bluuebunny/crossref_metadata_2025 huggingface dataset:
Autophagy and Breast Cancer: Connected in Growth, Progression, and Therapy
Authors: Wu Qitong , Sharma Dipali
Published: April 2023

Despite an increase in the incidence of breast cancer worldwide, overall prognosis has been consistently improving owing to the development of multiple targeted therapies and novel combination regimens including endocrine therapies, aromatase inhibitors, Her2-targeted therapies, and cdk4/6 inhibitors. Immunotherapy is also being actively examined for some breast cancer subtypes. This overall positive outlook is marred by the development of resistance or reduced efficacy of the drug combinations, but the underlying mechanisms are somewhat unclear. It is interesting to note that cancer cells quickly adapt and evade most therapies by activating autophagy, a catabolic process designed to recycle damaged cellular components and provide energy. In this review, we discuss the role of autophagy and autophagy-associated proteins in breast cancer growth, drug sensitivity, tumor dormancy, stemness, and recurrence. We further explore how autophagy intersects and reduces the efficacy of endocrine therapies, targeted therapies, radiotherapy, chemotherapies as well as immunotherapy via modulating various intermediate proteins, miRs, and lncRNAs. Lastly, the potential application of autophagy inhibitors and bioactive molecules to improve the anticancer effects of drugs by circumventing the cytoprotective autophagy is discussed.
Epigenetic Mechanisms of Aging and Aging-Associated Diseases
Authors: la Torre Annamaria , Lo Vecchio Filomena , Greco Antonio
Published: April 2023

Aging is an inevitable outcome of life, characterized by a progressive decline in tissue and organ function. At a molecular level, it is marked by the gradual alterations of biomolecules. Indeed, important changes are observed on the DNA, as well as at a protein level, that are influenced by both genetic and environmental parameters. These molecular changes directly contribute to the development or progression of several human pathologies, including cancer, diabetes, osteoporosis, neurodegenerative disorders and others aging-related diseases. Additionally, they increase the risk of mortality. Therefore, deciphering the hallmarks of aging represents a possibility for identifying potential druggable targets to attenuate the aging process, and then the age-related comorbidities. Given the link between aging, genetic, and epigenetic alterations, and given the reversible nature of epigenetic mechanisms, the precisely understanding of these factors may provide a potential therapeutic approach for age-related decline and disease. In this review, we center on epigenetic regulatory mechanisms and their aging-associated changes, highlighting their inferences in age-associated diseases.
Hydrogen Evolution upon Ammonia Borane Solvolysis: Comparison between the Hydrolysis and Methanolysis Reactions
Authors: Kang Naixin , Wang Changlong , Astruc Didier
Published: April 2023

Hydrogen (H2) production is a key challenge for green carbon-free sustainable energy. Among the H2 evolution methods from H-rich materials, ammonia borane (AB) solvolysis stands as a privileged source under ambient and sub-ambient conditions given its stability, non-toxicity, and solubility in protic solvents, provided suitable and optimized nanocatalysts are used. In this paper dedicated to Prof. Avelino Corma, we comparatively review AB hydrolysis and alcoholysis (mostly methanolysis) in terms of nanocatalyst performances and discuss the advantages and inconveniences of these two AB solvolysis methods including AB regeneration.
Genetic Mapping and QTL Analysis of Fruit Traits in Melon (Cucumis melo L.)
Authors: Zhao Haiyong , Zhang Taifeng , Meng Xiaobing , Song Jiayan , Zhang Chen , Gao Peng
Published: April 2023

Melon (Cucumis melo L.) is an important horticultural cash crop and its quality traits directly affect consumer choice and market price. These traits are controlled by genetic as well as environmental factors. In this study, a quantitative trait locus (QTL) mapping strategy was used to identify the potential genetic loci controlling quality traits of melons (i.e., exocarp and pericarp firmness and soluble solid content) based on newly derived whole-genome single nucleotide polymorphism-based cleaved amplified polymorphic sequence (SNP-CAPS) markers. Specifically, SNPs of two melon varieties, M4-5 and M1-15, as revealed by whole-genome sequencing, were converted to the CAPS markers, which were used to construct a genetic linkage map comprising 12 chromosomes with a total length of 1414.88 cM, in the F2 population of M4-5 and M1-15. The six identified QTLs included: SSC6.1 and SSC11.1 related to soluble solid content; EF12.1 associated with exocarp firmness; and EPF3.1, EPF3.2 and EPF7.1 related to edible pericarp firmness. These genes were located on five chromosomes (3, 6, 7, 11, and 12) in the flanking regions of the CAPS markers. Moreover, the newly developed CAPS markers will be useful in guiding genetic engineering and molecular breeding in melon.
Effect of Pre-Modification by Water Jet Blasting Prior to Nitriding Vein-Like Precipitates in the Composite Diffusion Layer of M50NiL Steel
Authors: Gu Jiabao , Li Shaolong , Chen Jian , Liang Yilong , Yang Ming , Sun Yuguan , Ling Min
Published: April 2023

In this study, M50NiL steel was carburized (C), nitrided (N), and compound-carburized then nitrided (C + N). Vein-like grain boundaries (VLGBs) were observed in the diffusion layers of both the N and C + N states due to the limited opportunity for diffusion. Transmission electron microscopy (TEM) observation revealed that the VLGB organization differed in the N and C + N states. The VLGB organization consisted mainly of Fe4N in the N state and Fe3C and Fe4N in the C + N state. When the C state was pre-modified by a 200 MPa water jet and then nitrided (C + 200P + N), the increase in dislocation density resulted in a dislocation entanglement phenomenon that split the grains to form subcrystals. The increases in grain boundaries and dislocation density promoted the diffusion of atoms, and thus the VLGB structure was not observed in the diffusion layer of the C + 200P + N state.
Key Epidemic Parameters of the SIRV Model Determined from Past COVID-19 Mutant Waves
Authors: Schlickeiser Reinhard , Kröger Martin
Published: April 2023

Monitored infection and vaccination rates during past past waves of the coronavirus are used to infer a posteriori two-key parameter of the SIRV epidemic model, namely, the real-time variation in (i) the ratio of recovery to infection rate and (ii) the ratio of vaccination to infection rate. We demonstrate that using the classical SIR model, the ratio between recovery and infection rates tends to overestimate the true ratio, which is of relevance in predicting the dynamics of an epidemic in the presence of vaccinations.
Modeling Bainite Dual-Phase Steels: A High-Resolution Crystal Plasticity Simulation Study
Authors: Gallardo-Basile Francisco-José , Roters Franz , Jentner Robin M. , Srivastava Kinshuk , Scholl Sebastian , Diehl Martin
Published: April 2023

A bainite dual-phase (FB) steel containing polygonal ferrite and granular bainite is thermo-mechanically rolled, followed by an accelerated cooling. Two different cooling rates are applied to obtain two different materials. The aim of the study is to explore the reasons for the differences in the mechanical response experimentally observed for these two materials which are modeled by means of high-resolution crystal plasticity simulations with a phenomenological constitutive description. First, the CP parameters of the individual constituents are determined. Second, different three-dimensional (3D) representative volume elements (RVEs)—one of which includes the substructure of bainite—are used to study the mechanical properties of both FB microstructures. It is shown that, in contrast to the macroscopic response, the microscopic response differs among the RVEs. Third, a comparison of both materials is performed by analyzing their stress–strain response. The onset of plasticity in granular bainite is found to be different for both materials in addition to the strain partitioning, although they both obeyed the iso-work assumption. Finally, a parameter study is carried out in order to investigate the correlation between different microstructures and damage initiation that can be seen experimentally in this steel. It is shown that the difference in ultimate elongation may depend on whether the first voids appear within polygonal ferrite or at the phase boundary.
Highly Efficient and Multiband Metamaterial Microstrip-Based Radiating Structure Design Showing High Gain Performance for Wireless Communication Devices
Authors: Armghan Ammar , Lavadiya Sunil , Alsharari Meshari , Aliqab Khaled , Daher Malek G. , Patel Shobhit K.
Published: April 2023

High-speed wireless communication devices need antennas to operate at multiple frequencies with high gain. The need for such antennas is increasing day by day. The proposed metamaterial superstrate antenna gives a high gain and multiband performance, which is required in high-speed wireless communication devices. The designed antenna is also applicable for C- and X-band communication devices. The structure consists of a simple patch and multiple split-ring resonator metamaterials on the superstrate region. The performance optimization is achieved by adjusting the feed position, varying the height of the superstrate layer and changing the thickness of metamaterial rings. The proposed design is analyzed for 4 GHz to 12 GHz. The performance analysis regarding the reflection coefficient, directivity, gain and electric field is observed. FR4 is used as a dielectric material that makes the design low-cost. The proposed design represents a minimum reflection coefficient response of −49 dB, a bandwidth of 490 MHz, a maximum electric field of 1.29 × 104 v/m, good directivity and a broader radiation pattern. The comparison between the simulated and the measured results is incorporated in the manuscript. A comparison of the presented design with other articles is included to check the novelty of the design. The proposed method helps to target applications such as WiFi, Earth observation and microwave links.
Spatial Distribution, Diversity Mapping, and Gap Analysis of Wild Vigna Species Conserved in India’s National Genebank
Authors: Shankar Thendral Uma , Semwal Dinesh Prasad , Gupta Veena , Archak Sunil , Nair Ramakrishnan M. , Tripathi Kuldeep
Published: April 2023

The genus Vigna has several crop species that could be used to feasibly address nutritional security challenges in the subtropical and tropical regions of the world, particularly in climate-changing scenarios. Wild taxa of Vigna are a source of economically important traits and need to be studied. Out of the 34 wild Vigna species reported in India, 928 indigenous accessions belonging to 19 wild Vigna are conserved in India’s National Genebank (INGB) housed at the National Bureau of Plant Genetic Resources, New Delhi. Geospatial mapping has identified diversity-rich areas and the Western Ghats region exhibits the highest Shannon diversity values (H = 1.65–3.0). Using the complementarity procedure, six diversity hotspots were identified for the 34 wild Vigna, and these require utmost priority for exploration and germplasm collection. Due to the meagre amount of information available for wild Vigna, the BioClim model was used to successfully predict the Idukki district of Kerala as a suitable site for germplasm-collecting expeditions. Coastal areas identified as rich in twelve wild taxa, V. bourneae, V. dalzelliana, V. marina, V. sublobata, V. subramaniana, V. vexillata, V. stipulacea, V. trilobata, and V. trinervia, require immediate attention to protect hotspots as well as to collect accessions from these areas for ex situ conservation. A hotspot in the protected forest of Anshi National Park and Bhagwan Mahavira Wildlife Sanctuary was identified as an ideal spot for possible in situ conservation of V. konkanensis, V silvestris, and V. sublobata. The 15 wild Vigna species do not have representation in the INGB, and 11 Vigna species have been identified as endemic species to India. Priority needs to be given to these species for focussed exploration and germplasm collection. This paper discusses the future focus on explorations to be carried out for the collection of the germplasm of wild Vigna species.
Comparison of Machine Learning Models and the Fatty Liver Index in Predicting Lean Fatty Liver
Authors: Su Pei-Yuan , Chen Yang-Yuan , Lin Chun-Yu , Su Wei-Wen , Huang Siou-Ping , Yen Hsu-Heng
Published: April 2023

The reported prevalence of non-alcoholic fatty liver disease in studies of lean individuals ranges from 7.6% to 19.3%. The aim of the study was to develop machine-learning models for the prediction of fatty liver disease in lean individuals. The present retrospective study included 12,191 lean subjects with a body mass index < 23 kg/m2 who had undergone a health checkup from January 2009 to January 2019. Participants were divided into a training (70%, 8533 subjects) and a testing group (30%, 3568 subjects). A total of 27 clinical features were analyzed, except for medical history and history of alcohol or tobacco consumption. Among the 12,191 lean individuals included in the present study, 741 (6.1%) had fatty liver. The machine learning model comprising a two-class neural network using 10 features had the highest area under the receiver operating characteristic curve (AUROC) value (0.885) among all other algorithms. When applied to the testing group, we found the two-class neural network exhibited a slightly higher AUROC value for predicting fatty liver (0.868, 0.841–0.894) compared to the fatty liver index (FLI; 0.852, 0.824–0.81). In conclusion, the two-class neural network had greater predictive value for fatty liver than the FLI in lean individuals.
Reliability Analysis of Vertebral Landmark Labelling on Lumbar Spine X-ray Images
Authors: Jang Jun-Su , Kim Joong Il , Ku Boncho , Lee Jin-Hyun
Published: April 2023

Vertebral landmark labelling on X-ray images is important for objective and quantitative diagnosis. Most studies related to the reliability of labelling focus on the Cobb angle, and it is difficult to find studies describing landmark point locations. Since points are the most fundamental geometric feature that can generate lines and angles, the assessment of landmark point locations is essential. The aim of this study is to provide a reliability analysis of landmark points and vertebral endplate lines with a large number of lumbar spine X-ray images. A total of 1000 pairs of anteroposterior and lateral view lumbar spine images were prepared, and 12 manual medicine experts participated in the labelling process as raters. A standard operating procedure (SOP) was proposed by consensus of the raters based on manual medicine and provided guidelines for reducing sources of error in landmark labelling. High intraclass correlation coefficients ranging from 0.934 to 0.991 verified the reliability of the labelling process using the proposed SOP. We also presented means and standard deviations of measurement errors, which could be a valuable reference for evaluating both automated landmark detection algorithms and manual labelling by experts.
Whole-Tumor ADC Texture Analysis Is Able to Predict Breast Cancer Receptor Status
Authors: Szep Madalina , Pintican Roxana , Boca Bianca , Perja Andra , Duma Magdalena , Feier Diana , Epure Flavia , Fetica Bogdan , Eniu Dan , Roman Andrei , Dudea Sorin Marian , Chiorean Angelica
Published: April 2023

There are different breast cancer molecular subtypes with differences in incidence, treatment response and outcome. They are roughly divided into estrogen and progesterone receptor (ER and PR) negative and positive cancers. In this retrospective study, we included 185 patients augmented with 25 SMOTE patients and divided them into two groups: the training group consisted of 150 patients and the validation cohort consisted of 60 patients. Tumors were manually delineated and whole-volume tumor segmentation was used to extract first-order radiomic features. The ADC-based radiomics model reached an AUC of 0.81 in the training cohort and was confirmed in the validation set, which yielded an AUC of 0.93, in differentiating ER/PR positive from ER/PR negative status. We also tested a combined model using radiomics data together with ki67% proliferation index and histological grade, and obtained a higher AUC of 0.93, which was also confirmed in the validation group. In conclusion, whole-volume ADC texture analysis is able to predict hormonal status in breast cancer masses.
A Retrospective Database Study of Health Costs among United States Older Adults Who Documented Having Pain and Functional Impairment
Authors: Axon David R. , Ullah Humza
Published: April 2023

Contemporary estimates of the association between functional impairment and health costs among United States (US) older adults who documented having pain are unavailable. We used a retrospective database design and developed unadjusted and adjusted linear regression models to assess total, office, outpatient, emergency department, inpatient, and prescribed drug costs between older US adults with and without functional impairment. We included US adults aged ≥ 50 in the 2020 Medical Expenditure Panel Survey dataset who documented having pain in the past month. We also included only those who had positive health costs. Among the 40,092,210 US adults aged ≥ 50 who documented having pain in the past month, we found 37% had functional impairment. In adjusted linear regression models, we found adults with functional impairment (versus adults without functional impairment) had 57.2% higher total health costs and 54.1% higher prescribed drug costs. We did not observe any statistical differences between groups for office, outpatient, emergency department, or inpatient costs. In conclusion, the higher total and prescribed drug costs we found among US older adults with pain and a functional impairment draws attention to the financial burden of functional impairment among these individuals, which needs to be addressed.
A Review of Swarm Robotics in a NutShell
Authors: Shahzad Muhammad Muzamal , Saeed Zubair , Akhtar Asima , Munawar Hammad , Yousaf Muhammad Haroon , Baloach Naveed Khan , Hussain Fawad
Published: April 2023

A swarm of robots is the coordination of multiple robots that can perform a collective task and solve a problem more efficiently than a single robot. Over the last decade, this area of research has received significant interest from scientists due to its large field of applications in military or civil, including area exploration, target search and rescue, security and surveillance, agriculture, air defense, area coverage and real-time monitoring, providing wireless services, and delivery of goods. This research domain of collective behaviour draws inspiration from self-organizing systems in nature, such as honey bees, fish schools, social insects, bird flocks, and other social animals. By replicating the same set of interaction rules observed in these natural swarm systems, robot swarms can be created. The deployment of robot swarm or group of intelligent robots in a real-world scenario that can collectively perform a task or solve a problem is still a substantial research challenge. Swarm robots are differentiated from multi-agent robots by specific qualifying criteria, including the presence of at least three agents and the sharing of relative information such as altitude, position, and velocity among all agents. Each agent should be intelligent and follow the same set of interaction rules over the whole network. Also, the system’s stability should not be affected by leaving or disconnecting an agent from a swarm. This survey illustrates swarm systems’ basics and draws some projections from its history to its future. It discusses the important features of swarm robots, simulators, real-world applications, and future ideas.
Frequency Seismic Response for EEWS Testing on Uniaxial Shaking Table
Authors: Donciu Codrin , Serea Elena , Temneanu Marinel Costel
Published: April 2023

Earthquake early warning systems are used as important tools in earthquake risk management, providing timely information to residents and both public and private emergency managers. By doing this, the potential impact of large magnitude seismic events is significantly reduced. These systems use seismic sensors in order to acquire real-time data for the weaker but fast moving P wave (usually the first 3–5 s of the earthquake) and specific algorithms to predict the magnitude and the arrival time of the slower but more destructive surface waves. Most of these projection algorithms make use only of the vertical component of the acceleration and need extensive training in earthquake simulators in order to enhance their performance. Therefore, a low-inertial-mass uniaxial shaking table is proposed and analyzed in terms of frequency response in this paper, providing an effective cost/control ratio and high daily duty cycle. Furthermore, with the large variety of prediction algorithms, which use different frequency ranges, a new concept of selective frequency band error is also introduced and discussed in this paper as being a necessary tool for the final assessment of magnitude estimation algorithm error.
Entropy Generation in Peristaltic Transport of Hybrid Nanofluids with Thermal Conductivity Variations and Electromagnetic Effects
Authors: Alrashdi Abdulwahed Muaybid A.
Published: April 2023

Entropy generation in peristaltic transport of hybrid nanofluid possessing temperature-dependent thermal conductivity through a two-dimensional vertical channel is studied in this paper. The hybrid nanofluid consists of multi-walled carbon nanotubes mixed with zinc oxide suspended in engine oil. Flow is affected by a uniform external magnetic field, hence generating Lorentz force, Hall and heating effects. Given the vertical orientation of the channel, the analysis accounts for mixed convection. To study heat transfer in the current flow configuration, the model considers phenomena such as viscous dissipation, heat generation or absorption, and thermal radiation. The mathematical modeling process employs the lubrication approach and Galilean transformation for enhanced accuracy. The slip condition for the velocity and convective conditions for the temperature are considered at the boundaries. The study analyzes entropy generation using the Homotopy Analysis Method (HAM) and includes convergence curves for HAM solutions. Results are presented using graphs and bar charts. The analysis shows that higher Brinkman and thermal radiation parameters result in higher temperatures, while higher thermal conductivity parameters lead to reduced entropy generation and temperature profile. Additionally, higher Hall parameter values decrease entropy generation, while an increased Hartman number improves entropy generation.
Cost-Optimization-Based Quantum Key Distribution over Quantum Key Pool Optical Networks
Authors: Jia Jie , Dong Bowen , Kang Le , Xie Huanwen , Guo Banghong
Published: April 2023

The Measurement-Device-Independent-Quantum Key Distribution (MDI-QKD) has the advantage of extending the secure transmission distances. The MDI-QKD combined with the Hybrid-Trusted and Untrusted Relay (HTUR) is used to deploy large-scale QKD networks, which effectively saves deployment cost. We propose an improved scheme for the QKD network architecture and cost analysis, which simplifies the number of QKD transmitters and incorporates the quantum key pool (QKP) in the QKD network. We developed a novel Hybrid-QKD-Network-Cost (HQNC) heuristic algorithm to solve the cost optimization problem. Simulations verified that the scheme in this paper could save the cost by over 50 percent and 90 percent, respectively.
Identification Algorithm and Improvement of Modal Damping Ratios for Armature Assembly in a Hydraulic Servo-Valve with Magnetic Fluid
Authors: Peng Jinghui , Zhang Yayun , Li Songjing , Bao Wen , Tanaka Yutaka
Published: April 2023

The high-frequency vibration and resonance of armature assembly in the hydraulic servo valve are the main reasons for instability and failure. Magnetic fluid (MF) operating in the squeeze mode can be taken as an effective damper for resonance suppression in the servo valve. Due to excitation difficulty and the low signal-to-noise ratio of high-frequency vibration signals, the capability of MF to modify multiple-order modal damping ratios in a multi-degree-of-freedom system is still unclear. To reveal the mechanism of magnetic fluid for improving modal damping ratios, an algorithm for modal damping ratio identification is proposed. The modal damping ratios of the armature assembly with and without magnetic fluid are identified based on the tested resonance free decay responses. Four resonance frequencies of armature assembly are observed, and the corresponding damping ratios are identified. The equivalent modal damping ratios due to squeeze flow of MF are obtained. The results show that the proposed algorithm can identify damping ratios with an accuracy of up to 98.79%. The damping ratios are improved by double or more due to the magnetic fluid, and the maximum resonance amplitudes are significantly reduced by 65.2% (from 916.5 μm to 318.6 μm).
CoOx-Fe3O4/N-rGO Oxygen Reduction Catalyst for Anion-Exchange Membrane Fuel Cells
Authors: Singh Ramesh K. , Douglin John C. , Jiang Lanjie , Yassin Karam , Brandon Simon , Dekel Dario R.
Published: April 2023

Platinum group metal (PGM)-free oxygen reduction reaction (ORR) catalysts are of utmost importance for the rapid development of anion-exchange membrane fuel cell (AEMFC) technology. In this work, we demonstrate the improved ORR performance and stability of Co and Fe oxide-decorated/N-doped reduced graphene oxide (CoOx-Fe3O4/N-rGO) prepared via a hydrothermal method at the low temperature of 150 °C. The catalysts were characterized thoroughly using transmission electron microscopy, high-angle annular dark field-scanning electron microscopy, X-ray diffraction, N2 physisorption, Raman spectroscopy, and X-ray photoelectron spectroscopy to obtain information about morphology, elemental distribution, phases, porosity, defects, and surface elemental compositions. Significant ORR activity improvement (130 mV@-1.5 mA cm−2) was achieved with this catalyst compared to the pristine graphene oxide, and the ORR limiting current was even 12%@0.5 V higher than the commercial Pt/C. The enhanced ORR activity of CoOx-Fe3O4/N-rGO was attributed to the uniform dispersion of Co, Fe, and N on reduced graphene oxide (rGO) sheets. Furthermore, ORR accelerated stress tests revealed excellent durability, suggesting that this material could be a promising and durable catalyst. With a cathode layer of the CoOx-Fe3O4/N-rGO catalyst, we achieved a peak power density of 676 mW cm−2 in an operando H2-O2 AEMFC. To the best of our knowledge, this is the highest reported power density per cathode catalyst mass in a reported PGM-free cathode catalyst. Finally, we quantified the various cell polarization losses as a function of cathode catalyst loadings to obtain insights for future work with AEMFCs based on this catalyst. The improvement in the AEMFC performance using CoOx-Fe3O4/N-rGO as a cathode catalyst can be attributed to the synergistic effects of (i) the high turnover frequency of the transition metals (Co and Fe) for ORR and (ii) the enhancement provided by N doping to the metal distribution and stability.
Preparation of an Anodic Alumina-Supported Ni Catalyst and Development of a Catalytic Plate Reformer for the Steam Reforming of Methane
Authors: Dong Shan , Lin Yi , Hu Jiajun , Gu Chenglin , Ding Leilin , Zhang Xinjian , Jiang Shi , Guo Yu
Published: April 2023

A plate-type Al/Fe–Cr alloy/Al-clad substrate was used to prepare a sandwich-structured plate-type anodic alumina catalyst by anodization, post-modification treatment, and metal loading. The as-prepared plate-type catalyst was utilized in the design of a catalytic plate reactor for a methane steam reforming reaction, and a 3D model was developed to simulate the performance of tube-type and box-type reformers. The experimental results of the preparation of the clad materials showed that the hydrothermal treatment and subsequent high-temperature calcination transformed the amorphous skeletal alumina in the conventional anodic alumina layer into γ-alumina, and significantly increased its specific surface area. Simulation results showed that the temperature difference between the channel wall and the center of the gas phase of the thin-walled catalyst was only 30% of that of the particulate catalyst, indicating the potential advantages of the catalytic plate reactor in terms of heat transfer and energy saving. When the length-to-diameter ratio (or length-to-width ratio) of the reaction channel is small and the channel height is large, insufficient transverse mass transfer and backmixing are two major factors affecting reformer performance. For the tube-type channels, a length-to-diameter ratio of 10~35, and a diameter of 5~20 represent favorable choices. In contrast, for the box-type channel, the length-to-width ratio and the height should be set to 2~4 and 2~5 mm, respectively. Additionally, for box-type channels, the number of gas inlet ports has a significant effect on the reformer performance, and the distribution state provided by two inlet ports is close to the ideal distribution state.
A Comprehensive Review of GaN-Based Bi-directional On-Board Charger Topologies and Modulation Methods
Authors: Bay Olcay , Tran Manh , El Baghdadi Mohamed , Chakraborty Sajib , Hegazy Omar
Published: April 2023

The wide-scale adoption and accelerated growth of electric vehicle (EV) use and increasing demand for faster charging necessitate the research and development of power electronic converters to achieve high-power, compact, and reliable EV charging solutions. Although the fast charging concept is often associated with off-board DC chargers, the importance of on-board AC fast charging is undeniable with the increasing battery capacities. This article comprehensively reviews gallium nitride (GaN) semiconductor-based bidirectional on-board charger (OBC) topologies used in both 400 V and 800 V EV applications. Moreover, comparative evaluations of GaN-based bi-directional OBC topologies regarding power conversion losses (conduction loss and soft switching capabilities), power density, implementation considerations, power quality, electromagnetic interference, and reliability aspects have been presented. The status of commercially available GaN power modules, advancements in GaN technology, applicable industry standards, and application requirements for OBCs have been also included in this study. Finally, in light of forthcoming advancements in GaN power transistor technology, this study highlights potential areas of research related to the reviewed topologies. Such research can aid researchers and designers in improving the performance and user experience of electric vehicles, ultimately supporting the widespread adoption of EVs.
Alternative Energy and CO2 Emission in China: Evidence from Bounds Testing and Vector Error Correction Model Approach
Authors: Tao Hai , Mu Hailin , Li Nan , Wang Peng
Published: April 2023

This empirical study investigates the dynamic interconnection between fossil fuel consumption, alternative energy consumption, economic growth and carbon emissions in China over the 1981 to 2020 time period within a multivariate framework. The long-term relationships between the sequences are determined through the application of the Autoregressive Distributed Lag (ARDL) bounds test and augmented by the Johansen maximum likelihood procedure. The causal relationships between the variables are tested with the Granger causality technique based on the Vector Error Correction Model (VECM). Empirical results reveal the existence of a statistically significant negative relationship between alternative energy consumption and carbon emissions in the long-term equilibrium. Furthermore, the VECM results demonstrate that both carbon emissions and fossil fuel consumption have unidirectional effects on economic growth. Additionally, the study highlights a short-term unidirectional causal relationship from economic growth to alternative energy consumption. These findings suggest that a reduction in fossil fuel consumption in the short run may indirectly impede the development of alternative energy. The study proposes that China should expedite the development of alternative energy and control the expansion of fossil fuel consumption to attain its carbon reduction target without hindering economic growth.
Fault-Tolerant Control of Induction Motor with Current Sensors Based on Dual-Torque Model
Authors: Li Yongda , Gong Pingping
Published: April 2023

The safety of direct torque control (DTC) is strongly reliant on the accuracy and consistency of sensor measurement data. A fault-tolerant control paradigm based on a dual-torque model is proposed in this study. By introducing the vector product and scalar product of the stator flux and stator current vector, a new state variable is selected to derive a new dual-torque model of induction motor; it is combined with a current observer to propose a dual-torque model fault-tolerant control method. This technology calculates torque and reactive torque directly, reducing the system’s reliance on sensors, avoiding sensor-noise interference, and improving torque response speed while suppressing torque ripple. In addition, to improve system dependability and safety, a fault-tolerant control method is devised by combining the model with an adaptive virtual current observer. Ultimately, experiments validate the suggested method’s effectiveness and feasibility.
Computational Analysis of the Automation Strategies of Temperatures of Supplied Air, Chilled and Condensation Water in Commercial Buildings
Authors: Diaz-Valdivia Javier , Fiorelli Flávio A. S.
Published: April 2023

The automation strategies currently used in HVAC systems do not control the system temperature variables (supplied air, chilled, and condensation water temperatures) in an optimized way. Normally, these temperatures are fixed in design conditions, or vary according to the weather conditions. However, studies demonstrate that adequate control of these three temperatures can provide significant reductions in the energy consumption of the air conditioner system. Therefore, this work analyzes the benefits of individualized and integrated automation of these three variable temperatures in different tropical and subtropical weather conditions through computer simulation for a typical commercial building. The results of integrated automation show savings in consumption between 5.03% and 19.68% compared to a fixed control, and between 3.22% and 8.21% compared to a weather-based control alone, showing that the integrated strategies are better than both models adopted as market benchmarks.
Cracking Behavior of Heavy Petroleum Polar Species in Collision-Induced Dissociation and Thermal Visbreaking
Authors: Yu Haiyang , Fang Xieling , Jiang Xu , Wang Li , Zhang Ying , Zhang Linzhou
Published: April 2023

In thermal cracking and collision-induced dissociation (CID) processes, molecules/ions mainly undergo cleavage reactions. In theory, the cleavage reaction is preferred for weak bonds in both processes. The present study investigates the thermal cracking and CID behavior of polar compounds in vacuum residue. By controlling the thermal reaction temperature and collision energy, different degrees of fragmentation were achieved. The molecular composition before and after the cracking process was analyzed through electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). There was a correlation between the reaction temperature and the collision energy for the average carbon number value. Both desulfurization and decarboxylation were also observed in two processes due to the low C-S bond energy and poor stability of carboxylic acid groups. Nevertheless, the two processes still had some differences in reaction selectivity. Polar species tended to be directly dealkylated down to the C1–C5 substituted aromatic core in the CID process, showing a discontinuity in the carbon number vs. double bond equivalence (DBE) distribution for the CID product. On the contrary, the carbon number distribution in the thermal reaction showed a continuously reduced trend. In summary, the CID process can qualitatively reflect the cracking behavior. However, the product structural distribution of the thermal cracking product cannot be fully predicted, especially for sidechain cracking reactions. In addition, the research results can provide a new method to realize the simulation of the thermal cracking without energy and time consumption, so as to guide the selection of the feedstock and optimization of the reaction condition.
Pyrolysis of Oils from Unconventional Resources
Authors: Donaldson Burl , Hughes Brian , Coker Eric N. , Yilmaz Nadir
Published: April 2023

In this study, oils from various sources were subjected to pyrolysis conditions; that is, without oxidizer, as the samples were heated to 500 °C, and held at that temperature. The oils studied included: (1) heavy oil from Grassy Creek, Missouri; (2) oil from tar sands of Asphalt Ridge in Utah; (3) mid-continent oil shales of three formations (two of Chattanooga formation, Pennsylvanian (age) formation, and Woodford formation); and (4) a Colorado Piceance Basin shale. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) with either gas chromatography (GC) or mass spectrometry (MS) were used to quantify the produced gases evolved in the tests. Purge gases of helium, argon, and humid carbon dioxide were utilized. Larger scale pyrolysis tests were conducted in a tube furnace coupled to a MS and a GC. The results consistently showed that pyrolysis occurred between 300 °C and 500 °C, with the majority of gases being mainly hydrogen and light alkanes. This behavior was essentially consistent, regardless of the oil source.
A Review of Research on Advanced Control Methods for Underground Coal Gasification Processes
Authors: Kačur Ján , Laciak Marek , Durdán Milan , Flegner Patrik , Frančáková Rebecca
Published: April 2023

Underground coal gasification (UCG) is a clean coal mining technology without significant environmental impacts. This technology can also be used in deep, hard-to-reach seams or deposits affected by tectonic disturbances, where conventional mining is impossible. Several techniques and methods have been investigated worldwide to support the process control of UCG. Global research focuses on the control of UCG operating parameters to stabilize or to optimize the performance of the underground reactor during energy conversion. This paper studies recent research in the field of UCG control and compares individual control techniques and possibilities for practical application. The paper focuses on advanced control methods that can be implemented in an in situ control system (e.g., adaptive control, extremum seeking control, and robust control). The study investigates control methods that ensure desired syngas calorific value or maximization. The review showed that robust control techniques such as sliding mode control and model predictive control have the most significant potential, and achieve the best results despite their complexity. In addition, some methods have been investigated through simulation or experimentally. The paper aims to give the reader an overview of the given issue and to alert the practice to recent research in the given area.
Optical and Numerical Investigations on Combustion and OH Radical Behavior Inside an Optical Engine Operating in LTC Combustion Mode
Authors: Maroteaux Fadila , Mancaruso Ezio , Vaglieco Bianca Maria
Published: April 2023

Low Temperature Combustion (LTC) is a relevant process for internal combustion engines (ICE). This combustion mode is based on premixed fuel/air and fuel lean in-cylinder mixture allowing reduction in NOx and PM emissions while maintaining higher thermal efficiency. In order to investigate the effect of engine operating conditions on the behavior of LTC mode, including OH radical evolution, optical measurements and numerical simulations were performed on a transparent CR diesel engine. The homogeneity of the engine charge was obtained by using very early injection timings. In this study, varying injection strategies were investigated for different engine speeds. In parallel to the experimentation, simulations of LTC mode for the same experimental operations were carried out. The model used in this study is based on a stochastic reactor model. This model includes a turbulence (k-ε) model based on a zero-dimensional energy cascade to calculate the turbulent time scale during the cycle. On the other hand, due to the stochastic approach and to reduce initial heterogeneities of the mixture, a confidence parameter was introduced in the global model to consider the real variation ranges of engine. This latter was modeled as a function of the Reynolds number allowing to initiate heterogeneities of temperature and of species mass. OH radicals were estimated with high spatial and temporal resolution using chemiluminescence measurements. Simulated in-cylinder pressure and the OH radical rate were compared to the experimental data. A good agreement was observed in terms of in-cylinder pressure trace and ignition delay times, meaning that the confidence coefficient model is accurate to describe the initial heterogeneities of the mixture. The simulated OH rate profile has the same shape as the measured OH trace and the main ignition occurs at the same time. This study corroborates that the OH radical is an appropriate tool to identify combustion stages.
Quantification of Hydrolytic Sugars from Eucalyptus globulus Bio-Oil Aqueous Solution after Thermochemical Liquefaction
Authors: Silva Luciana , Orišková Sofia , Gonçalves Diogo , Paulo Ivo , Condeço José , Monteiro Miguel , Xavier Nuno M. , Rauter Amélia P. , Bordado João M. , Galhano dos Santos Rui
Published: April 2023

Eucalyptus globulus sawdust is a residue from the pulp and paper industry which has been underutilised and undervalued. The thermochemical liquefaction of sawdust can be considered an alternative for recycling this residue, as it results in the production of a bio-oil that, when extracted in water, allows the obtention of an aqueous solution composed of carbohydrates. The sugars resulting from the aqueous fraction of bio-oil can be valued by and applied in the industry to produce sustainable materials. For the first time, the sugar composition of the aqueous extract of bio-oil was disclosed, identified, and quantified by a high-pressure liquid chromatograph (HPLC) coupled to a refractive index (RID) detector containing fructose (36.58%) and glucose (33.33%) as the main components, sucrose (15.14%), trehalose (4.82%) and xylose (10.13%). The presence of these sugars was further confirmed by two-dimensional (2D) 1H-13C heteronuclear single-quantum correlation–nuclear magnetic resonance (HSQC–NMR) spectroscopy. Fourier-transform infrared (FTIR-ATR) and elemental analyses were also used. In addition, the pathway leading to the identified sugars is also suggested.
Wildfire Susceptibility of Land Use and Topographic Features in the Western United States: Implications for the Landscape Management
Authors: Zhai Jun , Ning Zhuo , Dahal Ram , Yang Shaoyang
Published: April 2023

Understanding the role of land use type and topographic features in shaping wildfire regimes received much attention because of the intensification of wildfire activities. The intensifying wildfires in the western United States are a great concern both for the environment and society. We investigate the patterns of wildfire occurrence in the western United States at the landscape level by using 118 wildfires with areas greater than 405 ha in the study year of 2018. The selection ratios were calculated to measure fire preference with regard to land cover type, slope, and aspect. The results suggest that grasslands, steeper slopes, and south-facing aspects were more susceptible to wildfires in the western United States. Additionally, there were regional variations in wildfire susceptibility in Washington, Oregon, and California. The most wildfire-prone land cover type in Washington was mixed forests, whereas that in Oregon and California was grassland. The findings of this study improve the understanding of the role of land use changes and topographic features in shaping wildfire patterns in the western United States, providing insights for managing wildfire risks for forest management strategies at the landscape level.
Analysis of Soil–Water Characteristics and Stability Evolution of Rainfall-Induced Landslide: A Case of the Siwan Village Landslide
Authors: Wen Haijia , Xiao Jiafeng , Wang Xiongfeng , Xiang Xuekun , Zhou Xinzhi
Published: April 2023

This paper aimed to study the soil–water characteristics and stability evolution law of rainfall-induced landslide. Taking the two landslide events in Siwan village as an example, the formation conditions of the disaster and landslide characteristics were analyzed. Additionally, the deformation characteristics and destruction mechanisms of landslides were discussed in-depth. The soil–water characteristics and hydraulic conductivity of the landslides were analyzed based on TRIM experiment results. Geo-Studio numerical software was further used for typical sections to analyze the stability of the evolution of the landslide events under rainfall conditions. The results showed that (1) The soil–water characteristic curve (SWCC) inversely varies with water content volume, and the sliding body has lower saturated water content and matrix suction than the sliding zone. The hydraulic conductivity function (HCF) increases with water content volume, and the sliding body has higher hydraulic conductivity (0.43 m/d) than the sliding zone (0.03 m/d). (2) Rainfall is the primary cause of landslides, and there is a hysteretic effect. Heavy rainfall will inevitably accelerate the formation of landslides in the analysis of the deformation characteristics and destruction mechanisms of rainfall-induced landslides. (3) Compared with the engineering analogy of the Fredlund and Xing (FX) model, the Van Genuchten–Mualem (VGM) model of the soil–water characteristics test based on the TRIM experimental system can better reflect the actual field situation. The numerical simulation method based on the TRIM experiments of the soil–water characteristics test is scientifically sound and reliable for the stability evolution of overburden rainfall-induced landslides.