bluuebunny/crossref_metadata_2025 huggingface dataset:
A Hot-Wire Anemometer with Automatically Adjusted Dynamic Properties for Wind Energy Spectrum Analysis
Authors: Ligęza Paweł , Jamróz Paweł
Published: June 2022

Hot-wire anemometric measurements are often related to the determination of flow parameters in a high frequency range. Such knowledge is particularly important when analyzing the flow phenomena in the vicinity of wind turbines. The reliability of obtained results is determined by the knowledge of the properties of the system used for measurements. It concerns both the static and dynamic characteristics of individual measurement channels. In studies of hot-wire anemometric systems, a problem related to the unstable transmission bands of such systems and their high dependence on measurement conditions and the system configuration itself has been commonly indicated. This paper presents the results of an investigation of a new type of hot-wire anemometer, allowing for automatic adjustment of its dynamic characteristics under real working conditions. The presented system is dedicated to the analysis of the wind energy spectrum in experimental laboratory tests on reduced-scale models and to specialized in situ measurements.
Design and Management of High Voltage Power Systems and Insulation Materials
Authors: Liu Feng , Wang Yani , Zhu Xi
Published: June 2022

To satisfy the fast-growing electricity demand, high-voltage power systems with higher performance and better stability are required, which raises challenges including the design of power systems, the control of high-power electronics, the synthesis and preparation of high-performance insulation materials, evaluation of the insulation conditions, dielectric insulation tests, material modification, environment protection, etc [...]
Dynamic Propagation and Shear Stress Disturbance of Multiple Hydraulic Fractures: Numerical Cases Study via Multi-Well Hydrofracturing Model with Varying Adjacent Spacings
Authors: Wang Yongliang , Liu Nana
Published: June 2022

Multi-well hydrofracturing is an important technology for forming complex fracture networks and increasing reservoir permeability. The distribution and design of horizontal wells affect fracture propagation; however, it is still unclear how the spacing between adjacent wells leads to fracture propagation, deflection and connection. In this study, the thermal-hydro-mechanical coupling effect in the hydrofracturing process is comprehensively considered and a multi-well hydrofracturing model based on the finite element–discrete element method is established. Using typical cases, the unstable propagation of hydraulic fractures in multiple horizontal wells under varying adjacent well spacings is studied. Combined with the shear stress shadow caused by in situ stress disturbed by fracture tip propagation, quantitative indexes (such as length, volume, deflection and unstable propagation behaviors of hydrofracturing fracture networks) are analyzed. The results show that the shear stress disturbance caused by multiple hydraulic fractures is a significant factor for multi-well hydrofracturing. Reducing well spacing will increase the stress shadow area and aggravate the mutual disturbance and deflection between fractures. The results of quantitative analysis show that the total length of hydraulic fractures decreases with the decrease of well spacing, and the total volume of hydraulic fractures increases with the decrease of well spacing. The results of unstable propagation and stress evolution of hydraulic fracture networks considering thermal-hydro-mechanical coupling obtained in this study can provide useful guidance for the valuation and design of hydrofracturing fracture networks in deep unconventional oil and gas reservoirs.
Aerodynamic Interactions of Wind Lenses at Close Proximities
Authors: Gunasekaran Sidaard , Peyton Madison , Novotny Neal
Published: June 2022

The fundamental aerodynamic interactions between a pair of wind lenses is experimentally investigated. In prior work, wind tunnel testing of lensed turbines in a side-by-side configuration revealed that one lensed turbine outperformed its counterpart in terms of power production. In the current study, particle image velocimetry (PIV) was performed in the wake of three different pairs of wind lens profiles and revealed an inherent bias in the wake properties at close proximities which led to one turbine outperforming the other. The merged wake location is skewed to a single lens in the lens pair depending on the extent of cancellation of inboard vorticity magnitude. At 0.1 to 0.2 x/D,the individual wakes merge as one, at which point the vortex shedding frequency and the modal strength behind the lens pairs is reduced. Coincidentally, it is at this spacing that the net power output of lensed turbines placed in a side-by-side configuration reaches the maximum.
Simplified Recovery Process for Resistive Solder Bond (RSB) Hotspots Caused by Poor Soldering of Crystalline Silicon Photovoltaic Modules Using Resin
Authors: Lee Koo , Cho Sung Bae , Yi Junsin , Chang Hyo Sik
Published: June 2022

When the thickness of the solar cell wafer and the amount of Ag to be used decreases, it is the best method to recover the power of the module after use at a minimum cost and reuse the module itself. Economic recovery technology can be applied to the power degradation, caused by the resistive solder bond (RSB) hotspot by poor soldering, because the recovery process can be simplified compared to the power loss that is often greater than 30%. This study demonstrated a quick recovery of the RSB hotspot with on-site recovery technology applied with resin and verified the performance and long-term reliability of on-site recovery technology, compared to the factory recovery method, where the back sheet is removed and laminated to recover the module. Both the factory and field recovery methods confirmed recovery results closer to the initial rated power output of the samples. Each sample was degraded by the RSB hotspot to ~62–65% of the initial power output, and the recovery process successfully recovered it to ~96–99%. In on-site recovery, verification of the possible EVA solvothermal swelling, which is the effect of organic solvents contained in the resin on EVA, is essential for verifying the long-term reliability of the recovered module. In this study, the power degradations of the on-site recovered samples after a TC 200 cycle test are −2.14% and −0.95%, respectively, which are within the certification test standard of the new manufacturing module. Existing factory recovery costs not only in the recovery process, but also in a total of 22 stages, such as the transfer of the target module. The largest advantage is that the on-site recovery process can be restarted in the field after only eight stages.
Evaluation Method of Naturalistic Driving Behaviour for Shared-Electrical Car
Authors: Ji Shaobo , Zhang Ke , Tian Guohong , Yu Zeting , Lan Xin , Su Shibin , Cheng Yong
Published: June 2022

Evaluation of driving behaviour is helpful for policy development, and for designing infrastructure and an intelligent safety system for a car. This study focused on a quantitative evaluation method of driving behaviour based on the shared-electrical car. The data were obtained from the OBD interface via CAN bus and transferred to a server by 4G network. Eleven types of NDS data were selected as the indexes for driving behaviour evaluation. Kullback–Leibler divergence was calculated to confirm the minimum data quantity and ensure the effectiveness of the analysis. The distribution of the main driving behaviour parameters was compared and the change trend of the parameters was analysed in conjunction with car speed to identify the threshold for recognition of aberrant driving behaviour. The weights of indexes were confirmed by combining the analytic hierarchy process and entropy weight method. The scoring rule was confirmed according to the distribution of the indexes. A score-based evaluation method was proposed and verified by the driving behaviour data collected from randomly chosen drivers.
Predicting Mining Areas Deformations under the Condition of High Strength and Depth of Cover
Authors: Strzałkowski Piotr
Published: June 2022

This paper presents an analysis of mining area deformations in the rock mass consisting of high depth and strength strata deposited in the cover. The analysis of land surveying results enabled the identification of the parameters required to predict subsidence, which differed from the typical parameters for the Upper Silesian Coal Basin. The parameters of the Budryk–Knothe theory were determined based on the results of geodetic measurements. The calculations of the final state of deformations for planned mining were made using the average and characteristics for the study area parameter values. Based on experience, it is known that the range of subsidence trough depends on the mechanical properties of the rock mass. This study shows that the presence of high-strength rocks also reduces the value of the coefficient of roof control. Subsequently, calculations were made by a computer simulation of longwall mining to determine the course of indices of deformation over time. The calculations were conducted twice: on the assumption that the impact was immediate and on the assumption of the parameter values typical for the basin, and formula expressing the course of subsidence over time with the parameter values based on the measurement results. The obtained distributions of deformation indicators were diametrically opposed to each other. The results of the calculations with the parameter values appropriate for the region indicate that it is possible to carry out a planned mining operation without creating a risk to objects on the surface.
Will Oil Price Volatility Cause Market Panic?
Authors: Hong Min , Wang Xiaolei , Li Zhenghui
Published: June 2022

It is generally known that violent oil price volatility will cause market panic; however, the extent to which is worthy of empirical test. Firstly, this paper employs the TVP-VAR model to analyze the time-varying impacts of oil price volatility on the panic index using monthly data from January 1990 to November 2021. Then, after using the SVAR model to decompose the oil price volatility, this paper uses the PDL model to analyze the heterogeneous impacts of oil price volatility from different sources. Finally, based on the results of oil decomposition, this paper uses the TARCH model to analyze the asymmetric impacts of oil price volatility in different directions. The results show that: (1) oil price volatility can indeed cause market panic, and these impacts exhibit time-varying characteristics; (2) oil price volatility from different sources has different impacts on the panic index, and the order from high to low is oil-specific demand shocks, supply shocks, and aggregate demand shocks; and (3) oil price volatility has asymmetric impacts on the panic index, and positive shocks have greater impacts than negative.
The Concept of Using an Expert System and Multi-Valued Logic Trees to Assess the Energy Consumption of an Electric Car in Selected Driving Cycles
Authors: Deptuła Adam , Augustynowicz Andrzej , Stosiak Michał , Towarnicki Krzysztof , Karpenko Mykola
Published: June 2022

This paper presents the concept of an expert system supporting the decision-making process of rational energy consumption by an electric car. The driving style and the average speed achieved are very important in terms of the driving range. In addition, the influence of ambient temperature on the efficiency of the electric vehicle and ultimately on energy consumption is very important. The proposed system, based on the method of multi-valued logic trees, allows minimizing the objective function, which is aimed at minimizing the energy consumption of an electric car at different ambient temperatures. The generated decisions, directed to the energy management system, can be processed in a variety of temporal and situational dimensions. The application of the system can also provide prompts to the driver on how to adjust the driving style by operating the accelerator and brake pedal. The expert system is an open system, allowing for further generalizations and modifications.
Joint Scheduling Optimization of a Short-Term Hydrothermal Power System Based on an Elite Collaborative Search Algorithm
Authors: Duan Jiefeng , Jiang Zhiqiang
Published: June 2022

The joint scheduling optimization of hydrothermal power is one of the most important optimization problems in the power system, which is a non-linear, multi-dimensional, non-convex complex optimization problem, and its difficulty in solving is increasing with the expansion of the grid-connected scale of hydropower systems in recent years. In this paper, three effective improvement strategies are proposed given the shortcomings of the standard collaborative search algorithm, which easily falls into local optimization and weakening of global search ability in later stages. Based on this, an elite collaborative search algorithm (ECSA) coupled with three improvement strategies is established. On this basis, taking the classic joint scheduling problem of a hydrothermal power system as an example, the optimization model with the goal of the least pollutant gas emission is constructed, and the system constraint treatment method is proposed. In addition, five algorithms, i.e., ECSA, CSA, PSO, GWO, and WOA are used to solve the model, respectively. Through the comparison of results, taking the median as an example, the emission of polluting gases of ESCA is reduced by about 1.8%, 13.1%, 38.2%, and 11.2%, respectively, and it can be found that ECSA has obvious advantages in the convergence speed and quality compared with the other four algorithms, and it has a strong ability for global search and jumps out of the local optimal.
Optimization of a Hybrid Energy System with District Heating and Cooling Considering Off-Design Characteristics of Components, an Effort on Optimal Compressed Air Energy Storage Integration
Authors: Chen Shang , Arabkoohsar Ahmad , Chen Guodong , Nielsen Mads Pagh
Published: June 2022

In this work, the optimal design of a hybrid energy complex, including wind turbines, an internal combustion engine, and an adiabatic compressed air energy storage system is investigated. A novel bi-level optimization strategy is proposed for optimizing the capacity and operational power of each component of the system based on techno-economic considerations. The article presents information and discussions about the impacts of the partial-load operation of the energy storage system components on the optimal rated power and working strategies. The off-design characteristics are proven to have a huge negative impact on the efficiency and economy of the hybrid system. The efficiency reduction of the compressed air energy storage system is about 21% in summer and 8.9% in winter, when the system is operating in partial-load conditions. The operation cost of the system is reduced significantly when carrying out the proposed bi-level optimization strategy.
Surface Drilling Parameters and Drilling Optimization Techniques: Are They Useful Tools in Gas Hydrate Detection?
Authors: Wspanialy Adam , Kyaw Moe
Published: June 2022

This paper examines the application of surface drilling parameters and drilling optimization techniques, such as mechanical specific energy (MSE) and equivalent strength (EST), in detecting hydrate gas-bearing sediments during drilling operations. Gas hydrates are usually detected from 3D seismic imaging and later confirmed with Measurement-While-Drilling (MWD)/Logging-While-Drilling (LWD) data and collected core samples. Here, we describe an analysis of the time-based surface drilling parameters recorded from two wells drilled during the International Ocean Discovery Program (IODP) Expedition 372A offshore of New Zealand and the Indian National Gas Hydrate Program Expedition 02 (NGHP-02) offshore of India. The investigation revealed that drilling parameters, as well as MSE/EST methods, can and should be used to monitor and optimize the drilling process and to detect lithological/tectonic (fractures, fault zones, rock hardness, etc.) changes in the drilled substrata and signs of the dynamic changes in the downhole environment (tool vibration, washouts, pack-offs, etc.). However, surface drilling parameters with MSE models cannot explicitly determine the hydrate gas-bearing sediments. This qualitative analysis of whether the gas-bearing sediments consist of hydrates can only be accomplished with the use of the MWD/LWD suite, preferably located as close as possible to the bit.
The Effects of Pore Geometry on Late Time Solute Transport with the Presence of Recirculation Zone
Authors: Yang Peijie , Wu Guangwei , Gu Sha , Guan Qin , Wang Lichun
Published: June 2022

The solute transport process in porous media is central to understanding many geophysical processes and determines the success of engineered applications. However, fundamental understanding of solute transport in heterogeneous porous media remains challenging especially when inertial effects are significant. To address this challenge, we employed direct numerical simulations in a variety of intrapore geometries at a high Reynolds number (Re = 10) flow regime, where recirculation zones (RZs) are present with significant inertial effects. We find that the volume of RZs depends on pore geometries. Moreover, RZs serve as an immobile domain that can trap and release solutes that lead to non-Fickian transport, characterized by the early arrival and heavy tailing of breakthrough curves and bimodal residence time distributions (RTDs). Lastly, the late time portion of RTDs is fitted to the power law function with determined exponent n, where n depends on the pore geometries and consequently the volume of RZs. Our study sheds light on the mechanisms of an immobile zone on the solute transport, especially improving our understanding of late time transport tailing in pressurized heterogeneous porous media.
Compressed Air Energy Storage Capacity Configuration and Economic Evaluation Considering the Uncertainty of Wind Energy
Authors: Yu Qihui , Tian Li , Li Xiaodong , Tan Xin
Published: June 2022

The random nature of wind energy is an important reason for the low energy utilization rate of wind farms. The use of a compressed air energy storage system (CAES) can help reduce the random characteristics of wind power generation while also increasing the utilization rate of wind energy. However, the unreasonable capacity allocation of the CAES system results in high capital investment and a long payback period. In order to improve the economic benefits of energy storage, this paper studies the capacity configuration of compressed air energy storage systems under the condition of wind energy uncertainty. First, the typical hourly power distribution of wind power generation was obtained using historical data. Factors such as user load demand, time-of-use price of the power grid, system investment cost, power shortage cost, and power sales revenue were considered. Then, a model was built with the charging and discharging power and gas storage capacity of the CAES system as constraints, and the maximum return on investment and the minimum volume of the gas storage tank as targets. NSGA-II and TOPSIS optimal selection methods were used to solve the problem. Finally, the model was used to optimize a power operation case. The results show that in the case of an hourly load power demand of a factory using 3.2 MW, a wind farm would need to keep four wind turbines running every day, and a compressed air energy storage system with a rated power of 1 MW and a rated capacity of 7 MW would ensure the best project benefit. In this mode, 1.24 × 103 MWh of wind abandoning power could be reduced annually, 2.6 × 104 kg of carbon emissions could be reduced by increasing energy storage within the operation cycle, and the payback period of investment would only be 4.8 years.
A Review on the Materials Science and Device Physics of Semitransparent Organic Photovoltaics
Authors: Schopp Nora , Brus Viktor V.
Published: June 2022

In this review, the current state of materials science and the device physics of semitransparent organic solar cells is summarized. Relevant synthetic strategies to narrow the band gap of organic semiconducting molecules are outlined, and recent developments in the polymer donor and near-infrared absorbing acceptor materials are discussed. Next, an overview of transparent electrodes is given, including oxides, multi-stacks, thin metal, and solution processed electrodes, as well as considerations that are unique to ST-OPVs. The remainder of this review focuses on the device engineering of ST-OPVs. The figures of merit and the theoretical limitations of ST-OPVs are covered, as well as strategies to improve the light utilization efficiency. Lastly, the importance of creating an in-depth understanding of the device physics of ST-OPVs is emphasized and the existing works that answer fundamental questions about the inherent changes in the optoelectronic processes in transparent devices are presented in a condensed way. This last part outlines the changes that are unique for devices with increased transparency and the resulting implications, serving as a point of reference for the systematic development of next-generation ST-OPVs.
Analysis of Floating Offshore Wind Platform Hydrodynamics Using Underwater SPIV: A Review
Authors: Belvasi Navid , Judge Frances , Murphy Jimmy , Desmond Cian
Published: June 2022

There is a need for new numerical tools to capture the physics of floating offshore wind turbines (FOWTs) more accurately to refine engineering designs and reduce costs. The conventional measurement apparatuses in tank tests, including wave probes, velocity and current profilers, and Doppler sensors, are unable to provide a full 3D picture of velocity, pressure, turbulence, and vorticity profile. In tank tests, use of the underwater stereoscopic particle image velocimetry (SPIV) method to fully characterise the 3D flow field around floating wind platforms can overcome some of the limitations associated with classical measurement techniques and provide a rich source of validation data to advance high-fidelity numerical tools. The underwater SPIV method has been widely used for marine and offshore applications, including ship and propeller wakes, wave dynamics, and tidal stream turbines; however, to date, this technology has not seen widespread use for the hydrodynamic study of FOWTs. This paper provides a critical review of the suitability of underwater SPIV for analysing the hydrodynamics of FOWTs, reviews the challenges of using the method for FOWT tank test applications, and discusses the contributions the method can make to mitigating current research gaps in FOWT tank tests.
Parametric Study of Methyl Orange Removal Using Metal–Organic Frameworks Based on Factorial Experimental Design Analysis
Authors: Karami Abdollah , Shomal Reem , Sabouni Rana , Al-Sayah Mohammad H. , Aidan Ahmed
Published: June 2022

Wastewater treatment plants (WWTPs) are one of the most energy-intensive industries. Every stage of wastewater treatment consumes energy, which is the primary contributor to WWTP costs. Adsorbents and process optimization are critical for energy savings. The removal of dyes from industrial wastewater by adsorption using commercially available adsorbents is inefficient. Metal–organic frameworks (MOFs) have outstanding properties that can improve separation performance over current commercial adsorbents, and thus, these materials represent a milestone in improving dye removal in water treatment methods. In this work, three types of metal–organic frameworks (Fe-BTC, Cu-BTC, and ZIF-8) have been investigated as prospective adsorbents for methyl orange removal from water in batch setups. The results showed that at 15 mg/L MO initial concentration and 100 mg dosage, Fe-BTC had the highest removal efficiency of 91%, followed by ZIF-8 (63%), and finally Cu-BTC (35%), which exhibited structural damage due to its instability in water. Fe-BTC maintained consistent adsorption capacity over a wide range of pH values. Furthermore, a 23 full factorial design analysis was implemented to evaluate the conditions for maximum MO-removal efficiency. The main effects, interaction effects, analysis of variance (ANOVA), and the Pareto chart were reported. The statistical analysis demonstrated that the MOF type was the most significant factor, followed by dosage and initial concentration. The analysis indicated that the type of MOF and dosage had a positive effect on the removal efficiency, while the initial concentration had a negative effect. The two-way and three-way interactions were also found to be significant.
Solar Energy Resources and Photovoltaic Power Potential of an Underutilised Region: A Case of Alice, South Africa
Authors: Overen Ochuko Kelvin , Meyer Edson Leroy
Published: June 2022

Despite South Africa’s international recognition in solar energy investments, the country is struggling to meet its growing energy needs. In recent years, national blackouts and load shedding have been a recurring experience in the country. The high cost of electrification and the overstrained national grid have left several rural communities without access to electricity. This study aims to explore the solar energy resources and performance of a 3.8 kWp stand-alone residential photovoltaic (PV) power system in one of the underutilised regions in South Africa. The study mainly uses ground measured solar radiation data to evaluate the solar resources of Alice and compare them with those in other parts of the world with mega solar PV projects. The components of solar radiation considered are global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance (DHI). The average total daily GHI, DNI, and DHI of Alice were 4.98, 5.74, and 1.44 kWh/m2. Clear sky conditions were found to occur on 233 days in the monitoring year, resulting in an average total daily GHI of 6.13 kWh/m2, DNI of 6.73 kWh/m2 and DHI of 0.17 kWh/m2. The findings indicated that Alice possesses abundant solar resources for PV and concentrated solar power generation, and is comparable to other regions internationally.
Influence of Long-Term Mine Activity on Hydraulic Relations between Separate Hydrogeological Units—New Aspects of Regional Water Circulation Assessment
Authors: Zdechlik Robert , Różkowski Kazimierz , Śledzik Mariusz
Published: June 2022

In the course of the documentation works aimed at updating exploitable resources of the groundwater intake, an unexpected change in hydrodynamic field arrangement was observed in a fragment of the area. In relation to the observations made so far, lasting several decades, the groundwater table switched its slope, indicating the flow in the opposite direction than originally. Initially, in the range of the surveyed hydrogeological structure, no object was identified whose draining character could cause such an effect. No significant groundwater extraction or drainage points were documented within a radius of several kilometers. It was only the extended scope of spatial analysis that made it possible to identify the probable cause of a local change in the water table position as a mining pit located in the neighboring hydrogeological structure. The two adjacent hydrogeological structures treated separately so far revealed an experimentally confirmed hydraulic connection. An in-depth analysis of the problem showed the necessity of modifying the existing model of the structure in order to map the observed interactions. An additional simulation module of General-Head Boundary type was applied. The quantity of lateral groundwater exchange between two hydrogeological structures was estimated using mathematical modeling at 3.4 thousand m3/d (reconstructed current state, after model calibration). Further work should aim at treating reservoirs as hydraulically connected after exceeding limiting parameters.
Novel Combustion Techniques for Clean Energy
Authors: Krzywanski Jaroslaw , Nowak Wojciech , Sztekler Karol
Published: June 2022

This Special Issue contains successful submissions as an answer to the invitation to bring together research on advances in design, modeling, and performance of novel combustion techniques for clean energy [...]
Economic Evaluation of Renewable Hydrogen Integration into Steelworks for the Production of Methanol and Methane
Authors: Bampaou Michael , Panopoulos Kyriakos , Seferlis Panos , Sasiain Amaia , Haag Stephane , Wolf-Zoellner Philipp , Lehner Markus , Rog Leokadia , Rompalski Przemyslaw , Kolb Sebastian , Kieberger Nina , Dettori Stefano , Matino Ismael , Colla Valentina
Published: June 2022

This work investigates the cost-efficient integration of renewable hydrogen into steelworks for the production of methane and methanol as an efficient way to decarbonize the steel industry. Three case studies that utilize a mixture of steelworks off-gases (blast furnace gas, coke oven gas, and basic oxygen furnace gas), which differ on the amount of used off-gases as well as on the end product (methane and/or methanol), are analyzed and evaluated in terms of their economic performance. The most influential cost factors are identified and sensitivity analyses are conducted for different operating and economic parameters. Renewable hydrogen produced by PEM electrolysis is the most expensive component in this scheme and responsible for over 80% of the total costs. Progress in the hydrogen economy (lower electrolyzer capital costs, improved electrolyzer efficiency, and lower electricity prices) is necessary to establish this technology in the future.
Smart Mobility in a Smart City in the Context of Generation Z Sustainability, Use of ICT, and Participation
Authors: Wawer Monika , Grzesiuk Kalina , Jegorow Dorota
Published: June 2022

Smart sustainable cities represent a great challenge for the modern world. Generation Z (Gen Z), whose representatives are now entering adult life, will play a key role in the implementation of this concept. The purpose of this study is to investigate the nature of the relationship between the evaluation of smart mobility’s importance for a smart city and the attitudes and behaviours of Generation Z members in the context of sustainability, use of ICT, and their declarative and actual participation in smart city activities. The diagnostic survey method was used to achieve the research objective. The authors designed the questionnaire based on a literature analysis. The research sample consisted of 484 representatives of Generation Z—students of universities located in a smart city, Lublin (Poland). The collected data was statistically analysed using the following methods and statistical tests: Cronbach’s alpha, Pearson’s chi-square test for independence, symmetric measures: Cramer’s V, and the contingency coefficient. The analysis of the obtained research results confirms that the conscious approach of Generation Z to sustainability has a significant and positive impact on their evaluation of actions taken in the field of smart mobility for a smart city. A similar relationship was confirmed with regard to the relationship between ICT use and smart mobility evaluation. The significant and positive impact of young people’s participation in smart cities on their evaluation of smart mobility solutions’ importance was not fully and unequivocally confirmed. In conclusion, the Generation Z representatives’ awareness of the importance of sustainability and caring for the natural environment was confirmed by their desire to be pro-ecological in the areas of smart mobility studied in the paper. Moreover, young people who constantly use the latest technologies see their huge potential for the development of smart mobility in cities. However, despite the growing expectations of citizens’ active attitudes and their increasing participation in smart mobility development, it seems that the representatives of Generation Z are not really interested in it. Their declarations of willingness to join various opinion-forming and decision making processes do not actually transform them into active co-creators of smart mobility solutions. Changing this approach can be an educational, organisational and technological challenge for smart city authorities. The obtained research results could be used as guidelines for facilitating the search for innovative solutions in the area of smart mobility, improving the quality of life of smart city residents based on the principle of sustainable development.
Study on Chemical Kinetics Mechanism of Ignition Characteristics of Dimethyl Ether Blended with Small Molecular Alkanes
Authors: Niu Kai , Yao Baofeng , Xu Yonghong , Zhang Hongguang , Shi Zhicheng , Wang Yan
Published: June 2022

Dimethyl ether (DME)/C1-C4 alkane mixtures are ideal fuel for homogeneous charge compression ignition (HCCI) engines. The comparison of ignition delay and multi-stage ignition for DME/C1-C4 alkane mixtures can provide theoretical guidance for expanding the load range and controlling the ignition time of DME HCCI engines. However, the interaction mechanism between DME and C1-C4 alkane under engine relevant high-pressure and low-temperature conditions remains to be revealed, especially the comprehensive comparison of the negative temperature coefficient (NTC) and multi-stage ignition characteristic. Therefore, the CHEMKIN-PRO software is used to calculate the ignition delay process of DME/C1-C4 alkane mixtures (50%/50%) at different compressed temperatures (600–2000 K), pressures (20–50 bar), and equivalence ratios (0.5–2.0) and the multi-stage ignition process of DME/C1-C4 alkane mixtures (50%/50%) over the temperature of 650 K, pressure of 20 bar, and equivalence ratio range of 0.3–0.5. The results show that the ignition delay of the mixtures exhibits a typical NTC characteristic, which is more prominent at a low equivalence ratio and pressure range. The initial temperature of DME/CH4 mixtures of the NTC region is the highest. In the NTC region, the ignition delay DME/CH4 mixtures are the shortest, whereas DME/C3H8 mixtures are the longest. At low-temperature and lean-burn conditions, DME/C1-C4 alkane mixtures exhibit a distinct three-stage ignition characteristic. The time corresponding to heat release rate and pressure peak is the shortest for DME/CH4 mixtures, and it is the longest for DME/C3H8 mixtures. Kinetic analysis indicates that small molecular alkane competes with the OH radical produced in the oxidation process of DME, which inhibits the oxidation of DME and promotes the oxidation of small molecular alkane. The concentration of active radicals and the OH radical production rate of elementary reactions are the highest for DME/CH4 mixtures, and they are the lowest for DME/C3H8 mixtures.
Harvesting Local Energy: A Case Study of Community-Led Bioenergy Development in Galena, Alaska
Authors: Menghwani Vikas , Walker Chad , Kalke Tim , Noble Bram , Poelzer Greg
Published: June 2022

Community-led bioenergy projects show great promise to address a range of issues for remote and Indigenous Arctic communities that typically rely on diesel for meeting their energy demands. However, there is very little research devoted to better understanding what makes individual projects successful. In this study, we analyze the case of the Galena Bioenergy Project (Alaska)—a biomass heating project that uses locally sourced woody biomass to help meet the heating demands of a large educational campus. Using project documents and other publicly available reports, we evaluate the project’s success using three indicators: operational, environmental, and community level socio-economic benefits. We find that the project shows signs of success in all three respects. It has a reliable fuel supply chain for operations, makes contributions towards greenhouse gas reductions by replacing diesel and has improved energy and economic security for the community. We also examine enabling factors behind the project’s success and identify the following factors as crucial: community-level input and support, state level financial support, access to forest biomass with no competing use, predictable demand and committed leadership. Our findings have important implications for other remote communities across the Boreal zone—especially those with nearby forest resources. Our examination of this case study ultimately highlights potential pathways for long-term success and, more specifically, shows how biomass resources might be best utilized through community-led initiatives to sustainably support energy security in Arctic communities.
A Hybrid Method for Prediction of Ash Fouling on Heat Transfer Surfaces
Authors: Cui Fangshu , Qin Sheng , Zhang Jing , Li Mengwei , Shi Yuanhao
Published: June 2022

Soot blowing optimization is a key, but challenging question in the health management of coal-fired power plant boiler. The monitoring and prediction of ash fouling for heat transfer surfaces is an important way to solve this problem. This study provides a hybrid data-driven model based on advanced machine-learning techniques for ash fouling prediction. First, the cleanliness factor is utilized to represent the level of ash fouling, which is the original data from the distributed control system. The wavelet threshold denoising algorithm is employed as the data preprocessing approach. Based on the empirical mode decomposition (EMD), the denoised cleanliness factor data is decoupled into a series of intrinsic mode functions (IMFs) and a residual component. Second, the support vector regression (SVR) model is used to fit the residual, and the Gaussian process regression (GPR) model is applied to estimate the IMFs. The cleanliness factor data of ash accumulation on the heat transfer surface of diverse devices are deployed to appraise the performance of the proposed SVR + GPR model in comparison with the sole SVR, sole GPR, SVR + EDM and GPR + EDM models. The illustrative results prove that the hybrid SVR + GPR model is superior to other models and can obtain satisfactory effects both in one-step- and the multistep-ahead cleanliness factor predictions.
Qualitative–Quantitative Warning Modeling of Energy Consumption Processes in Inland Waterway Freight Transport on River Sections for Environmental Management
Authors: Szaruga Elżbieta , Załoga Elżbieta
Published: June 2022

The article concerns the assessment of the energy consumption of inland waterway freight transport on river sections in the context of environmental management. The research question was: Does the choice of the route determine the total energy consumption of inland waterway transport and therefore affect the potential of cargo transport of this mode? The article aims to indicate the directions of energy consumption by inland waterway freight transport depending on the route selection, the volume of transport, and the length of the route. The study was carried out on nine sections of the Odra River in Poland during the years 2015–2020. Statistical and econometric techniques were used, i.e., ANOVA, generalized linear models, Eta coefficients, Lasso and Ridge regularization, and X-average control charts (Six Sigma tool). Based on early warning models, river sections were identified that favor the rationalization of energy consumption in terms of the network. The sensitivity of the energy consumption of inland waterway transport to changes in the average distance and in the volume of transport was examined. With the use of Six Sigma tools, the instability of the energy consumption processes of inland waterway transport was identified, paying attention to the source of the mismatch, which was the increase in the average transport distance in the sections, where energy consumption increased due to the operational and navigation conditions of these sections.
Research on a Limit Analytical Method for a Low-Speed Micro Permanent Magnet Torque Motor with Back Winding
Authors: Guo Shuangshuang , Zhao Bo , Zhang Cunshan , Lu Binglin , Chu Yukang , Yang Peng
Published: June 2022

The conventional permanent magnet torque motor (PMTM) is slotted on the inner surface of the stator core. When the size of the stator core is small, the winding coils are difficult to embed into the slots. To solve the problem, a novel PMTM is presented, which is slotted on the outer surface of the stator core. As a result, the winding coils can be conveniently embedded into the slots from the outer surface of the stator core. The novel structure of the PMTM with back winding (BWPMTM) is introduced, and the advantage of the novel structure is analyzed. Furthermore, this paper proposes a limit analytical method to solve the optimal parameters of the motor which comprehensively considers four constraints: no-load back electromotive force (EMF), torque, temperature and slot space factor. The optimal parameters of the motor are directly solved to maximize torque density within the constrained range. This method avoids repeated iterative processes and greatly reduces the amount of calculation for PMTM design. Electromagnetic performance and thermal performance are analyzed based on the finite element model (FEM). Finally, the building of a prototype and the experimental results obtained with it are discussed. The rationality of the novel structure and the limit analytical method are verified.
Does the Moderating Role of Financial Development on Energy Utilization Contributes to Environmental Sustainability in GCC Economies?
Authors: Omer Halmat , Bein Murad
Published: June 2022

This present research examined the association among carbon emissions, financial development, economic growth, natural resources, and energy usage in GCC nations within the environmental Kuznets curve framework by applying the datasets between 1995 and 2019. It used some empirical approaches, including second-generation unit roots and cointegration methods and method of moments quantile regression (MMQR). We detected a cointegrating interconnection between carbon emissions and financial development, energy usage, economic growth, natural resources, and squared of economic growth in the long term. Furthermore, the findings of the MMQR reveal that economic growth, financial development, energy usage, and natural resources degrade the environment, as well as proving the presence of the EKC hypothesis. Moreover, the results also demonstrated that financial development greatly moderates energy usage in order to attain environmental sustainability. Furthermore, the fixed-effect ordinary least squares, fully modified ordinary least squares, and dynamic ordinary least squares were also used in the study as a soundness check of the MMQR approach. The path of causality moves from financial development, economic growth, and squared of economic growth to CO2 emissions. Lastly, the causality direction runs from carbon emissions to energy usage. Based on these findings, the energy mix of the region must be revised by ensuring the promotion of sustainable energy sources and other energy-efficient technology in order to attain the quality of the environment.
Numerical Simulation Analysis on Hydraulic Optimization of the Integrated Pump Gate
Authors: Li Songbai , Shen Changrong , Sun Tao , Cheng Li , Lei Shuaihao , Xia Chenzhi , Zhang Chenghua
Published: June 2022

Based on the Reynolds time mean N-S equation and standard k-ε turbulence model and using Computational Fluid Dynamics technology, this study aims to integrate the brake pump to carry out numerical simulation. Through the adoption of different arrangements of impending height and spacing, the hydraulic characteristics of the full tubular pump unit are analyzed. The two-dimensional streamline, velocity and pressure distribution, and three-dimensional streamline, axial velocity and vorticity distribution of the front pool of each scheme are displayed. The results show that the recommended pump installation height is 0.8 Dd, the maximum limit value of the pump station design specification; in the dual-pump mode, the recommended pump spacing is 2.00 Ds.
Stone Fruit Seed: A Source of Renewable Fuel for Transport
Authors: Anwar M. , Rasul M. , Hassan N. , Jahirul M. , Haque Rezwanul , Hasan M. , Mustayen A. , Karami R. , Schaller D.
Published: June 2022

This study investigated the suitability of stone fruit seed as a source of biodiesel for transport. Stone fruit oil (SFO) was extracted from the seed and converted into biodiesel. The biodiesel yield of 95.75% was produced using the alkaline catalysed transesterification process with a methanol-to-oil molar ratio of 6:1, KOH catalyst concentration of 0.5 wt% (weight %), and a reaction temperature of 55 °C for 60 min. The physicochemical properties of the produced biodiesel were determined and found to be the closest match of standard diesel. The engine performance, emissions and combustion behaviour of a four-cylinder diesel engine fuelled with SFO biodiesel blends of 5%, 10% and 20% with diesel, v/v basis, were tested. The testing was performed at 100% engine load with speed ranging from 200 to 2400 rpm. The average brake specific fuel consumption and brake thermal efficiency of SFO blends were found to be 4.7% to 15.4% higher and 3.9% to 11.4% lower than those of diesel, respectively. The results also revealed that SFO biodiesel blends have marginally lower in-cylinder pressure and a higher heat release rate compared to diesel. The mass fraction burned results of SFO biodiesel blends were found to be slightly faster than those of diesel. The SFO biodiesel 5% blend produced about 1.9% higher NOx emissions and 17.4% lower unburnt HC with 23.4% lower particulate matter (PM) compared to diesel fuel. To summarise, SFO biodiesel blends are recommended as a suitable transport fuel for addressing engine emissions problems and improving combustion performance with a marginal sacrifice of engine efficiency.
Intelligent Transportation System Applications and Logistics Resources for Logistics Customer Service in Road Freight Transport Enterprises
Authors: Kadłubek Marta , Thalassinos Eleftherios , Domagała Joanna , Grabowska Sandra , Saniuk Sebastian
Published: June 2022

Road freight transport involves many adversities, along with the growing effect of carbon dioxide transmitted by vehicles on the natural environment, greenhouse gas emissions, or extensive energy use. Within the smart mobility concept, the acknowledged management of enterprises’ relationships with customers within their service is profoundly determined by the deployment of compelling Intelligent Transportation Systems (ITSs) applications in forming united cooperation with the customers. The paper proposes selected ITS applications as an advancement of logistics customer service in road freight transport enterprises that is divided into a group of six applications which are critical within the area of vehicle support, improving the energy efficiency of transport and reducing the negative impact of transport on the natural environment, reducing transport time but increasing connectivity and comfort, as well as a group of ten different applications chosen as crucial for general management support and increasing accessibility, cohesiveness, and control in management processes in road freight transport enterprises. The study also presents the effect of ITS applications on logistics customer service as dependent on an alignment between the group of ITS applications and logistics resources of road freight transport enterprises. The model proposed in the paper was analyzed based on the survey data obtained from 164 road freight transport enterprises in Poland.