020. Additionally, we utilize bootstrap regression techniques to examine the influence of operating characteristics on energy efficiency. The results indicate that the evaluated DWTPs exhibited poor energy performance, with an average energy efficiency score of 0.197. The estimated potential energy savings were found to be 0.005 kWh/m3. Several factors, such as the age of the facility, source of raw water, and treatment technology, were identified as significant drivers of energy efficiency in DWTPs. The insights gained from our study can be valuable for policymakers in making informed decisions regarding the adoption of practices that promote efficient and sustainable energy use within the water cycle.

Evaluation of the efficiency of agricultural higher education institutions of Ukraine and the dynamics of its change by data envelopment analysis

Presently, the process of assessing the effectiveness of higher education institutions and analysing the dynamics of its change needs to be improved, which determines the relevance of this study. The purpose of this study was to improve the assessment of the efficiency of agricultural higher education institutions of Ukraine in the scientific and journalistic context, as well as to investigate the changes in dynamics using the non-parametric method of assessing the relative efficiency of data envelopment analysis. The study used methods of statistical processing and data analysis, linear programming, computer computing to solve research problems, and logical and analytical methods to determine the purpose of the study, the means of achieving it, substantiate the findings of the study, and formulate conclusions. To evaluate the effectiveness of scientific and publishing activities of these higher education institutions, the input-oriented model of variable returns to scale of the data envelopment analysis method was applied. Using statistical data for 2020- 2022, the net technical efficiency of scientific and publishing activities of 37 agricultural higher education institutions of Ukraine was assessed. Based on the results of the assessment, a rating of agricultural higher education institutions in Ukraine was compiled. It was found that in 2021 and 2022, 27% of the surveyed higher education institutions were 100% effective. The average net technical efficiency in 2021 and 2022 was 0.91. In 2021-2022, 27% of agricultural higher education institutions increased the efficiency of scientific and publishing activities, 59% did not change, and 14% decreased. On average, there was a 1% increase in the use of educational resources in the field of agricultural higher education. Thus, the scientific and publication activities of agricultural higher education institutions during the study period are progressive. The findings of this study can be used for a reasonable ranking of higher education institutions according to the efficiency of scientific and publishing activities, analysis of the dynamics of changes in efficiency.

Aza[5]helicene‐Derived Semiconducting Polymers for Improved Performance in Perovskite Solar Cells: Exploring Energetic and Morphological Influences

AbstractThe strategic design of solution‐processable semiconducting polymers possessing both matched energy levels and elevated glass transition temperatures is of urgent importance in the progression of thermally robust n‐i‐p perovskite solar cells with efficiencies exceeding 25 %. In this work, we employed direct arylation polymerization to achieve the high‐yield synthesis of three aza[5]helicene‐derived copolymers with distinct HOMO energy levels and exceptional glass transition temperatures. Upon integration of these semiconducting polymers into formamidinium lead triiodide‐based perovskite solar cells, marked disparities in photovoltaic parameters manifest, primarily stemming from variations in the electrical conductivity and film morphology of the hole transport layers. The p‐A5HP‐E‐POZOD‐E copolymer, featuring a main chain comprising alternating repeats of aza[5]helicene, ethylenedioxythiophene, phenoxazine, and ethylenedioxythiophene, attains an initial average efficiency of 25.5 %, markedly surpassing reference materials such as spiro‐OMeTAD (23.0 %), PTAA (17.0 %), and P3HT (11.6 %). Notably, p‐A5HP‐E‐POZOD‐E exhibits a high cohesive energy density, resulting in enhanced Young's modulus and diminished external species diffusion coefficients, thereby conferring perovskite solar cells with exceptional 85 °C tolerance and operational stability.

An advanced solid-state RF power source maximizing energy efficiency for optimal superconducting RF cavity charging

Abstract This paper outlines an experimental demonstration of an envelope tracking (ET) technique applied to a kilowatt-level single-ended solid-state power amplifier (SSPA), aimed at enhancing the charging efficiency of superconducting radio frequency (SRF) cavities by reducing reflection power while maintaining a high degree of efficiency. The technique is particularly designed for the pulsed operation of the European Spallation Source (ESS) at a nominal frequency of 352 MHz, with a 5% duty cycle and a pulse width of 3.5 ms. The study introduces an optimal charging scheme using a solid-state-based amplifier to maintain high efficiency, allowing for power ramp-up while minimizing reflections from SRF cavities and optimizing SSPA efficiency. A fast envelope tracking power supply (ETPS) system is implemented for the approximately 300 ms charging time required by the SRF cavities at ESS. The ETPS system, demonstrated on a single module as a proof-of-concept with scalability potential to a 400 kW power station, indicates an overall average efficiency of 70% and a 24% energy saving over traditional vacuum-tube based amplifiers. This demonstrates the ET technique’s effectiveness at the kilowatt level for efficient SRF cavity charging with reduced reflection, offering significant efficiency and energy savings.

Study on the allocation efficiency of medical and health resources in Hainan Province: Based on the super-efficiency SBM-Malmquist model.

The equity and efficiency of medical and health resource allocation is the key point of health reform in all countries. Poor allocation efficiency of health resources will seriously affect the sustainable and high-quality development of health causes. Hainan Province is the only free trade port with Chinese characteristics in China, which means that Hainan has ushered in a brand-new development under the policy of free trade port. This study aims to adopt policies to improve the efficiency of medical and health resource allocation in Hainan Province and provide references for other regions. In this study, the Super-efficiency SBM and Malmquist models were used to analyze the static and dynamic efficiency of medical and health resource allocation in Hainan Province during 2016-2020. The results showed that, statically, the average efficiency of comprehensive allocation of health resources in Hainan Province from 2016 to 2020 was 0.975, showing poor overall performance and significant regional differences. Dynamically, the average index of allocation efficiency of medical and health resources was 0.934, showing a negative growth trend. The technical efficiency and scale efficiency of health resource allocation efficiency showed positive growth, while the technical progress and pure technical efficiency showed negative growth. It shows that it is influenced by both scale efficiency and technological progress, among which technological progress is the key factor. Therefore, some policy suggestions are put forward to further optimize the allocation of medical and health resources and improve utilization efficiency.

Aza[5]helicene-Derived Semiconducting Polymers for Improved Performance in Perovskite Solar Cells: Exploring Energetic and Morphological Influences.

The strategic design of solution-processable semiconducting polymers possessing both matched energy levels and elevated glass transition temperatures is of urgent importance in the progression of thermally robust n-i-p perovskite solar cells with efficiencies exceeding 25 %. In this work, we employed direct arylation polymerization to achieve the high-yield synthesis of three aza[5]helicene-derived copolymers with distinct HOMO energy levels and exceptional glass transition temperatures. Upon integration of these semiconducting polymers into formamidinium lead triiodide-based perovskite solar cells, marked disparities in photovoltaic parameters manifest, primarily stemming from variations in the electrical conductivity and film morphology of the hole transport layers. The p-A5HP-E-POZOD-E copolymer, featuring a main chain comprising alternating repeats of aza[5]helicene, ethylenedioxythiophene, phenoxazine, and ethylenedioxythiophene, attains an initial average efficiency of 25.5 %, markedly surpassing reference materials such as spiro-OMeTAD (23.0 %), PTAA (17.0 %), and P3HT (11.6 %). Notably, p-A5HP-E-POZOD-E exhibits a high cohesive energy density, resulting in enhanced Young's modulus and diminished external species diffusion coefficients, thereby conferring perovskite solar cells with exceptional 85 °C tolerance and operational stability.

Preparation of carbon dots using aminoquinoline as nitrogen source as full ultraviolet bands absorber and application of LED UV leakage protection

LED has the advantages of small size, low power consumption, instant lighting, etc., but there is a risk of ultraviolet leakage. Long-term exposure to ultraviolet rays can lead to skin pigmentation, photoaging and additional hazards. Carbon dots (CDs) are excellent material for UV-light absorber because of their multi-functional groups and extreme stability. In this paper, A-CDs which have wide absorption range from 200 to 500 nm were prepared by one-pot hydrothermal carbonization. Then, 3&4A-CDs is prepared in two ways, CDs mixing and raw material mixing, which with average and efficient absorption efficiency both in UVA bands and UVB bands. After 180 h of accelerated aging and switched the pH value, ultraviolet absorption intensity of 3&4A-CDs still remained above 97% and 99%, and the emission wavelength did not alter. Finally, 3&4A-CDs@CMC films were synthesized and the 0.45 wt% 3&4A-CDs@CMC film could reach 100% absorption in the full UV bond. After 180 h of accelerated aging experiments, ultraviolet absorption intensity of 3&4A-CDs@CMC film still remained above 95%. Due to the extremely excellent ultraviolet absorption efficiency of the 3&4A-CDs, the 0.45 wt% 3&4A-CDs@CMC film can effectively avoid the leakage of ultraviolet light without affecting the visible light emitting effect of LED. At present, the synthetic process of 3&4A-CDs is simple, low cost and environmentally friendly.

Evaluating the effectiveness of precision farming technologies in the activities of agricultural enterprises

This paper describes approaches to improving the efficiency of agricultural enterprises. It has been established that the use of technology transfer, in particular, precision farming technologies, makes it possible to enhance the efficiency of agricultural enterprises, in particular, to increase the yield of agricultural crops and, accordingly, to improve the profitability of enterprises. As an example, the activities of agricultural enterprises in the Republic of Kazakhstan were analyzed. The share of agricultural enterprises in the Republic of Kazakhstan that use elements of precision farming technology in their activities was determined. It was established that since 2019, the use of precision farming technologies in the activities of agricultural enterprises in the Republic of Kazakhstan has intensified. At the same time, from 60 to 75 % of enterprises already use elements of precision farming technologies in their activities. Using crop yield data for the past 32 years, estimates of the effectiveness of using precision farming technologies by agro-enterprises in the Republic of Kazakhstan were constructed based on forecasting yield indicators using the linear-weighted moving average method. The efficiency of using precision farming technologies in the activities of agricultural enterprises in the Republic of Kazakhstan in 2022 reached 8.46 %, and the average efficiency for the period 2019–2022 was 4.21 %. Therefore, the use of precision farming technologies makes it possible to improve the validity of decision-making in the management of an agricultural enterprise and to obtain a higher profit from the sale of produced agricultural products for any agricultural enterprise in the world. On average, the results allow us to estimate the possible profit of an agro-enterprise when growing agricultural crops in the case of using precision farming technology