The role of the Rashba coupling in spin current of monolayer gapped graphene

In the current work we have investigated the influence of the Rashba spin-orbit coupling on spin-current of a single layer gapped graphene. It was shown that the Rashba coupling has a considerable role in generation of the spin-current of vertical spins in mono-layer graphene. The behavior of the spin-current is determined by density of impurities. It was also shown that the spin-current of the system could increase by increasing the Rashba coupling strength and band-gap of the graphene and the sign of the spin-current could be controlled by the direction of the current-driving electric field

Studying the efficacy of fipronil (WG 80%) against alfalfa weevil, Hypera postica (Coleoptera: Curculionidae)

The alfalfa weevil, Hypera postica Gyll. (Coleoptera: Curculionidae), is a key pest of alfalfa in different regions of the world where it causes sometimes complete crop destruction. Application of insecticides is the most important and major control method of this pest. The efficacy of fipronil (WG 80%), 50, 70 and 90 g/ha along with fosalon (EC 35%), 2.5 l/ha and malathion (EC 57%), 3 l/ha were assessed against this pest in the field based on a completely randomized block design. Based on Henderson–Tilton formula, on the fourteenth day after treatment, the minimum efficacy of fipronil, 50, 70 and 90 g/ha, fosalon, 2.5 l/ha and malathion, 3 l/ha bait was 80%, 89%, 98%, 76% and 75%, respectively. Results showed that fipronil (WG 80%) at 50–70 g/ha can be used against alfalfa weevil

Comparison of the Effect of Peer-led Education and Education by the Healthcare Personnel on Awareness, Attitude and Performance of Lettered People toward Organ Donation

BACKGROUND AND OBJECTIVE: Lack of donation is one of the major limitations of organ transplantation. Promoting organ donation requires increased awareness and creation of a positive attitude through training in specific ways. The purpose of this study was to compare the effect of peer-led education and education by healthcare personnel on awareness, attitude and performance of lettered people in regard with organ donation. METHODS: This case-control clinical trial was performed on 120 lettered people who were randomly assigned to three groups of 40, including peer-led, healthcare personnel and control groups. The two intervention groups underwent training sessions. Before and after the intervention, the data were collected and compared using questionnaires in three groups in three areas of awareness, attitude and performance. FINDINGS: Most of the lettered people (58.33%) were female. 61.66% had a bachelor's degree and 60.83% were teachers at elementary school. There was a significant difference in the mean scores of awareness, attitude and performance toward organ donation in the two intervention groups before the intervention (in peer-led group were 11.52 ± 2.12, 92.05 ± 10.24, and 1.87 ± 1.42 and in healthcare group were 11.30 ± 3.00, 90.73 ± 10.92, and 1.38 ± 1.29, respectively) and after the intervention (in peer-led group were 15.47 ± 1.13, 98.78 ± 5.70, and 3.53 ± 0.50 and in healthcare group were 15.13 ± 1.49, 96.95 ± 5.52, and 3.05 ± 0.81, respectively) ( P < 0.05). The mean score of attitude and performance of the lettered people in the peer-led group was significantly higher than the other groups (P < 0.05). CONCLUSION: The results of the study showed that peer-led education is a more effective method than education by healthcare personnel to promote and institutionalize organ donation

Coupled Elastodynamics of Piston Compression Ring Subject to Sweep Excitation

The piston compression ring's primary function is to seal the combustion chamber, thus mitigating gas leakage to the crankcase and avoiding loss of pressure loading. As a result, the ring is meant to conform closely to the cylinder surface which promotes increased friction. The compression ring is subjected to combustion pressure loading, ring tension, varying inertial force and friction. It is a slender ring of low mass, thus undergoes complex elastodynamic behaviour, when subjected to a multitude of forces. These motions occur in the ring's radial in-plane and axial out-of-plane dynamics, which comprise flutter, ring axial jump, compression-extension, ring twist and rotational drag. An implication of these motions can be loss of sealing, gas blow-by, loss of power and lubricant degradation/oil loss, to name but a few. Consequently, understanding and accurately predicting ring dynamic behaviour under transient conditions is an important step in any subsequent modelling for evaluation of cylinder system efficiency. There have been a plethora of investigations for ring dynamics, often decoupling the ring behaviour in its in-plane and out-of-plane motions. This approach disregards any transfer of dynamic energy from one degree of freedom to another which is only applicable to rectangular ring cross-sections. Alternatively, there are computationally intensive approaches such as finite element analysis which are not conducive for inclusion in any subsequent system level engine modelling where ring response alters in an instantaneous manner. This would require embedded finite element analysis within a transient analysis. This paper presents a finite difference numerical analysis for coupled in-plane and out-of-plane motions of compression rings with practical cross-sectional geometries, which are mostly not rectangular. The formulated method can be integrated into a system level transient cyclic analysis of ring-bore contact. The presented approach takes into account the energy transfer between different degrees of freedom. The predictions are validated against precise non-contact measurements of ring elastodynamic behaviour under amplitude-frequency sweeps. This approach has not hitherto been reported in literature and constitutes the main contribution of the paper

Implementation of a Simple Actuator Disk for Large-Eddy Simulation in the Weather Research and Forecasting Model (WRF-SADLES v1.2) for wind turbine wake simulation

In this study, we present the development of a Simple Actuator Disk model for Large-Eddy Simulation (SADLES), implemented within the Weather Research and Forecasting (WRF) model, which is widely used in atmospheric research. The WRF-SADLES model supports both idealized studies and realistic applications through downscaling from realistic data, with a focus on resolutions of tens of meters. Through comparative analysis with the Parallelized Large-eddy Simulation Model (PALM) at resolutions of 10 and 30 m, we validate the effectiveness of WRF-SADLES in simulating the wake characteristics of a 5 MW wind turbine. Results indicate good agreement between WRF-SADLES at 30 m resolution and 10 m resolution and the PALM model. Additionally, we demonstrate a practical case study of WRF-SADLES by downscaling ERA5 reanalysis data using a nesting method to simulate turbine wakes at the Alpha Ventus wind farm in the south of the North Sea. The meso-to-micro downscaling simulation reveals that the wake effect simulated by WRF-SADLES at the FINO1 offshore meteorological mast station aligns well with the cup anemometer and lidar measurements. Furthermore, we investigate an event of farm-to-farm interaction, observing a 16 % reduction in ambient wind speed and a 38 % decrease in average turbine power at Alpha Ventus due to the presence of a wind farm to the southwest. WRF-SADLES offers a promising balance between computational efficiency and accuracy for wind turbine wake simulations, making it valuable for wind energy assessments and wind farm planning.</p

Optimisation of the vehicle transmission and the gear-shifting strategy for the minimum fuel consumption and the minimum nitrogen oxide emissions

The paper outlines a computationally efficient analytical method for evaluating the fuel consumption and the nitrogen oxide emissions during manoeuvres pertaining to the New European Driving Cycle. An integrated optimisation procedure is also included in the analyses with minimisation of the brake specific fuel consumption and minimisation of the nitrogen oxide emissions as objective functions. A set of optimum gear ratios are determined for a four-speed transmission, a five-speed transmission and six-speed transmission as the governing parameters in the optimisation process. The analysis highlights the determination of gear-shifting objective-driven strategies based on the minimisation of either of the declared objective functions. A reduction of 7.5% in the brake specific fuel consumption and a reduction of 6.75% in nitrogen oxide emissions are attainable in the best-case scenario for a six-speed transmission and a gear-shifting strategy based on the lowest brake specific fuel consumption for the case of an engine. The novel integrated analytical simulations and multi-objective optimisation have not been hitherto reported in literature. It provides the opportunity for an objective intelligent-based approach to the use of gear shift indicator technology. The results of this study also show that transmission optimisation can act as an effective and inexpensive mean to enhance the fuel efficiency and to reduce the emissions

Impact of melatonin supplementation in the rat spermatogenesis subjected to forced swimming exercise

Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters

Effect of cylinder de-activation on the tribological performance of compression ring conjunction

The paper presents transient thermal-mixed-hydrodynamics of piston compression ring-cylinder liner conjunction for a 4-cylinder 4-stroke gasoline engine during a part of the New European Drive Cycle (NEDC). Analyses are carried out with and without cylinder de-activation (CDA) technology in order to investigate its effect upon the generated tribological conditions. In particular, the effect of CDA upon frictional power loss is studied. The predictions show that overall power losses in the piston-ring cylinder system worsen by as much as 10% because of the increased combustion pressures and liner temperatures in the active cylinders of an engine operating under CDA. This finding shows the down-side of this progressively employed technology, which otherwise is effective in terms of combustion efficiency with additional benefits for operation of catalytic converters. The expounded approach has not hitherto been reported in literature

Chaotic Genetic Algorithm based on Explicit Memory with a new Strategy for Updating and Retrieval of Memory in Dynamic Environments

Many of the problems considered in optimization and learning assume that solutions exist in a dynamic. Hence, algorithms are required that dynamically adapt with the problem’s conditions and search new conditions. Mostly, utilization of information from the past allows to quickly adapting changes after. This is the idea underlining the use of memory in this field, what involves key design issues concerning the memory content, the process of update, and the process of retrieval. In this article, we used chaotic genetic algorithm (GA) with memory for solving dynamic optimization problems. A chaotic system has much more accurate prediction of the future rather than random system. The proposed method used a new memory with diversity maximization. Here we proposed a new strategy for updating memory and retrieval memory. Experimental study is conducted based on the Moving Peaks Benchmark to test the performance of the proposed method in comparison with several state-of-the-art algorithms from the literature. Experimental results show superiority and more effectiveness of the proposed algorithm in dynamic environments