Minimum Efficiency Research Articles

Practicable Artificial Photosynthesis: Its Relevance, Fundamental Challenges and Opportunities

The single main resource for the survival of humankind on this planet is the sunlight and it is freely coming to every home like the life-supporting gas, oxygen, is coming to every individual. When society becomes master in harvesting such a precious, Omnipresent, carbon-neutral, clean, freely and abundantly available renewable energy resource sunlight in a suitable form of chemical energy such as, H2, O2, CO, methanol, gasoline (petrol), diesel, etc., with a minimum conversion efficiency of 10% by using carbon dioxide (CO2) and water (H2O) as energy storing materials, which is referred to as the “Practicable Artificial Photosynthesis (PAP)” process, it can be employed for commercial practice with economic viability to meet all the energy needs of the society without any back-up by electricity generated at thermal power plants by burning greenhouse gas CO2 releasing fossil fuels. In fact, the PAP process is the only option available today for humankind to make energy, environment, economy, and life sustainable on our only habitable planet, Earth. In this article, (i) how the PAP process can change the global energy economy and energy dynamics of the world while solving all the humanities top 10 problems for the next 50 years, (ii) how the entire CO2 gas generated as a waste across the globe at all the major outlets can be eventually converted into petrol (i.e., gasoline) given the fossil fuels cannot sustain our civilization’s economic growth, (iii) the effectiveness of existing CO2 sequestration vs. carbon capture and utilization (CCU) processes, (iv) nature’s response to anthropogenic CO2 gas rise in the atmosphere, (v) steps involved in the realization of a desirable PAP process, (vi) why silicon photovoltaic cell (SPVC) solar panels cannot solve the energy problems of our society considering the outcome of Germany’s Energiewende program, etc., have been meticulously presented and described in this article.

Efficient implementation on accuracy improvement of the two-dimensional node-to-segment contact approach for explicit dynamic analysis

The penalty-method-based node-to-segment (NTS) approach is widely employed in the explicit dynamic analysis owing to its computational efficiency and implementation simplicity. However, the classical approach does not pass the contact patch test and results in severe inaccuracies. This study attempts the accuracy enhancement of an explicit dynamic contact analysis with minimum efficiency loss using the NTS algorithm with the modified area regularization technique (NTS-mAR). The computational procedure is compared to an allied modified penalty-method-based NTS approach, i.e., the virtual node-to-segment algorithm passing the patch test (VTS-PPT). Then, an extension to an explicit dynamic analysis framework is attempted, wherein the speed of the contact force calculation significantly influences the overall computational efficiency. The cost of the remaining computation was minimized by employing a lumped mass matrix and a one-point integration rule for the internal force. Elastoplasticity was considered to extend its application. The accuracy improvement compared to the classical one-pass NTS approach was similar for the modified approaches. The VTS-PPT approach requires more than twice the cost of contact force estimation compared with the classical one-pass NTS approach. In contrast, NTS-mAR approach induces a cost increase from 6 to 36% that of classical one-pass NTS approaches. For the given examples, the NTS-mAR approach is beneficial when an improvement in accuracy is desired with minimum efficiency loss.

Comparison of Different Optimization Techniques for Model-Based Design of a Buck Zero Voltage Switching Quasi-Resonant Direct Current to Direct Current Converter

The present paper provides a comparison of different optimization techniques applied to the model-based design of a Buck Zero Voltage Switching (ZVS) Quasi-Resonant DC-DC Converter. The comparison was made both on the basis of the duration of the optimization procedures and in terms of guaranteeing the performance of the power electronic device. The main task of the paper is to present various techniques based on the use of mathematical software for the optimal design of Quasi-Resonant DC-DC converters. These topologies were chosen because in them, the design is carried out according to computational procedures, in which several iterations are often necessary for the successful completion of the process. An optimization procedure with a target function reference curve of the output voltage was used. In this way, the optimization is performed without the need for a complete design of the device but only by using base ratios, design constraints, and past experience to determine initial values and intervals of change in circuit parameters. This is also the main advantage of the used optimization of the reference curve type of the output, compared to applying other objective functions, such as achieving minimum losses or maximum efficiency of the device.

A numerical study on the performance of a hybrid ventilation and power generation system

Ventilation, cooling and power are essential requirements of buildings. Integration of solar chimney, earth-air heat exchanger and photovoltaic panel forms a new hybridsystem, which is able to provide simultaneous ventilation, cooling capacity and electricity in an effective manner for buildings. The contribution of this study is to quantitatively identify the thermal and electrical performances of the hybrid system using a comprehensive validated numerical model. In addition, a parametric study was also performed to examine the effect of the number of EAHE pipe and solar collector on the performance of the hybrid system in order to further enhance the system performance. The results revealed that the peak daytime ventilation of the proposed hybrid system is reduced by 22.05 % compared to the ventilation system of solar chimney integrated with earth-air heat exchanger, and the outlet air temperature is reduced by 0.12 °C in average; the indoor temperatures for the hybrid and ventilation systems are slightly different. Moreover, the minimum electrical efficiency of hybrid system is 1.34 % higher than that for stand-alone photovoltaic system. Increasing the number of earth-air heat exchangers leads to more than 36.43 % increase in peak ventilation volume and 3.7 % improvement in electrical efficiency. In addition, increasing the quantity of solar chimney-photovoltaic modules can effectively increase the induced ventilation volume, and the outlet air temperature, but has slight effect on the temperature and electrical efficiency of photovoltaic panel. Therefore, the hybrid system not only can supply appropriate ventilation but also can generate electric power to buildings. The findings provide a preliminary guidance for optimizing design of the hybrid system.

Sensitivity of the causative agent of net blotch of barley (Pyrenophora teres Drechsler) to fungicides

The research was carried to study the effect of fungicides of various classes on the intrapopulation structure of Pyrenophora teres in terms of sensitivity to toxicants, virulence and racial composition. The work was performed using eight treatment options in different doses (control without fungicide, 25 %, 50 %, 75 %, 100 % (the norm), 125 %, 150 %, 175 %, 200 %) fungicides Magnello, EC (1 l/ha), Capella, M (1 l/ha), Kolosal Pro, MC (0.4 l/ha), Quadris, SC (1.2 l/ha), Amistar Trio, EC (1 l/ha), Orgamika C, L (0.4 l/ha) of plants and introduction to a nutrient medium with a pure culture of P. teres. The racial composition of the populations was determined using an international set of differentiator varieties. When treating plants with fungicides with the norm allowed for use in agriculture, the minimum efficiency values were found in the preparations Quadris, SC (52.3 %), Orgamika C, L (66.8 %), the maximum - Magnello, EC (88.2 %) and Kolosal Pro, MC (97.0 %). The average virulence of the population isolated after Quadris, SC treatment was revealed to be maximum - 3.4 points (at the control level). The greatest racial diversity was found in P. teres populations isolated after treatment with fungicides based on triazoles Magnello, EC (CF=0.10) and strobilurines Quadris, SC (CF=0.10). The maximum intrapopulation heterogeneity was revealed in populations isolated after treatment with fungicides based on triazoles and Bacillus amyloliquefaciens: Kolosal Pro, MC (Sh=2.16), Capella, M (Sh=2.14), Magnello, EC (Sh=2.10)) and Orgamika C, L (Sh=2.12). When introducing the permitted rate of drugs into the pure culture of P. teres, on average, the growth of colonies slowed down from 86.1 % (Quadris, SC) to 100 % (Amistar Trio, EC). Preparations based on strobilurines and Bacillus amyloliquefaciens completely prevented sporulation. The results obtained allow us to conclude that there is a shift in sensitivity to the studied drugs.

Thermodynamic and thermo-economic analyses of a coupled heat-pump system for low-grade exhaust-air heat exchange in mines

ABSTRACT Combining mine exhaust waste heat with existing heat pump technology is a promising technical route to realise the efficient extraction and scientific use of low-grade waste heat resources in mines and to solve the problem of insufficient heat supply in remote mining areas. This study proposes a new type of mine-exhaust-air heat exchange coupled with heat-pump waste-heat-utilisation system based on deep enthalpy heat extraction. Using a mining area in Northwest China as a representative case, this study establishes a systematic exergy analytical model and a thermo-economic model. Through an in-depth analysis of the different evaporation temperatures and condensing temperatures, the system’s energy efficiency ratio (COP) reaches its optimal performance, with the total exergy efficiency surpassing 90%. The minimum efficiency of the subsystem return air heat exchanger is 35%. The unit thermal costs of the mine exhaust air waste heat utilisation system and a conventional coal-fired boiler system are 0.1291 and 0.1573 million RMB/kW·h, respectively. This is a thermal economics cost saving of 21%. The studied system demonstrates great economic viability and the potential for energy saving throughout its life cycle.

A Critical Review of The Process and Challenges of Silicon Crystal Growth for Photovoltaic Applications

AbstractCrystalline silicon (c‐Si) solar cells have been accepted as the only environmentally and economically acceptable alternative source to fossil fuels. The majority of commercially available solar cells of all Photovoltaic (PV) cells produced worldwide, are made of crystalline silicon. Due to their excellent price/performance ratio and their demonstrated ecological durability, crystalline silicon wafers are by far the most common absorber material used in the production of solar cells and modules today. These wafers are primarily made using either a directional solidification that produces large‐grained multi‐crystalline (mc‐Si) wafers with a greater defect density or a solar‐optimized Czochralski (Cz) growing method that produces crystalline silicon with low defect density (c‐Si). The grown crystalline wafer contains foreign atoms that enhance the wire saw damage, reduce the minority carrier lifetime as a result get the minimum conversion efficiency of the solar cells. The current review illustrates how the elements of the furnace system affect impurity production and distribution of the developed silicon ingot and how the growth process affects the chemical reaction. Additionally, it covers the outcomes of simulations and experiments conducted on the growing process of c‐Si and mc‐Si ingots and recommends the most appropriate processing parameters, geometrical system, and argon gas flow rate.

Removal of most frequent microplastic types and sizes in secondary effluent using Al2(SO4)3: choosing variables by a fuzzy Delphi method

Microplastics (MPs) as an emerging pollutant can affect aquatic organisms through physical ingestion, chemical problems and possible creation of biological layers on their surfaces in the environment. One of the significant ways for MPs to enter the aquatic environment is through the effluent discharge of wastewater treatment plants (WWTPs). In this study, first, the concentration and characteristics of MPs in secondary wastewater effluent, and the influential variables related to the coagulation process, for MPs removal were identified using systematic reviews of previous studies. Then, the most proper MPs characterization and coagulation variables were chosen by experts’ opinions using a fuzzy Delphi method. Therefore, the experiment tested in conditions close to the full-scale wastewater treatments. Finally, in the laboratory removal of MPs by coagulation of polyamide (PA), polystyrene (PS), and polyethylene (PE), < 125 and 300–600 μm in size, was tested by a jar test applying Al2(SO4)3 in doses of 5 to 100 mg/L plus 15 mg/L polyacrylamide as a coagulant aid. Using R and Excel software, the results were analyzed statistically. It was concluded that the maximum and minimum removal efficiency was 74.7 and 1.39% for small PA and large PE, respectively. Smaller MPs were found to have higher removal efficiency. The MPs type PA achieved greater removal efficiency than PS, while PE had the least removal efficiency.

Control technologies to prevent aerosol-based disease transmission in animal agriculture production settings: a review of established and emerging approaches.

Transmission of infectious agents via aerosols is an ever-present concern in animal agriculture production settings, as the aerosol route to disease transmission can lead to difficult-to-control and costly diseases, such as porcine respiratory and reproductive syndrome virus and influenza A virus. It is increasingly necessary to implement control technologies to mitigate aerosol-based disease transmission. Here, we review currently utilized and prospective future aerosol control technologies to collect and potentially inactivate pathogens in aerosols, with an emphasis on technologies that can be incorporated into mechanically driven (forced air) ventilation systems to prevent aerosol-based disease spread from facility to facility. Broadly, we find that control technologies can be grouped into three categories: (1) currently implemented technologies; (2) scaled technologies used in industrial and medical settings; and (3) emerging technologies. Category (1) solely consists of fibrous filter media, which have been demonstrated to reduce the spread of PRRSV between swine production facilities. We review the mechanisms by which filters function and are rated (minimum efficiency reporting values). Category (2) consists of electrostatic precipitators (ESPs), used industrially to collect aerosol particles in higher flow rate systems, and ultraviolet C (UV-C) systems, used in medical settings to inactivate pathogens. Finally, category (3) consists of a variety of technologies, including ionization-based systems, microwaves, and those generating reactive oxygen species, often with the goal of pathogen inactivation in aerosols. As such technologies are typically first tested through varied means at the laboratory scale, we additionally review control technology testing techniques at various stages of development, from laboratory studies to field demonstration, and in doing so, suggest uniform testing and report standards are needed. Testing standards should consider the cost-benefit of implementing the technologies applicable to the livestock species of interest. Finally, we examine economic models for implementing aerosol control technologies, defining the collected infectious particles per unit energy demand.

The Effectiveness of a Mechanical Ventilation System for Indoor PM2.5 in Residential Houses.

The mechanical ventilation systems used in houses are designed to reduce carbon dioxide emissions while minimizing the energy loss resulting from ventilation. However, the increase in indoor fine particulate (PM2.5) concentration because of external PM2.5 influx through the ventilation system poses a problem. Here, we analyzed the changes in indoor PM2.5 concentration, distinguishing between cases of high and low outdoor PM2.5 concentrations and considering the efficiency of the filters used in residential mechanical ventilation systems. When using filters with the minimum efficiency reporting value (MERV) of 10 in the ventilation system, the outdoor PM2.5 concentration was 5 μg/m³; compared to the initial concentration, the indoor PM2.5 concentration after 60 min decreased to 73%. When the outdoor PM2.5 concentration was 30-40 μg/m³, the indoor PM2.5 concentration reached 91%. However, when MERV 13 filters were used, the indoor PM2.5 concentration consistently dropped to 73-76%, regardless of the outdoor PM2.5 concentration. Furthermore, by comparing the established equation with the mass balance model, the error was confirmed to be within 5%, indicating a good fit. This allows for the prediction of indoor PM2.5 under various conditions when using mechanical ventilation systems, enabling the formulation of strategies for maintaining indoor PM2.5, as recommended by the World Health Organization.

Investigation of a Solar-Powered Evaporative Cooling System under Tunisian Climate

The demand for cooling continues to increase in line with environmental changes and a greater desire for human comfort. In north Africa and middle eastern countries, and particularly in Tunisia, cooling constitutes a big problem as it is recommended for human and animal breeding. This study aimed to analyze the performance and suitability of an evaporative cooling system powered by solar energy and to assess the economic and environmental impact under Tunisian weather conditions. Numerical modeling and simulations were performed, revealing the effects of inlet air temperature and relative humidity on system performances. An experimental study based on the construction of an evaporative cooling prototype formed by environmentally friendly and locally available components was also performed. This study showed the dependence of the process performances on the humidity and temperature of the ambient air. The obtained results revealed that the efficiency of the evaporative cooler exceeds 90%, with maximum efficiency being reached at a high wet-bulb depression, while minimum efficiency was observed when the dry air has a high relative humidity and a low dry-bulb temperature. Experimental results showed that, for input temperatures ranges between 36 and 47 °C and relative air humidity between 15 and 50%, a direct humidifier produces air with a temperature range between 25 and 29 °C and humidity range between 55% and 85%. Thus, evaporative cooling is feasible and suitable under Tunisian climate conditions during the hot season.

Experimental analysis of methylammonium and Formamidinium-based halide perovskite properties for optoelectronic applications

Nowadays, the toxicity of lead in metal-halide perovskites is the most precarious obstruction in the commercialization of perovskite-based optoelectronic devices. However, Pb-free metal halide perovskites as environment-friendly materials because of their exceptional properties, such as band-gap tunability, narrow emission spectra, low toxicity and easy solution-processability, are potential candidates for optoelectronic applications. Recently, literature reported the poor structural stability and low-emission intensity of Bi-based perovskite NCs. Still, this paper focuses on the fabrication of Formamidinium (FA)-based Bi mixed halide and Methylammonium(MA)-based Bi-pure halide perovskites using Ligand-Assisted Reprecipitation Technique (LARP) technique. XRD diffraction patterns of FA-based perovskites were slightly broad, signifying the nanocrystalline form and limited size of perovskite nanocrystals. While the XRD diffraction patterns of MA3Bi2X9 (X = Cl/Br/I) perovskites were narrow, signifying the amorphous nature and larger size of perovskite nanocrystals. The peak positions were varied in MA-based bismuth halide perovskites with respect to the halide variation from Br to Cl to I ions. The optical study shows the variation in band gap and average lifetime with respect to halide variation leading to enhanced optical properties for device applications. The band-gap of FA3Bi2BrxCl1-x & FA3Bi2IxCl1-x perovskites was calculated to be around 3.7 & 3.8 eV, respectively, while in MA-halide perovskites the band-gap was calculated to be 2.8 eV, 3.1 eV & 3.4 eV with respect to halide variation from I to Cl to Br in perovskite samples using Tauc's plot respectively. Moreover, simulation is carried out using the SCAPS-1D software to study the various parameters in MA & FA-based Bi-pure or mixed halide perovskites. Here, we discussed the variation in efficiency with respect to the thickness variation from 100 to 500 nm for MA3Bi2I9 halide perovskites. These MA3Bi2I9 halide perovskites show minimum efficiency of 4.65 % at 100 nm thickness, while the perovskite sample exhibits maximum efficiency of 10.32 % at 500 nm thickness. Thus, the results stated that the thickness of absorber layers directly affects the device characteristics for optoelectronic applications.

Maximum slacks-based measure of efficiency in network data envelopment analysis: A case of garment manufacturing

The conventional slacks-based measure (SBM) model is widely applied to measure the relative efficiency of a set of decision making units (DMUs) because the measured efficiency is not affected by weakly efficient frontiers. This model seeks the target point on the production frontier that is farthest to the assessed DMU to calculate efficiency, which requires more effort for the DMU to reach to become efficient. This paper develops a model to calculate the maximum SBM efficiency for general network production systems. Different from the conventional minimum SBM efficiency that is always less than the radial efficiency for inefficient DMUs, the maximum SBM efficiency can be greater than the radial efficiency. The measured efficiency satisfies the monotonicity property. The efficiencies of the component divisions of the network system can also be calculated at the same time. A garment manufacturing company whose major operations comprise cutting and sewing is studied using the developed model. The results show that the average maximum SBM efficiency is 35 % higher than the average minimum SBM efficiency and the sewing operation contributes more to the system efficiency than the cutting operation does.

Synthesis and characterization of silver nanoparticles and nanocomposites using Echinochloa pyramidalis (Antelope grass) plant parts and the application of the nanocomposite for the removal of PAHs from bitumen seepage water

Aqueous extracts of the leaf, stem and root of Echinochloa pyramidalis have been used as a reducing agent to synthesize silver nanoparticles. The synthesized nanoparticles were characterized by UV, FTIR, SEM, TEM and XRD. The nanoparticles showed absorption spectra in the visible region and crystallite sizes of 14, 2.70 and 4.9 nm for the leaf, stem and root-based nanoparticles while the respective particle sizes were 15.3, 12.6 and 10.3 nm respectively. The FTIR spectra of the nanoparticles indicated evidence of changes in the functional groups that indicated an interaction between the nanoparticles and the phytochemicals in the respective plant parts. Micrographs obtained from scanning electron microscope (SEM) reveal some protruding internal structures. The synthesized nanoparticles were also used as precursors to synthesize nanocomposites by combining them with the leaf, stem and root of the Echinochloa pyramidalis of the plant. The nanoparticles and the corresponding nanocomposites showed pore sizes that define mesoporous dimension, functional groups that were comparable to those in the parent nanoparticles, and modified surface morphology. However, BET surface area to volume ratios were relatively higher for the composites than the nanoparticles while the reverse trend was observed for pore diameter and pore volume. The composites were found to be excellent adsorbents for the removal of some PAHs from bitumen seepage water and recorded an average minimum removal efficiency of 90% and a maximum of almost 100%.

The Design of a System for the Induction Hardening of Steels Using Simulation Parameters

This paper presents the development of a piece of induction hardening equipment based on the foundations of the design, starting from zero. It was intended for steels in general, and was tested on unalloyed low- and medium-carbon steels, whereas the results for EN 1C60 steel are shown in this study. The EN 1C60 steel showed average results, and was chosen as a representative of a wider group of engineering steels. The main objective of this work was to develop a flexible system for mild steel hardening that can be used for various hardening depths and steel types. The system design’s priorities were the use of standard electronic components to avoid supply chain disruptions and to achieve high energy efficiency. The construction of the prototype in full detail is also presented. The optimal process parameters are listed, as well as the procedure of their obtaining by using the appropriate simulation method. The key parameters were adjusted in consecutive steps. This study resulted in high matching between the model predictions and experimental results. The basic goal of this research was achieved, with the system having a minimum energy efficiency of 75.3%, a most frequent energy efficiency of 90% and a maximum energy efficiency of 95.1%.

Energy-economic and exergy-environment performance evaluation of solar energy integrated essential oil extraction system

Solar Steam distillation system (SSDS) for essential oil extraction from medicinal plants is developed and analysed based on energy, exergy, economic, exergoeconomic, environmental and enviroeconomic point of view. System is analysed for various batch sizes of two different medicinal plants (Peppermint and Eucalyptus) and compared. Maximum and minimum system efficiency is calculated as 48.68 % and 43.25 % for 2 kg of peppermint and 6 kg of eucalyptus, respectively, whereas highest and lowest exergy efficiency of system is 27.96 % and 22.50 % for 6 kg and 4 kg of eucalyptus leaves, respectively. Estimated return on investment (ROI), internal rate of return (IRR) and payback period (PBP) of SSDS producing 72 L of peppermint oil per year were 14.03 %, 18.77 % and 5.67 years, respectively over the projected economic life span of 25 years. 11.43 and 19.94 % with increase in lifespan of system by 5 enhanced exergoeconomic parameters for peppermint oil and 10 years, respectively at same interest rate of 5 % while 11.30 and 19.90 %, respectively increase the corresponding values for eucalyptus oil. CO2 mitigated over the lifespan from SSDS for peppermint oil and eucalyptus oil based on energy approach is found as 2.37, 4.74, 7.11 tons CO2 and 1.97, 3.95, 5.9 tons CO2 for 2, 4 and 6 kg batch size, respectively. Whereas, the corresponding values based on exergy approach are 0.15, 0.11, 0.14 tons CO2 and 0.12, 0.09, 0.12 tons CO2, respectively.

An EEDI based method to better the selection of form and propulsion parameters and improve energy efficiency during preliminary designs of single screw seagoing general/bulk cargo ship

The third phase of the Energy Efficiency Design Index (EEDI) regulations, which came into force in 2022, states that new ships should reduce their emissions by at least 30% compared to the minimum energy efficiency level (EEDI baseline) set by the IMO's MEPC in 2013. Apart from its vital role in decarbonizing the global fleet and improving the transportation efficiency, the EEDI that is considered herein is a measure of vessel's mechanical performance. A simplified EEDI (SEEDI) is used to judge a series of designs in order to identify all possible efficient designs and to select the best option. A code was employed to iterate over all practical ranges of hull and propeller parameters to extract complete designs from methodical design and propeller series. All possible methods of manipulating form and propulsion parameters that might lead to reducing the SEEDI were investigated. The modifications were made while taking into consideration the practical and economical ranges of the non-dimensional ratios and form coefficients. Compared to the use of energy saving devices and slow steaming, significant reductions (up to 25%) in the SEEDI have been achieved after applying the proposed method.

Investigation of the Influence of Formation Water on the Efficiency of CO2 Miscible Flooding at the Core Scale

This study investigated the impact of formation water on the mass transfer between CO2 and crude oil in low-permeability reservoirs through CO2 miscible flooding. Formation water leads to water blocks, which affect the effectiveness of CO2 miscible flooding. Therefore, we studied the impact and mechanisms of formation water on the CO2-oil miscibility. The microscale interaction between formation water-CO2-core samples was investigated using CT scanning technology to analyze its influence on core permeability parameters. In addition, CO2 miscible flooding experiments were conducted using the core displacement method to determine the effects of formation water salinity and average water saturation on minimum miscibility pressure (MMP) and oil displacement efficiency. The CT scanning results indicate that high-salinity formation water leads to a decrease in the porosity and permeability of the core as well as pore and throat sizes under miscible pressure conditions. The experimental results of CO2 miscible flooding demonstrate that CO2-oil MMP decreases as the salinity of the formation water increases. Moreover, as the average water saturation in the core increases, the water block effect strengthens, resulting in an increase in MMP. The recovery factors of cores with average water saturations of 30%, 45%, and 60% are 89.8%, 88.6%, and 87.5%, respectively, indicating that the water block effect lowers the oil displacement efficiency and miscibility.

Modification, Fabrication and Performance Evaluation of Manual Weeder

The weed should be controlled and eliminated at their early stage. Depending upon the weed density, 20 to 30 percent loss in grain yield is quite usual which might increase up to 80 percent if adequate crop management practice is not observed. The present study was conducted in Prayagraj district of Uttar Pradesh, The manual weeder was fabricated by using locally available material. The developed weeder is capable of reducing time wastage, labor requirement and power consumption. The performance evaluated in terms of weeding efficiency and capacity of weeder. The minimum losses, maximum efficiency and highest quality are achieved by the developed weeder. The average efficiency of weeder was observed for single point type shovel and duck type shovel as 88.51% and 85.043% respectively. The average capacity of weeder was observed for single point type shovel and duck type shovel as 0.0512 ha/day and 0.0492 ha/day respectively

Improving agricultural efficiency with solar-powered tractors and magnetohydrodynamic entropy generation in copper–silver nanofluid flow

This study examines the impact of solar-powered tractor on agricultural productivity and energy efficiency. The implementation of solar energy in tractors has the potential to reduce dependence on non-renewable energy sources, minimize carbon emissions, and promote sustainable farming practices. This research investigates the reduction of energy consumption and enhancement of productivity by evaluating magnetohydrodynamic (MHD) entropy production through the flow of nanofluids containing copper-engine oil (Cu-EO) and silver-engine oil (Ag-EO). The study also evaluates the effectiveness of thermal transport in solar-powered tractors through several properties such as solar thermal radiation, viscous dissipation, slippery velocity, and porous media. The investigation analyzed the thermodynamics of entropy generation in a non-Newtonian Williamson nanofluid, with the aim of assessing its energy equilibrium and the effects of diverse physical parameters. In order to enable numerical investigation, similarity variables were implemented to transform partial differential equations into ordinary differential equations, and the Chebyshev collocation spectral method was applied to solve the governing equations. It has been revealed that the Ag−EO Williamson nanofluid have a smoother flow compared to the Cu−EO mixture fluid. Furthermore, Williamson-nanofluid demonstrate superior thermal conductivity and heat transfer characteristics compared to the base fluid, making them appropriate for utilization in cooling systems and heat exchangers in various industries. The boundary layer exhibits the maximum temperature while employing lamina-shaped particles, whilst the lowest temperature is shown when utilizing spherical-shaped nanoparticles. The Ag-EO nanofluid an efficiency rate of approximately 2.64 % with a minimum efficiency rate of 3.22 %. The findings will help develop eco-friendly agricultural methods that promote economic development while mitigating harm to the environment.