maximum efficiency
Recently Published Documents


TOTAL DOCUMENTS

2239
(FIVE YEARS 925)

H-INDEX

48
(FIVE YEARS 9)

2023 ◽  
Vol 83 ◽  
Author(s):  
E. M. M. Bartieres ◽  
D. M. Dresch ◽  
L. C. Reis ◽  
Z. V. Pereira ◽  
R. M. Mussury ◽  
...  

Abstract The objective of this study was to evaluate the activity of antioxidant enzymes, the functioning of the photosystem II and quality of C. xanthocarpa seedlings cultivated under intermittent water deficit and shading levels and the influence of shading on recovery potential after suspension of the stress conditions. The seedlings were subjected to three levels of shading (0, 30, and 70%), six periods of evaluation (start: 0 days; 1st and 2nd photosynthesis zero: 1st and 2nd P0; 1st and 2nd recovery: 1stand 2nd REC; and END), and two forms of irrigation (control: periodically irrigated to maintain 70% substrate water retention capacity, and intermittent irrigation: suspension of irrigation). The plants subjected to intermittent irrigation conditions at 0% shading showed a reduction in water potential (Ψw) and potential quantum efficiency of photosystem II (Fv/Fm) and maximum efficiency of the photochemical process (Fv/F0) and an increase in basal quantum production of the non-photochemical processes (F0/Fm). Superoxide dismutase (SOD) activity was higher in the leaves than in the roots. The C. xanthocarpa is a species sensitive to water deficit but presents strategies to adapt to an environment under temporary water restriction, which are more temporary are most efficient under shading. The seedlings with water deficit at all levels of shading exhibited higher protective antioxidant activity and lower quality at 0% shading. The shading minimizes prevents permanent damage to the photosystem II and after the re-irrigation, the evaluated characteristics showed recovery with respect to the control group, except POD and SOD activities in the leaves.


Author(s):  
Sukarno Budi Utomo ◽  
Iwan Setiawan ◽  
Berkah Fajar ◽  
Sonny Hady Winoto ◽  
Arief Marwanto

The lack of wind speed capacity and the emission of photons from sunlight are the problem in a hybrid system of photovoltaic (PV) panels and wind turbines. To overcome this shortcoming, the incremental conductance (IC) algorithm is applied that could control the converter work cycle and the switching of the buck boost therefore maximum efficiency of maximum power point tracking (MPPT) is reached. The operation of the PV-wind hybrid system, consisting of a 100 W PV array device and a 400 W wind subsystem, 12 V/100 Ah battery energy storage and LED, the PV-wind system requires a hybrid controller for battery charging and usage and load lamp and it’s conducted in experimental setup. The experimental has shown that an average increase in power generated was 38.8% compared to a single system of PV panels or a single wind turbine sub-system. Therefore, the potential opportunities for increasing power production in the tropics wheather could be carried out and applied with this model.


2022 ◽  
Author(s):  
Zohaib Ali ◽  
Khuram Ali

Abstract Present study investigates the performance of BaSi2 based BSF structure solar cell. SCAPS 1D simulator has been employed to investigate the heterostructure solar cell. To decrease the recombination loss due to minority carrier, a new configuration is proposed by inclusion of the p-type cuprous oxide (Cu2O) as BSF layer. The Cu2O BSF layer width varying in range 0.1 to 0.4 µm to analyze the feasibility of device for optimum performance. The anticipated structure consists of ZnO/CdS/BaSi2/Cu2O layers and offers the maximum efficiency of above 24%. Parameters for example open circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), conversion efficiency (η) and quantum efficiency (QE) of the device have been analyzed graphically. The optimized structure may have significant impact on future development of advanced photovoltaic devices.


2022 ◽  
Author(s):  
M Sukumar ◽  
M. Mathankumar ◽  
Chandra Sekhar Dash ◽  
M. Sundararajan ◽  
Mohd Ubaidullah ◽  
...  

Abstract We report the synthesis of multiferroic BiFeO3 perovskite nanoparticles using the microwave combustion technique. Phase evolution is investigated by X-ray diffraction (XRD), which confirms that the formation of a secondary α-Bi2O3 phase with a monoclinic structure along with the existing rhombohedral (BiFeO3) structure. The average crystalline size has been found at 50 nm. The optical band gap was calculated from the Tauc’s plot it has been found 2.18 eV, as measured by diffuse reflectance spectroscopy (DRS). The appearances of Fourier transform infrared spectroscopy (FT-IR) absorption bands at 550 and 444 cm-1 were correlated to the rhombohedral stretching modes of bismuth ferrite nanostructure. The morphology observations using scanning electron microscopy (SEM) showed the formation of nanosized grains with pores. Energy-dispersive X-ray analysis (EDX) was done to confirm the extent of Bi3+, Fe3+, and O2- in the samples. The magnetization-Field (M-H) hysteresis curves recorded from the vibrating sample magnetometer (VSM) revealed the appearance of ferrimagnetic behavior at room temperature. The specific surface area characterized by N2 adsorption-desorption isotherm is found 44.86 m2 g-1 using Brunauer-Emmett-Teller (BET) technique. The as-fabricated BiFeO3 perovskite nanoparticles were investigated for their superior catalytic activity in two applications, which include (i) the conversion of glycerol to formic acid in a selective liquid phase batch reactor at atmospheric pressure. This bismuth-based nanoparticles exhibit as an efficient multifunctional catalyst with high conversion and selectivity efficiency around 99.2% and 98.5%, respectively, (ii) the photocatalytic degradation of rhodamine B under visible light irradiation is found maximum efficiency (99.9%), when a small amount of H2O2 was added during photocatalysis, indicating the samples possessed photo-Fenton like catalytic activity. Finally, we concluded that the BiFeO3 perovskite nanoparticles' high performance in future multifunctional devices is demonstrated by the simultaneous enhancement of catalytic and photocatalytic activities.


Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 272
Author(s):  
Éva S. Vanamee ◽  
Gábor Lippner ◽  
Denise L. Faustman

Here, we hypothesize that, in biological systems such as cell surface receptors that relay external signals, clustering leads to substantial improvements in signaling efficiency. Representing cooperative signaling networks as planar graphs and applying Euler’s polyhedron formula, we can show that clustering may result in an up to a 200% boost in signaling amplitude dictated solely by the size and geometry of the network. This is a fundamental relationship that applies to all clustered systems regardless of its components. Nature has figured out a way to maximize the signaling amplitude in receptors that relay weak external signals. In addition, in cell-to-cell interactions, clustering both receptors and ligands may result in maximum efficiency and synchronization. The importance of clustering geometry in signaling efficiency goes beyond biological systems and can inform the design of amplifiers in nonbiological systems.


Author(s):  
Oleksandra V. Olshanska ◽  
Yulia V. Tymoshenko

This article seeks to assess the effectiveness of attracting foreign investment in Ukraine. Within the scope of the research, investment activity is considered a key driver for economic development. It is emphasised that boosting economic growth in Ukraine depends heavily on attracting foreign investment as their effects extend to encouraging the national output, the speed of its technological advancements as well as the scale and pace of economic restructuring. The purpose and objectives of the study are to explore and evaluate the effectiveness of foreign investment in Ukraine's economy along with offering the authors’ understanding of the key factors affecting the investment climate and suggesting the most promising pathways to foster investment efficiency in Ukraine. It is argued that this study has a number of significant implications to Ukraine, since investment processes to a great extent underpin market development strategies, and entail the most important mechanisms for creating appropriate environment to overcome the structural economic crisis, implement structural changes in the production sector, promote innovation and enhance economic performance at the micro- and macrolevels. The research methodology involves general scientific methods of analysis and synthesis, and the generalization techniques. The findings reveal a whole range of crucial factors behind the investment process crisis and lack of effective tools for investing into the national economic development. The authors assert that a country's position in the investment ranking is a sort of a ‘business card’ for the investor who is looking for new capital investment opportunities. Currently, from this perspective, Ukraine's chances to attract foreign investment seem quite miserable. However, the findings verify that in the context of modern globalization, to spur foreign capital attraction into Ukraine, creating a favourable investment climate is paramount. The study has identified factors that affect the process of shaping the investment climate, among which the most important are a group of economic, political and geographical factors. According to the research results, a proactive government strategy and a comprehensive approach to resolving the current challenges related to investment activities at the micro- and macrolevels will contribute to realizing Ukraine’s investment potential with maximum efficiency that will lay a solid background for sustainable economic development in the future.


Author(s):  
Ibrahim Elganidi ◽  
Basem Elarbe ◽  
Norida Ridzuan ◽  
Norhayati Abdullah

AbstractWax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesised Polymer. The chemical structure of poly(BA-co-SMA-co-MA) has been identified through the use of Fourier transform infrared as well as nuclear magnetic resonance. The experimental findings demonstrated that the ideal conditions for obtaining the highest yield were 1.5% initiator concentration, reaction time and temperature of 8 h and 100 °C, respectively, and monomer ratio of 1:1:1 (BA:SMA:MA). Under these ideal conditions, the prepared terpolymer reduced the crude oil viscosity at 30 °C and 1500 ppm from 7.2 to 3.2 mPa.s. The cold finger experiment demonstrated that after poly(BA-co-SMA-co-MA) was used as a wax inhibitor, the maximum efficiency of paraffin inhibition of 45.6% was achieved at 200 rpm and 5 °C. Besides, the best performance in depressing the pour point by ΔPP 14 ℃ observed at the concentration of 1500 ppm, which can change the growth characteristics of wax crystals and delay the aggregation of asphaltene and resin, thus effectively improving the flowability of crude oil.


Author(s):  
Mukesh Pratap Singh ◽  
Mohd Amir

Abstract We have investigated the effect of emitter design key parameters such as depth factor and the peak concentration for different types of emitter diffusion profiles (uniform, exponential, Gaussian, and Erfc) on the performance of silicon (Si) solar cells. The value of the depth factor is optimized as 0.1 µm for all these emitter diffusion profiles. Afterward, the peak concentration value is optimized for all the diffusion profiles. A close examination of relative diffusion lengths, conductivities, recombination rates, internal and external quantum efficiencies for these diffusion profiles revealed that among all the considered emitter diffusion profiles, the Erfc profile exhibits the maximum efficiency of 23.53% with an optimized peak concentration of 2×1020 cm-3 for emitter and 1×1019 cm-3 for the back surface filed doping. PC1D was used for all the simulations.


2022 ◽  
Vol 24 (5) ◽  
pp. 479-486
Author(s):  
M. V. Shestakova ◽  
A. S. Ametov ◽  
M. B. Antsiferov ◽  
T. P. Bardymova ◽  
F. V. Valeeva ◽  
...  

Inhibitors of the sodium-glucose cotransporter type 2 (SGLT2i) are a modern class of antihyperglycemic drugs with an insulin-independent mechanism of action. Due to its ability to effectively lower blood glucose levels, improve a number of other cardiometabolic parameters (body weight, blood pressure, uric acid), as well as reduce cardiovascular and renal risks, SGLT2i have become drugs of choice for many of patients with type 2 diabetes mellitus (T2DM). Meanwhile, along with the generally recognized classes-effects of this group of drugs, there are intragroup features, including those associated with their different selectivity in sodium-glucose cotransporters of types 1 and 2 (SGLT1 and SGLT 2). For example, one of the most studied SGLT2i, canagliflozin, in addition to its inhibitory activity against SGLT2, can also moderately block SGLT1 in the intestine and kidneys that could give a maximum efficiency in the control glycemia and others cardiometabolic parameters. In addition, canagliflozin improves not only cardiovascular, but also renal prognosis in patients with T2DM, which is reflected in the corresponding indications in the summary of product characteristics of the drug. This document summarize the established and new data regarding the efficacy and safety of canagliflozin, as well as its place in the treatment of T2DM.


Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 311
Author(s):  
Charles Bronzo Barbosa Farias ◽  
Robson Carmelo Santos Barreiros ◽  
Milena Fernandes da da Silva ◽  
Alessandro Alberto Casazza ◽  
Attilio Converti ◽  
...  

The unbridled use of fossil fuels is a serious problem that has become increasingly evident over the years. As such fuels contribute considerably to environmental pollution, there is a need to find new, sustainable sources of energy with low emissions of greenhouse gases. Climate change poses a substantial challenge for the scientific community. Thus, the use of renewable energy through technologies that offer maximum efficiency with minimal pollution and carbon emissions has become a major goal. Technology related to the use of hydrogen as a fuel is one of the most promising solutions for future systems of clean energy. The aim of the present review was to provide an overview of elements related to the potential use of hydrogen as an alternative energy source, considering its specific chemical and physical characteristics as well as prospects for an increase in the participation of hydrogen fuel in the world energy matrix.


Sign in / Sign up

Export Citation Format

Share Document