Utilization Coefficient Research Articles

Numerical simulation of the influence of operating parameters on the inner characteristics in a hydrogen-enriched shaft furnace

The hydrogen-enriched shaft furnace faces the challenge of insufficient heat due to the endothermic reaction involved in hydrogen reduction of iron ore. The optimization of operating parameters is crucial in maximizing the utilization of energy, leading to enhanced gas utilization rate and metallization rate. This work established a 2D shaft furnace model based on an actual MIDREX shaft furnace to examine the impact of operating parameters on the reduction process. The findings reveal that reducing the gas velocity leads to a decrease in Fe concentration but an increase in CO utilization coefficient. The H2 utilization coefficient, however, shows less sensitivity to changes in gas velocity. Increasing the gas temperature enhances the Fe concentration and improves the gas utilization coefficient increases. An increase in central supply gas velocity results in a decline in Fe concentration, an increase in the CO utilization coefficient, while only slightly affecting the H2 utilization coefficient.

Effect of combined side-wall air supply on ventilation and respiratory pollutant dispersion characteristics of high-speed trains

The ventilation system significantly affects the energy saving, thermal comfort, and pollutant dispersion characteristics of high-speed trains. Using Computational Fluid Dynamics (CFD), the effects of combining side-wall air supply with side roof or ceiling air supply, on the performance of a high-speed train ventilation system is studied. The results show that the addition of side-wall air supply aids energy saving and emission reduction, resulting in an increase in energy utilisation coefficient of between 5% and 30%. The number of measurement points with wind speed less than 0.3 m/s increases by 3%∼9%, which can improve passenger comfort. Also, the concentration of pollutants can be reduced by 6%∼29%, and the diffusion distance along the length of the train can be reduced by 18%∼45%, which means more efficient ventilation and a shorter diffusion range of pollutants. However, it reduces temperature uniformity. The results of this study can be used for ventilation optimisation of high-speed trains, to reduce ventilation energy consumption, improve thermal comfort, and increase ventilation efficiency.

Quality and selling format choices in a supply chain considering remanufacturing competition

PurposeThe purpose of this study is to explore the interplay between the selection of selling formats of remanufactured products for a third-party remanufacturer (TPR) and the quality decision of an original equipment manufacturer (OEM).Design/methodology/approachThis study considers a remanufacturing supply chain, where the OEM sells new products through a platform retailer, but the products remanufactured by the TPR can be sold via a direct or indirect channel. The authors model a Stackelberg game and explore the optimal quality decision of the OEM and selling format choice of the TPR.FindingsThe OEM's optimal decision depends mainly on consumers' discounted utility coefficient and cost-scale factor of remanufactured products. A higher consumers' valuation of the remanufactured product will not result in a higher retail price, but may lead to an increase in new product's sales. Given the cost-scale factor, the TPR prefers to sell directly no matter what the value of consumers' discounted utility coefficient is. An all-win situation is achieved with selling directly when consumers' discounted utility coefficient is sufficiently large.Practical implicationsThese results provide some support to the operational strategies of the OEM and TPR.Originality/valueThis study firstly endogenizes the quality decision and combines the selling format selection of the TPR and the quality decision of the OEM to explore the interplay between these two important decisions.

Effects of private health insurance on medical expenditure and health service utilization in South Korea: a quantile regression analysis

BackgroundDespite universal health insurance, South Korea has seen a sharp increase in the number of people enrolled in supplemental private health insurance (PHI) during the last decade. This study examined how private health insurance enrollment affects medical expenditure and health service utilization.MethodsUnbalanced panel data for adults aged 19 and older were constructed using the 2016–2018 Korea Health Panel Survey. Quantile regression for medical cost, and quantile count regression for health service utilization were utilized using propensity score-matched data. We included 17 variables representing demographic, socioeconomic, and health information, as well as medical costs and use of outpatient and inpatient care.ResultsWe discovered that PHI enrollees’ socioeconomic and health status is more likely to be better than PHI non-enrollees’. Results showed that private health insurance had a greater effect on the lower quantiles of the conditional distribution of outpatient costs (coefficient 0.149 at the 10th quantile and 0.121 at the 25th quantile) and higher quantiles of inpaitent care utilization (coefficient 0.321 at the 90th quantile for days of hospitalization and 0.076 at the 90th quantile for number of inpatient visits).ConclusionsPHI enrollment is positively correlated with outpatient costs and inpatient care utilization. Government policies should consider these heterogeneous distributional effects of private health insurance.

NITROGEN FERTILIZERS ROLE IN GRAIN CROPS PRODUCTIVITY IN SOUTH-EAST KAZAKHSTAN

Seeking to improve the efficiency of nitrogen fertilizers for grain crops led to conducting this study on developing methods using 15N in 2015–2017 at the Kazakh Research Institute of Agriculture, Almalybak Village, Almaty Region, Southeastern Kazakhstan. Nitrogen use efficiency using the stable isotope 15N in microfield experiments revealed that the assimilation of nitrogen fertilizers by grain crops largely depends on the norms, timing, fertilization method, and varietal parameters of the concerned crop. Based on morphophysiological methods of monitoring plant development conditions, the nitrogen fertilizers’ role based on the development has been affirmative, with the optimal timing of their application also determined. Results show that grain crops use nitrogen productively with partial application at the beginning of tillering and tubing, respectively, and stages III and V of organogenesis. With the use of nitrogen fertilizers, the significant varietal differences were evident. The help of an isotope label established the accurate nitrogen utilization coefficients of fertilizers based on the options ranging from 14.7% to 32.2%. Using the isotope method provides an opportunity for further development of practicing the most efficient techniques of applying fertilizers, which is an imperative method for determining the effectiveness of nitrogen fertilizers.

Повышение эффективности использования твердого топлива на промышленных ТЭЦ

Currently, in this country solid fuel at industrial thermal power plants, as a rule, is burned by a layer or flaring method in boilers with generation of steam which is directed to a steam turbine. This technology of generating thermal and electrical energy is characterized by relatively low efficiency and significant emissions of pollutants into the atmosphere. At the same time, the use of solid fuel in industrial energy with its preliminary gasification can significantly increase the efficiency of electricity generation and at the same time reduce the negative impact on the environment. The results of an analytical comparison of two schemes to use solid fuel in industrial energy are used as the material of the research. These two schemes are a traditional scheme and an alternative one based on its preliminary gasification. In this paper, to assess the effectiveness of the schemes under consideration, the scientific methodology of system analysis is applied. It allows us to consider any energy object as a unified system consisting of interrelated elements. The system analysis is carried out based on mathematical modeling of the technological process to obtain thermal and electrical energy. A complex balance mathematical model of an industrial thermal power plant with preliminary coal gasification is developed. The results of calculation using a mathematical model have shown that the construction of industrial combined‒cycle thermal power plants with preliminary coal gasification instead of traditional steam turbine ones will increase the key indicator of the energy efficiency of thermal power plants, coefficient of fuel utilization from 60 to 74 %. Based on the methodology of system analysis, an optimal thermal scheme of an industrial combined-cycle thermal power plant with preliminary coal gasification has been developed. Numerical values of the basic operating conditions of the thermal power plants and energy efficiency indicators have been determined using a mathematical model. The use of solid fuel at industrial thermal power plants with its preliminary gasification is a very promising direction to develop industrial energy in Russia since this method to extract the bound chemical energy of solid fuel can significantly increase the fuel utilization coefficient and the production of electrical energy and at the same time reduce emissions of contamination material into the atmosphere

Effect of Two Pepper Powders (Piper nigrum and Piper guineense) as A Feed Additive in The Ration on Intake and In vivo Digestibility in cavies (Cavia porcellus L.)

Background: Cavies are an essential element in a rural landscape in some African countries as food resources or income sources. Purpose: To study the effects of two peppers (Piper nigrum and Piper guineense) as a feed additive in ration on feed intake and In vivo digestibility of nutrients in cavies in order to improve their productivity. Methods: The experiment consisted of a completely random design of four groups of 5 males and five females per group (40 cavies with weights of 450±50g). The control diet was given to group 1 animals (T0) containing no pepper. The cavies in groups 2 (T1), 3 (T2), and 4 (T3) were fed 0.5% Piper nigrum powder, 0.5% Piper guineense powder, and 0.25% Piper nigrum powder + 0.25% Piper guineense powder, respectively. Similarly, Trypsacum laxum grass was weighed before being served. Results: The study showed that although not significantly (p>0.05), Dry matter (DM), Organic Matter (OM), crude protein (CP), and crude fiber (CF) were higher in animals fed the T0 control ratio compared to the other groups (37.94 g DM/d/animal; 33.71 g DM/d/animal; 5.28 g DM/d/animal and 6.45 g DM/d/animal respectively). In addition, the incorporation of the two peppers (Piper nigrum and Piper guineense) as a feed additive in the ration non-significantly (p>0.05) increased the apparent digestive utilization coefficients (aDUC) of food constituents (DM, OM, CP, and CF) in the cavies. Conclusion: Based on these results, the use of pepper powder in the ration can be considered at an incorporation rate of 0.5% for good feed intake and up to 0.5% for better digestive utilization of nutrients in guinea pigs. The use of a synergy (0.25% of Piper nigrum + 0.25% of Piper guineense) can be considered.

Fertilizer nitrogen use by cereal crops in arid conditions of Buryatia

The results of research in a long-term (1982–2021) stationary experiment to determine the coefficients of nitrogen use of mineral fertilizers by the crops of grain and fallow crop rotation in the conditions of the dry-steppe zone of Buryatia are presented. Chestnut loamy sand soil on the studied variants was characterized by very low content of humus, total nitrogen and nitrates before sowing of the crops. During the research period, the prevalence of dry years was noted. Nitrogen use coefficients of mineral fertilizers in the conditions of the dry-steppe zone of Buryatia on average for 39 years of research were 69% for wheat, 54% for oats and 90% for oats for grain haylage. The variation of the coefficients was significantly influenced by summer moistening conditions. They were 32% under extreme and severe drought, 57% under moderate and weak drought, and increased significantly (up to 124%) under favorable moisture conditions. The utilization of nitrogen of solid mineral fertilizers was maximum in the third crop (oats for grain haylage) and more responsive to the atmospheric moistening. The smallest consumption coefficients and the range of its changes were observed in oats for grain. The first crop of the rotation (fallow wheat) occupied an intermediate position in this assessment. The data on the influence of soil moisture and hydrothermal conditions of separate critical periods of vegetation on the variation of the coefficient of mineral fertilizer nitrogen utilization (N40) by wheat, oats, and oats for grain haylage were obtained. The correlation analysis showed that the most critical period for nitrogen consumption in wheat is June (r = 0.61), in oats – July (r = 0.51) and July–August for oats for grain haylage (r = 0.50–0.52). Multiple linear models of dependence of N fertilizer use coefficients on productive moisture content and hydrothermal conditions were made.

On Energy Assessment of Titanium Alloys Belt Grinding Involving Abrasive Wear Effects

Improved energy utilisation, precision, and quality are critical in the current trend of low-carbon green manufacturing. In this study, three abrasive belts were prepared at various wear stages and characterised quantitatively. The effects of abrasive belt wear on the specific grinding energy partition were investigated by evaluating robotic belt grinding of titanium plates. A specific grinding energy model based on subdivided tangential forces of cutting and sliding was developed for investigating specific energy and energy utilisation coefficient EUC. The surface morphology and Abbott–Firestone curves of the belts were introduced to analyse the experimental findings from the perspective of the micro cutting behaviour. The specific grinding energy increased with abrasive belt wear, especially when the belt was near the end of its life. Moreover, the belt wear could lead to a predominance change of sliding and chip formation energy. The highest EUC was observed in the middle of the belt life because of its retained sharp cutting edge and uniform distribution of the grit protrusion height. This study provides guidance for balancing the energy consumption and energy utilization efficiency of belt grinding.

Estimating the economic value of hydropeaking externalities in regulated rivers

Hydropower is a flexible form of electricity generation providing both baseload and balancing power to accommodate intermittent renewables in the energy mix. However, hydropower also generates various externalities. This study investigates individuals' preferences for policies aiming to reduce short-term regulations (i.e., hydropeaking in regulated rivers) while accounting for associated externalities with a discrete choice experiment. This is the first valuation study focusing on hydropeaking that considers both negative and positive externalities. The results imply that most individuals prefer stronger restrictions on short-term regulations to mitigate local environmental impacts. Individuals especially value improvements in recreational use, fish stocks, and the ecological state. On the other hand, potential increases in CO2 emissions are linked with a clear disutility. The estimated benefits obtained from an improved state of the river environment due to such restrictions exceed the disutility caused by increased CO2 emissions. The results also reveal unobserved preference heterogeneity among individuals, which should be accounted for in the willingness-to-pay (WTP) estimation using a model specification with correlated utility coefficients. Overall, the findings can inform policy-makers and environmental managers on the economic value of hydropeaking externalities and further guide the sustainable management of rivers regulated for hydropower generation.

Fertilization of Annual Grasses on Gray Forest Soils of the Vladimir Opole

In a long-term stationary experiment, the effect of fertilizers on the yield of annual grasses (vetch and pea mixtures) and the nitrifying activity of gray forest soils were studied. For 8 years, both without the use of fertilizers and with them, the yield of herbs changed by 1.72–1.88 times. It was found that the use of nitrogen of mineral fertilizers provided 88.3% of the total variation in their yield, the aftereffect of manure – 8.1, the aftereffect of РК fertilizers – 1.8%. For 7 out of 8 years, a high degree of correlation between the yield of grasses and the reserves of N-NO3 in the 0–40 cm layer of soil in the phase of grass germination was revealed. At the same time, the minimum reserves of N-NO3 were formed at a hydrothermal coefficient for the growing season equal to 1.21. The use of fertilizers, increased moisture content and temperatures during the growing season of grasses led to an increase in the nitrification activity of gray forest soil. It is proposed to evaluate the participation of mobile forms of nitrogen in plant nutrition in relation to the content of N-NO3 in the soil to the content of N-NH4 in the water extract (1 : 1). The values of this parameter in the phases of germination and harvesting of grasses confirmed the determining role of N-NO3 reserves in the nutrition of annual grasses. The difference coefficients of the use of nitrogen Naa in doses N60 and N75, which ranged from 40 to 49%, were calculated. An algorithm for calculating the size of the accumulation of N-NO3 during the growing season of grasses is proposed. In nitrogen-fertilized variants, a good coincidence of the utilization coefficients of accumulating N-NO3 reserves with the difference ones has been established.

Evaluation of heating performances of different ventilation methods in an office

In this study, 12 cases were investigated in an office-layout room using experiments and computational fluid dynamics (CFD) simulations. The heating performances of four ventilation methods (i.e. mixing ventilation (MV), stratum ventilation (SV), deflection ventilation (DeV) and impinging jet ventilation (IJV)) were comprehensively compared by various evaluation indexes (i.e. predicted mean vote (PMV), draught rate (DR), vertical air temperature difference (△T), air diffusion performance index (ADPI), energy utilization coefficient (EUC), air change efficiency (ACE) and contaminant removal efficiency (CRE)). Better thermal comfort was found in rooms heated by SV and DeV. The PMV, DR and △T under SV and DeV complied with Category B of ISO 7730:2005, and the ADPI was in full compliance with the stipulation of ANSI/ASHRAE 113-2022. For the energy-saving characteristic, the targeted-occupied-zone ventilation methods (i.e. SV, DeV and IJV) can effectively deliver warm air to the occupied zone, with the EUC values higher than unity and thus providing a good potential for energy saving. SV and IJV showed slightly higher ACEs in the breathing zone. The contaminant removal effectiveness of SV, DeV and IJV was comparable. Under the combined influence of occupant thermal plumes and locations of exhausts, MV showed a high CRE. However, the CRE under MV decreased significantly when the exhausts were not above occupants. In the case of supply air parameters in this study, the entropy-weight method indicated that DeV and SV had a better overall performance for winter heating, followed by IJV and then MV.

Study on the thermodynamic performance of a coupled compressed air energy storage system in a coal-fired power plant

Coupled energy storage can improve flexibility levels, increase renewable energy consumption, and alleviate the energy crisis of thermal power systems. In this article, 11 coupling schemes for the CAES and CFPP systems are proposed, and a mathematical model for the coupled system is established. An optimal coupling scheme is determined through simulation analysis and comparison by using the heat rate and energy utilization coefficient as evaluation indicators. In the energy release stage, the energy utilization coefficient of the coupled system increases by 2.842 %, and the heat rate in the energy storage stage decreases by 50.546 kJ · (kWh) −1, with a return water temperature of 120 °C. The effects of key parameters, such as compressor inlet air temperature, storage chamber pressure, and expander inlet temperature, on the thermodynamic performance of the coupled system are explored, and the NSGA-II multiobjective optimization algorithm and TOPSIS optimization algorithm are used to optimize the key parameters and obtain the optimal performance-related parameters of the system: a compressor inlet air temperature of 35 °C, expander inlet air temperature of 105.4 °C, and storage pressure of 9.105 MPa. At this time, the RTE of the system is 55.573 %, and the ηhe value is 1.59. The results indicate that the coupled CAES energy storage stage can assist the CFPP in absorbing renewable energy, and the energy release stage can alleviate the pressure of its high electricity load demand, effectively improving its flexibility.

PERSPECTIVES AND FEATURES OF BRANCH UTILIZATION TECHNOLOGIES IN INTENSIVE GARDENS AND PARKS

In most countries of Europe and North America, wood chips obtained in the process of cutting brushwood and branches are widely used in intensive gardens and parks as a mulching agent. Technologies that involve the disposal of branches have a wide list of technological operations. One of the most common involves manual pruning with the help of simple technical tools such as a chainsaw and cordless saws. The cut wood is transported and piled into piles, which are burned when there is enough accumulation. This technology is primarily environmentally harmful, as it pollutes the environment. Therefore, the property of using chopped branches as mulch between rows in gardens and park alleys is quite an important factor. The goal is to study the application of the technology of cutting branches into chips with a high-tech unit, which will make it possible to reduce labor costs by approximately 1.5 times, fuel costs by 1.4 times, eliminate environmental pollution, replenish the soil with organic and mineral additives and use additional areas of land. which are now set aside for wood burning sites. Technologies that involve the disposal of branches after trimming the crown of trees have the most diverse directions of use of the pruning product and a wide list of technological operations. Each of them is interesting in its own way, has advantages and disadvantages, and therefore requires more detailed coverage. One of the oldest and most primitive technologies involves manually loading cut wood onto vehicles, taking the branches to storage sites, where they are burned. This technology is poorly mechanized and requires extensive use of unproductive manual labor. The coefficient of utilization of the carrying capacity of vehicles is very low, as it is impossible to place the collected wood tightly under load. Currently, it is used in small farms.

MATHEMATICAL MODEL OF THE AUTOMATION OF THE COMMON RAIL SYSTEM DIAGNOSTIC PROCESS OF THE YAMZ-5340 SERIES DIVIGUNS

Failures of systems and mechanisms of the internal combustion engine are among the first among the total number of failures of tractors and cars. To determine them, a significant number of methods and means of determining the technical condition (diagnosis) are used. Functional-cost analysis is a heuristic method aimed at identifying the possibilities of reducing the cost and increasing the quality of the object, which is considered as a system with an orientation to a functional approach at all stages of its life cycle. This scientific article presents a functional and cost analysis of the anti-lock braking system of cars. A functional model of this system was developed and its functions were classified. The classification of the functions of the functional model of the anti-lock braking system of cars is also presented. The utility coefficients of this system are actually determined by constructing a matrix of advantages according to the known methodology. The generalizing cost criterion in the design of technical and production systems takes into account costs at all stages of the system's life cycle. To estimate these costs, a matrix of the anti-lock braking system of cars was created, with which the cost factors are calculated. Constructed function utility diagrams, function location, function-cost and cost diagrams allowed to use the functions of the anti-lock braking system of cars, which have a positive function-cost indicator and the highest rating among the presented functions. Such an operation or functions, marked by the highest functional value indicator and rank, are key to the further development of the system or the achievement of the goal of the analysis.

FUNCTIONAL-COST ANALYSIS OF THE ANTI-LOCK BRAKING SYSTEM (ABS) OF CARS

Functional-cost analysis is a method that has a heuristic nature and is used to identify opportunities to reduce costs and improve the quality of an object, which is considered as a system with a functional orientation at all stages of its life cycle. This article considers the application of functional cost analysis for the anti-lock braking system of cars. As part of this study, a functional model of the car's anti-lock braking system was developed and its functions were classified. The classification of functions within the framework of the functional model of the anti-lock braking system of cars was also carried out. To determine the utility coefficients of this system, a matrix of priorities was built using a known calculation method. When designing technical or production systems, the general cost criterion takes into account costs at all stages of the system's life cycle. For this evaluation, a matrix of anti-lock braking system of cars was created, which allows to compensate the cost factor. The results of the study are the construction of a diagram of the utility of the functions of the anti-lock braking system of cars, a diagram of the location of the system functions taking into account the utility factor, a functional cost diagram of the system, a diagram of the costs of the system functions, a diagram of the location of the system functions taking into account the cost factor, a diagram of the value of the indicator of the functional cost of the system functions, and diagrams of the location of system functions with the calculation of the functional cost indicator. Based on the analysis of this diagram, the functions of the anti-lock braking system of the car were determined, which have a positive functional value indicator and the highest rating among the functional functions. operations or functions that have the highest functional value indicator and rank.

Research on circulating heat recovery law of single horizontal well for hot dry rock geothermal resources

Hot dry rock is essential to geothermal resources because of its advantages of clean green, good stability, large reserves, and high utilization coefficient. However, there are few large-scale and commercial mining schemes due to increased development costs, induced earthquakes, and low recovery during fracturing. Based on the above background, the concept of hot dry rock development for circulating heat recovery in the single horizontal well is put forward, injection and recovery of circulating working fluid are realized by single horizontal well, interchange of hollow pipe in well with liquid flow passage in wall annulus is realized by the fast connection of flow passage transformation, and flow direction control of thermal fluid is recognized by its unique bottom hole structure, to achieve the goal of cleanliness, low energy consumption, and high-efficiency heat recovery, to achieve the purpose of avoiding a series of problems caused by reservoir fracturing. A mathematical model has been created to calculate heat recovery efficiency in a single horizontal well. This model analyzes the impact of critical parameters in mining hot dry rock geothermal resources from single horizontal wells. The results show that the flow rate of circulating working fluid, the wellbore’s horizontal section length, and the formation’s thermal conductivity greatly influence thermal recovery. For instance, a domestic hot dry rock project can recover heat up to 3.08 MW through cyclic mining with a single horizontal well over 30 years.

Evaluation of the ventilation mode in an ISO class 6 electronic cleanroom by the AHP-entropy weight method

As ISO Class 6 electronic cleanrooms are required to meet stringent environmental control standards during production, an energy-efficient ventilation mode is required to maintain an appropriate thermal and humidity environment and a comfortable workplace. However, the optimum air supply distribution to ensure thermal comfort, energy efficiency and cleanliness is unclear. Therefore, numerical simulations were carried out to determine the workspace satisfaction, energy utilization coefficient satisfaction and contaminant-removal satisfaction with FFU-clean bench coverage(C) ranging from 25% to 100%. We use the AHP-entropy weight method to evaluate four different ventilation modes for different cleanroom design targets, and then select suitable ventilation modes to meet them. The results show that in the core work area, the temperature difference, relative humidity difference and air velocity difference increase with increasing coverage. Furthermore, when the C = 25%, the priority of thermal comfort and cleanliness of employees is satisfied. Moreover, when C = 50%, high energy efficiency of the ventilation system is achieved. The AHP-entropy weight method evaluation system provides a theoretical basis for the selection of cleanroom ventilation design solutions.

Numerical modeling and application of the effects of fish movement on flow field in recirculating aquaculture system

Hydrodynamics plays a crucial role in the recirculating aquaculture system (RAS). An efficient flow field is essential for removing residual bait and feces, creating a healthy environment for fish growth, development, and overall welfare. Hydrodynamics not only influences fish growth and development, but the presence and movement of fish also impact the flow dynamics within the culture tank. This article proposes a fluid-solid coupled model based on computational fluid dynamics (CFD) to investigate the interaction between fish movement and the flow field. Firstly, we established a numerical model of a circular tank using tetrahedral meshing. Several bionic fish were introduced into the tank simultaneously, and their movements were defined using UDF (User-Defined Function) files. Secondly, we evaluated the effects of different numbers of fish movements on the velocity and uniformity of the flow field within the tank. To quantitatively analyze the impact of different numbers of bionic fish on the flow field in the culture tank, we calculated the average velocity, velocity uniformity coefficients, and energy-effective utilization coefficients in three different planes (Y = 0.05, Y = 0.1, and Y = 0.15). This study demonstrated that the presence of fish and their tail-swinging motion enhanced the stability of the flow field and reduced low flow velocity zones in the culture tank. As the number of fish increased, the velocity significantly decreased, and the velocity uniformity decreased as well. The results highlight the effectiveness of the numerical modeling method for the fluid-solid coupling of fish interactions with the system's flow field. Furthermore, the model aligns with experimental results and can be utilized to study fish movement and flow fields effectively.

Consumers’ acceptance of the explosion, toxicity, and odor potential of ammonia: A survey on consumers’ choice of an ammonia-based hydrogen refueling station

Ammonia can help decarbonize energy systems as a hydrogen energy carrier or a carbon-free fuel. However, consumers’ acceptance of ammonia will be low because ammonia has the potential for explosion, toxicity, and odor. This study analyzed consumers’ ammonia acceptance based on a survey method by assuming hydrogen refueling stations with six attributes, including explosion, toxicity, and odor potential of gases for hydrogen production. Respondents avoided the negative attributes of ammonia in the order of the explosion (−1.788), toxicity (−1.025), and odor (−0.222) potential. A carbon tax (USD 205.338/ton CO2 eq) increased ammonia acceptance, but its effects on the acceptance rate were only 5 %p. Additionally, respondents who had knowledge of ammonia safety had a lower reluctance toward ammonia. The utility coefficients of the explosion and toxicity potential of ammonia were −1.630 and −0.907 for respondents with the knowledge, and −1.949 and −1.136 for those without the knowledge. Therefore, it is important to improve the perception of ammonia safety rather than depend on the greenness of ammonia and monetary incentives. It is also important to develop technological measures to control the explosion potential of ammonia, the most significant factor in determining ammonia acceptance.