bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Pumping System Supplied by a PV Generator and with a Switched Reluctance Motor Using a Drive Based on a Multilevel Converter with Reduced Switches
Authors: Pires Vitor Fernão , Foito Daniel , Cordeiro Armando , Amaral Tito G. , Chen Hao , Pires Armando , Martins João F.
Published: March 2023

Pumping systems play a fundamental role in many applications. One of the applications in which these systems are very important is to pump water. However, in the real world context, the use of renewable energies to supply this kind of system becomes essential. Thus, this paper proposes a water pumping system powered by a photovoltaic (PV) generator. In addition, due to its interesting characteristics, such low manufacturing cost, free of rare-earth elements, simple design and robustness for pumping systems, a switched reluctance motor (SRM) is used. The power electronic system to be used in the PV generator and to control the SRM consists of a DC/DC converter with a bipolar output and a multilevel converter. The adopted DC/DC converter uses only one switch, so its topology can be considered as a derivation of the combination of a Zeta converter with a buck–boost converter. Another important aspect is that this converter allows continuous input current, which is desirable for PV panels. The topology selected to control the SRM is a multilevel converter. This proposed topology was adopted with the purpose of reducing the number of power semiconductors. A maximum power point algorithm (MPPT) associated with the DC/DC converter to obtain the maximum power of the PV panels is also proposed. This MPPT will be developed based on the concept of the time derivative of the power and voltage. It will be verified that with the increase in solar irradiance, the generated power will also increase. From this particular case study, it will be verified that changes in the irradiance from 1000 W/m2 to 400 W/m2 will correspond to a change in the motor speed from 1220 rpm to 170 rpm. The characteristics and operation of the proposed system will be verified through several simulation and experimental studies.
Assessing the Impact of Rutting Depth of Bituminous Airport Runway Pavements on Aircraft Landing Braking Distance during Intense Precipitation
Authors: Toraldo Emanuele , Ketabdari Misagh , Battista Gianluca , Crispino Maurizio
Published: March 2023

A runway pavement during its useful life is subject to a series of deteriorations because of repeated load cycles and environmental conditions. One of the most common deteriorations is the formation of rutting (surface depression in the wheel path) on the runway surface. Rutting negatively affects aircraft performance during landings and will behave even worse during precipitation or with the existence of fluid contaminations on the surface. This paper aims to develop a model for calculating aircraft braking distance during landing on wet-pavement runways affected by rutting based on dynamic skid resistances generated by tire–fluid–pavement interactions. Intense precipitation, variable rutting depths for a 100 m length step, water film depths (e.g., 1 to 26 mm), and aircraft wheel loads (e.g., 10 to 140 kN) are considered as the boundary conditions of the developed model. The output is a model that can estimate aircraft braking distance as a function of rutting depth and can perform further assessment of the probability of the occurrence of landing overrun. After validating the model with existing methodologies and calibrating it according to the actual landing distance required for each type of aircraft, an Italian airport is simulated using a model with real data regarding the level of service of its pavement surface characteristics.
Lipodystrophies from Insulin Injection: An Update of the Italian Consensus Statement of AMD-OSDI Study Group on Injection Technique
Authors: Gentile Sandro , Satta Ersilia , Guarino Giuseppina , Strollo Felice
Published: March 2023

The causes and metabolic consequences of lipohypertrophy (LH) from incorrect insulin injection techniques have been well-known for a long time and are the subject of countless publications. However, only some researchers propose structured research modalities for LH and programs to teach patients how to prevent them and minimize their effects, thus contributing to complete rehabilitation. Experts and scientific societies have produced consensus documents and recommendations to spread the culture of LH and its complications among clinicians. However, they should go deeper into LH detection methods. This short article analyzes the recent literature on the best way to explore and find more or less evident LH lesions by using a structured and validated clinical methodology to benefit the many clinicians without access to technological equipment such as ultrasonography. This text also aims to bring awareness that since the last published recommendations on injection techniques, new needles for insulin injection, more technologically advanced and suitable for specific populations, have come to market but still need a thorough evaluation.
Search for Damped Oscillating Structures from Charged Pion Electromagnetic Form Factor Data
Authors: Bartoš Erik , Dubnička Stanislav , Dubničková Anna Zuzana
Published: March 2023

The damped oscillating structures recently revealed by a three parametric formula from the proton “effective” form factor data extracted of the measured total cross section σtotbare(e+e−→pp¯) still seem to have an unknown origin. The conjectures of their direct manifestation of the quark-gluon structure of the proton indicate that they are not specific only of the proton and neutron, but they have to be one’s own, similar to other hadrons. Therefore, the oscillatory structures from the charged pion electromagnetic form factor timelike data, extracted of the process e+e−→π+π− are investigated by using the same procedure as in the case of the proton. The analysis shows the appearance of the oscillating structures in the description of the charged pion electromagnetic form factor timelike data by three parametric formula with a rather large value of χ2/ndf, while the description of the data by the physically well-founded Unitary and Analytic model has not revealed any damped oscillating structures. From the obtained result on the most simple object of strong interactions, one can conclude that damped oscillating structures received from the “effective” proton form factor data are probably generated by a utilization of the improper three parametric formula which does not describe these data with sufficient precision.
Papaver somniferum and Papaver rhoeas Classification Based on Visible Capsule Images Using a Modified MobileNetV3-Small Network with Transfer Learning
Authors: Zhu Jin , Zhang Chuanhui , Zhang Changjiang
Published: March 2023

Traditional identification methods for Papaver somniferum and Papaver rhoeas (PSPR) consume much time and labor, require strict experimental conditions, and usually cause damage to the plant. This work presents a novel method for fast, accurate, and nondestructive identification of PSPR. First, to fill the gap in the PSPR dataset, we construct a PSPR visible capsule image dataset. Second, we propose a modified MobileNetV3-Small network with transfer learning, and we solve the problem of low classification accuracy and slow model convergence due to the small number of PSPR capsule image samples. Experimental results demonstrate that the modified MobileNetV3-Small is effective for fast, accurate, and nondestructive PSPR classification.
Computing the Integrated Information of a Quantum Mechanism
Authors: Albantakis Larissa , Prentner Robert , Durham Ian
Published: March 2023

Originally conceived as a theory of consciousness, integrated information theory (IIT) provides a theoretical framework intended to characterize the compositional causal information that a system, in its current state, specifies about itself. However, it remains to be determined whether IIT as a theory of consciousness is compatible with quantum mechanics as a theory of microphysics. Here, we present an extension of IIT’s latest formalism to evaluate the mechanism integrated information (φ) of a system subset to discrete, finite-dimensional quantum systems (e.g., quantum logic gates). To that end, we translate a recently developed, unique measure of intrinsic information into a density matrix formulation and extend the notion of conditional independence to accommodate quantum entanglement. The compositional nature of the IIT analysis might shed some light on the internal structure of composite quantum states and operators that cannot be obtained using standard information-theoretical analysis. Finally, our results should inform theoretical arguments about the link between consciousness, causation, and physics from the classical to the quantum.
Remora Optimization Algorithm with Enhanced Randomness for Large-Scale Measurement Field Deployment Technology
Authors: Yan Dongming , Liu Yue , Li Lijuan , Lin Xuezhu , Guo Lili
Published: March 2023

In the large-scale measurement field, deployment planning usually uses the Monte Carlo method for simulation analysis, which has high algorithm complexity. At the same time, traditional station planning is inefficient and unable to calculate overall accessibility due to the occlusion of tooling. To solve this problem, in this study, we first introduced a Poisson-like randomness strategy and an enhanced randomness strategy to improve the remora optimization algorithm (ROA), i.e., the PROA. Simultaneously, its convergence speed and robustness were verified in different dimensions using the CEC benchmark function. The convergence speed of 67.5–74% of the results is better than the ROA, and the robustness results of 66.67–75% are better than those of the ROA. Second, a deployment model was established for the large-scale measurement field to obtain the maximum visible area of the target to be measured. Finally, the PROA was used as the optimizer to solve optimal deployment planning; the performance of the PROA was verified by simulation analysis. In the case of six stations, the maximum visible area of the PROA reaches 83.02%, which is 18.07% higher than that of the ROA. Compared with the traditional method, this model shortens the deployment time and calculates the overall accessibility, which is of practical significance for improving assembly efficiency in large-size measurement field environments.
Charged Particles Transverse Momentum and Pseudorapidity Distribution in Hadronic Collisions at LHC Energies
Authors: Ajaz Muhammad , Haj Ismail Abd Al Karim , Ullah Mian Mateen , Khan Rashid , Shehzadi Ramoona , Adil Khan Muhammad , AbdelKader Atef , Waqas Muhammad , Dawi Elmuez A. , Tabassam Uzma
Published: March 2023

We present an analysis of the pseudorapidity η and transverse momentum pT distributions of charged hadrons in pp collisions for the kinematic range of 0<pT<4 GeV/c and |η|<2.4 at 0.9, 2.36, and 7 TeV. Charged particles are produced in pp collision using several Monte Carlo event generators (Pythia Simple, Vincia, Dire showers, Sibyll2.3d, QGSJETII-04, EPOS-LHC) and compared with CMS data at LHC. It is observed that the Simple parton showers can explain the CMS data very well for pT>1 GeV/c at 0.9 and 2.36 TeV within the experimental errors, while Dire overshoots and Vicia undershoots the data by 50% each. At 7 TeV, the Dire module presents a good prediction, whereas the Simple and Vincia modules underestimate the data within 30% and 50%. Comparing the Simple module of the Pythia model and the predictions of the CRMC models with the experimental data shows that at 0.9 TeV, EPOS-LHC has better results than the others. At 2.36 GeV, the cosmic rays Monte Carlo (CRMC) models have better prediction than the Simple module of Pythia at low pT, while QGSJETII-04 predicts well at high pT. QGSJETII-04 and EPOS-LHC have closer results than the Pythia-Simple and Sibyll2.3d at 7 TeV. In the case of the pseudorapidity distributions, only the Pythia-Simple reproduced the experimental measurements at all energies. The Dire module overestimates, while Vincia underestimates the data in decreasing order of discrepancy (20%, 12%, 5%) with energy. All CRMC models underestimate the data over the entire η range at all energies by 20%. The angular ordering of partons and the parton fragmentation could be possible reasons for this deviation. Furthermore, we used the two-component standard distribution to fit the pT spectra to the experimental data and extracted the effective temperature (Teff) and the multiplicity parameter (N0). It is observed that Teff increases with the increase in the center of mass energy. The fit yielded 0.20368±0.01, 0.22348±0.011, and 0.24128±0.012 GeV for 0.9, 2.36, and 7 TeV, respectively. This shows that the system at higher energies freezes out earlier than lower ones because they quickly attain the equilibrium state.
Effectiveness of Subtitles in L2 Classrooms: A Meta-Analysis Study
Authors: Alotaibi Hind M. , Mahdi Hassan Saleh , Alwathnani Deema
Published: March 2023

The use of subtitles in language-learning environments has received considerable attention. Nevertheless, conclusive findings have yet to be reached regarding the effectiveness of integrating subtitles into L2 classrooms. This meta-analysis examined the overall effectiveness of subtitles to enhance learners’ L2. A total of 26 experimental studies conducted between 2010 and 2022 were analyzed to examine the performance of L2 classroom learners based on integrating subtitles as a teaching/learning tool, compared to learners who did not use subtitles. A meta-analysis investigated how effect sizes varied depending on L2 skills (listening, speaking, reading, writing, grammar, vocabulary, and pronunciation), institutional level (school, university, and language institute), participants’ native language (L1), language proficiency, and implementation mode. The results indicated that integrating subtitles into L2 classrooms have a medium effect size (d = 0.69), and the effect sizes of different variables affecting the use of subtitles in language learning are reported. Several pedagogical implications are discussed in light of the findings, which can help promote the successful integration of subtitles in L2 classrooms.
Object Detection for Hazardous Material Vehicles Based on Improved YOLOv5 Algorithm
Authors: Zhu Pengcheng , Chen Bolun , Liu Bushi , Qi Zifan , Wang Shanshan , Wang Ling
Published: March 2023

Hazardous material vehicles are a non-negligible mobile source of danger in transport and pose a significant safety risk. At present, the current detection technology is well developed, but it also faces a series of challenges such as a significant amount of computational effort and unsatisfactory accuracy. To address these issues, this paper proposes a method based on YOLOv5 to improve the detection accuracy of hazardous material vehicles. The method introduces an attention module in the YOLOv5 backbone network as well as the neck network to achieve the purpose of extracting better features by assigning different weights to different parts of the feature map to suppress non-critical information. In order to enhance the fusion capability of the model under different sized feature maps, the SPPF (Spatial Pyramid Pooling-Fast) layer in the network is replaced by the SPPCSPC (Spatial Pyramid Pooling Cross Stage Partial Conv) layer. In addition, the bounding box loss function was replaced with the SIoU loss function in order to effectively speed up the bounding box regression and enhance the localization accuracy of the model. Experiments on the dataset show that the improved model has effectively improved the detection accuracy of hazardous chemical vehicles compared with the original model. Our model is of great significance for achieving traffic accident monitoring and effective emergency rescue.
Influence of Oxygen/Steam Addition on the Quality of Producer Gas during Direct (Air) Gasification of Residual Forest Biomass
Authors: Gomes Helena G. M. F. , Matos Manuel A. A. , Tarelho Luís A. C.
Published: March 2023

Biomass gasification is a relevant option to produce a gaseous fuel, it faces, however, several barriers regarding its quality for energetic applications. Therefore, in this study, air-steam and O2-enriched air mixtures were used as gasification agents during the gasification of residual biomass from eucalyptus to improve the producer gas quality. The steam addition promoted an increase in CO2 and H2 concentrations, whilst decreasing the CO and CH4 concentrations. The steam addition had no evident impact on the lower heating value of the dry producer gas and a positive effect on gas yield and the H2:CO molar ratio, attaining the later values up to 1.6 molH2∙mol−1CO. The increase in O2 concentration in the gasification agent (φ) promoted an increase in all combustible species and CO2 concentrations. The lower heating value of the dry producer gas underwent an increase of 57%, reaching a value of 7.5 MJ∙Nm−3dry gas, when the φ increased from 20 to 40 %vol.O2, dry GA. The gas yield had a significant decrease (33%) with φ increase. This work showed that the addition of steam or O2 during air gasification of residual biomass improved producer gas quality, overcoming some of the barriers found in conventional air gasification technology.
Optimization of Microalgal Biomass Production in Vertical Tubular Photobioreactors
Authors: Hawrot-Paw Małgorzata , Sąsiadek Magdalena
Published: March 2023

Microalgal biomass is a promising alternative and renewable substrate for bioenergy production. The main problem for its commercial application is to obtain and keep a high level of production by providing microalgae with appropriate conditions for growth. The aim of this study was to determine optimal culture conditions such as temperature, photoperiod, and pH. The amount of biomass by gravimetry, optical density by spectrophotometry, and productivity were analyzed. Suitable values of cultivation parameters allowed for the increased growth and biomass productivity of Arthrospira platensis (4.24 g·L−1), Chlamydomonas reinchardtii (1.19 g·L−1), Chlorella vulgaris (2.37 g·L−1), and Dunaliella salina (4.50 g·L−1) and optical density for Ch. reinchardtii and C. vulgaris. These species had maximum biomass productivity of 0.72, 0.12, 0.36, and 0.77 g·L−1·d−1, respectively. Productivity was determined by cultivation temperature and for Ch. reinchardtii also by pH.
A Position-Insensitive Nonlinear Inductive Power Transfer System Employing Saturable Inductor
Authors: Yang Xu , Yang Junfeng , Fan Jing , Wang Bao , Li Dingzhen
Published: March 2023

Most of the practical inductive power transfer (IPT) systems are the ones with variable coupling coefficients and loads. The output voltage, current and power are affected by the variation in coupling coefficient and load. In this paper, a novel approach based on a nonlinear resonator is proposed to obtain stable output voltage, which is independent of coupling coefficient and load variation. First, the theory and properties of nonlinear resonators are analyzed by Duffing equation. Then, a nonlinear IPT system with a magnetic saturation inductor is proposed, and the saturable inductor modeling and its effect on system performance are further studied. Finally, the experimental prototype is built to validate the effectiveness of the nonlinear IPT system. The experimental results show that when the coupling coefficient varies from 0.32 to 0.24 and the load resistance varies from 80Ω to 120Ω, the system works in a nonlinear state, the output voltage ripple is 1.77%, and the overall efficiency of the system is not less than 82.60%. The experimental results are basically consistent with the theoretical analysis. The novel design approach improves the output voltage stability with respect to position misalignment and load variation, and the bandwidth of the system is also enhanced.
Effect of Wire Design (Profile) on Sand Retention Parameters of Wire-Wrapped Screens for Conventional Production: Prepack Sand Retention Testing Results
Authors: Tananykhin Dmitry , Grigorev Maxim , Simonova Elena , Korolev Maxim , Stecyuk Ilya , Farrakhov Linar
Published: March 2023

There are many technologies to implement sand control in sand-prone wells, drilled in either weakly or nonconsolidated sandstones. Technologies that are used to prevent sanding can be divided into the following groups: screens (wire-wrapped screens, slotted liners, premium screens, and mesh screens), gravel packs, chemical consolidation, and technological ways (oriented perforation and bottomhole pressure limitation) of sanding prevention. Each particular technology in these groups has their own design and construction features. Today, slotted liners are the most well-studied technology in terms of design, however, this type of sand control screen is not always accessible, and some companies tend towards using wire-wrapped screens over slotted liners. This paper aims to study the design criteria of wire-wrapped screens and provides new data regarding the way in which wire design affects the sanding process. Wires with triangular (wedge), trapezoidal, and drop-shaped profiles were tested using prepack sand retention test methodology to measure the possible impact of wire profile on sand retention capabilities and other parameters of the sand control screen. It was concluded that a trapezoidal profile of wire has shown the best result both in terms of sand production (small amount of suspended particles in the effluent) and in particle size distribution in the effluent, that is, they are the smallest compared to other wire profiles. As for retained permeability, in the current series of experiments, high sand retention did not affect retained permeability, although it can be speculated that this is mostly due to the relatively high particle size distribution of the reservoir.
DER Participation in Ancillary Services Market: An Analysis of Current Trends and Future Opportunities
Authors: Arosio Martina , Falabretti Davide
Published: March 2023

In an effort to push for low-carbon transition, national governments and regulatory authorities are working to define market structures and legislative frameworks able to effectively support the spreading of electricity production from renewables. To this purpose, the opening of national Ancillary Services Markets (ASMs) to Distributed Energy Resources (DERs) plays a key role. However, pricing schemes and rules in place (e.g., incentives) can act as a barrier to the supply of regulation services by small-sized and renewable-based power plants. In this context, the present work evaluates the economic opportunities for DERs provided by the provision of tertiary reserve and balancing control in the Italian ASM. The research is carried out through the collection and processing of price data from the Italian electricity and gas markets over 4 years (2019–2022). Considering a reference architecture where DER units bid on the market through a Balancing Service Provider, the potential revenues on the ASM of a non-programmable or partially programmable DER unit are compared to the earnings expected of a conventional power plant in order to highlight whether unfair competition can represent a barrier. Then, possible evolutions in the current remuneration schemes are analyzed, to evaluate whether they can be able to support a better DER integration. From the analysis, it emerges that, even if negative prices could be useful to increase the competitiveness of RES-based power plants for downward regulation, the loss of the incentives can act as a deterrent to the offering of services on the market by DERs. Therefore, other regulatory options, such as the incentives retention in case of downward regulation, could also be needed.
Optimal Planning of Solar Photovoltaic (PV) and Wind-Based DGs for Achieving Techno-Economic Objectives across Various Load Models
Authors: Rehman Habib Ur , Hussain Arif , Haider Waseem , Ali Sayyed Ahmad , Kazmi Syed Ali Abbas , Huzaifa Muhammad
Published: March 2023

Over the last few decades, distributed generation (DG) has become the most viable option in distribution systems (DSs) to mitigate the power losses caused by the substantial increase in electricity demand and to improve the voltage profile by enhancing power system reliability. In this study, two metaheuristic algorithms, artificial gorilla troops optimization (GTO) and Tasmanian devil optimization (TDO), are presented to examine the utilization of DGs, as well as the optimal placement and sizing in DSs, with a special emphasis on maximizing the voltage stability index and minimizing the total operating cost index and active power loss, along with the minimizing of voltage deviation. The robustness of the algorithms is examined on the IEEE 33-bus and IEEE 69-bus radial distribution networks (RDNs) for PV- and wind-based DGs. The obtained results are compared with the existing literature to validate the effectiveness of the algorithms. The reduction in active power loss is 93.15% and 96.87% of the initial value for the 33-bus and 69-bus RDNs, respectively, while the other parameters, i.e., operating cost index, voltage deviation, and voltage stability index, are also improved. This validates the efficiency of the algorithms. The proposed study is also carried out by considering different voltage-dependent load models, including industrial, residential, and commercial types.
Multi-Agent-Based Controller for Microgrids: An Overview and Case Study
Authors: Altin Necmi , Eyimaya Süleyman Emre , Nasiri Adel
Published: March 2023

A microgrid can be defined as a grid of interconnected distributed energy resources, loads and energy storage systems. In microgrid systems containing renewable energy resources, the coordinated operation of distributed generation units is important to ensure the stability of the microgrid. A microgrid needs a successful control scheme to achieve its design goals. Undesirable situations such as distorted voltage profile and frequency fluctuations are significantly reduced by installing the appropriate hardware such as energy storage systems, and control strategies. The multi-agent system is one of the approaches used to control microgrids. The application of multi-agent systems in electric power systems is becoming popular because of their inherent benefits such as autonomy, responsiveness, and social ability. This study provides an overview of the agent concept and multi-agent systems, as well as reviews of recent research studies on multi-agent systems’ application in microgrid control systems. In addition, a multi-agent-based controller and energy management system design is proposed for the DC microgrid in the study. The designed microgrid is composed of a photovoltaic system consisting of 30 series-connected PV modules, a wind turbine, a synchronous generator, a battery-based energy storage system, critical and non-critical DC loads, the grid and the control system. The microgrid is controlled by the designed multi-agent-based controller. The proposed multi-agent-based controller has a distributed generation agent, battery agent, load agent and grid agent. The roles of each agent and communication among the agents are designed properly and coordinated to achieve control goals, which basically are the DC bus voltage quality and system stability. The designed microgrid and proposed multi-agent-based controller are tested for two different scenarios, and the performance of the controller has been verified with MATLAB/Simulink simulations. The simulation results show that the proposed controller provides constant DC voltage for any operation condition. Additionally, the system stability is ensured with the proposed controller for variable renewable generation and variable load conditions.
Experimental Study on Mineral Dissolution and Carbonation Efficiency Applied to pH-Swing Mineral Carbonation for Improved CO2 Sequestration
Authors: Galina Natália R. , Arce Gretta L. A. F. , Maroto-Valer Mercedes , Ávila Ivonete
Published: March 2023

Mineral carbonation incurs high operating costs, as large amounts of chemicals and energy must be used in the process. Its implementation on an industrial scale requires reducing expenditures on chemicals and energy consumption. Thus, this work aimed to investigate the significant factors involved in pH-swing mineral carbonation and their effects on CO2 capture efficiency. A central composite rotatable design (CCRD) was employed for optimizing the operational parameters of the acid dissolution of serpentinite. The results showed that temperature exerts a significant effect on magnesium dissolution. By adjusting the reaction temperature to 100 °C and setting the hydrochloric acid concentration to 2.5 molar, 96% magnesium extraction was achieved within 120 min of the reaction and 91% within 30 min of the reaction. The optimal efficiency of carbon dioxide capture was 40–50%, at higher values than those found in literature, and 90% at 150 bar and high pressures. It was found that it is technically possible to reduce the reaction time to 30 min and maintain magnesium extraction levels above 90% through the present carbonation experiments.
Zero-Phase FIR Filter Design Algorithm for Repetitive Controllers
Authors: de Lima Pedro V. S. G. , Neto Rafael C. , Neves Francisco A. S. , Bradaschia Fabrício , de Souza Helber E. P. , Barbosa Eduardo J.
Published: March 2023

Repetitive controllers (RCs) are linear control structures based on the internal model principle. This control strategy is known for its ability to control periodic reference signals, even if these signals have many harmonic components. Despite being a solution that results in a good performance, several parameters of the repetitive controller need to be correctly tuned to guarantee its stability. Among these parameters, one that has high impact on the system performance and stability is the finite impulse response (FIR) filter, which is usually used to increase the stability domain of RC-based controllers. In this context, this paper presents a complete tutorial for designing the zero-phase FIR filter, which is often used to stabilize control systems that use RC-based controllers. In addition, this paper presents a Matlab® application developed for performing the stability analysis of RC systems and designing its FIR filter. Simulation and experimental results of a shunt active power filter are used to validate the algorithm and the Matlab® application.
Examining Preference for Energy-Related Information through a Choice Experiment
Authors: Nakano Makiko
Published: March 2023

Many studies have shown that providing information on energy consumption to a household is effective, to some extent, in encouraging its energy conservation behavior. These studies provided information free of charge. However, depending on the type of information, a household must bear costs, such as installing the necessary equipment to obtain the information. Are people willing to pay for the information? In this study, a questionnaire survey was conducted to examine willingness to pay (WTP) for energy-related information using a choice experiment. The data were analyzed using conditional logit and latent class models. Positive WTP was estimated for information on the total energy consumption amount for the entire house, detailed electricity usage amount for each major home appliance, electricity rates by time zone, and power source composition of electricity. No significant positive results were obtained for comparison with the other households, as the class that accounted for about 40% of the analyzed sample had negative WTP for this information. When electricity companies provide comparative information, it is better to carefully consider how and to whom they provide it. The results of the latent class model show that preferences vary among classes. Although some preference variations exist, some households have a positive WTP for information on energy consumption.
Critical Assessments of the Potential for Integrating Renewable Energy into Isolated Grids on Vietnamese Islands: The Case of the An-Binh Grid
Authors: Le Hang Thi-Thuy , Riva Sanseverino Eleonora , Nguyen Ninh Quang , Di Silvestre Maria Luisa , Favuzza Salvatore , Doan Van Binh , Musca Rossano
Published: March 2023

Renewable electricity for off-grid areas is widely seen as one of the top choices in supporting local economic development in most countries, and so is Vietnam. Over the years, many isolated networks using renewable energy sources have been deployed for off-grid areas in Vietnam. However, the use of these energy sources in Vietnam’s isolated networks is still facing many challenges due to its infancy here. The issues of reliability and vulnerability of these networks are not given the expected attention. Another challenge is that the issues of the operational security of these systems could also be negatively affected by the variable nature of renewable sources, including static and dynamic security. For this reason, this study aims to contribute to a better understanding of integrating renewable energy into isolated networks, and in this case, using solar power for the An-Binh Island grid in Vietnam. The findings from this study suggest that choosing the right structure of the power mix could contribute to improving the operational security of isolated networks. Moreover, several solutions to enhance the reliability of this grid are also proposed. The NEPLAN environment was selected for simulation and analysis for all the scenarios in this study.
Study on Nonlinear Dielectric Properties of Micro Silica
Authors: Xue Yucui , Guo Wenmin , Sun Yunlong , Li Zhonghua , Han Yongsen , Jia Hongxu
Published: March 2023

Inorganic insulating powder can potentially be used in nuclear power plant cables, fire-resistant cables, and so on due to its high heat resistance and radiation resistance. It is of great academic and engineering value to study the dielectric properties of inorganic insulating powder. In this paper, we aim to study the nonlinear dielectric properties via the measurement of the time-domain polarization current spectrum under the application of a DC electric field. Three kinds of silica powders are measured by a measurement system with adjustable pressure. The effects of powder shape, particle size, and packing pressure and temperature on the dependence of relaxation polarization and electrical conductivity on the applied electric field are studied. The experimental results show that the relationship between electrical conductivity and the electric field of inorganic insulating powder presents two different characteristics, i.e., field-induced enhancement and field-induced weakening. The relationship between conductance and temperature shows an increase with temperature. That is, the electrical conductivity increases or decreases with the increase in temperature. The inorganic powder insulation can be regarded as a composite, which is composed of inorganic powder particles and air gaps. The interface between the powder particles and air gaps contributes a lot to the polarization of inorganic insulating powder. The phenomena (including the field-induced weakening characteristic between relaxation polarization and electric field and the decrease characteristic of polarization with increasing temperature) can be explained by a simplified interface polarization mechanism.
A Hyper-Integrated Mobility as a Service (MaaS) to Gamification and Carbon Market Enterprise Architecture Framework for Sustainable Environment
Authors: Ozpinar Alper
Published: March 2023

Various human activities emit greenhouse gasses (GHGs) that contribute to global climate change. These include the burning of fossil fuels for energy production, transportation, and industrial uses, and the clearing of forests to create farmland and pasture, all for urban and industrial development. As a result, temperatures around the world are rising, extreme weather events are occurring more frequently, and human health is suffering because of these changes. As a result of massive traffic, agriculture, and urbanization, the natural environment is being destroyed, negatively affecting humans and other living things. Humanity plans to live in smart cities within this ecosystem as the world evolves around these mutations. A smart city uses technology and data to improve the quality of life of its citizens and the efficiency of its urban systems. Smart cities have the potential to be more sustainable because they use technology and data to improve the efficiency of urban systems and reduce the negative impact of human activities on the environment. Smart cities can also use technology to improve green transportation and waste management and reduce water consumption, which can help conserve natural resources and protect the environment. Smart cities can create livable, efficient, and sustainable urban environments using technology and data. This paper presents a new Enterprise Architecture Framework for reducing carbon emissions for environmental sustainability that combines gamification and green behavior with blockchain architecture to ensure a system that is trustworthy, secure, and scalable for shareholders, citizens, service providers, and technology vendors. In order to achieve this, the hyper-integrated framework approach explains a roadmap for how sustainability for reducing carbon emissions from transportation is based on an optimized MaaS approach improved by gamification. As part of this study, a computational model and a formulation are proposed to calculate the activity exchange values in the MaaS ecosystem for swapping, changing, and bartering for assets within the integrated system. This paper aims to propose the framework and a module interoperability approach, so numerical values for computation parameters are not included as they may belong to other research studies. In spite of this, a case study section has been provided as an example of a calculation approach.
Thermal Performance of Slotted Light Steel-Framed Composite Wall
Authors: Yang Zhijian , Sun Lisuo , Nan Bo , Wei Shunli
Published: March 2023

In this study, calibrated hot box and finite element simulation methods were used to study the influence of a slotted web on the thermal performance of a lightweight steel stud composite wall. By comparing the results from the simulations and experiments, the accuracy of the finite element method was verified; this method was then used for parameter analyses. The results showed that the wall’s thermal transfer coefficient is inversely proportional to increases in the length of the slot and height of the stud web, leading to improvements in the thermal insulation effect; vice versa, the wall thermal transfer coefficient increases when the slot transverse spacing and stud thickness increase, and the insulation effect correspondingly worsens. The stud spacing influences the insulation performance of the wall by changing the proportion of studs within a certain wall. The greater the proportion of studs, the greater the stud thermal bridging, the faster the thermal loss, and the worse the insulation effect of the wall. In practice, the height of the stud web can be set as required. Preferably, for practical applications, the number of rows of slots is 5–7, the length of the slots is 70–80 mm, the transverse distance of the slots is 6–8 mm, the thickness of each stud is 1 or 1.2 mm, and the distance of each stud is 600 mm.
Hydrothermal Carbonization of Sewage Sludge into Solid Biofuel: Influences of Process Conditions on the Energetic Properties of Hydrochar
Authors: Roslan Siti Zaharah , Zainudin Siti Fairuz , Mohd Aris Alijah , Chin Khor Bee , Musa Mohibah , Mohamad Daud Ahmad Rafizan , Syed Hassan Syed Shatir A.
Published: March 2023

Hydrothermal carbonization (HTC) is an attractive, green technology for the management of sewage sludge. In this study, low-value secondary sewage sludge was subjected to an HTC treatment in a 1 L batch hydrothermal reactor and transformed into a high-energy-density hydrochar under varying HTC conditions (temperature of 150–300 °C, carbonization time of 30–150 min and a solid loading of 10–30%). The resulting hydrochar fuel characteristics were analyzed for ultimate and proximate analyses, functional group composition and energetic parameters. It was found that the hydrochar yield decreased with the increasing HTC temperature and reaction time, primarily due to the loss of organic volatile matter and functional groups. Under the optimum conditions of 150 °C, 30 min of carbonization time and 30% solid loading, 80.56% of the hydrochar was recovered, providing a maximum energy yield of 90.32% and a high heating value of 18.49 MJ/kg. Compared to the raw sewage sludge (H/C ratio of 2.67 and O/C ratio of 0.51), the hydrochar also had lower H/C and O/C atomic ratios of 1.42 and 0.18, respectively. The results suggest that significant dehydration and decarboxylation during the HTC treatment of sewage sludge have resulted in the formation of carbonaceous hydrochar with energetic properties close to the sub-bituminous coals.
Clustering Electrical Customers with Source Power and Aggregation Constraints: A Reliability-Based Approach in Power Distribution Systems
Authors: Gomes Thiago , Borniatti André , Garcia Vinícius , Santos Laura , Knak Neto Nelson , Garcia Rui
Published: March 2023

Reliability is an important issue in electricity distribution systems, with strict regulatory policies and investments needed to improve it. This paper presents a mixed integer linear programming (MILP) model for clustering electrical customers, maximizing system reliability and minimizing outage costs. However, the evaluation of reliability and its corresponding nonlinear function represent a significant challenge, making the use of mathematical programming models difficult. The proposed heuristic procedure overcomes this challenge by using a linear formulation of reliability indicators and incorporating them into the MILP model for clustering electrical customers. The model is mainly defined on a density-based heuristic that constrains the set of possible medians, thus dealing with the combinatorial complexity associated with the problem of empowered p-medians. The proposed model proved to be effective in improving the reliability of real electrical distribution systems and reducing compensation costs. Three substation cluster scenarios were explored, in which the total utility compensations were reduced by approximately USD 86,000 (1.80%), USD 67,400 (1.41%), and USD 64,000 (1.3%). The solutions suggest a direct relationship between the reduction in the compensation costs and the system reliability. In addition, the alternative modeling approach to the problem served to match the performance between the distribution system reliability indicators.
Algorithm for Fast Detection of Stator Turn Faultsin Variable-Speed Synchronous Generators
Authors: Rocha Rodolfo V. , Monaro Renato M.
Published: March 2023

Faults between stator winding turns of synchronous generators have led to specific changes in the harmonic content of currents. In this paper, these changes are used to detect faults in variable-speed synchronous generators connected to three-level converters during their operation. Currents typically measured for control purposes are used to avoid installation of additional sensors. The neutral point current of the three-level converter is also evaluated under faults in the generator. Encoder-tuned dynamic filters based on Park transformation and Fourier coefficients together with low-pass filters are used to detect the selected harmonics under variable speeds. The geometric loci of these components are proposed as a method to distinguish between healthy and faulty conditions. Simulation and experimental data are used to test sensitivity, selectivity and detection time of the proposed technique for different fault types. Generalization for a different generator is also presented and tested. Most fault cases were detected using the harmonics.
Multi-Scroll Attractor and Multi-Stable Dynamics of a Three-Dimensional Jerk System
Authors: Li Fudong , Zeng Jingru
Published: March 2023

A multi-scroll attractor reflects the structural diversity of the dynamic system, and multi-stability behavior reflects its state diversity. Multi-scroll and multi-stability chaotic systems can produce complex random sequences, which have important application values in the field of data security. However, current works on multi-scroll–multi-steady behavior have been carried out separately, rather than simultaneously. This paper considers a three-dimensional Jerk system with a sinusoidal nonlinear term. The basic dynamic behaviors, such as the stability of equilibrium points, bifurcation of parameters and initial values, phase diagrams, and basins of attraction, were analyzed. It was found that the system has infinite equilibrium points. Moreover, the system not only generates complex dynamics, such as single-scroll, double-scroll, and multi-scroll but also realizes the self-reproduction of these dynamic characteristics by controlling the initial value of the system. Therefore, by expanding the equilibrium point, the effective controls of the system’s structural diversity and state diversity are realized at the same time, having important theoretical significance and application value.
Effects of Pruning on Vegetation Growth and Soil Properties in Poplar Plantations
Authors: Huang Kaidong , Xu Cheng , Qian Zhuangzhuang , Zhang Kang , Tang Luozhong
Published: March 2023

Artificial pruning is an important silvicultural practice that can produce clear wood in poplar plantations. This study focused on the growth of poplar, understory vegetation diversity and soil properties in response to different pruning intensities in poplar plantations. We implemented three different pruning treatments based on the height-to-crown base (HCB) to tree height (H) ratio in Populus deltoides ‘Nanlin 3804′ plantations: CK (no pruning), a 1/3 pruning treatment and a 1/2 pruning treatment. The poplar growth conditions, understory vegetation biodiversity and soil properties were investigated for one year after pruning. Compared with CK, the 1/2 pruning treatment significantly decreased the increment of diameter at breast height (DBHi) and stem volume increment (Vi) by 16.4% and 12.8%, respectively. Meanwhile, pruning significantly promoted understory vegetation biomass and increased the Shannon–Weiner diversity index of understory vegetation, and these variables were positively correlated with pruning intensity. The 1/2 pruning treatment significantly reduced the contents of soil nitrate nitrogen (NO3-N), total inorganic nitrogen (IN) and microbial biomass nitrogen (MBN) by 21.9%, 13.9% and 22.4%, respectively. However, the 1/3 pruning treatment had no significant influence. Pruning mainlyaffectedthe soil enzyme activity in the surface (0–10 cm) layer. The 1/3 and 1/2 pruning treatments significantly decreased soil urease activity by 20.1% and 15.0%, respectively. Furthermore, nonmetric multidimensional scaling analysis showed that the seasonal variation in soil properties was significant, and significant differences among pruning treatments were mainly observed in July and October. Redundancy analysis showed that the growth of aboveground vegetation was significantly correlated with soil properties, particularly soil IN content and urease activity. Therefore, the results highlighted that pruning could promote the growth of understory vegetation and accelerate the transformation of soil nutrients. The 1/2 pruning treatment significantly inhibited the growth of poplar in terms of DBH and V, while the 1/3 pruning treatment promoted the growth of poplar in the short term. Overall, we think that the 1/3 pruning intensity is more suitable for pruning practice.