bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal Structure, Thermal Expansion and Luminescence of Ca10.5−xNix(VO4)7
Authors: Mosafer Houri S. Rahimi , Paszkowicz Wojciech , Minikayev Roman , Martin Christine , Kozłowski Mirosław , Chukova Oksana , Zhydachevskyy Yaroslav , Nedilko Serhii
Published: May 2023

The structural and luminescence properties of a new material, Ca10.5−xNix(VO4)7, formed by substitution of a fraction of calcium by nickel, are studied as a function of the Ni content (x). The powder X-ray diffraction results for the polycrystals, synthesized using a solid-state reaction method, show that in the studied temperature range (300–1150 K), the structure of the unsubstituted material (space group R3c, whitlockite-β-Ca3(PO4)2 structure type) is conserved up to the solubility limit, x = 0.72(2), determined on the basis of variation of unit cell size with x. The samples of nominal composition exceeding this limit contain a significant amount of the impurity phase.The structural refinements demonstrate that Ni atoms preferentially occupy the M5 site (one of the five independent Ca sites, M1–M5). The unit cell size was equally studied in the range of 300–1150 K, leading to the determination of the thermal expansion coefficients. It was found that with rising Ni content, the room temperature volumetric thermal expansion decreases from 41.80 MK−1 (x = 0.16) to 39.24 MK−1 (x = 0.66) and to 38.92 MK−1 at the solubility limit, this reduction being in line with earlier reported data for x=0. In the unit cell variation, around 800–900 K, a weak anomaly is observed, detectable most clearly for the axial ratio; it is also visible at thermal expansion coefficient temperature dependence. Substitution of Ca by Ni ions reduces the optical band gap of Ca10.5−xNix(VO4)7 from 3.56 (x = 0) to 3.29 and 3.16 eV observed for Ni-containing samples (x = 0.33 and 0.66, respectively). Observed bands in the absorption and photoluminescence spectra are assigned to electronic transitions in both VO43− groups and Ni2+ ions, confirming that Ni mainly occupies the M5 site. The band gap narrowing and decrease in photoluminescence intensity when the Ni concentration increases makes Ni-substituted compounds attractive for application, e.g., as photocatalysts.
Phase Field Modeling of Crack Growth with Viscoplasticity
Authors: Shi Qianyu , Yu Hongjun , Wang Xiangyuhan , Huang Kai , Han Jian
Published: May 2023

The fracture of viscoplastic materials is a complex process due to its time-dependent and plastic responses. Numerical simulation for fractures plays a significant role in crack prediction and failure analysis. In recent years, the phase field model has become a competitive approach to predict crack growth and has been extended to inelastic materials, such as elasto-plastic, viscoelastic and viscoplastic materials, etc. However, the contribution of inelastic energy to crack growth is seldom studied. For this reason, we implement the fracture phase field model coupled with a viscoplastic constitutive in a finite element framework, in which the elastic energy and inelastic energy are used as crack driving forces. The implicit algorithm for a viscoplastic constitutive is presented; this procedure is suitable for other viscoplastic constitutive relations. The strain rate effect, creep effect, stress relaxation effect and cyclic loading responses are tested using a single-element model with different inelastic energy contributions. A titanium alloy plate specimen and a stainless-steel plate specimen under tension are studied and compared with the experimental observations in the existing literature. The results show that the above typical damage phenomenon and fracture process can be well reproduced. The inelastic energy significantly accelerates the evolution of the phase field of viscoplastic materials. For cyclic loadings, the acceleration effect for low frequency is more significant than for high frequency. The influence of the weight factor of inelastic energy β on the force-displacement curve mainly occurs after reaching the maximum force point. With the increase of β, the force drops faster in the force-displacement curve. The inelastic energy has a slight effect on the crack growth paths.
Impact of Tuned Oxidation on the Surface Energy of Sintered Samples Produced from Atomised B-Doped Al-Cu-Fe Quasicrystalline Powders
Authors: Kušter Monika , Kovač Janez , Samardžija Zoran , Komelj Matej , Semsari Parapari Sorour , Podlogar Matejka , Dubois Jean-Marie , Šturm Sašo
Published: May 2023

Super-hydrophobic surfaces and coatings have stimulated a great deal of research, with the aim being to achieve better wetting properties. Factors such as surface chemistry and roughness play an important role in changing the surface energy, which in turn leads to changes in the wettability. Here, we have analysed the time dependence of the oxide layer and possible surface adsorbates on the surface topography of an Al59Cu25Fe13B3 quasicrystalline material in relation to changes in the wettability. The quasicrystalline matrix phase was 94% of the sample volume, and it was covered by a very smooth, amorphous oxide layer. The AlB12 and AlFe2B2 boron-rich phases were embedded in the quasicrystalline material as a result of the 3 at.% boron addition, which made atomisation of the material a simpler process. Under ambient conditions, the sample was naturally covered by an oxide layer; therefore, it is referred to as “surfenergy” to distinguish it from the conventional surface energy of a bare quasicrystal surface. The growth of the oxide layer with atmospheric ageing and annealing at 500 °C in air for various times was investigated for both cases. The phase most prone to oxidation was the boron-rich AlFe2B2, which influenced the topography of the surface and accordingly the wetting behaviour of the specimen. We demonstrated that the surfenergy depends on the polar component, which is the most sensitive to the operating conditions. A correlation between the surfenergy components and the surface roughness was found. In addition, theoretical models to determine the wettability were included.
Functional State and Rehabilitation of Patients after Primary Brain Tumor Surgery for Malignant and Nonmalignant Tumors: A Prospective Observational Study
Authors: Krajewski Stanisław , Furtak Jacek , Zawadka-Kunikowska Monika , Kachelski Michał , Soboń Jakub , Harat Marek
Published: May 2023

The aim of this study was to compare the pre- and postoperative function of patients qualifying for resection of malignant and nonmalignant primary brain tumors to determine the relationship among tumor type, function, and the course of rehabilitation after surgery. This single-center, prospective, observational study recruited 92 patients requiring prolonged postoperative rehabilitation during their inpatient stay, who were divided into a nonmalignant tumor group (n = 66) and a malignant tumor group (n = 26). Functional status and gait efficiency were assessed using a battery of instruments. Motor skills, postoperative complications, and length of hospital stay (LoS) were recorded and compared between groups. The frequency and severity of postoperative complications, the time needed to attain individual motor skills, and the proportion of patients losing independent gait (~30%) were similar between groups. However, paralysis and paresis were more frequent in the malignant tumor group before surgery (p < 0.001). While nonmalignant tumor patients deteriorated more according to all scales after surgery, patients with malignant tumors were still characterized by worse ADL, independence, and performance at discharge. Worse functional outcomes in the malignant tumor group did not affect LoS or rehabilitation. Patients with malignant and nonmalignant tumors have similar rehabilitation needs, and patient expectation—especially those with nonmalignant tumors—should be appropriately managed.
Multi-Institutional Patterns of Use of Tumor-Treating Fields for Patients with Malignant Pleural Mesothelioma
Authors: Kutuk Tugce , Walker Joshua M. , Ballo Matthew T. , Cameron Robert B. , Alvarez Jean Bustamante , Chawla Sheema , Luk Eric , Behl Deepti , Dal Pra Alan , Morganstein Neil , Refaat Tamer , Sheybani Arshin , Squillante Christian , Zhang Jun , Kotecha Rupesh
Published: May 2023

(1) Background: The objective of this analysis was to evaluate the device usage rates and patterns of use regarding Tumor-Treating Fields (TTFields) for patients with malignant pleural mesothelioma (MPM) throughout the US. (2) Methods: We evaluated de-identified data from 33 patients with MPM enrolled in FDA-required HDE protocols at 14 institutions across the US from September 2019 to March 2022. (3) Results: The median number of total TTFields usage days was 72 (range: 6–649 days), and the total treatment duration was 160 months for all patients. A low usage rate (defined as less than 6 h per day, 25%) was observed in 34 (21.2%) months. The median TTFields usage in the first 3 months was 12 h per day (range: 1.9–21.6 h), representing 50% (range: 8–90%) of the potential daily duration. The median TTFields usage after 3 months decreased to 9.1 h per day (range: 3.1–17 h), representing 38% (range: 13–71%) of the daily duration, and was lower than usage in the first 3 months (p = 0.01). (4) Conclusions: This study represents the first multicenter analysis of real-world TTFields usage based on usage patterns for MPM patients in clinical practice. The real-world usage level was lower than the suggested daily usage. Further initiatives and guidelines should be developed to evaluate the impact of this finding on tumor control.
Young Myeloma Patients: A Systematic Review of Manifestations and Outcomes
Authors: Tanguay Mégane , Dagenais Christophe , LeBlanc Richard , Ahmad Imran , Claveau Jean-Sébastien , Roy Jean
Published: May 2023

Multiple myeloma usually affects older adults. However, younger patients constitute a significant subset as approximately 10% of cases occur in subjects younger than 50 years old. Young patients, who are underrepresented in the literature, are diagnosed during their most productive years of life, urging the need for tailored treatment approaches. This literature review aims to report recent studies specifically addressing young patients with a focus on characteristics at diagnosis, cytogenetics, treatments, and outcomes. We searched PubMed for studies involving young patients with multiple myeloma ≤50 years old. The time span of our literature review search was from 1 January 2010 to 31 December 2022. Overall, 16 retrospective studies were analyzed for this review. Young patients with multiple myeloma tend to have less advanced disease, more frequent light chain subtypes, and survive longer compared to their older counterparts. However, available studies included a limited number of patients; the newest revised international staging system was not used to stratify patients, cytogenetics varied from one cohort to another, and most patients did not receive contemporary triplet/quadruplet treatments. This review emphasizes the need to perform contemporary, large-scale retrospective studies to improve knowledge regarding the presentation and outcomes of young myeloma patients in the era of modern treatments.
The Mosquitoes of Querétaro, Mexico: Distribution, Ecology, and Discovery of Shannoniana huasteca n. sp. (Diptera: Culicidae)
Authors: Ortega-Morales Aldo I. , Hernández-Triana Luis M. , Siller-Rodríguez Quetzaly K.
Published: May 2023

In order to document the diversity and distribution of mosquitoes inhabiting the Querétaro State of México, collection trips were conducted in all physiographic regions and sub-regions of the state (Sierra Madre Oriental, Central Plateau, and Neo-Volcanic Axis). In addition, mosquito specimens collected in Querétaro and deposited in the Collection of Arthropods of Medical Importance (CAIM) were re-examined. A total of 2718 specimens (570 larvae, 384 larval exuviae, 537 pupal exuviae, 30 pupae, 807 females, 368 males, and 22 male genitalia) were analyzed. In total, 2 subfamilies, namely Anophelinae and Culicinae, 5 tribes, 12 genera, 20 subgenera, and 50 species were found. Of these, 3 tribes, 8 genera, 11 subgenera, and 33 species are new records for the mosquito fauna of Querétaro. Two undescribed species were found, and one of them, Shannoniana huasteca Ortega n. sp., is described here using morphology and Cytochrome oxidase subunit 1 (COI) DNA barcoding. Taxonomic notes, new distribution limits, comments about the medical importance of species, and a key to identify adult females of Shannoniana species are provided.
Evaluation of the Influence of Habitat Heterogeneity and Human Activities on the Distribution of Microbial Diversity in a High Elevation Drop River
Authors: Qin Haiming , Jia Xinyue , Wang Lu , Wang Ziyue , Chen Xinlei , Wang Yaowei , Sun Minfang , Qi Qin , Yang Yuewei
Published: May 2023

The aim of this work was to investigate the microbial diversity characteristics and driving factors in a high elevation drop river and to analyze the potential risks of river microorganisms to human health. In March 2019, we analyzed the microbial diversity characteristics in surface water and sludge from the Huotong River using high-throughput sequencing. The Huotong River is of great importance to the production and life of the people living along this river. The sampling points were set at the estuary of the river, on a downstream section of the river, on an upstream section of the main river, at one tributary flowing through a town, at one tributary with a barrage, and at the source of one tributary. The results showed significant differences in bacterial diversity in different areas of the river. For example, actinomycetes were less abundant in water samples from the headwaters of tributaries and more abundant upriver. The results revealed that different intensities of human activities had significant different effects on functional flora. Anthropogenic disturbance and human activities reduced the abundance of probiotic bacteria and increased the abundance of pathogenic bacteria in the river. The changes in functional floral diversity may pose potential threats to human health.
Lobster Position Estimation Using YOLOv7 for Potential Guidance of FANUC Robotic Arm in American Lobster Processing
Authors: Chelouati Nawal , Bouslimani Yassine , Ghribi Mohsen
Published: May 2023

The American lobster (Homarus americanus) is the most valuable seafood on Canada’s Atlantic coast, generating over CAD 800 million in export revenue alone for New Brunswick. However, labor shortages plague the lobster industry, and lobsters must be processed quickly to maintain food safety and quality assurance standards. This paper proposes a lobster estimation orientation approach using a convolutional neural network model, with the aim of guiding the FANUC LR Mate 200 iD robotic arm for lobster manipulation. To validate this technique, four state-of-the-art object detection algorithms were evaluated on an American lobster images dataset: YOLOv7, YOLOv7-tiny, YOLOV4, and YOLOv3. In comparison to other versions, YOLOv7 demonstrated a superior performance with an F1-score of 95.2%, a mean average precision (mAP) of 95.3%, a recall rate of 95.1%, and 111 frames per second (fps). Object detection models were deployed on the NVIDIA Jetson Xavier NX, with YOLOv7-tiny achieving the highest fps rate of 25.6 on this platform. Due to its outstanding performance, YOLOv7 was selected for developing lobster orientation estimation. This approach has the potential to improve efficiency in lobster processing and address the challenges faced by the industry, including labor shortages and compliance with food safety and quality standards.
Orthogonal Polynomials with Singularly Perturbed Freud Weights
Authors: Min Chao , Wang Liwei
Published: May 2023

In this paper, we are concerned with polynomials that are orthogonal with respect to the singularly perturbed Freud weight functions. By using Chen and Ismail’s ladder operator approach, we derive the difference equations and differential-difference equations satisfied by the recurrence coefficients. We also obtain the differential-difference equations and the second-order differential equations for the orthogonal polynomials, with the coefficients all expressed in terms of the recurrence coefficients.
Attitude Synchronization of a Group of Rigid Bodies Using Exponential Coordinates
Authors: Sidón-Ayala Miguel , Pliego-Jiménez Javier , Cruz-Hernandez César
Published: May 2023

Currently, managing a group of satellites or robot manipulators requires coordinating their motion and work in a cooperative way to complete complex tasks. The attitude motion coordination and synchronization problems are challenging since attitude motion evolves in non-Euclidean spaces. Moreover, the equation of motions of the rigid body are highly nonlinear. This paper studies the attitude synchronization problem of a group of fully actuated rigid bodies over a directed communication topology. To design the synchronization control law, we exploit the cascade structure of the rigid body’s kinematic and dynamic models. First, we propose a kinematic control law that induces attitude synchronization. As a second step, an angular velocity-tracking control law is designed for the dynamic subsystem. We use the exponential coordinates of rotation to describe the body’s attitude. Such coordinates are a natural and minimal parametrization of rotation matrices which almost describe every rotation on the Special Orthogonal group SO(3). We provide simulation results to show the performance of the proposed synchronization controller.
Multiscale Attention Fusion for Depth Map Super-Resolution Generative Adversarial Networks
Authors: Xu Dan , Fan Xiaopeng , Gao Wen
Published: May 2023

Color images have long been used as an important supplementary information to guide the super-resolution of depth maps. However, how to quantitatively measure the guiding effect of color images on depth maps has always been a neglected issue. To solve this problem, inspired by the recent excellent results achieved in color image super-resolution by generative adversarial networks, we propose a depth map super-resolution framework with generative adversarial networks using multiscale attention fusion. Fusion of the color features and depth features at the same scale under the hierarchical fusion attention module effectively measure the guiding effect of the color image on the depth map. The fusion of joint color–depth features at different scales balances the impact of different scale features on the super-resolution of the depth map. The loss function of a generator composed of content loss, adversarial loss, and edge loss helps restore clearer edges of the depth map. Experimental results on different types of benchmark depth map datasets show that the proposed multiscale attention fusion based depth map super-resolution framework has significant subjective and objective improvements over the latest algorithms, verifying the validity and generalization ability of the model.
Investigating the Drying Process of Ceramic Sanitary Ware at Low Temperature
Authors: Gomez Ricardo S. , Gomes Kelly C. , Gurgel José M. A. M. , Alves Laís B. , Magalhães Hortência L. F. , Queiroga Raíssa A. , Sousa Gustavo C. P. , Oliveira Aline S. , Vilela Anderson F. , Silva Bruna T. A. , Vasconcelos Danielle B. T. , Brito Glauco R. F. , Lima Antonio G. B.
Published: May 2023

Drying is one of the stages with the highest energy consumption in the manufacturing process of ceramic materials and aims to reduce the product’s moisture to levels necessary for safe firing stage, reducing the chances of defect formation. For sanitary ware, there is an additional energy cost in the pre-drying stage, which takes place immediately after removing the parts from the molds, and is carried out in an environment with lower temperatures (ranging from 30 to 40 °C). This work aims to experimentally study the drying process of sanitary ware at low temperatures, with particular reference to sanitary toilets with industrial dimensions. Four drying experiments were carried out in an oven with different operating conditions (temperature and relative humidity). The results indicate that an increase in temperature and reduction in relative humidity provoke a faster drying rate. For some physical situations, it is more interesting to dedicate efforts to reducing the relative humidity of the drying air instead of seeking solutions to raise its temperature. Furthermore, a correlation between the linear retraction and moisture content was observed; the greater the moisture loss, the greater the sample shrinkage.
Joint Prediction of the State of Charge and the State of Health of Lithium-Ion Batteries Based on the PSO-XGBoost Algorithm
Authors: An Jiakun , Guo Wei , Lv Tingyan , Zhao Ziheng , He Chunguang , Zhao Hongshan
Published: May 2023

Lithium-ion batteries are widely used in power grids as a common form of energy storage in power stations. The state of charge (SOC) and state of health (SOH) reflect the capacity and lifetime variation in the Li-ion batteries, and they are important state parameters of Li-ion batteries. Therefore, the establishment of accurate SOC and SOH prediction models is an essential prerequisite for the correct assessment of the status of lithium batteries, the improvement of the operational accuracy of energy-storage stations, and the development of maintenance plans for energy-storage stations. This paper first analyzes the correlation between SOC and SOH, and then proposes a joint SOC and SOH prediction model using the particle swarm optimization (PSO) algorithm to optimize the extreme gradient boosting algorithm (XGBoost), which takes into account the dynamic correlation between SOC and SOH dynamics, thus enabling more accurate SOC and SOH prediction. Finally, the prediction model is validated using the Oxford battery aging dataset. The correlation between SOC and SOH is verified by comparing the joint prediction results with the SOC individual prediction results. Then, the prediction results of the PSO-XGBoost model, the traditional XGBoost model, and the long short-term memory neural network are compared to verify the effectiveness and accuracy of the PSO-XGBoost model.
A CRITIC–TOPSIS Multi-Criteria Decision-Making Approach for Optimum Site Selection for Solar PV Farm
Authors: Hassan Imad , Alhamrouni Ibrahim , Azhan Nurul Hanis
Published: May 2023

This research work proposes a new hybrid framework to assess suitable sites and technical potentials for large-scale solar photovoltaic (PV) systems by integrating two multi-criteria decision-making (MCDM) techniques. The evaluation of sites for PV plants was performed using the MCDM method, taking into account a wide range of variables, including climate, technical, geographical, and economic variables, with factor weights determined using the CRITIC technique. Five Saudi Arabian cities with abundant solar radiation served as illustrations of this study’s framework. For classification, the TOPSIS method was employed to rank the five alternatives. The results show that Riyadh is ranked first with a performance score of 72%, followed by Jeddah with a performance score of 65%, and the remaining three cities, namely, Al Ahsa, Dammam, and Abha scored less than 50%. Lastly, the reliability and robustness of the results obtained were examined using sensitivity analysis. The findings of this study can be used to pinpoint possible places that could be used to build solar power plants and to promote the expansion of generating facilities and electrical grids.
The Role of Internet of Things on Electric Vehicle Charging Infrastructure and Consumer Experience
Authors: Emodi Nnaemeka V. , Akuru Udochukwu B. , Dioha Michael O. , Adoba Patrick , Kuhudzai Remeredzai J. , Bamisile Olusola
Published: May 2023

The drive for net-zero emission and global decarbonization spurred the need for a worldwide transition towards cleaner energy options. The fossil-fuel-dominated global transportation system is a target for these initiatives, accounting for 37% of recent carbon emissions. This has accelerated the adoption of electric vehicles (EVs) into the global market to cut down carbon emissions and improve efficiency in the transportation sector. In the face of this growth, limitations in EV charging infrastructure still loom large amongst EV consumers. Resolving this bottleneck requires systematic approaches to ensure seamless operation and integration into the existing transport systems. This study examines the critical role of IoT in addressing the challenges of EV public charging through reviewing the literature to understand the inter-relation and highlighting its attendant impact on consumer experience. Findings show that while IoT serves as a strong tool to foster public interest through favorable public policy, its novel and innovative nature faces developmental challenges based on existing government policies that could hinder the interest of potential investors. Therefore, governments should consider evaluating existing policies and practices to ascertain their suitability for IoT adoption in EVs, ensuring that they do not constitute unintentional barriers.
Modeling Thermal Radiation in Combustion Environments: Progress and Challenges
Authors: Mazumder Sandip , Roy Somesh P.
Published: May 2023

Modeling thermal radiation in combustion environments can be extremely challenging for two main reasons. First, the radiative transfer equation (RTE), which is the cornerstone of modeling radiation in such environments, is a five-dimensional integro-differential equation. Second, the absorption and scattering coefficients of molecular gases and particulates prevalent in combustion environments oscillate strongly with the wavenumber (or wavelength), i.e., the medium is strongly nongray, requiring the solution of the RTE for a large number of wavenumbers. This article reviews the progress that has been made in this area to date with an emphasis on the work performed over the past three decades. Progress in both deterministic and stochastic (Monte Carlo) solutions of the RTE is reviewed, in addition to the review of the treatment of the spectral properties of gases, soot, and fuel droplets that dominate combustion environments, i.e., spectral or nongray models. The application of the various state-of-the-art nongray models and RTE solution methods to flames (particularly turbulent), fires, combustors, and other combustion systems are summarized along with a critical discussion of the pros and cons of the models and methods. Finally, the challenges that remain in modeling thermal radiation in combustion systems are highlighted and future outlooks are shared.
Optimization of PI Controller Parameters by GWO Algorithm for Five-Phase Asynchronous Motor
Authors: Fodil Malika , Djerioui Ali , Ladjal Mohamed , Saim Abdelhakim , Berrabah Fouad , Mekki Hemza , Zeghlache Samir , Houari Azeddine , Benkhoris Mohamed Fouad
Published: May 2023

Operation at low speed and high torque can lead to the generation of strong ripples in the speed, which can deteriorate the system. To reduce the speed oscillations when operating a five-phase asynchronous motor at low speed, in this article, we propose a control method based on Gray Wolf optimization (GWO) algorithms to adjust the parameters of proportional–integral (PI) controllers. Proportional–integral controllers are commonly used in control systems to regulate the speed and current of a motor. The controller parameters, such as the integral gain and proportional gain, can be adjusted to improve the control performance. Specifically, reducing the integral gain can help reduce the oscillations at low speeds. The proportional–integral controller is insensitive to parametric variations; however, when we employ a GWO optimization strategy based on PI controller parameters, and when we choose gains wisely, the system becomes more reliable. The obtained results show that the hybrid control of the five-phase induction motor (IM) offers high performance in the permanent and transient states. In addition, with this proposed strategy controller, disturbances do not affect motor performance.
A Comparative Review of Capacity Measurement in Energy Storage Devices
Authors: Townsend Ashleigh , Gouws Rupert
Published: May 2023

Energy storage devices are fast becoming a necessity when considering a renewable energy harvesting system. This improves the intermittency of the source as well as significantly increasing the harvesting capacity of the system. However, most energy storage devices have a large limitation with regards to their usable life—this aspect is especially relevant to batteries. The degradation of batteries (and energy storage devices) plays a large role in determining their feasibility and the degradation is determined through capacity estimations—due to the inability/difficulty of directly measuring instantaneous capacity. This article aims to research the various methods used to estimate the capacity as well as the applications of these measurements aimed at reducing the degradation of the energy storage device. Through this research, the advantages and disadvantages of the measurements and their applications will be revealed, which will then highlight an area in which these estimations or their applications can be improved. The novelty of this paper lies in the graphical representation of the capacity measurement techniques, and how they relate to each other, as well as the relations and differences between their applications, highlighting the limitations in how the measurements are used.
Coordinated Control Design for Ethical Maneuvering of Autonomous Vehicles
Authors: Németh Balázs
Published: May 2023

This paper proposes a coordinated control design method, with which the autonomous vehicle is able to perform ethical maneuvers. The starting point of the provided method is a thorough analysis on the ethical concepts for autonomous vehicle control design methods. Using the results of the analysis, an own concept is provided based on some principles of Protestant ethics. The concept focuses on improving trust in vehicle control through clear rules and predictable vehicle motion, and it is in line with the state-of-the-art ethical vehicle control methods. Moreover, an optimal Model Predictive Control (MPC) design method is formed, in which the provided ethical concept is incorporated. The outputs of the optimal control are steering angle and velocity profile, with which the ethical maneuvering can be achieved. The contribution of the paper is a coordinated control design method, which is able to involve ethical principles. Moreover, the application of Protestant ethics in this context is also a novel achievement in the paper. The effectiveness of the method through different simulation scenarios is illustrated.
Study on CO2 Huff-n-Puff Development Rule of Horizontal Wells in Heavy Oil Reservoir by Taking Liuguanzhuang Oilfield in Dagang as an Example
Authors: Xu Zhenhua , Zhou Lianwu , Ma Shuiping , Qin Jianxun , Huang Xiaodi , Han Bo , Yang Longqing , Luo Yun , Liu Pengcheng
Published: May 2023

Heavy oil reservoirs are often characterized by high viscosity and poor mobility, which is more complex with the presence of bottom water. The conventional vertical well development method has low oil recovery efficiency and limited controlled reserves of a single well. In addition, water cut can increase dramatically when the edge-bottom water breaks through. Horizontal well and CO2 huff-n-puff is an effective alternative development model for heavy oil reservoirs. This development method makes efficient use of CO2 and accords with the “Carbon Capture, Utilization, and Storage (CCUS)”. The horizontal well can increase the drainage area. The dissolution of CO2 improves the mobility of crude oil and increases formation energy. In this paper, we established numerical simulation models based on the Liuguanzhuang oilfield in Dagang. The characteristics and producing rules of the horizontal well and CO2 huff-n-puff development in the heavy oil reservoir were studied. The results show that the production characteristics of horizontal well and CO2 huff-n-puff were similar to Steam-Assisted Gravity Drainage (SAGD). CO2 forms a viscosity reduction area above the horizontal well and the heavy oil flows into the wellbore due to gravity after viscosity reduction. The CO2 huff-n-puff can effectively enhance the production area of horizontal wells compared with the depletion development. However, the improvement in the production area gradually decreased as CO2 huff-n-puff cycles continued. There was a boundary of production area against the horizontal well, with the main production of heavy oil occurring at the upper and either end of the horizontal well. The CO2 huff-n-puff has a restraining effect on the edge-bottom water, which is confirmed via the proposed theoretical model.
Radiation Effect on Heat Transfer in Narrow Cavities
Authors: Zhou Wen-He , Sun Lei , Li Si-Si , Wu Jian-Yun
Published: May 2023

The thermal comfort and air-conditioning energy consumption of vehicles or trains are dependent on the thermal resistance of its envelopes, which could be enhanced by improving the radiation characteristics of the narrow cavities scattered in their envelopes. However, the study for a feasible method and its effectiveness has been given little attention. This paper introduces a method that involves pasting aluminum foil on the inner wall to change the radiation characteristics of the narrow cavity and analyzed its effects on narrow-cavity heat transfer by experimental and numerical methods. The results indicate that the radiation effect on heat transfer in a narrow cavity made of conventional material is dominant, with a rate larger than 75%, and that pasting aluminum foil is an effective and feasible method of weakening the radiation rate in narrow-cavity heat transfer, decreasing it to less than 10%. This paper will provide a reference to improve the insulation characteristics of vehicle enclosure.
CCUS: The Road to Net-Zero
Authors: Suleman Humbul , Nasir Rizwan
Published: May 2023

As the world continues to grapple with the pressing issue of climate change, the development and implementation of carbon capture, utilisation, and storage (CCUS) technologies are becoming increasingly important [...]
Roadmap to a Sustainable Energy System: Is Uncertainty a Major Barrier to Investments for Building Energy Retrofit Projects in Wide City Compartments?
Authors: Gabrielli Laura , Ruggeri Aurora Greta , Scarpa Massimiliano
Published: May 2023

Along the roadmap to a Sustainable Real Estate-Scape, energy retrofit campaigns on wide city compartments represent a pivotal task, where the importance of the collaboration between the public and private sectors is crucial. Energy retrofit programs on building assets are subject to multiple uncertainty factors (e.g., climate, energy-economy forecasts, etc.) that act as a primary barrier to investment in this field. This paper aims to discuss risk management techniques to understand better how to deal with this kind of uncertainty. The research specifically addresses the techniques of sensitivity analysis and Monte Carlo simulation, focusing first on the phase of variables selection and their probability definition, including climatic, environmental, energy, economic, financial, and stochastic parameters. In this article, it is suggested to include correlation coefficients in the input variables of risk analysis, preferring the two-dimension Monte Carlo simulation to its simple version, since the results are more reliable when separating aleatory from epistemic uncertainty; thus, the results are more reliable. Moreover, it is seen how a sensitivity analysis based on percentile variations of the inputs provides a more accurate representation of risk if compared to the most common sensitivity analysis based on percentage deviations of the inputs. Conducting a sensitivity analysis using percentile variations gives realistic and reliable results, reflecting the tailored definition of uncertainty around the inputs on the basis of specific market analyses or historical series.
Integrated Fault Detection, Classification and Section Identification (I-FDCSI) Method for Real Distribution Networks Using μPMUs
Authors: Medattil Ibrahim Abdul Haleem , Sharma Madhu , Subramaniam Rajkumar Vetrivel
Published: May 2023

This paper presents a rules-based integrated fault detection, classification and section identification (I-FDCSI) method for real distribution networks (DN) using micro-phasor measurement units (μPMUs). The proposed method utilizes the high-resolution synchronized realistic measurements from the strategically installed μPMUs to detect and classify different types of faults and identify the faulty section of the distribution network. The I-FDCSI method is based on a set of rules developed using expert knowledge and statistical analysis of the generated realistic measurements. The algorithms mainly use line currents per phase reported by the different μPMUs to calculate the minimum and maximum short circuit current ratios. The algorithms were then fine-tuned with all the possible types and classes of fault simulations at all possible sections of the network with different fault parameter values. The proposed I-FDCSI method addresses the inherent challenges of DN by leveraging the high-precision measurements provided by μPMUs to accurately detect, classify, and sectionalise faults. To ensure the applicability of the developed IFDCSI method, it is further tested and validated with all the possible real-time events on a real distribution network and its performance has been compared with the conventional fault detection, classification and section identification methods. The results demonstrate that the I-FDCSI method has a higher accuracy and faster response time compared to the conventional methods and facilitates faster service restoration, thus improving the reliability and resiliency indices of DN.
Enhancing Urban Heating Systems Planning through Spatially Explicit Participatory Modeling
Authors: Yu Hyunkyo , Ahlgren Erik O.
Published: May 2023

Effective planning of urban heating systems is crucial for achieving net-zero emissions at the city level. In particular, the spatial dimension plays a pivotal role in shaping the design and operation of these systems. Nonetheless, the integration of urban spatial and energy planning is rarely performed. To address this deficit, the current study proposes a participatory modeling methodology that explicitly incorporates the spatial dimension to facilitate integration and decision-making in the planning of urban heating systems. The methodology is applied to a case municipality to evaluate its benefits and implications for stakeholders involved in urban heat planning. The results reveal that the participatory nature of the methodology enhances the legitimacy, transparency, and relevance of the modeling process by engaging urban stakeholders, so as to exploit their valuable knowledge, experience, and understanding of the local context and related challenges. The developed methodology provides a spatial representation of district heating expansion, heating technology transition at the district-building level, and the installed capacities in each district, thereby improving the coherence of urban heat planning integrated with other urban plans. Consequently, the incorporation of the spatial dimension adds a nuanced layer of modeling outcomes to standard city level optimization models.
Natural Gas Demand Forecasting Model Based on LASSO and Polynomial Models and Its Application: A Case Study of China
Authors: Liu Huanying , Liu Yulin , Wang Changhao , Song Yanling , Jiang Wei , Li Cuicui , Zhang Shouxin , Hong Bingyuan
Published: May 2023

China aims to reduce carbon dioxide emissions and achieve peak carbon and carbon neutrality goals. Natural gas, as a high-quality fossil fuel energy, is an important transition resource for China in the process of carbon reduction, so it is necessary to predict China’s natural gas demand. In this paper, a novel natural gas demand combination forecasting model is constructed to accurately predict the future natural gas demand. The Lasso model and the polynomial model are used to build a combinatorial model, which overcomes the shortcomings of traditional models, which have low data dimensions and poor prediction abilities. In the modeling process, the cross-validation method is used to adjust the modeling parameters. By comparing the performance of the combinatorial forecasting model, the single forecasting model and other commonly used forecasting models, the results show that the error (2.99%) of the combinatorial forecasting model is the smallest, which verifies the high accuracy and good stability advantages of the combinatorial forecasting model. Finally, the paper analyzes the relevant data from 1999 to 2022 and predicts China’s natural gas demand in the next 10 years. The results show that the annual growth rate of China’s natural gas demand in the next 10 years will reach 13.33%, at 8.3 × 1011 m3 in 2033, which proves that China urgently needs to rapidly develop the gas supply capacity of gas supply enterprises. This study integrates the impact of multiple factors on the natural gas demand, predicts China’s natural gas demand from 2023 to 2033, and provides decision-making support for China’s energy structure adjustment and natural gas import trade.
Development and Control of a Switched Capacitor Multilevel Inverter
Authors: Mustafa Safwan , Sarwar Adil , Tariq Mohd , Ahmad Shafiq , Mahmoud Haitham A.
Published: May 2023

This article offers a novel boost inverter construction with a Nine-level quadruple voltage boosting waveform. The primary drawback of conventional MLI is the need for a high voltage DC-DC converter to increase the voltage when using renewable energy sources. Consequently, the developed method, complete with a quadruple voltage boost ability, can alleviate that shortcoming by automatically increased the incoming voltage. A single DC source, two switching capacitors, and eleven switches are all that are used in the newly presented architecture. The voltage of the capacitor automatically balances. The switched capacitor MLI is distinguished by the fewer parts that are required and the substitution of a capacitor for a DC source. The switching capacitor has to be charged and discharged properly in order to produce the nine-level output voltage waveform. The SPSC unit makes these levels attainable. To achieve voltage boosting, switched capacitors are coupled in parallel and series in the conduction channel. The quality of this proposed topology has been analyzed through different parameters based on the components count, THD, and cost; the resulting efficiency reaches 97.85%. The switching order of the proposed method has been controlled by the Nearest Level Modulation Method (NLC). MATLAB and PLECS software were used to evaluate the constructed Nine-level converter.
CFD Prediction of a Double Impulse Burner for Glass Furnaces
Authors: Cravero Carlo , Lamberti Alessandro , Poggio Luca
Published: May 2023

Recently, growing environmental awareness has radically changed the way the problems and priorities of industry are dealt with. Energy issues have become an issue of primary importance, both in terms of consumption and polluting emissions. However, for the green transition to happen, the first step is to have a deeper knowledge of the phenomena involved in processes with a special focus on combustion. The glass industry is one of the most energy-intensive since a temperature of over 1400 °C is required to keep glass molten, with a large consumption of natural gas used for combustion. A fundamental element to control the process is the burner. In this study, the CFD (Computational Fluid Dynamics) prediction of the internal streams repartition and the velocity profile at the exit, at different geometrical setups and operating conditions, of an industrial burner for glass furnaces is presented, with the aim of developing a surrogate model to provide these two important quantities quickly. The study of the repartition of the mass flow inside a double impulse burner and the subsequential velocity profile outside the burner is a novelty in the glass industry. The CFD prediction of the operating conditions is a crucial aspect because it is an essential boundary condition for the simulation of the reactive process from the diffusive flame found in glass furnaces. Different operating and geometrical conditions of the burner have been tested using Ansys CFX code, and results (velocity profile and mass flow repartition) have been organized in surrogate models. Results showed that the repartition of the fuel streams is mainly influenced by the position of the barrel, while the total flow rate is strongly influenced by the total inlet pressure. The internal flow varies from 20% to 50% of the total mass flow inside the burner, while the velocity magnitude outside the burner varies from 80 to 300 m/s approximately. The reconstruction of velocity profiles at the exit of the burners with surrogate models showed an acceptable match with numerical simulations.
Biomass Estimation of Urban Forests Using LiDAR and High-Resolution Aerial Imagery in Athens–Clarke County, GA
Authors: Henn Katrina Ariel , Peduzzi Alicia
Published: May 2023

The benefits and services of urban forests are becoming increasingly well documented, with carbon storage being the main focus of attention. Recent efforts in urban remote sensing have incorporated additional data such as LiDAR data but have been limited to sections of an urban area or only certain species. Existing models are not generalizable to remaining unmeasured urban trees. To make a generalizable individual urban tree model, we used metrics from NAIP aerial imagery and NOAA and USGS LiDAR data for 2013 and 2019, and two crown-level urban tree biomass models were developed. We ran a LASSO regression, which selected the best variables for the biomass model, followed by a 10-fold cross-validation. The 2013 model had an adjusted R2 value of 0.85 and an RMSE of 1797 kg, whereas the 2019 model had an adjusted R2 value of 0.87 and an RMSE of 1444 kg. The 2019 model was then applied to the rest of the unsampled trees to estimate the total biomass and total carbon stored for all the trees in the county. Recommendations include changes to ground inventory techniques to adapt to the current methods and limitations of remote sensing biomass estimation.
The Use of Black Pine Bark for Improving the Properties of Wood Pellets
Authors: Lykidis Charalampos , Kamperidou Vasiliki , Mantanis George I.
Published: May 2023

The requirement for alternative raw materials for fuel pellets that would enable the use of readily available low-cost renewable resources and waste materials, such as bark, has always attracted interest. The aim of the current work was to assess the effect of black pine (Pinus nigra L.) bark content (0%–100%) as well as densification temperature on the properties of black pine wood pellets produced in a single pellet die. The quality assessment of the pellets was carried out by the determination of radial compression strength, density, moisture content, ash content, and surface roughness. The results showed that adding black pine bark to the pellet feedstock resulted in the production of substantially smoother and moderately denser pellets, which also exhibited higher mechanical strength than that of the respective pellets of pure wood. Finally, it was shown that black pine bark can be a valuable raw material, which can induce improved bonding of biomass particles and may provide the opportunity to create pellets of favorable characteristics at a lower temperature compared to those made of pure wood.