Energetic Efficiency Research Articles

Changes in running biomechanics during the 2017 IAAF world championships men's 1500 m final.

The aim of this study was to analyze key kinematic, spatiotemporal, and global mechanical characteristics in world-class middle-distance racing. Eight men were recorded halfway along the home straight on the second, third, and final laps in the 2017 IAAF World Championship 1500 m final. Video data (150 Hz) from three high-definition camcorders were digitized to calculate relevant variables, subsequently analyzed in relation to running speed and finishing position. Better-placed finishers had greater hip extension at initial contact and through late stance, greater knee excursion throughout stance, and longer overstriding distances. Step length did not change with faster speeds as runners relied on increasing step frequency, but the highest-finishing athletes had longer contact phases and greater fluctuations in speed through the step cycle, which were related to higher normalized peak horizontal forces. The best athletes also had lower leg stiffnesses and vertical stiffnesses. The extended contact phase and greater compression could allow for more sustained force production, enabling better acceleration and maintenance of sprinting speed, indicating a trade-off between aerobic energetic efficiency and anaerobic power capacity. Coaches should note that these factors, as well as the best athletes' greater overstriding distances, show that elite 1500 m runners might prioritize a technique that favors running speed over economy.

Employing a booster/ejector-assisted organic flash cycle to heat recovery of SOFC system; Exergy- and economic-based optimization

Integrating heat recovery units into modern power plants is a good way to improve their efficiency in the future. To address this challenge, this study aims to design and develop an electricity/cooling cogeneration system (ECCS) that uses a solid oxide fuel cell (SOFC), fed by CH4, along with a booster/ejector-assisted organic flash cycle that recovers heat from the exhausted gasses. An extended evaluation of the output of the proposed ECCS is conducted based on energy-exergy, environmental, and exergoeconomic criteria, in which the SOFC's current density (JSOFC), the SOFC operating temperature (TSOFC), along with the flashing tank temperature (TFT), are considered variables. Accordingly, the exergetic efficiency and cost of products as objective functions are optimized by the NSGA-II method. The optimum state is reachable at TFT=370 K, TSOFC=895 K, and JSOFC=5000 A/m2. Here, the exergetic efficiency and cost of products are calculated at 53.23% and 43.27 $/GJ. Accordingly, energetic efficiency and total exergoeconomic factor are enhanced by 1.33% and 1.96%, respectively, compared with the based case. Moreover, a variation in TFT does not have any effect on the pollution damage cost (PDC) at all, in fact, the PDC remains at 3.066 $/h regardless of the variation in TFT.

Study of employing a thermoelectric generator and an alkali metal thermal electric converter for waste heat recovery of a solid oxide fuel cell

Although solid oxide fuel cell is an appropriate candidate in the power generation sector, its high waste heat is a problem that should be managed to convert it into a positive feature. Accordingly, this study suggests a novel system for an efficient waste heat recovery of solid oxide fuel cell. Hence, the solid oxide fuel cell is coupled with a thermoelectric generator and an alkali metal thermal electric converter, where the alkali metal thermal electric converter recovers the waste heat of the solid oxide fuel cell, then the thermoelectric generator is used to recover the waste heat of alkali metal thermal electric converter. The plant's performance is evaluated against the current density to indicate the feasibility of the integrity, the optimum current density range, and the maximum current density corresponding to the best productivity of the scheme. Furthermore, eight different parameters are considered to assess the scheme's sensitivity. SOFC operating temperature, average pore diameter, proportional coefficient, TEG temperature, and temperature-independent exchange current coefficient positively influenced the evaluated variables. The highest power density is 10005 W/m2 at the maximum current density of 13066 A/m2 resulting in energetic and exergetic efficiencies of 43.30 % and 46.67 %, correspondingly.

4E assessment of integrated photovoltaic/thermal-based adsorption-electrolyzer for cooling and green hydrogen production

An energetic, exergetic, economic, and environmental multicriteria evaluation of the feasibility for an integrated system comprised of an adsorption system and proton exchange membrane electrolyzer operating via photovoltaic/thermal collectors is introduced. The present system produces concurrent green hydrogen, cooling, and hot water under the meteorological conditions of Alexandria, Egypt. The generated electricity from photovoltaic/thermal collectors drives the electrolyzer for hydrogen production. The waste heat from photovoltaic/thermal collectors drives the adsorption unit during summer for cooling purposes, while in winter, it is used for domestic hot water supply. The adopted analysis is built in Simulink and consequently justified with existing literature. The transient variation of temperature profiles, cooling capacity, heating power, COP, input and output exergies, energetic and exergetic efficiencies are investigated. Investigating the daily performance of the adsorption cooling system during the summer exhibits an average daily COP of 0.47 and a system cooling capacity of about 7 kW. The results reported that the adopted system annually yields cooling, heating, and hydrogen of 8282 kWh, 1723 kWh, and 626 kg, respectively. Moreover, it is exhibited that the present system could attain annual energetic and exergetic efficiencies of 12.3% and 10.6%, respectively. The proposed system demonstrated a substantial payback period of 0.8 years and carbon dioxide mitigation of 52.2 tons. Consequently, combining the photovoltaic/thermal collectors with adsorption cooling systems and electrolyzers could be pronouncedly appropriate for multigeneration systems.

Selection for Growth Does Not Affect Apparent Energetic Efficiency of Jejunal Glucose Uptake in Mice

Five-wk-old male mice from high growth (M16) and randomly bred control (ICR) lines, plus their reciprocal crosses, ICR × M16 and M16 × ICR, were used to investigate whether whole-body O2 consumption, jejunal respiration, jejunal glucose absorption and the apparent energetic efficiency of jejunal active glucose uptake in mice are altered by genetic selection for growth as well as by heterosis and maternal effects. Whole-body O2 consumption was measured in 12 mice from each line or cross. The mice were later killed for measurement of jejunal O2, using tissue respiration chambers and jejunal glucose transport determined by 3H-3-O-methylglucose accumulation. No heterosis or maternal effects were detected in jejunal glucose active transport and active glucose uptake. Selection for growth (M16 vs. ICR) increased daily gain (1.54 vs. 1.09 g, P < 0.001), small intestinal length and weight, but did not enhance jejunal glucose transport. The apparent energetic efficiency of jejunal active glucose uptake among lines was not different (54.0, 50.4, 51.6 and 47.1 nmol ATP expended/nmol glucose uptake for M16, ICR, M16 × ICR and ICR × M16, respectively, P > 0.63). Selection for growth in mice did not result in more energetically efficient jejunal glucose absorption.

Selection for Body Composition Does Not Affect Energetic Efficiency of Jejunal Glucose Uptake in Mice

Five-wk-old male mice from three lines were used to examine whether the apparent energetic efficiency of active jejunal glucose uptake in mouse jejunum is altered by genetic selection for different body composition. The mice lines were selected as follows: HE, high percentage of body fat with no change in body weight as a constraint; LF, low percentage of body fat; and RS, randomly bred control. Body weight was similar in all lines. Total jejunal O2 consumption and ouabain-sensitive O2 consumption were used to estimate the energy expenditure associated with glucose absorption and Na+/K+-ATPase activity. Tritiated 3-O-methyl-D-glucose was used to determine glucose uptake by mouse jejunum. Line LF, when compared with line HE, had lower body fat as indicated by epididymal fat pad weight (143 vs. 362 mg/mouse, P < 0.001). There were no significant differences in small intestinal weight, length and density (mg/cm) between LF and HE lines. Jejunal villus width was greater in line LF compared with line HE (115 vs. 92 µm, P < 0.002). Jejunal glucose transport and O2 consumption were not different between LF and HE lines. Ouabain-sensitive O2 consumption was not significantly different among the three lines. No differences were noted in the apparent energetic efficiency of active glucose uptake among lines.

Optimum, Suboptimal and Solar Sailing Orbital Maneuvers for a Spacecraft Orbiting the Earth

The present research performs numerical studies to search for the best maneuvers, from the point of view of minimum time, to make adjustments in the semi-major axis, eccentricity and inclination of a spacecraft traveling around the Earth. For those maneuvers, low thrust propulsion is used under optimal and sub-optimal assumptions, to verify the main differences in terms of transfer time. In addition, solar sail dynamics is used. The spacecraft is assumed to have a propulsion with a fixed magnitude and that the control is based on choosing the direction of the propulsion. It is found that optimal control gives the minimum transfer time, while sub-optimal control restricted the control to follow a predescribed function, which is assumed to be a constant or linear function in time. Finally, solar sails present themselves as an option where fuel is a critical factor, given their much longer maneuver duration, but with a zero fuel consumption. The numerical-analytical modeling of optimization methods developed in this study can break any type of symmetry in the solutions. In turn, they can increase their energetic efficiency. The present research compares those results in detail, in particular looking at the transfer time in all cases studied.

Development, exergoeconomic assessment and optimization of a novel municipal solid waste-incineration and solar thermal energy based integrated power plant: An effort to improve the performance of the power plant

Due to the growing population rate and increasing social activities, the content of municipal solid waste (MSW) production is increasing. Energy production from MSW is one of the promising ways to dispose of waste and reduce the limitations of fossil energies. However, this technology has a relatively low efficiency due to the high volume of moisture and inert materials in MSW and the lower heating value of waste. The integration of solar thermal collectors is one of the suggested solutions to increase the temperature of inlet steam to the power generation cycle in order to improve the power plant performance. In this regards, the present study develops a comprehensive thermodynamic-conceptual and exergoeconomic investigation of the performance of a MSW-incineration (MSWI) plant integrated with a parabolic trough collector (PTC)-based solar field. Accordingly, the temperature of the steam elevates by the solar field before entering the electric power generation cycle. Additionally, the solar unit is integrated with a phase change material (PCM)-based storage system. The use of storage tank at the delivery line of PTC can improve the power plant’s reliability. A comprehensive comparison of the developed power plant with the conventional MSWI power plant is presented. In addition, the technical and economic behaviors of the considered power plant have been optimized under two different single and multi-objective optimization scenarios. The outcomes indicated that the developed power plant can provide 15.75% and 15.68% higher energetic and exergetic efficiencies compared to MSWI power plant. In addition, the rate of electric power obtained from S-MSWI power plant is almost 16.1% more compared to MSWI power plant. However, the total cost rate of MSWI plant is almost 24.13% lower compared to the developed power plant. But, the value of LCOE in the developed power plant is approximately 8.93% lower than MSWI power plant. It was also found that, the multi-objective optimization can provide better and optimal results to energy engineers and decision makers compared the single-optimization. The conceptual design of the implementation of the solar field is also developed in a specific geographical condition. Additionally, this research comes from the key technology of the National Key Laboratory of Environmental Protection.

The Synergistic Effect of Simultaneous Ultrasound Heating and Disintegration on the Technological Efficiency and Energetic Balance of Anaerobic Digestion of High-Load Slaughter Poultry Sewage

Regulations in force urge for thermal pre-treatment of post-slaughter waste prior to its anaerobic digestion. Increased interest in biomethane as a fuel in gas networks or vehicles of road transport forces the need to look for heating methods that are alternative to heat recovery from cogeneration. The goal of this study was to determine the synergistic effect of simultaneous ultrasound heating and disintegration on the technological efficiency and energetic balance of the anaerobic digestion of high-load slaughter poultry wastewater. The highest efficiency of anaerobic digestion was obtained for the ultrasound thermal pre-treatment (60 min, 90 °C, OLR = 2.0 gCOD/dm3). In this experimental variant, the biogas production rate reached 9.0 ± 0.2 cm3/gCOD·h, biogas yield was 492 ± 10 cm3/gCOD, and the biogas produced contained 69.8 ± 1.4% CH4. Given the incurred energy outputs, the highest net energetic efficiencies, i.e., 5.92 ± 0.43 Wh and 5.80 ± 0.42 Wh, were obtained in the variants with the conventional thermal pre-treatment (60 min, 70 °C, OLR = 6.0 gCOD/dm3) and ultrasound thermal pre-treatment (60 min, 70 °C, OLR = 6.0 gCOD/dm3), respectively.

Improving the Energetic Efficiency of Biogas Plants Using Enzymatic Additives to Anaerobic Digestion

This study was carried out to estimate the relevance of biological supplementation in improving the economic efficiency of anaerobic digestion (AD). Three kinds of silages—maize, grass, and igniscum—were initially inoculated with digestate and then supplemented with one of four vaccines containing different bacteria species (APD®, PPT®, JENOR®) or a yeast and mold mixture (HAP®). In addition, each plant silage was fermented without any additives (control A—maize silage, B—grass silage, and C—igniscum silage). The biodegradability process was performed in batch tests at a mesophilic temperature (38 °C). To compare the energetic efficiency of AD, the process kinetics, biogas, and methane production were analyzed. We found that the applied supplementation measures improved biogas production in the case of maize and igniscum (7–62% higher than controls), but decreased the yield of AD when grass silage was fermented (2–34% lower than controls). The greatest increase in methane production (by 79%) was observed when maize silage was digested with the PPT® pretreatment, with 427 Nm3∙Mg−1 VS (volatile solids).

Increasing the Energy Efficiency of Gas Boosters for Hydrogen Storage and for Refueling Stations

A new electrically driven gas booster is described as an alternative to the classical air-driven gas boosters known for their poor energetic efficiency. These boosters are used in small scale Hydrogen storage facilities and in refueling stations for Hydrogen vehicles. In such applications the overall energy count is of significance and must include the efficiency of the compression stage. The proposed system uses an electric motor instead of the pneumatic actuator and increases the total efficiency of the compression process. Two mechanical principles are studied for the transformation of the rotational motion of the motor to the linear displacement of the compressor pistons. The strongly fluctuating power of the compressor is smoothed by an active capacitive auxiliary storage device connected to the DC circuit of the power converter. The proposed system has been verified by numeric simulation, including the thermodynamic phenomena, the kinetics of the new compressor drive and the the operation of the circuits of the power smoothing system.

Increased adiposity is associated with altered skeletal muscle energetics.

The objective of this pilot study was to characterize relationships between skeletal muscle energy metabolism and body composition in healthy adults with varied amounts and distribution of adipose tissue. In vivo muscle energetics were quantified using dynamic 31P magnetic resonance spectroscopy with knee extension exercise standardized to subject lean body mass. Spearman's correlation analysis examined relationships between muscle metabolism indices and measures of adiposity including body mass index (BMI), total body fat, and quadriceps intermuscular adipose tissue (IMAT). Post hoc partial correlations were examined controlling for additional body composition measures. Kruskal-Wallis tests with Dunn-Sidak post hoc comparisons evaluated group differences in energy metabolism based on body composition profiles (i.e., lean, normal-weight obese, and overweight-obese) and IMAT tertiles. BMI negatively correlated with end-exercise muscle pH after correcting for IMAT and total body fat (r = -0.46, P = 0.034). Total adiposity negatively correlated with maximum oxidative capacity after correcting for IMAT (r = -0.54, P = 0.013). IMAT positively correlated with muscle proton buffering capacity after correcting for total body fat (r = 0.53, P = 0.023). Body composition groups showed differences in end-exercise fall in [PCr] with normalized workload (P = 0.036; post hoc: overweight-obese < lean, P = 0.029) and maximum oxidative capacity (P = 0.021; post hoc: normal-weight obese < lean, P = 0.016). IMAT tertiles showed differences in end-exercise fall in [PCr] with normalized workload (P = 0.035; post hoc: 3rd < 1st, P = 0.047). Taken together, these results support increased adiposity is associated with reduced muscle energetic efficiency with more reliance on glycolysis, and when accompanied with reduced lean mass, is associated with reduced maximum oxidative capacity.NEW & NOTEWORTHY Skeletal muscle energy production is influenced by both lean body mass and adipose tissue but the effect of their distribution on energy metabolism is unclear. This study examined variations in quadriceps muscle energy metabolism in healthy adults with varied relative amounts of lean and adipose tissue. Results suggest increased adiposity is associated with reduced muscle energetic efficiency with more reliance on glycolysis, and when accompanied with reduced lean mass, is associated with reduced maximum oxidative capacity.

Exergoeconomic evaluation of a new carbon-free hydrogen and freshwater production system based on biomass gasification process

Abstract This article is based on the conceptual-thermodynamic design and exergoeconomic investigation of a new poly-generation system driven by a biomass fuel (i.e. wood). In the proposed energy system, a Rankine power process, a gasification process, a desalination process (i.e. multi-effect desalination, MED) and a water electrolyzer (i.e. solid oxide electrolyzer cell, SOEC) are installed in a hybrid form. Electric energy, fresh water and hydrogen gas are the useful output products of the proposed energy system. The proposed energy system indicates an innovative framework for the carbon-free production of these products, which introduces an environmentally friendly and efficient schematic. The findings of the research indicated that the proposed energy system is capable of producing more than 1.8 MW of electric power. Other useful output products of the proposed energy system include hydrogen fuel and fresh water, which were calculated as 0.0036 kg/s and 9.92 m3/h, respectively. It was also calculated that the proposed energy system can achieve energetic and exergetic efficiencies equal to 37.1% and 17.8%, respectively. The total unit exergy cost of the products and the exergy destruction rate of the proposed energy system were equal to 15.9$/GJ and 8640 kW, respectively. Parametric analysis is also presented in order to identify the input variables affecting the performance of the energy system. Further, the behavior of the system under four different types of biomass was evaluated and compared.

Glu-rich N-terminal variable region of troponin T functions as a myofilament Ca2+-reservoir to reduce SR Ca2+-cycling.

The long Glu-rich N-terminal segment of avian pectoral muscle troponin T (TnT) and C-terminal extension of insect TnT are multi-valent Ca2+-binding sites with physiologically relevant affinities. Genetic deletion of the Glu-rich C-terminal extension of insect TnT decreases muscle and heart functions but increases the tolerance of cardiomyocytes to Ca2+ overloading, indicating decreased [Ca2+]i. In contrast, cardiomyocytes from gene-edited mice expressing modified cardiac TnT with N-terminal variable region replaced by a C-terminal segment of insect TnT (51E-cTnT) show higher shortening amplitude and contraction and relaxation velocities than that of wild type (WT) control. Isolated 51E-cTnT cardiomyocytes exhibited shorter resting sarcomeres, which can be corrected by inhibiting myosin ATPase, indicating increased resting [Ca2+]i. A similar gain-of-function model,fast skeletal muscle TnTgene-edited mice with the N-terminal variable region replaced by the N-terminal segment of adult turkey pectoral muscle TnT (Tx9-fsTnT), shows normal baseline muscle functions but slower and less rising of contractile force during caffeine-induced Ca2+ release from sarcoplasmic reticulum (SR) than that of WT control, indicating a decreased SR Ca2+ store. Consistently, 51E-cTnT mouse hearts respond to beta-adrenergic stimulation or Ca2+ agonist with higher than WT ventricular peak pressure and diastolic velocity. The data support a hypothesis that the Glu-rich segments of insect and avian flight muscle TnT function as myofilament Ca2+ reservoirs to tune muscle kinetics and reduce the amount of Ca2+ cycled during contraction and relaxation. The functional effects are prominent in heterozygotes of the genetically modified flies and mice whereas the loss-of-function in Drosophila TnT and gain-of-function in 51E-cTnT and Tx9-fsTnT mice both produced homozygote lethality, indicating sensitive dose effects of the myofilament Ca2+ reservoir for use as a potent mechanism to improve energetic efficiency of cardiac and skeletal muscles.

Inactivation of the waterborne marine pathogen Vibrio alginolyticus by photo-chemical processes driven by UV-A, UV-B, or UV-C LED combined with H2O2 or HSO5−

Ultraviolet (UV) radiation is a well-implemented process for water disinfection. The development of emergent UV sources, such as light-emitting diodes (LEDs), has afforded new possibilities for advanced oxidation processes. The emission wavelength is considered to be an important factor for photo-chemical processes in terms of both biological damage and energetic efficiency, as the inactivation mechanisms and mode-of-action may differ according to the wavelength that is applied. In addition, these processes merit exploration for inactivating emerging pathogens, such as marine vibrios, that are important bacteria to control in maritime activities. The main goal of this study was to compare the disinfection efficacy of several UV-LED driven processes with different modes of action. First, the effect of UV-LEDs was assessed at different UV ranges (UV-A, UV-B, or UV-C). Second, the possible enhancement of a combination with hydrogen peroxide (H2O2) or peroxymonosulfate salt (HSO5−) was investigated under two different application strategies, i.e. simultaneous or sequential. The results obtained indicate a high sensitivity of Vibrio alginolyticus to UV radiation, especially under UV-B (kobs = 0.24 cm2/mJ) and UV-C (kobs = 1.47 cm2/mJ) irradiation. The highest inactivation rate constants were obtained for UV/HSO5− (kobs (cm2/mJ)=0.0007 (UV-A); 0.39 (UV-B); 1.79 (UV-C)) with respect to UV/H2O2 (kobs (cm2/mJ)=0.0006 (UV-A); 0.26 (UV-B); and 1.54 (UV-C)) processes, however, regrowth was avoided only with UV/H2O2. Additionally, the disinfection enhancement caused by a chemical addition was more evident in the order UV-A > UV-B > UV-C. By applying H2O2 (10 mg/L) or HSO5− (2.5 mg/L) in a sequential mode before the UV, negligible effects were obtained in comparison with the simultaneous application. Finally, promising electrical energy per order (EEO) values were obtained as follows: UV/HSO5− (EEO (kWh/m3)=1.68 (UV-A); 0.20 (UV-B); 0.04 (UV-C)) and UV/H2O2 (EEO (kWh/m3)=2.15 (UV-A); 0.32 (UV-B); 0.04 (UV-C)), demonstrating the potential of UV-LEDs for disinfection in particular activities such as the aquaculture industry or maritime transport.

A solar energy driven thermochemical cycle based integrated system for hydrogen production

In this study, an assessment of a newly developed solar energy-driven thermochemical cycle for hydrogen generation and potentially injection into the natural gas pipeline is performed. The hydrogen, produced by the heavy element halide cycle, is blended with natural gas at particular ratios. A blend of 80% natural gas and 20% hydrogen by volume is supplied to the community for the gas turbine system, gas cooker, and combi boiler. The desalination units are integrated to produce freshwater for a community, which potentially consists of 10,000 houses. The present integrated system is then analyzed through the energy and exergy approaches. The parametric studies are further performed for different volumetric hydrogen ratios, ambient temperature, and the number of houses. Here, 0.005 kg/s of hydrogen and 0.19 kg/s of natural gas are provided to the gas turbine system to generate electricity and heat. A heat recovery steam generator is utilized both for organic Rankine cycle and multi-effect distillation unit. A total of 4.5 MW electricity is generated by the gas turbine and the organic Rankine cycles. Moreover, a total of 34.62 kg/s of freshwater is provided by two specific reverse osmosis and multi-effect distillation units. The overall exergetic and energetic efficiencies of the present integrated system are obtained as 21.3% and 26.1% for the selected operating conditions.

Exergo-economic and exergo-environmental evaluations and multi-objective optimization of a novel multi-generation plant powered by geothermal energy

An innovative multi-generation energy system is proposed to generate simultaneous power, drinking water, cooling, heating, and H2. The aimed plant comprised of an absorption chiller, a heat pump unit, a reverse osmoses unit, a double flash cycle, and a proton exchange membrane. The devised system is surveyed comprehensively based on the thermodynamic, thermo-economic, and exergoenvironmental indicators for offering an in-depth assessment of the plant. Besides, multi-objective optimization has been employed in the proposed system. The net proportions of output work, unit cost, thermal and exergetic efficiencies, and H2, and purified water production of the system are 99.25 kW, 124 $/GJ, 24.4%, 32.1%, 1.218 kg/h, and 0.9662 kg/s, separately. The outcomes related to thermodynamic and thermo-economic evaluations demonstrate that the greatest amount of total cost rate occurred in the first employed turbine. Owing to the findings of the parametric study, by increasing geothermal temperature, exergoenvironmental parameters are reduced, and with increasing the pressure of FT1, cooling load and energetic efficiency increase while SUCP, net output work, and exergetic efficiency decrease dramatically.

Sustainability and exergoeconomic assessments of a new MSW-to-energy incineration multi-generation process integrated with the concentrating solar collector, alkaline electrolyzer, and a reverse osmosis unit

The current article develops a conceptual study and simulation of a multigeneration process based on the solid waste-incineration power plant coupled with a field of solar thermal system. The considered multi-generation layout is comprised of a municipal solid waste incineration unit, a steam cycle, the concentrating solar thermal collectors (based on the parabolic trough collectors), an organic steam cycle, a desalination unit (based on a reverse osmosis unit), and a hydrogen fuel production unit (based on the alkaline electrolyzer). The planned multi-generation process can produce electricity, thermal energy, hydrogen energy, and freshwater. The paper addresses a multi-generation process with a new structure, configuration and relationships between the units of the process. A comprehensive thermodynamic-conceptual, exergoeconomic and sustainability evaluations of the multi-generation process is developed. The findings indicated that the process can achieve energetic and exergetic efficiencies of 21.72% and 16.94%, respectively. Moreover, approximately 42.2 MW of the exergy is destroyed by the process. In such a context, the total cost and sustainability index of the proposed process were 653.03 USD/h and 1.72, respectively. It was also found that the Levelized Cost of Energy of the system was almost 0.072 USD/kWh. A parametric analysis is also provided to identify influencing factors.

Moisture Determination for Fine-Sized Copper Ore by Computer Vision and Thermovision Methods.

The moisture of bulk material has a significant impact on the energetic efficiency of dry grinding, resultant particle size distribution and particle shape, and conditions of powder transport. This research aims to develop computer vision and thermovision techniques for the on-site estimation of moisture content in copper ore, for use, e.g., in dry grinding installations. The influence of particle size on the results of moisture estimation is also studied. The tested granular material was copper ore of particle size 0-2 mm and relative moisture content of 0.5-11%. Both vision and thermovision images were taken at standard and macro scales. The results suggest that median-intensity vision images monotonically reflect copper ore moisture in the range of about 0.5-5%. Suitable models were identified and cross-validated here. In contrary, thermograms should not be analyzed simply for their mean temperature but treated with computer vision processing algorithms.

Is quantum computing green? An estimate for an energy-efficiency quantum advantage

The quantum advantage threshold determines when a quantum processing unit (QPU) is more efficient with respect to classical computing hardware in terms of algorithmic complexity. The ‘green’ quantum advantage threshold—based on a comparison of energetic efficiency between the two—is going to play a fundamental role in the comparison between quantum and classical hardware. Indeed, its characterization would enable better decisions on energy-saving strategies, e.g. for distributing the workload in hybrid quantum–classical algorithms. Here, we show that the green quantum advantage threshold crucially depends on (a) the quality of the experimental quantum gates and (b) the entanglement generated in the QPU. Indeed, for noisy intermediate-scale quantum hardware and algorithms requiring a moderate amount of entanglement, a classical tensor network emulation can be more energy-efficient at equal final state fidelity than quantum computation. We compute the green quantum advantage threshold for a few paradigmatic examples in terms of algorithms and hardware platforms, and identify algorithms with a power-law decay of singular values of bipartitions—with power-law exponent —as the green quantum advantage threshold in the near future.