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A novel cycle model of the capacitive salinity/heat engine mainly consisting of nano-porous super-capacitors is established for harvesting mixed free energy caused by salinity difference between the river water and the seawater, and the thermal energy due to the temperature difference. The heat engine is charged and discharged in the cycle of a low temperature brine and a high temperature fresh water, respectively. The analytical expressions of the cyclic work output and efficiency are given. General performance characteristics of the capacitive salinity/heat engine are analyzed. The temperature of the heat reservoir and salt concentration of seawater are optimized to improve the efficiency of the capacitive salinity/heat engine. The optimal selection ranges of several main parameters are provided. When the Stern distance is equal to 1 nm and the charging voltage is equal to 3.5V, the energy conversion efficiency of the capacitive salinity/heat engine is about 40%, while the pure thermal efficiency in the cycle is about 16.9%. The energy conversion efficiency of the capacitive salinity/heat engine is significantly larger than that of the capacitive heat engine. The results obtained can facilitate the application of this technology to real life, which can reduce the consumption of fossil fuels.

Due to the fluctuation of LNG supply, the profile of power generation has a mismatch with that of power demand, which causes power shortage at the demand peak time and power overcapacity at the valley time. To address this issue, a combined system containing standalone power generation subsystem and liquid air energy storage subsystem is proposed. The energy storage subsystem stores the surplus cold energy of LNG at the valley time, and it is released as power supplement at the peak time. As a stable heat source, geothermal energy is utilized to enhance the work output. Considering the uncertainties of power supply and power demand, Gaussian distribution model is introduced. Finally, the energy storage subsystem obtains 138 kW net work output of unit mass flow of LNG, achieving at least 29% improvement compared with previous works in the literature. The stored power can reach 148 MW/day and can meet the power shortage in the boundary condition of Gaussian distribution, which is a unique work in contrast to previous studies. The combined system achieves the net present value of 326.7 million dollars at the end of span year, and 3.6 dynamic payback years.

In the past decade, compressed air vehicles have attracted much attention because of their zero pollution, high efficiency, environmental friendliness and relative maturity. To further explore the potential of compressed air technology in vehicles, three-stage and four-stage compressed air engine systems are optimized in present study by analyzing the energy and exergy distribution from a technological viewpoint. Their characteristics are compared in terms of shaft work, coolth, overall efficiency, and exergy distribution. Stage expansion ratios differ under maximum work output. The shaft work and coolth of both systems are increased with the increase of working pressure, turbine inlet temperature, or stage efficiency. Three-stage compressed air engine systems have a lower work output and coolth than four-stage compressed air engine systems at given operation condition. The overall efficiencies of these two systems are comparable to those of conventional diesel engines and fuel cell vehicles. Exergy losses of the two systems are composed by the exergy loss in the turbines, heat exchangers, and exits. The analyses suggest that increasing the number of stages, improving stage efficiency, and utilizing coolth to reduce the exergy loss in heat exchangers are effective ways to decrease the total exergy loss and improve the work output and overall efficiency of the compressed air engine systems.

Photo-responsive nematic polymers can transduce light into mechanical work, but the rate is limited by the quasi-static deformation. To enhance the work output, a strategy of exploiting photo-triggered snap-through of glassy nematic shallow spherical shells with hemeotropic director alignment is examined here. The criterion for the nonlinear instability is derived analytically by using the modified iteration method. It is shown that, for thin shells of small height and large basal radius, snap-through can be caused by an incident light with moderate irradiation intensity. The phenomenon may inspire some new designs of contactless and ultra-fast actuation devices with high-rate output of mechanical work.

CA50 and IMEP (indicated mean effective pressure) are two critical parameters indicating the combustion process and work output. CA50 and IMEP are playing important roles in advanced combustion modeling and control for compression-ignition and spark-ignition engines. However, both CA50 and IMEP are calculated by using the in-cylinder pressure trace, the failure or aging/wearing of cylinder pressure sensors can significantly damage the accuracy of CA50 and IMEP. In this paper, the effects of different measurement error sources, especially the pressure offset and thermal shock, on CA50 and IMEP are analyzed. The results show that thermal shock reduces the IMEP calculation accuracy, while the CA50 is sensitive to all measurement errors. To improve the accuracy and reliability of CA50 calculation, a neural network was trained to capture the CA50 by utilizing other in-cylinder information, including the temperature, pressure, oxygen concentration, injection mass as well as injection time. By treating the CA50 as “dummy” state, smooth variable structure filter is used to integrate the CA50 calculated from in-cylinder pressure and the neural network. The experimental results validate the accuracy and robustness of the proposed method.

The objective of this article is to provide an historical perspective on a review of "Heat production and chemical change in muscle" written by Roger C. Woledge and published in Progress in Biophysics and Molecular Biology 50 years ago. We first provide a brief but broad summary of the history of muscle chemistry prior to 1971 and then address the central theme of the 1971 review - that of energy balance. Energy balance is a method to establish whether all the energetically significant biochemical reactions accompanying muscle contraction have been identified. Woledge adopted the method to compare the measured enthalpy output (i.e., the sum of the heat output and work output) to that expected from the extent of known biochemical reactions. Prior work had suggested that the observed and expected enthalpy outputs were similar but Woledge proposed that the expected heat had been overestimated and that, hence, there must be an unidentified reaction that accounted for as much as half the heat produced by a contracting muscle. We describe investigations carried out after the review that vindicated that view, ultimately characterising the processes producing the unexplained enthalpy which, in turn, led to identification of the hitherto unknown reaction. Those experiments and a more recent resurrection of the approach using fluorescent probes to monitor ATP turnover have now accounted for the processes that underlie the complex time courses of muscle heat production and ATP turnover during contraction, at least in the classical frog sartorius muscle preparation. However, the few studies performed on mammalian muscles since then have produced results that are difficult to reconcile with the ideas derived from energy balance studies of amphibian and fish muscles, thereby suggesting a new objective for energy balance studies.

Weed control is one of the major problems in crop and vegetable production in Nigeria. Most of the peasant farmers use manual weeders in their cultivation, a process that is costly, labour intensive and time consuming. The process does not also give the farmer adequate returns to enable him breakeven. It is, therefore, necessary to design a weeding equipment which minimize the human effort and provide efficient work output for the peasant farmer. This study focus on designing, construction and evaluation of a hand-pushed weed control machine that would eliminate the challenges being faced by the farmer in weeding. Materials selected to suit the construction of the weeder are durable and locally available, easily replaced if damaged and at affordable cost. They include mild steel (3mm, 5mm), 30 mm circular (hollow) pipes, 10 mm diameter steel rod, and 40 cm pneumatic tyre. The developed weeding machine was evaluated in the experimental farm of IAR with impressive results. It works well in sandy loam soil of about 25.65% moisture content and requires less labour force compared to the manual hoe. It has about 84.7% weeding efficiency, 0.0129ha/hr effectivefield capacity, 0.019ha/hr theoretical field capacity and 68% field efficiency. The average cost of the weeding is N21, 000:00. Keywords: Manual weeding, hand-pushed weeder, weeding efficiency, field efficiency

The experimental efficacy of a work station that is ergonomically designed owes its overall reliance on production engineering, especially considering assembly line balancing besides the sustained work output of the assembly line and its snags caused in the production process have been acknowledged since long. The manifestation of these irregularities and consequent inadequacies on persistent shoulder – neck exposure have been studied for this paper with the help of work aids. A conducive workplace based on better ergonomic work station design, influences stress decreased due to the undue strain of repeated actions in an assembly line situation. This makes for resultant assembly line need to get balanced and subsequent to the production most irregularities decrease. It also results in the perpetuation of idle time across the assembly line outputs as compared to when no work aids have been introduced. Focus The researcher contribution of this paper is the experimentation conducted on a work table designed for the finishing line segment of the garment manufacturing assembly line. The folding table, as it has been called has flexibility of adjustment of work angle and some advantages over the conventional fixed surface tables. Method Designing aspect apart this Table has been experimented with for usage and stability in the garment manufacturing assembling at three different units. The pilot results have been examined in the light of work done by earlier scholars. Scope The musculoskeletal strain experienced by workers in the garment manufacturing units impacts directly on their work output resulting long term physical and socio-economic implications that tend to effect work output efficiency in the long run. Results and Findings Decreased stress levels show indications of positive usage of this work aid. However, testing is still going on to confirm the preliminary results

Muscle fatigue is a limiting factor of human performance. It is unclear whether sex-based differences in fatigability exist during dynamic exercise of varying velocities of contraction. We aimed at exploring sex differences in muscle fatigue elicited by maximal isokinetic muscle contractions performed at different angular velocities. Twenty-six healthy participants (13 men: 23.2 ± 1.5; 13 women: 21.9 ± 3.0 years) were tested for concentric knee-extension at slow, moderate and fast angular isokinetic velocity (60, 180 and 300º.s−1, respectively), on non-consecutive days. The impact of sex on fatigue resistance and consecutive recovery for each isokinetic condition was explored by calculating the percent change in maximal voluntary isometric contraction (MVIC) and in rate of torque development (RTD), from pre- to post-isokinetic exercise (30 repetitions). The isokinetic fatigue index was also determined. No sex differences were obtained in response to isokinetic contractions completed at 60º.s−1. After performing muscle contractions at 300º.s−1, women had a significantly greater loss in MVIC than men (− 18.4 ± 5.5 vs. − 12.9 ± 3.8%; p = 0.009) and larger decreases in work output during isokinetic exercise (− 34.2 ± 8.9 vs − 27.5 ± 10.6%; p = 0.017). Recovery of initial MVIC strength was greater for women post-exercise at 180º.s−1 (15.6 ± 4.1% vs. 6.7 ± 9.5; p = 0.003). No differences were found between sexes in any condition for RTD from pre- to post-fatigue. These results suggest the presence of a sexually dimorphic fatigability in response to dynamic (isokinetic) contractions favouring men at higher absolute velocities of contraction.

Comprehensive functional characterization of cardiac tissue includes investigation of length and load dependence. Such measurements have been slow to develop in engineered heart tissues (EHTs), whose mechanical characterizations have been limited primarily to isometric and near-isometric behaviors. A more realistic assessment of myocardial function would include force-velocity curves to characterize power output and force-length loops mimicking the cardiac cycle to characterize work output. We developed a system that produces force-velocity curves and work loops in human EHTs using an adaptive iterative control scheme. We used human EHTs in this system to perform a detailed characterization of the cardiac β-myosin specific inhibitor, mavacamten. Consistent with the clinically proposed application of this drug to treat hypertrophic cardiomyopathy, our data support the premise that mavacamten improves diastolic function through reduction of diastolic stiffness and isometric relaxation time. Meanwhile, the effects of mavacamten on length- and load-dependent muscle performance were mixed. The drug attenuated the length-dependent response at small stretch values but showed normal length dependency at longer lengths. Peak power output of mavacamten-treated EHTs showed reduced power output as expected but also shifted peak power output to a lower load. Here, we demonstrate a robust method for the generation of isotonic contraction series and work loops in engineered heart tissues using an adaptive-iterative method. This approach reveals new features of mavacamten pharmacology, including previously unappreciated effects on intrinsic myosin dynamics and preservation of Frank-Starling behavior at longer muscle lengths. NEW & NOTEWORTHY We applied innovative methods to comprehensively characterize the length and load-dependent behaviors of engineered human cardiac muscle when treated with the cardiac β-myosin specific inhibitor mavacamten, a drug on the verge of clinical implementation for hypertrophic cardiomyopathy. We find mechanistic support for the role of mavacamten in improving diastolic function of cardiac tissue and note novel effects on work and power.

The workforce of plastic crushing and product printing at CV. XYZ experiences fatigue most quickly, so when working often makes mistakes and lacks concentration at work which causes a decrease in work output. The workload on the operator of the plastic crushing section has oxygen consumption of 0.953 liters / minute categorized by Weight, with a Cardiovascular Load percentage of 30.54% categorized as required for improvement based on the results of Bourdon Wiersma 10.4 seconds speed level category Good Enough, accuracy level 12.7 Doubtful category, a constant level of 5.7 seconds Fair category. The operator of the product printing section has an oxygen consumption of 1,083 liters / minute categorized by Weight, with a percentage of Cardiovascular Load of 35.71% categorized as needed an improvement based on the results of the Bourdon Wiersma speed level of 10.9 seconds the category Good Enough, the level of accuracy 17.6 Doubts category - Doubt, a constant level of 7.01 seconds in the Doubt-free category. Improvements that can be made to plastic crushing and product printing operators are adding rest periods, rolling workers' systems, improving workplace conditions to be more ergonomic, and managing work shifts.. Keywords: Oxygen Consumption, Accuracy, Speed, Constant.

Kalina power cycle is considered as an efficient cycle for utilizing low grade energy from renewable sources like solar, geothermal and for heat recovery. A simple Kalina cycle utilises a turbine for work extraction. Power producing devices like turbines work efficiently under multi staging. This work aims at improving the power output and thus the efficiency of a Kalina cycle by adopting two stage expansion. In the present work, a modification to Kalina cycle is proposed with two turbines in stages and reheating in between. The modified Kalina cycle is modeled and analysed thermodynamically for different intermediate pressures. The effect of intermediate pressure on parameters like separator temperature, vapour fraction at the exit of low pressure turbine, net work output, net heat input and efficiency of the cycle has been analysed. The simulation result shows that the efficiency of the modified cycle improves up to 4.04% compared to the simple cycle. The results obtained underline the dependency of intermediate pressure on the performance parameters of the cycle.

Conventional vehicles depend on crude energy extracted from the fossil fuels such as diesel and petrol, which undergoes internal combustion to liberate the chemical energy stored inside the fuel. This energy is then converted into mechanical energy inside the engine to produce the necessary work for propelling the vehicle accompanied with release of incomplete combustion products such as CO and CO2. Now days a lot of research is concentrated on developing more efficient and eco-friendly ways of generating the energy for propulsion so as to reduce the amount of carbon footprint in the atmosphere. The present work is an effort in the direction of generation of energy for propelling the vehicles in an environmental friendly way by utilising compressed air. During the process of compression, work is being done on the air, which causes an increment in the total pressure of the air. This increment of the total pressure is stored as the energy inside the compressed air, which will be utilised for the running the vane of the motor to generate the necessary work for propulsion. The present work utilises the compressed air at 3 atm to run the motor. The work output of the motor for different vane angles was measured for various casing diameters of 50 mm, 100 mm, 150 mm respectively and the results were plotted. The average time of running of the motor was found out to be 7 h.

In rural areas electricity is either unavailable or available for limited period. So performing many activities with the help of animal driven rotary mode power can be a good alternative. The bullocks can be used in rotary mode power transmission system, post-harvest operations like mini rice mill, flour milling, chaff cutting, dal milling, groundnut decortications, oil extraction, threshing Shevai making machine and other stationery operations. Draught animals are used for a limited period for agricultural work 40 to 50 days and the rest of the time they stand idle. The farmer has to feed them throughout the year despite no work output during off season, leading to high maintenance cost as compared to power output. But this idle period can be utilized and converted to work through rotary mode operation. The proposed research work presents the performance evaluation of shevai machine unit. The mean draft was 418.1N which was 4.84 per cent of bodyweight of the bullocks. The increase in respiration rate, pulse rate decreased with duration. The rpm of bullock from 30 min. of trials was initially 65 and reduced to 60 at load condition. The mean rpm of the shevai machine shaft was observed to be 150. The output of machine gradually decreased with duration may be due to a decrease in the speed of the shaft of the shevai machine. The mean output was found to be 8 kg/h were as the output of shevai machine operated with an electric motor was 10 kg/h. The average power output from the bullock over three times 30 minutes of working in Shevai machine was 0.498Kw. The operation of the Shevai machine was found to be feasible considering the draft ability of Red Kandhari type bullocks. The total cost of operation of unit was calculated Rs. 8.33 Rs / h with an output capacity of flour mill observed 1.0 hp.

The respective performances of hypothetical Stirling engine and Stirling cooler in Vuilleumier machines are usually unclear. In this paper, a method of alternate combination of adiabatic sub-model with considering the losses and isothermal sub-model without considering the losses was proposed. The engine's work output is obtained by combining adiabatic engine and isothermal cooler, while the cooler's work input is obtained by combining adiabatic cooler and isothermal engine. Then, engine's thermal efficiency and cooler's coefficient of performance (COP) were obtained. The relative Carnot efficiency of hypothetical engine was 45%–57% at conditions of 550 °C hot temperature and 50 °C–70 °C warm temperature. The relative Carnot efficiency of hypothetical cooler was 44%–51% at conditions of −20 °C~10 °C cold temperature and 50 °C~70 °C warm temperature. In addition, a comparison of Vuilleumier machines’ COP based on a complete adiabatic model and the hybrid model was made. The ratio of COPV,hybrid over COPV,adia was in the range of 0.9~0.94. It indicated that the respective thermal efficiency and COPcooler in the hybrid model could approach to those in a complete adiabatic model.

This work investigates a class of finite-time nonzero-rate electrochemical systems with the generalized reaction type ( a A + b B ⇔ x X + y Y ) and considers various internal irreversibility losses, including activation overpotential, ohmic overpotential, and concentration overpotential. By applying finite time thermodynamics and optimal control theory, the optimal currents for the maximum work output and the maximum profit of both the well-stirred and the diffusive flow fuel cells are derived. Results show that for the well-stirred fuel cell, the optimal current always remains constant versus the time, irrespective of whether the maximum work output or the maximum profit is chosen as the optimization objective, which is independent of various overpotential losses. The optimal voltage-current profile of a diffusive flow fuel cell corresponding to the maximum work output is a parabolic curve. The current versus time profile of the maximum work output decreases sharply in the first half and changes slightly in the second half, whereas that of the maximum profit decreases sharply in the first half and increases sharply in the second half. The optimal current paths for these two optimization objectives are significantly different from each other. The change in the reaction order significantly affects the optimization results for different optimization objectives. In general, the current versus voltage profile of the maximum work output of the electrochemical system with the simple reaction ( A + B ⇔ X + Y ) is a typical parabolic curve, whereas that of the complex reaction ( A + 2 B ⇔ 2 X + Y ) is a monotonic increasing curve. The results can provide some theoretical guidelines for the optimum designs and operations of electrochemical systems.

A heavy-duty gas turbine, designed for natural gas, was used to burn the syngas with two different calorific values. This study was mainly to optimize the flow matching scheme for the gas turbine. Two models of gas turbine burning syngas with different calorific values were established and the calculation models of different flow matching schemes were provided. The optimum scheme was obtained by evaluating thermal efficiency and work output under different operating conditions. The results showed that the highest unit efficiency was achieved by, without significant drop in work output, increasing the throat area of the turbine nozzle and reducing the initial temperature of the gas. On the premise of ensuring the safety of the gas turbine unit, increasing the pressure ratio of the compressor could further improve the unit efficiency and the work output. Simply adjusting the angle of the inlet guide vane fails to match the flow of compressor and turbine. The measures such as reducing inlet temperature of turbine or air bleed still need to be adopted, but the thermal efficiency dropped significantly in this process.

This study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

The work output of [001] Ni55Fe18Ga27 single crystals was studied under different loading conditions (cooling under 0, 30, 70 and 100 MPa and heating under 150 MPa) in torsion mode. It was shown that during thermal cycling, the functional properties, such as martensitic transformation temperatures, shape memory effect value and work output, of Ni55Fe18Ga27 single crystals stabilized after a few thermal cycles and then barely varied. A maximum work output of 1.15 MJ/m3 was found when the sample was cooled without stress or under a stress of 30 MPa and heated under a stress of 150 MPa. Simultaneously, it was observed that if the stress that was acted on cooling was 30 MPa, then less plastic strain appeared in the sample during thermal cycling.

Parabolic dish solar collector system has capability to gain higher efficiency by converting solar radiations to thermal heat due to its higher concentration ratio. This paper examines the exergo-economic analysis, net work and hydrogen production rate by integrating the parabolic dish solar collector with two high temperature supercritical carbon dioxide (s-CO2) recompression Brayton cycles. Pressurized water (H2O) is used as a working fluid in the solar collector loop. The various input parameters (direct normal irradiance, ambient temperature, inlet temperature, turbine inlet temperature and minimum cycle temperature) are varied to analyze the effect on net power output, hydrogen production rate, integrated system energetic and exergetic efficiencies. The simulations has been carried out using engineering equation solver (EES). The outputs demonstrate that the net power output of the integrated reheat recompression s-CO2 Brayton system is 3177 kW, whereas, without reheat integrated system has almost 1800 kW net work output. The overall energetic and exergetic efficiencies of former system is 30.37% and 32.7%, respectively and almost 11.6% higher than the later system. The hydrogen production rate of the solarized reheat and without reheat integrated systems is 0.0125 g/sec and 0.007 g/sec, accordingly and it increases with rise in direct normal irradiance and ambient temperature. The receiver has the highest exergy destruction rate (nearly 44%) among the system components. The levelized electricity cost (LEC) of 0.2831 $/kWh with payback period of 9.5 years has proved the economic feasibility of the system design. The increase in plant life from 10 to 32 years with 8% interest rate will decrease the LEC from (0.434-0.266) $/kWh. Recuperators have more potential for improvement and their cost rate of exergy is higher as compared to the other components.

The present work deals with the development of thermodynamic model of low temperature basic Organic Rankine Cycle (ORC) system and a chevron plate heat exchanger evaporator sub-model using Engineering Equation Solver (EES). Work output is evaluated using the ORC thermodynamic model, while the evaporator sub-model calculates the total surface area of the heat exchanger. Using these mathematical models, the effect of evaporation pressure, expander inlet temperature and pinch point temperature difference (PPTD) on the network output and evaporator cost are studied. In addition to this, the effect of plate spacing and plate width of chevron plate heat exchanger on pressure drop and evaporator cost are analyzed in detail. Finally, thermodynamic and geometric optimization is carried out using genetic algorithm to identify the optimum parameters at which the network output is maximized and pressure drop in the evaporator is minimized. Sensitivity analysis showed that optimum evaporator pressure existed at which network output is maximum. Thermodynamic optimization showed that work output was maximum (5.03 kW) at evaporator pressure of 5.77 bar. No improvement in the work output was seen with increase in PPTD and expander inlet temperature. Increase in plate width and plate spacing led to increase in evaporator cost and decrease in pressure drop.

Globally, there has been concern about the environmental adversities created by fossil fuel-fired power plants. It has led to the emergence of different technological solutions in the form of newer thermodynamic cycles for power plants. The supercritical carbon dioxide cycle run on the utilization of carbon dioxide holds the capability to mitigate the impact of emissions from fossil fuel-fired power plants. In this study, the supercritical carbon dioxide cycle is powered by solar energy using heliostat fields. The operating range of supercritical carbon dioxide cycle permits for the integration of low-temperature cycles for effective utilization of the heat remaining unutilized in it. This paper considers the supercritical carbon dioxide cycle integrated with the steam Rankine cycle for better energy transactions in it. The thermodynamic modeling of sCO2 steam Rankine cycle based combined power cycle has been carried out based on energy analysis. It aims for the optimal utilization of heat available with the exhaust from the sCO2 cycle. Results obtained based on parametric variation have been presented and analyzed here. The conclusions obtained are of relevance to the power sector professionals engaged in evolving the efficient combined power cycle with supercritical carbon dioxide cycle. At the turbine inlet pressure of 290 bar, the turbine inlet temperature of 700 °C in sCO2 cycle and steam generation at 50 bar in steam Rankine cycle, the overall cycle efficiency is obtained as 43.87% and overall specific work output is 1520.68 kJ/kg of sCO2 without any harmful emission to the atmosphere.

The aim was to investigate the potential differences in muscle (vastus lateralis) and cerebral (prefrontal cortex) oxygenation levels as well as in the number of repetitions and total work output between isokinetic eccentric and concentric exercise at a moderate relative intensity until exhaustion. Ten recreationally active young men underwent two isokinetic exercise sessions either concentric or eccentric, one on each randomly selected leg. The protocols were performed at 60°/s and an intensity corresponding to 60% of the maximal voluntary contraction (MVC) of each contraction type. Concentric torque was significantly lower compared to eccentric torque in both peak values and at values corresponding to 60% of MVC [230 ± 18 Nm vs. 276 ± 19 Nm (P = .014) and 137 ± 12 Nm vs. 168 ± 11 Nm, respectively (P = .010)]. The participants performed 40% more contractions during eccentric compared to concentric exercise [122 ± 15 vs. 78 ± 7, respectively]. No differences were found in the levels of oxyhaemoglobin, deoxyhemoglobin, total haemoglobin and tissue saturation index when eccentric and eccentric exercise regimes were compared (all P > .05). Our results demonstrate that eccentric exercise of moderate intensity leads to greater resistance to fatigue and more work output compared to concentric exercise, despite the comparable muscle and cerebral oxygenation levels.

We investigate the performance of a quantum battery exposed to local Markovian and non-Markovian dephasing noises. The battery is initially prepared as the ground state of a one-dimensional transverse $XY$ model with open boundary condition and is charged (discharged) via interactions with local bosonic reservoirs. We show that in the transient regime, quantum battery (QB) can store energy faster and has a higher maximum extractable work, quantified via ergotropy, when it is affected by local phase-flip or bit-flip Markovian noise compared to the case when there is no noise in the system. In both the charging and discharging processes, we report the enhancement in work-output as well as in ergotropy when all the spins are affected by non-Markovian Ohmic bath both in the transient and the steady-state regimes, thereby showing a counter-intuitive advantage of decoherence in QB. Both in Markovian and non-Markovian cases, we identify the system parameters and the corresponding noise models which lead to maximum enhancement of work-output and ergotropy. Moreover, we show that the benefit due to noise persists even with the initial state being prepared at a moderate temperature., Comment: v1: 10 pages, 9 Figures; v2: 12 pages, 12 Figures, new results about ergotropy added, almost published version