Technical Performance Indicators Research Articles

A techno-economic assessment of sCO2 Brayton cycles for low-grade geothermal reservoirs

CO2-based power cycles have recently received much attention because they have several advantages over traditional power cycles in a wide variety of applications. For low-grade heat sources such as geothermal energy, the research has focused on the transcritical CO2 Rankine cycle (TCRC). However, the TCRC requires relatively low-temperature heat sinks to condense the CO2 and operate properly, preventing its deployment in many locations. A straightforward solution is to use a supercritical CO2 Brayton cycle (SCBC) instead. Nonetheless, in the context of binary cycle geothermal power plants, there is a lack of information about the feasibility of implementing SCBCs. Therefore, to elucidate the viability of employing SCBCs for power generation using geothermal heat, this paper presents an assessment of the thermodynamic and economic performances of four SCBC configurations. For this purpose, thermodynamic and economic models of the system, along with a thermal-hydraulic model of the heat exchangers, were developed. Net power output and net present value were used as technical and economic performance indicators, respectively. Subsequently, base case simulations were conducted, and multi-objective optimization using NSGA-II was performed. Results show that, using 20 kg/s of geothermal brine at 150 °C as the heat source and cooling water at 25 °C as the heat sink, an intercooled recuperated Brayton cycle (IRBC) is superior to the other considered configurations. It can achieve up to 932.07 kW of net power output at the optimal thermodynamic conditions and 4.45 × 103 USD of net present value at the optimal economic conditions. Besides, balancing the thermodynamic and economic performances, the IRBC attains the highest overall performance. In conclusion, using SCBCs in binary cycle geothermal power plants could be feasible, and the IRBC is a suitable layout.

Real time prediction of match outcomes in Australian football

ABSTRACT This study aimed to determine whether machine learning models based on technical performance and not score margin could be used to predict end-of-match outcome of Australian football matches in real-time. If efficacious, these models could be used to generate insights about team performance and support the decision-making of coaches during matches. A database of 168 team technical performance indicators from 829 Australian Football League matches played between 2017 and 2021 was used. Two feature sets (data-driven and data-informed) were used to train and evaluate six models (generalised linear model, random forest and adaboost) on match outcome prediction (Win/Loss) over 120 epochs (a representation of normalised time during each match). All models performed well (mean classification accuracy = 73.5–75.8%) in comparison with a benchmark score-based model (mean classification accuracy = 77.4%). Data-informed feature sets performed better than data-driven in most cases. Classification accuracy was low at the start of a match (45.7–48.8%) but increased to a peak near the end of a match (87.2–92.7%). These findings suggest that any of the employed models can be used to formulate in-match decision support. The model which is best in practice will depend on factors such as time-cost trade-off, feasibility and the perceived value of its suggestions.

The influence of technical performance indicators on the results of the Chinese Football Super League at different stages of the season-based on evidence from the 2010–2019 seasons

This study explored the different influences of technical indicators on match results in different stages of football league play. Sample data from 2400 Chinese Super League matches during 2010–2019 were divided into three season stages according to round sequence: the early stage (1–10 rounds), the middle stage (11–20 rounds), and the late stage (21–30 rounds). A two-way, fixed-effect ordered logit model was then constructed and used, together with Fisher’s combination test, to compare regression results. The study results showed that: (1) when controlling for other variables, as the league progresses, an increase in goals will gradually increase the possibility of better match results, and this increase shows significant differences between the early and late stages ( p < 0.05). The possibility of better match results by an extra goal is 0.075 times higher in the late stage than the early stage. (2) While maintaining all control variables, as the season progresses, the increase in red card penalties will gradually multiply the probability of worse match outcomes, and this increase is also significantly different between the early and middle stages and between the early and late stages ( p < 0.05). The possibility of worse match outcomes due to the presence of an extra red card is 0.377 times higher in the middle stage and 0.476 times higher in the late stage than the early stage.

Evaluation of a novel disposable esophagogastroduodenoscopy system in emergency, bedside, and intraoperative settings: Pilot study (with videos).

The disposable esophagogastroduodenoscopy (EGD) system is a novel endoscopic device which is highly portable and is designed to eliminate the risk of cross-infection caused by reusable EGD. This study aimed to investigate the feasibility and safety of disposable EGD in emergency, bedside, and intraoperative settings. This was a prospective, single-center, noncomparative study. Disposable EGD was used for emergency, bedside, and intraoperative endoscopies in 30 patients. The primary end-point was the technical success rate of the disposable EGD. Secondary end-points included technical performance indicators including clinical operability, image quality score, procedure time, the incidence of device malfunction and/or failure, and the incidence of adverse events. A total of 30 patients underwent diagnosis and/or treatment with disposable EGD. Therapeutic EGD was performed on 13/30 patients, including hemostasis (n = 3), foreign body retrieval (n = 6), nasoenteric tube placement (n = 3), and percutaneous endoscopic gastrostomy (n = 1). The technical success rate was 100%: all procedures and indicated interventions were completed without changing to a conventional upper endoscope. The mean image quality score obtained immediately after procedure completion was 3.72 ± 0.56. The mean (± SD) procedure time was 7.4 (± 7.6) min. There were no device malfunctions or failures, device-related adverse events, or overall adverse events. The disposable EGD may be a feasible alternative to the traditional EGD in emergency, bedside, and intraoperative settings. Preliminary data show that it is a safe and effective tool for diagnosis and treatment in emergency and bedside upper gastrointestinal cases. Chinese Clinical Trial Registry (Trial ID: ChiCTR2100051452, https://www.chictr.org.cn/showprojen.aspx?proj=134284).

Justification of the optimal type of well completion profile based on a retrospective assessment of the technical and economic performance indicators

To date, significant foreign and domestic experience has been accumulated in the construction and operation of horizontal, multilateral and multilateral wells, as well as the restoration of an idle well stock by drilling sidetracks and sidetracks into various productive formations: low-permeability and highly dissected, with low values of effective oil-saturated thicknesses, degraded hydrodynamic connection with the contour area, etc. In this regard, it becomes extremely important to make a decision on choosing the optimal well profile in specific geological and physical conditions. The relevance of the work is also confirmed by the fact that at some development sites there is a decrease in the oil production rate of horizontal wells to the level of directional wells in the initial period of operation. Based on a significant difference in the reservoir properties of oil fields in the Perm Territory, all the analyzed objects operated by horizontal wells are combined into several groups: “northern” (N) and two “southern” (S1 and S2). The main parameter in the selection of groups was the coefficient of mobility of oil. The well-by-well technical and economic assessment performed in the article, based on the actual values of production over a long period, made it possible to identify the optimal well profile depending on the geological and physical characteristics of the reservoir. Combining the main geological characteristics that affect the technological parameters of well operation, with an economic assessment, the dependences of the net present value on the formation hydraulic conductivity were built. Dependences built for the first time make it possible to reasonably select the well profile in specific geological and physical conditions. Also in the work for a variety of geological and physical conditions, the value of the minimum profitable oil production for various well profiles is determined. Thus, the basis has been created, which is necessary for determining the profile of wells when planning production drilling.

Feasibility Analysis of a Fuel Cell-Based Tri-Generation Energy System Via the Adoption of a Multi-Objective Optimization Tool

Abstract The present paper investigates the feasibility of a tri-generation energy system in an industrial scenario with a modest size in terms of levels of electricity, heat, and cooling consumption. The technology under consideration is the fuel cell technology, both solid oxide fuel cells and proton exchange membrane fuel cells (PEMFCs), compared to other more mature technologies, such as micro gas turbines. The proposed investigation takes into account several scenarios: the existing economy and state-of-the-art technical key performance indicators of the involved energy systems; the state-of-the-art technical key performance indicators of the involved technologies and economic subsidies; and a future scenario that takes into account economies of scale and better performance using the key metrics for fuel cell technology forecasted as 2030 target at European level. The PEMFCs with lithium-ion storage showed total efficiencies in the order of 75% over three reference periods. In terms of emissions, they guarantee a decrease in carbon dioxide equivalent released into the atmosphere equal to 40% of the reference emissions for a separate generation.

Technical Differences over the Course of the Match: An Analysis of Three Elite Teams in the UEFA Champions League.

The purpose of this study was to evaluate the evolution of technical performance indicators over the course of football matches in the UEFA Champions League. Three elite football teams were the sample of the present study and were analyzed throughout four consecutive seasons within the previously mentioned competition. Data from 15 min periods were collected from Wyscout and elaborated. The effects of match location and competition stage were analyzed on nine technical indicators, including ball possession and variables related to offense and goal scoring. The effects of independent variables were assessed both independently and combined. The results showed a significant increase in the frequency of occurrence and accuracy of most of the parameters towards the end of the match. The effect of match location was generally significant with higher rates for teams playing at home. Differences were noted between the two stages of the competition with higher values in the technical indicators registered during the group stage. The existence of significant differences between the initial and final periods of football games was suggested by the results. The so-called home advantage was confirmed. Different team approaches between longer stages (e.g., group stage) and elimination games (i.e., knockout phase) were suggested by the results.

Comprehensive Low Voltage Microgrid Planning Methodology for Rural Electrification

Recently, DC-powered devices such as loads (USB plugs, chargers, LED lighting) and distributed energy resources (solar photovoltaic and battery energy storage) have been increasingly used. Therefore, their connection to the grid requires AC/DC converters, which raises the question of operating part of the grid in DC in order to connect DC loads to DC producers and storage. In Cambodia, the electrification rate is only about 82% of the population in 2021 in rural areas. The objective of this work is to propose a low voltage microgrid comprehensive planning tool for electrification of developing countries. From the data collected on consumption needs, the objective is to find the optimal electrification scheme, i.e., AC or AC/DC distribution, optimal topology and distributed energy resources allocation and operation for both grid-connected and off-grid mode. A set of technical, economic, and environmental key performance indicators allows for comparison of solutions. The interest and efficiency of such a tool are illustrated on a real case study, an island area. Moreover, uncertainties on load consumption are also considered to assess the sensitivity and robustness of the proposed algorithm. The results show that, although the overall cost of the hybrid AC/DC microgrid is slightly higher than that of the AC microgrid, it allows a gradual electrification avoiding large initial investments.

Solar Operated Electric Scarecrow

This research presents an innovative method for agricultural pest control using an electric scarecrow system that runs on solar power and is controlled by the YOLOv5 object detection model. Historically, traditional scarecrows have not proven very effective at keeping out pests because they are immovable and have low accuracy in intrusion detection. To address these limitations, our innovative approach makes use of solar energy for continuous operation and the YOLOv5 deep learning architecture for real time pest identification. Our system's main component is a solar powered platform that is placed in agricultural fields with motion sensors and cameras. The YOLOv5 model is used to evaluate live camera feeds and is deployed on edge devices to rapidly and correctly identify pests. The scarecrow's electric system releases deterrents when it detects something. This study provides a thorough examination of the technical details, performance indicators, and financial sustainability of the solar powered electric scarecrow. According to the research, this creative approach has the potential to completely transform crop protection techniques by providing a cost effective and environmentally friendly substitute for conventional scarecrow systems.

Improving Belarusian energy system reliability in the context of Belarusian NPP commissioning

The article presents the results of computational experiments confirming the efficacy of the phase-shifting transformer (PST) as a type of a phase-shifter, which is to be installed at the backbone 750/330 kV substation Belorusskaya, in the repair and post-emergency states of the Belarusian power system, as well as an analysis of technical and economic performance indicators.

Beach volleyball set and technical performance indicators for elite women’s teams

Beach volleyball set and technical performance indicators for elite women’s teams

Design, Technical and Economic Optimization of Renewable Energy-Based Electric Vehicle Charging Stations in Africa: The Case of Nigeria

The transportation sector accounts for more than 70% of Nigeria’s energy consumption. This sector has been the major consumer of fossil fuels in the past 20 years. In this study, the technical and economic feasibility of an electrical vehicle (EV) charging scheme is investigated based on the availability of renewable energy (RE) sources in six sites representing diverse geographic and climatic conditions in Nigeria. The HOMER Pro® microgrid software with the grid-search and proprietary derivative-free optimization techniques is used to assess the viability of the proposed EV charging scheme. The PV/WT/battery charging station with a quantity of two WT, 174 kW of PV panels, a quantity of 380 batteries storage, and a converter of 109 kW located in Sokoto provide the best economic metrics with the lowest NPC, electricity cost, and initial costs of USD547,717, USD0.211/kWh, and USD449,134, respectively. The optimal charging scheme is able to reliably satisfy most of the EV charging demand as it presents a small percentage of the unmet load, which is the lowest when compared with the corresponding values of the other charging stations. Moreover, the optimal charging system in all six locations is able to sufficiently meet the EV charge requirement with maximum uptime. A sensitivity analysis was conducted to check the robustness of the optimum charging scheme. This sensitivity analysis reveals that the technical and economic performance indicators of the optimum charging station are sensitive to the changes in the sensitivity variables. Furthermore, the outcomes ensure that the hybrid system of RE sources and EVs can minimize carbon and other pollutant emissions. The results and findings in this study can be implemented by all relevant parties involved to accelerate the development of EVs not only in Nigeria but also in other parts of the African continent and the rest of the world.

The influence of removing home advantage on the Chinese Football Super League.

Due to the COVID-19 pandemic, the 2020 season Chinese Super League (CSL) was held in neutral venues, this study aims to analyse the impact of removing home advantage (HA) in CSL. 240 games of the CSL 2019 season (home and away double round-robin system) and 160 games of the 2020 season (in neutral venues) were analysed. 27 technical and tactical performance indicators were involved as dependent variables. A multiple linear regression model was established to analyse the influence of removing HA on the performance indicators. After moving from home stadium to neutral venue in 2020 season, goal, shot, shot on target, shot from outside box, shot from inside box, shot on target from inside box, corner kick, key pass, cross, breakthrough, tackle decreased significantly (p < 0.05), while yellow card and foul increased steeply (p < 0.05). Comparing with playing away match, in neutral venue, free kicks and pass accuracy enhanced radically (p < 0.05), while tackle, clearance and block shot dropped noticeably (p < 0.05). When removing HA and playing in the neutral venue, teams' performance dropped significantly. This study confirmed the positive impact of HA on the teams' performance and may help elite football teams make proper playing strategies regarding different match locations.

The test method of the thunder and lightning direct effect protection equipment

In order to avoid the harm caused by the direct effect of lightning, modern new ships are equipped with lightning direct effect protection devices. However, due to the harsh environment such as high temperature, high humidity and high salt, it is easy to change its performance indicators and affect the lightning protection effect. Taking the direct lightning protection device with gaps installed at the rear end of the ship antenna as an example, through the study of its working principle and main technical indicators, the items that need to be tested regularly are determined, and the corresponding test methods are formulated. Through a large number of experiments and test data verification, the conclusion that the method can effectively reflect the main technical indicators of lightning protection facilities and then effectively evaluate the protection effect of lightning protection facilities is drawn. The research results of this paper are of great significance to regularly test the lightning direct effect protection equipment, accurately grasp the changes of its technical performance indicators, and ensure the protection effect of lightning direct effect.

Real-time data-based performance analysis of a large-scale building applied PV system

Solar photovoltaic (PV) is one of the fastest-growing renewable technologies. Building applied photovoltaic systems can significantly help reduce the energy and environmental loads of buildings. This study analyzes the performance of a 425 kW building applied photovoltaic system by investigating important technical, economic, and environmental parameters. These analyses have been carried out with the help of year-long real-time performance data. The technical performance indicators examined in this study include direct current and alternating current power output, array yield, specific (final) yield, references yield, array losses, module and overall PV conversion efficiency, capacity factor, and performance ratio. The main strengths of the study include the large size of the BAPV system, and a comprehensive techno-economic and environmental analysis based upon real-time monitored data. The PV system has been found to annually produce 835.60 MWh and 814.88 MWh of DC and AC power output, respectively. The performance ratio varies from 74.03% in August to 84.62% in January with an annual figure of 78.09%. The annual capacity factor is determined to be 21.85%. For a project life of 25 years, the simple payback period and Net Present Value have been calculated to be 6.92 years and USD 866,565.24, respectively. Over the project lifetime, the savings of CO2, CH4 and N2O are calculated to be 15,666 tons, 483.75 kg, and 83.25 kg respectively.

Classical and Process Intensification Methods for Acetic Acid Concentration: Technical and Environmental Assessment

This study aims to investigate, from a technical and an environmental perspective, various alternatives for acetic acid concentration for maximizing acetic acid production, its purity, and in the meantime, minimizing the energy usage and the environmental impact. Liquid–liquid extraction followed by azeotropic distillation using different solvents such as: (i) ethyl acetate, (ii) isopropyl acetate, and (iii) a mixture containing isopropyl acetate and isopropanol were first explored, using process flow modeling software. The three cases were compared considering various technical key performance indicators (i.e., acetic acid flow-rate, acetic acid purity, acetic acid recovery, power consumption, thermal energy used, and number of equipment units involved) leading to the conclusion that the usage of the isopropyl acetate—isopropanol mixture leads to better technical results. The isopropanol-isopropyl acetate mixture was furthermore investigated in other two cases where process intensification methods, based on thermally coupled respectively the double-effect distillation process, are proposed. The highest quantity of pure acetic acid (e.g., 136 kmol/h) and the highest recovery rate (e.g., 97.74%) were obtained using the double-effect method. A cradle-to-gate life cycle assessment, involving ReCiPe method, was used to calculate and compare various environmental impact indicators (i.e., climate change, freshwater toxicity potential, human toxicity, etc.). Several steam sources (i.e., hard coal, heavy fuel oil, light fuel oil, natural gas, and biomass) were considered in the environmental evaluation. The results of the life cycle assessment show a reduction, by almost half, in all the environmental impact indicators when the double effect method is compared to the thermally coupled process. The usage of biomass for steam generation lead to lower impacts compared to steam generation using fossil fuels (i.e., hard coal, heavy fuel oil, light fuel oil, natural gas).

Exploring goalkeepers’ technical-tactical performances according to match location, team quality and nationality in the English Premier League

This study aimed to examine the influence of match location, team quality and players’ nationality on technical and tactical performance indicators in elite goalkeepers. The sample was composed by 87 goalkeepers from the English Premier League during five seasons (from 2011/12 to 2015/16). Twenty-four variables were selected in order to characterize offensive, defensive and disciplinary goalkeeper’s behavior. Different non-parametric test (p&lt;0.05) showed statistically significant differences in all the variables in terms of match location, excepting interceptions, fouls and unsuccesful short distributions. Moreover, statistically significant differences were also found amongst teams’ level in terms of successful passes, goals received inside the box and successful long distribution, both in national and foreign goalkeepers. Finally, only national players exhibit a significant increase in goals received outside-box (top level teams), saves inside-box (intermediate level teams) and unsuccessful long distribution regardless teams quality. The data provided in this study might help goalkeepers’ coaches to modulate the frequency and number of actions performed by goalkeepers during training sessions, and help managers to make decisions when signing goalkeepers according to their nationality.

A generalised optimal design methodology for distributed energy systems

The optimal combination of energy conversion and storage technologies with local energy demand is a key but in its result not obvious challenge of distributed energy. Although a variety of possible approaches to the optimal design of limited technology selections can be found in the literature, the previous design step, the actual technology selection, and the subsequent step, the selection of the optimal operating strategy, are often neglected. We develop and demonstrate a methodology, which can optimise energy systems with arbitrary technology selection and under multi-criteria optimality definitions. The energy system modelled in oemof.solph is optimised using a MOEA/D approach with regard to economic, ecological and technical key performance indicators. The aim is to find trends and tendencies with a methodology that is as generalised as possible in order to integrate it into the decision-making process in energy system planning. We demonstrate the method by means of a German district for which an integrated supply concept is being sought. Different evaluation and visualisation possibilities are presented and the chances and limitations of the developed methodology are identified. We show that not only the choice of technology, but especially its sizing and operational strategy have a decisive influence on the optimality.

Thermal Engineering Tests of Heating Boiler Houses when Working on Peat Fuel

Modern development of society and the economy is generally accompanied by abandonment of non-renewable fuels in the system of existing attitudes toward environmental issues and resource conservation. The paper presents the results of complex operational tests of КВм-2.0 water boilers with automatic stoker and КВр-0.4K at heat supply facilities of the Arkhangelsk region under the typical operating conditions on coal, fuel mixtures, and also peat briquettes and sod peat. Experimental work was carried out using modern methods and advanced technical means. Within the framework of the research on the conversion of boilers to peat fuel, balance experiments were carried out; technical, economic and environmental performance indicators were obtained; the selection and analysis of focal residues were carried out, fine solid and soot particles polluted into the environment were studied in detail. The paper presents graphs of changes in gross efficiency, heat loss with exhaust gas, heat loss with incomplete combustion, and concentrations of sulfur and nitrogen oxides during the cycle between loading peat briquettes into the КВр-0.4K boiler, as well as graphs of changes in the heat balance components and gross efficiency all boiler units under investigation. The conversion of heat generating plants to peat fuel combustion makes it possible to achieve a significant reduction in emissions of solid and soot particles without upgrading ash-collecting plants. Complex experimental studies conducted of existing hot water boilers with a nominal heating capacity of 0.4 and 2.0 MW have shown the possibility, as well as the energy-environmental efficiency of burning briquetted and sod peat in the combustion chambers of these heat generating plants.

Impact Assessment of Different Battery Energy Storage Technologies in Distribution Grids with High Penetration of Renewable Energies

The need for increasing further the penetration of Renewable Energy Sources (RESs) is demanding a change in the way distribution grids are managed. In particular, the RESs intermittent and stochastic nature is finding in Battery Energy Storage (BES) systems its most immediate countermeasure. This work presents a reality-based assessment and comparison of the impact of three different BES technologies on distribution grids with high RES penetration, namely Li-ion, Zn-Air and Redox Flow. To this end, a benchmark distribution grid with real prosumers’ generation and load profiles is considered, with the RES penetration purposely scaled up in such a way as to violate the grid operational limits. Then, further to the BES(s) placement on the most affected grid location(s), the impact of the three BES types is assessed considering two Use Cases: 1) Voltage &amp; Congestion Management and 2) Peak Shaving &amp; Energy shifting. Assessment is conducted by evaluating a set of technical Key Performance Indicators (KPIs), together with a simplified economic analysis.