bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Atmospheric Transport of Sea-Spray Aerosols in a Coastal Zone Using a High-Resolution Model
Authors: Limoges Alix , Piazzola Jacques , Yohia Christophe , Rodier Quentin , Bruch William , Canepa Elisa , Sagaut Pierre
Published: June 2024

Fine-scale models for the transport of marine aerosols are of great interest for the study of micro-climates and air quality in areas of complex topography, such as in urbanized coastal areas. To this end, the MIO laboratory implemented the Meso-NH model in its LES version over the northwest Mediterranean coastal zone using a recent sea-spray source function. Simulated meteorological parameters and aerosol concentrations are compared to experimental data acquired in the Mediterranean coastal zone in spring 2008 on board the R/V Atalante. Key findings indicate that the large eddy simulation (LES) mode closely matches with the experimental data, enabling an in-depth analysis of the numerical model ability to predict variations in aerosol concentrations. These variations are influenced by different wind directions, which lead to various fetch distances typical of coastal zones.
Comprehensive Detection of Particle Radiation Effects on the Orbital Platform of the Upper Stage of the Chinese CZ-4C Carrier Rocket
Authors: Shen Guohong , Chang Zheng , Zhang Huanxin , Wang Chunqin , Sun Ying , Quan Zida , Zhang Xianguo , Sun Yueqiang
Published: June 2024

Based on the characteristics of space particle radiation in the Sun-synchronous orbit (SSO), a space particle radiation effect comprehensive measuring instrument (SPRECMI) was installed on the orbital platform of the upper stage of the Chinese CZ-4C carrier rocket, which can acquire the high-energy proton energy spectra, linear energy transfer (LET) spectra of particles, and radiation dose rate. The particle radiation detection data were obtained at 1000 km altitude for the first time, which can be used mainly for scientific research of the space environment, in-orbit fault analysis, and the operational control management of spacecraft, and can also serve as reference data for component validation tests. After SPRECMI’s development, accelerator calibration and simulations were conducted, and the results demonstrated that all the measured indicators, including the high-energy proton spectra (energy range: 21.8–275.0 MeV, precision: <3.3%), total radiation dose (dose range: 0–1.04 × 106 rad, sensitivity: 6.2 µrad/h), and the LET spectra (range: 0.001–37.20 MeV/(mg/cm2), >37.2 MeV/(mg/cm2)), met the relevant requirements. Furthermore, the in-orbit flight test revealed that the detection results of the load components were consistent with the physical characteristics of the particle radiation environment of the spacecraft’s orbit.
Study on Wind Profile Characteristics Using Cluster Analysis
Authors: Wang Yanru , Tian Shengbao , Fu Bin , Zhang Maoyu , Wang Xu , Zheng Shuqin , Zhang Chuanxiong , Zhou Lei
Published: June 2024

The accurate characterization of typhoon wind profile properties is of great importance in the field of wind engineering and wind design of high-rise structures. In this paper, the average typhoon wind profile characteristics are investigated using the 930 m height measurement data of Typhoon Lekima 2019 obtained from the observations of the mobile acoustic profiling radar deployed in the coastal area. Specifically, this paper adopts a cohesive hierarchical cluster analysis method to classify the mean wind profiles of Super Typhoon Lekima 2019, and the optimal number of clusters is obtained as two classes by the profile coefficient with the sum of squares of clustering errors, the Calinski–Harabasz index, and the Davies–Bouldin index, and the two classes of typical wind profiles are named as cluster 1 type and cluster 2 type. The model fitting analysis of the two types of typical wind profiles was carried out in the height range of 0~300 m after classification, and the effects of fitting the cluster 1-type mean wind profiles with the Vickery model and the Snaiki and Wu model and the cluster 2-type mean wind profiles with the Power-law model, the Log-law model, and the Deaves–Harris and Gryning models were discussed. The results show that the cohesive hierarchical cluster analysis method used in this paper can effectively categorize the mean typhoon profiles. In addition, this paper has some reference significance for future research on the characteristics of measured typhoon wind profiles and engineering applications such as the wind-resistant design of high-rise structures.
Impact of Integrating Flameless Combustion Technology and Sludge–Fly Ash Recirculation on PCDE Emissions in Hazardous Waste Thermal Treatment Systems
Authors: Lin Sheng-Lun , Duan Lu-Lu , Wu Jhong-Lin , Huang Chien-Er , Song Meng-Jie
Published: June 2024

Polychlorinated diphenyl ethers (PCDEs), persistent environmental pollutants, are found in flue gas from incinerators. While air pollution control systems (APCSs) capture pollutants, the resulting sludge/fly ash (SFA) requires further treatment due to residual PCDEs and other harmful substances. This study investigated a hazardous waste thermal treatment system (HAWTTS) utilizing flameless combustion technology alongside a multistage APCS (scrubbers, cyclone demisters, bag houses). SFA from the APCS was recirculated for secondary combustion. PCDE levels were measured before and after each unit within the HAWTTS. The HAWTTS achieved a remarkable overall PCDE removal efficiency of 99%. However, the incinerator alone was less effective for low-chlorine PCDEs. Scrubbers and bag houses exhibited lower removal efficiencies (17.8% and 30.9%, respectively) due to the memory effect. Conversely, the cyclone demister achieved a high removal rate (98.2%). Following complete APCS treatment, PCDE emissions were significantly reduced to 1.02 ng/Nm3. While SFA still contained some PCDEs, the flameless combustion’s uniform temperature distribution enhanced combustion efficiency, minimizing overall PCDE emissions. This system demonstrates significant potential for mitigating PCDE pollution from incinerators. Further research could focus on optimizing treatment processes to address residual PCDEs in SFA.
Application of Natural Language Processing and Genetic Algorithm to Fine-Tune Hyperparameters of Classifiers for Economic Activities Analysis
Authors: Malashin Ivan , Masich Igor , Tynchenko Vadim , Nelyub Vladimir , Borodulin Aleksei , Gantimurov Andrei
Published: June 2024

This study proposes a method for classifying economic activity descriptors to match Nomenclature of Economic Activities (NACE) codes, employing a blend of machine learning techniques and expert evaluation. By leveraging natural language processing (NLP) methods to vectorize activity descriptors and utilizing genetic algorithm (GA) optimization to fine-tune hyperparameters in multi-class classifiers like Naive Bayes, Decision Trees, Random Forests, and Multilayer Perceptrons, our aim is to boost the accuracy and reliability of an economic classification system. This system faces challenges due to the absence of precise target labels in the dataset. Hence, it is essential to initially check the accuracy of utilized methods based on expert evaluations using a small dataset before generalizing to a larger one.
The Anxious Brain: The Influence of Stress on the Nervous System
Authors: Stoyanov Drozdstoy
Published: June 2024

Anxiety disorders, including generalized anxiety, panic disorder, and post-traumatic stress, constitute the most frequent mental disorders and occur in about 14–18% of the overall population [...]
CD59 Protects Primary Human Cerebrovascular Smooth Muscle Cells from Cytolytic Membrane Attack Complex
Authors: Whinnery Carson D. , Nie Ying , Boskovic Danilo S. , Soriano Salvador , Kirsch Wolff M.
Published: June 2024

Cerebral amyloid angiopathy is characterized by a weakening of the small- and medium-sized cerebral arteries, as their smooth muscle cells are progressively replaced with acellular amyloid β, increasing vessel fragility and vulnerability to microhemorrhage. In this context, an aberrant overactivation of the complement system would further aggravate this process. The surface protein CD59 protects most cells from complement-induced cytotoxicity, but expression levels can fluctuate due to disease and varying cell types. The degree to which CD59 protects human cerebral vascular smooth muscle (HCSM) cells from complement-induced cytotoxicity has not yet been determined. To address this shortcoming, we selectively blocked the activity of HCSM-expressed CD59 with an antibody, and challenged the cells with complement, then measured cellular viability. Unblocked HCSM cells proved resistant to all tested concentrations of complement, and this resistance decreased progressively with increasing concentrations of anti-CD59 antibody. Complete CD59 blockage, however, did not result in a total loss of cellular viability, suggesting that additional factors may have some protective functions. Taken together, this implies that CD59 plays a predominant role in HCSM cellular protection against complement-induced cytotoxicity. The overexpression of CD59 could be an effective means of protecting these cells from excessive complement system activity, with consequent reductions in the incidence of microhemorrhage. The precise extent to which cellular repair mechanisms and other complement repair proteins contribute to this resistance has yet to be fully elucidated.
Neurocognitive and Neuropsychiatric Sequelae in Long COVID-19 Infection
Authors: Almeria Marta , Cejudo Juan Carlos , Deus Joan , Krupinski Jerzy
Published: June 2024

Objective: To characterize the cognitive profile of long COVID-19 subjects and its possible association with clinical symptoms, emotional disturbance, biomarkers, and disease severity. Methods: We performed a single-center cross-sectional cohort study. Subjects between 20 and 60 years old with confirmed COVID-19 infection were included. The assessment was performed 6 months following hospital or ambulatory discharge. Excluded were those with prior neurocognitive impairment and severe neurological/neuropsychiatric disorders. Demographic and laboratory data were extracted from medical records. Results: Altogether, 108 participants were included, 64 were male (59.25%), and the mean age was 49.10 years. The patients were classified into four groups: non-hospitalized (NH, n = 10), hospitalized without Intensive Care Unit (ICU) or oxygen therapy (HOSPI, n = 21), hospitalized without ICU but with oxygen therapy (OXY, n = 56), and ICU (ICU, n = 21) patients. In total, 38 (35.18%) reported Subjective Cognitive Complaints (SCC). No differences were found considering illness severity between groups. Females had more persistent clinical symptoms and SCC than males. Persistent dyspnea and headache were associated with higher scores in anxiety and depression. Persistent fatigue, anxiety, and depression were associated with worse overall cognition. Conclusions: No cognitive impairment was found regarding the severity of post-COVID-19 infection. SCC was not associated with a worse cognitive performance, but with higher anxiety and depression. Persistent clinical symptoms were frequent independent of illness severity. Fatigue, anxiety, and depression were linked to poorer cognitive function. Tests for attention, processing speed, and executive function were the most sensitive in detecting cognitive changes in these patients.
Effects of Practicing Closed- vs. Open-Skill Exercises on Executive Functions in Individuals with Attention Deficit Hyperactivity Disorder (ADHD)—A Meta-Analysis and Systematic Review
Authors: Qiu Chunyue , Zhai Qun , Chen Shuangru
Published: June 2024

(1) Background: Previous studies have identified discrepancies in improvements in executive functioning in typically developing children when comparing closed- and open-skill exercise interventions. However, there is limited research on executive functioning in attention deficit hyperactivity disorder (ADHD). This study aims to conduct a systematic review and meta-analysis to explore the impact of closed- and open-skill exercises on ADHD populations. (2) Methods: The PRISMA guidelines for systematic reviews were followed to search seven databases to evaluate and analyze studies published from 2013 to 2023. Prospero: CRD42023460452. (3) Results: A meta-analysis of 578 subjects with ADHD in 11 RCTs (Randomized control trial) and 3 NRS (Non-randomized studies) revealed that closed-skill exercise significantly improved executive function subdomains, including inhibitory control (standardized mean differences (SMD) = −1.00), cognitive flexibility (SMD = −1.33), and working memory (SMD = −0.85). Furthermore, open-skill exercise was found to have a positive effect on inhibitory control (SMD = −1.98) and cognitive flexibility (SMD = −0.97) in ADHD patients. Both types of exercise interventions demonstrated an improvement in executive function compared to controls, with open-skill exercises exhibiting superior effects (Qb = 6.26). (4) Conclusions: The review recommends a 12-week intervention cycle with exercise at least twice a week of moderate or higher intensity as suitable for ADHD individuals. This review also encourages individuals with ADHD to engage in exercises involving multiple motor skill types.
Role of the Subgrade Reaction Modulus in the Design of Foundations for Adjacent Buildings
Authors: Khosravifardshirazi Ali , Tavana Babak , Javadi Akbar A. , Johari Ali , Gholzom Shima , Khosravifardshirazi Behnaz , Akrami Mohammad
Published: June 2024

This paper examines the effects of soil–structure and structure–soil–structure interactions in the design of foundations for adjacent concrete buildings, which are located on soft soils. The study employs an elasto-plastic model through static (quasi-dynamic) analysis using the direct finite element method by applying earthquake loads in one time step. Two concrete buildings, one with 6 stories and another with 12 stories, were modelled and numerically analysed using ANSYS. The foundations of these two buildings were analysed separately and compared when they were assumed to be adjacent to each other. The designs of the buildings’ foundations were evaluated independently and in comparison with each other to determine the impact of these interactions. The results indicated that accounting for the effects of both interactions increases the total deformation of the foundations. Additionally, the study found that adjusting the subgrade reaction modulus values (Ks) for different sections of the foundation can be a practical method to address both interaction effects simultaneously. This method also optimizes the weight of reinforcement material (Wr) by reducing it by 15% and modifying the positions and quantities of reinforcements used and considering various subgrade reaction modulus values in foundation design.
Safety Leadership: A Catalyst for Positive Safety Climate on Construction Sites
Authors: Sankar S. Senthamizh , Anandh K. S. , Prasanna K.
Published: June 2024

Limited research exists on safety leadership and safety climate in developing countries, despite their established importance in the construction industry. This study addresses this gap by investigating how immediate superiors’ safety leadership behaviours influence safety climate perceptions among construction professionals in southern India. Using a quantitative approach, the study collected valid questionnaire surveys among 279 construction professionals by convenience sampling across various construction sites. The survey revealed that safety leadership significantly and positively predicts five key safety climate factors: management’s commitment to safety, safety equipment and procedures, safety training, communication and openness, and group dynamics and safety culture. These findings highlight the critical role immediate superiors play in shaping safety climate perceptions through their commitment, communication, and employee involvement. This research underscores the importance of investing in safety leadership development to improve safety outcomes, reduce accidents and injuries, and enhance regulatory compliance within the Indian construction industry.
Feasibility of Advanced Reflective Cracking Prediction and Detection for Pavement Management Systems Using Machine Learning and Image Detection
Authors: Shin Sung-Pil , Kim Kyungnam , Le Tri Ho Minh
Published: June 2024

This research manuscript presents a comprehensive investigation into the prediction and detection of reflective cracking in pavement infrastructure through a combination of machine learning approaches and advanced image detection techniques. Leveraging machine learning algorithms, reflective cracking prediction models were developed and optimized for accuracy and efficiency. Additionally, the efficacy of image detection methods, particularly utilizing Mask R-CNN, was explored for robust and precise identification of reflective cracking on pavement surfaces. The study not only aims to enhance the predictive capabilities of pavement management systems (PMSs) through machine learning-based models but also seeks to integrate advanced image detection technologies to support real-time monitoring and assessment of pavement conditions. By providing accurate and timely detection of reflective cracking, these methodologies contribute to the optimization of pavement maintenance strategies and the overall improvement of pavement infrastructure management practices. Results indicate that the developed machine learning models achieve an average predictive accuracy of over 85%, with some models achieving accuracies exceeding 90%. Moreover, the utilization of a mask region-based convolutional neural network (Mask R-CNN) for image detection demonstrates exceptional precision, with a detection accuracy of over 95% on average across different pavement types and weather conditions. The results demonstrate the promising performance of the developed machine learning models in predicting reflective cracking, while the utilization of Mask R-CNN showcases exceptional accuracy in the detection of reflective cracking from images. This research underscores the importance of leveraging cutting-edge technologies to address challenges in pavement infrastructure management, ultimately supporting the sustainability and longevity of transportation networks.
Supply Chain Landscape of 3D Printed Buildings: A Stakeholder Decision Support Framework
Authors: Ma Jiayue , Samarasinghe Don Amila Sajeevan , Rotimi James Olabode Bamidele , Zuo Kelvin
Published: June 2024

With the development of new construction technology, increasing attention is being paid to 3D printing due to its construction efficiency as well as its sustainability. Numerous researchers have determined its benefits in cost reduction, resource savings, safety assurance, etc. Although various advantages have been identified, there are limitations and challenges in technology implementation. Especially since it is a new construction method, 3D printing construction projects will have a very different supply chain compared to traditional projects. As part of a research programme investigating the 3D printing construction supply chain in a New Zealand context, this study systematically analysed the research about 3D printing adoption and supply chain challenges in the construction sector. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was adopted as the guideline for literature selection. PRISMA is designed to assist researchers in reporting the review research focus and methodology, and examining the findings from published literature. NVivo was then adopted to code and analyse the selected publications to gather the data necessary for our study. The literature was analysed from the perspectives of the research focus, research methods, and findings. Studies about 3D printing implementation, benefits and barriers, as well as its significance are also analysed. As a result, this research found existing research gaps, including the fragmented situation of management-related research in the 3D printing construction sector, insufficient research in top management for 3D printing construction implementation, and changes to supply chain management practices in 3D printing construction projects. A decision support system demo for supply chain management is drafted in this paper, which requires further study. The research outcome highlighted the existing studies in 3D printing construction implementation and supply chain, and initiated a research topic on supply chain decision making. The result contributes to the theoretical and practical development of 3D printing technology in the construction industry. This review paper also inspires future studies on supply chain frameworks and theoretical models.
Building Material Carbon Emission Prediction Models for Reinforced-Concrete Shear-Wall Urban Residential Buildings in Northern China
Authors: Liu Yiming , Xu Peiqi , Liu Nianxiong
Published: June 2024

Reinforced-concrete shear walls stand as the primary construction method for urban residential structures in northern China. In alignment with national carbon neutrality goals for residential construction, this study developed a set of prediction models with which to estimate the building material carbon emissions of reinforced-concrete shear-wall urban residential buildings. Specifically, this study clarified the boundaries, content, and calculation method for carbon emissions in the stage of material production. Using consumption data for building materials from 20 reinforced-concrete shear-wall urban residential buildings in northern China, the study evaluated the composition and distribution of building material carbon emissions. Linear and ridge regression was performed to fit the coupling relationship between spatial design parameters and building material carbon emissions. Adopting two technical approaches of direct and indirect prediction, 10 carbon emission prediction models based on residential design parameters were established and validated. The results indicate that, although the indirect prediction models, based on concrete, steel, cement mortar, and the transparent envelope, had relatively low accuracy in estimating carbon emissions from cement mortar and the transparent envelope, they performed well overall. Additionally, the prediction performance of the four models was similar. In contrast, except for M1 and M3, the other direct prediction models, based on the number of building stories, number of basement levels, number of primary rooms on the standard floor or in the unit, and building width and depth, also had good fitting and prediction performance. These models effectively predicted the total building material carbon emissions in the phases of conceptual design, schematic design, preliminary design, and working drawing. Three prediction models could produce fast and effective data support for the low-carbon design of urban residential buildings.
Ex Vivo Fluorescence Confocal Microscopy for Intraoperative Examinations of Lung Tumors as Alternative to Frozen Sections—A Proof-of-Concept Study
Authors: Kamm Max , Hildebrandt Felix , Titze Barbara , Höink Anna Janina , Vorwerk Hagen , Sievert Karl-Dietrich , Groetzner Jan , Titze Ulf
Published: June 2024

Background: Intraoperative frozen sections (FS) are frequently used to establish the diagnosis of lung cancer when preoperative examinations are not conclusive. The downside of FS is its resource-intensive nature and the risk of tissue depletion when small lesions are assessed. Ex vivo fluorescence confocal microscopy (FCM) is a novel microimaging method for loss-free examinations of native materials. We tested its suitability for the intraoperative diagnosis of lung tumors. Methods: Samples from 59 lung resection specimens containing 45 carcinomas were examined in the FCM. The diagnostic performance in the evaluation of malignancy and histological typing of lung tumors was evaluated in comparison with FS and the final diagnosis. Results: A total of 44/45 (98%) carcinomas were correctly identified as malignant in the FCM. A total of 33/44 (75%) carcinomas were correctly subtyped, which was comparable with the results of FS and conventional histology. Our tests documented the excellent visualization of cytological features of normal tissues and tumors. Compared to FS, FCM was technically less demanding and less personnel intensive. Conclusions: The ex vivo FCM is a fast, effective, and safe method for diagnosing and subtyping lung cancer and is, therefore, a promising alternative to FS. The method preserves the tissue without loss for subsequent examinations, which is an advantage in the diagnosis of small tumors and for biobanking.
Advancements in Materials Science and Photocatalysts for Sustainable Development
Authors: Vadivel Dhanalakshmi , Suryakumar Swetha , Casella Claudio , Speltini Andrea , Dondi Daniele
Published: June 2024

Materials science and catalysis advancements play a critical role in achieving sustainable development by managing environmental, energy, and resource challenges. Catalyst design advancements focus on enhancing selectivity to achieve sustainable chemical reactions, reducing energy consumption. Designing catalysts that are environmentally friendly and biodegradable is increasingly gaining importance. This aligns with the principles of green chemistry and contributes to minimizing the environmental impact of catalytic processes. These advances, taken as a whole, lead to more sustainable and efficient processes in industries ranging from energy production to pollutant removal, fueling the advancement toward a more sustainable future. Photochemistry, that is, the activation of a stable compound (catalyst) into the highly reactive excited state, is of particular importance, since photons—especially when they come from solar light—are a green and renewable resource. This review article has provided the overall idea of the photocatalysts and materials under green chemistry perspective from the standpoint of the concept of sustainable development.
Context-Dependent Regulation of Peripheral Nerve Abundance by the PI3K Pathway in the Tumor Microenvironment of Head and Neck Squamous Cell Carcinoma
Authors: Khorani Karam , Burkart Sebastian , Weusthof Christopher , Han Rui , Liang Siyuan , Stögbauer Fabian , Hess Jochen
Published: June 2024

Recent studies have highlighted neurons and their associated Schwann cells (SCs) as key regulators of cancer development. However, the mode of their interaction with tumor cells or other components of the tumor microenvironment (TME) remains elusive. We established an SC-related 43-gene set as a surrogate for peripheral nerves in the TME. Head and neck squamous cell carcinoma (HNSCC) from The Cancer Genome Atlas (TCGA) were classified into low, intermediate and high SC score groups based on the expression of this gene set. Perineural invasion (PNI) and TGF-β signaling were hallmarks of SChigh tumors, whereas SClow tumors were enriched for HPV16-positive OPSCC and higher PI3K-MTOR activity. The latter activity was partially explained by a higher frequency of PTEN mutation and PIK3CA copy number gain. The inverse association between PI3K-MTOR activity and peripheral nerve abundance was context-dependent and influenced by the TP53 mutation status. An in silico drug screening approach highlighted the potential vulnerabilities of HNSCC with variable SC scores and predicted a higher sensitivity of SClow tumors to DNA topoisomerase inhibitors. In conclusion, we have established a tool for assessing peripheral nerve abundance in the TME and provided new clinical and biological insights into their regulation. This knowledge may pave the way for new therapeutic strategies and impart proof of concept in appropriate preclinical models.
Synergistic Innovations: Organometallic Frameworks on Graphene Oxide for Sustainable Eco-Energy Solutions
Authors: Ayyakannu Sundaram Ganeshraja , EL-Mahdy Ahmed F. M. , Pham Phuong V. , Kunjiappan Selvaraj , Kumar Alagarsamy Santhana Krishna
Published: June 2024

Combining organometallic frameworks with graphene oxide presents a fresh strategy to enhance the electrochemical capabilities of supercapacitors, contributing to the advancement of sustainable energy solutions. Continued refinement of materials and device design holds promise for broader applications across energy storage and conversion systems. This featured application underscores the inventive utilization of organometallic frameworks on graphene oxide, shedding light on the creation of superior energy storage devices for eco-friendly solutions. This review article delves into the synergistic advancements resulting from the fusion of organometallic frameworks with graphene oxide, offering a thorough exploration of their utility in sustainable eco-energy solutions. This review encompasses various facets, including synthesis methodologies, amplified catalytic performances, and structural elucidations. Through collaborative efforts, notable progressions in photocatalysis, photovoltaics, and energy storage are showcased, illustrating the transformative potential of these hybrids in reshaping solar energy conversion and storage technologies. Moreover, the environmentally conscious features of organometallic–graphene oxide hybrids are underscored through their contributions to environmental remediation, addressing challenges in pollutant elimination, water purification, and air quality enhancement. The intricate structural characteristics of these hybrids are expounded upon to highlight their role in tailoring material properties for specific eco-energy applications. Despite promising advancements, challenges such as scalability and stability are candidly addressed, offering a pragmatic view of the current research landscape. The manuscript concludes by providing insights into prospective research avenues, guiding the scientific community towards surmounting hurdles and fully leveraging the potential of organometallic–graphene oxide hybrids for a sustainable and energy-efficient future.
SO2 Detection over a Wide Range of Concentrations: An Exploration on MOX-Based Gas Sensors
Authors: Rossi Arianna , Spagnoli Elena , Visonà Alan , Ahmed Danial , Marzocchi Marco , Guidi Vincenzo , Fabbri Barbara
Published: June 2024

Noxious gases such as sulfur-containing compounds can inflict several different adverse effects on human health even when present at extremely low concentrations. The accurate detection of these gases at sub-parts per million levels is imperative, particularly in fields where maintaining optimal air quality is crucial. In this study, we harnessed the capabilities of nanostructured metal-oxide semiconducting materials to detect sulfur dioxide, since they have been extensively explored starting from the last decades for their effectiveness in monitoring toxic gases. We systematically characterized the sensing performance of seven chemoresistive devices. As a result, the SnO2:Au sensor demonstrated to be the most promising candidate for sulfur dioxide detection, owing to its highly sensitivity (0.5–10 ppm), humidity-independent behavior (30 RH% onwards), and selectivity vs. different gases at an operating temperature of 400 °C. This comprehensive investigation facilitates a detailed performance comparison to other devices explored for the SO2 sensing, supporting advancements in gas detection technology for enhanced workplace and environmental safety.
Calculation of Stress Intensity Factor for Annular Double Cracks on Inner Surface of Pipeline
Authors: Cui Jintai , Li Huifang , Wu Zhiwei , Qian Caifu
Published: June 2024

Cracks in engineered pipelines often appear in the form of multiple cracks or crack clusters with interactions between them. It is important to study the interaction between cracks if the pipeline crack cluster is to be evaluated in terms of equivalence and safety assessment. In this paper, based on FRANC3D crack analysis software, the interaction between circumferential parallel double cracks on the inner surface of pipelines was investigated, the factors affecting the interaction were examined, and the empirical equations for calculating the stress intensity factor (SIF) of double cracks was proposed. The results show that if there is no bias between the double cracks, the crack leading edge is shielded, but if there is offset between the double cracks, the crack leading edge is subjected to different interactions at different locations. The distal end of the cracks is generally strengthened, while the proximal end of the cracks is probably more shielded. The interaction effects between cracks are dependent on their relative positions rather than the pipe size or concerned crack size. According to the numerical simulation, boundaries for shielding or enhancing interactions were obtained, and the stress intensity factor calculation equations were fitted.
Covalent Molecular Anchoring of Metal-Free Porphyrin on Graphitic Surfaces toward Improved Electrocatalytic Activities in Acidic Medium
Authors: Huynh Thi Mien Trung , Phan Thanh Hai
Published: June 2024

Robust engineering of two-dimensional (2D) materials via covalent grafting of organic molecules has been a great strategy for permanently tuningtheir physicochemical behaviors toward electrochemical energy applications. Herein, we demonstrated that a covalent functionalization approach of graphitic surfaces including graphene by a graftable porphyrin (g-Por) derivative, abbreviated as g-Por/HOPG or g-Por/G, is realizable. The efficiency of this approach is determined at both the molecular and global scales by using a state-of-the-art toolbox including cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). Consequently, g-Por molecules were proven to covalently graft on graphitic surfaces via C-C bonds, resulting in the formation of a robust novel hybrid 2D material visualized by AFM and STM imaging. Interestingly, the resulting robust molecular material was elucidated as a novel bifunctional catalyst for both the oxygen evolution (OER) and the hydrogen evolution reactions (HER) in acidic medium with highly catalytic stability and examined at the molecular level. These findings contribute to an in-depth understanding at the molecular level ofthe contribution of the synergetic effects of molecular structures toward the water-splitting process.
Evaluating the Yield of Three Legume Crop Varieties under Hawaii’s Micro-Climates
Authors: Ahmad Amjad A. , Radovich Theodore J. K. , Sugano Jari , Wang Koon-Hui , Nguyen Hue V. , Uyeda Jensen , Wages Sharon , Tavares Kylie , Kirk Emilie , Kantar Michael
Published: June 2024

Hawaii is known for its diverse micro-climates, making the evaluation of varieties at different locations an important strategy to determine the best varieties for each climate zone. Demand for dry beans in Hawaii has been rising due to the increase in production of value-added goods made from legumes. Initial field trials in 2017 were conducted to determine the best sowing date for dry beans in Hawaii since there were no previous such determinations. Field trials were conducted between 2018 and 2021 to evaluate 24 varieties of chickpea (Cicer arietinum), 21 varieties of common bean (Phaseolus vulgaris), and 10 varieties of cowpea (Vigna unguiculata) for their suitability and yield variability under Hawaii’s micro-climates. Preliminary sowing date trials were conducted in 2017, and a variety of trials were conducted between 2018 and 2021; seven field trials were conducted, including two in each of Oahu, Maui, and Hawaii County, and one in Kauai County. The trials were conducted in a randomized complete block design (RCBD) with three replicates. For all the study sites, 20-20-20 NPK fertilizer was applied at 30, 13, and 25 kg/ha N-P-K, respectively. A drip irrigation system was used in all locations as supplemental irrigation. Irrigation was used when needed and turned off 2 weeks prior to harvest. The results showed highly significant (p < 0.01) differences in yield between the varieties of each legume crop. Highly significant (p < 0.01) differences in yield were also found between the study locations. There was a significant (p < 0.05) decline in yield by 28% and 45% in chickpea and by 32% and 43% in common bean when planted 1 and 2 months, respectively, after the optimal mid-February planting on Oahu and Maui County. A decline of 21% and 50% in chickpea and 30 and 48% in common bean was recorded when planted 1 and 2 months, respectively, after the optimal mid-March planting in Hawaii County. The study results lead to developing site-specific recommendations for varieties and planting dates from each of the legume crops for each county. However, more studies are needed to develop site-specific recommendations for the micro-climates within each county.
Abundant Catalytic Edge Sites in Few-Layer Horizontally Aligned MoS2 Nanosheets Grown by Space-Confined Chemical Vapor Deposition
Authors: Velea Alin , Buruiana Angel-Theodor , Mihai Claudia , Matei Elena , Tite Teddy , Sava Florinel
Published: June 2024

Recently, a smart strategy for two-dimensional (2D) materials synthesis has emerged, namely space-confined chemical vapor deposition (CVD). Its extreme case is the microreactor method, in which the growth substrate is face-to-face stacked on the source substrate. In order to grow 2D transition metal dichalcogenides by this method, transition metal oxides, dispersed in very small amounts on the source substrate, are used as source materials in most of the published reports. In this paper, a colloidal dispersion of MoS2 in saline solution is used and MoS2 nanosheets with various shapes, sizes (between 5 and 60 μm) and thicknesses (2–4 layers) have been synthesized. Small MoS2 flakes (regular or defective) are present on the surface of the nanosheets. Catalytic sites, undercoordinated atoms located at the edges of MoS2 flakes and nanosheets, are produced in a high number by a layer-plus-island (Stranski–Krastanov) growth mechanism. Several double-resonance Raman bands (at 147, 177, 187, 225, 247, 375 cm−1) are assignable to single phonon processes in which the excited electron is elastically scattered on a defect. The narrow 247 cm−1 peak is identified as a topological defect-activated peak. These findings highlight the potential of defect engineering in material property optimization, particularly for solar water splitting applications.
Recent Progress of Floating-Zone Techniques for Bulk Single-Crystal Growth
Authors: Kikugawa Naoki
Published: June 2024

This review describes the recent progress of floating-zone techniques for bulk single-crystal growth. The most crucial point of the crucible-free technique is to keep the molten zone stable. It has been investigated and reported to yield a steeper temperature gradient at the liquid–solid interface along the growth direction and a homogeneous molten liquid along the rotation axis. This article overviews several recent achievements starting from the conventional setup, particularly for lamps equipped in horizontal or vertical configurations, tilting mirrors, shielding the irradiation, and filament sizes for the optical-lamp floating-zone furnaces. Also, the recently advancing laser-heated floating-zone furnaces are described. Throughout the article, the author emphasizes that the floating-zone technique has been a powerful tool for crystal growth since the 1950s with its roots in the zone-melting method, and it has still been advancing for further materials’ growth such as quantum materials with modern scientific concepts.
Near- and Far-Field Acoustic Characteristics and Sound Source Localization Performance of Low-Noise Propellers with Gapped Gurney Flap
Authors: Noda Ryusuke , Hoshiba Kotaro , Komatsuzaki Izumi , Nakata Toshiyuki , Liu Hao
Published: June 2024

With the rapid industrialization utilizing multi-rotor drones in recent years, an increase in urban flights is expected in the near future. This may potentially result in noise pollution due to the operation of drones. This study investigates the near- and far-field acoustic characteristics of low-noise propellers inspired by Gurney flaps. In addition, we examine the impact of these low-noise propellers on the sound source localization performance of drones equipped with a microphone array, which are expected to be used for rescuing people in disasters. Results from in-flight noise measurements indicate significant noise reduction mainly in frequency bands above 1 kHz in both the near- and far-field. An improvement in the success rate of sound source localization with low-noise propellers was also observed. However, the influence of the position of the microphone array with respect to the propellers is more pronounced than that of propeller shape manipulation, suggesting the importance of considering the positional relationships. Computational fluid dynamics analysis of the flow field around the propellers suggests potential mechanisms for noise reduction in the developed low-noise propellers. The results obtained in this study hold potential for contributing to the development of integrated drones aimed at reducing noise and improving sound source localization performance.
Optimization of PM Slotless Brushless DC Motors Considering Magnetic Saturation and Temperature Limitation
Authors: Xue Zhipeng , Li Quanwu , Liu Peng , Zhu Wenlong
Published: June 2024

When magnetic saturation occurs during the operation of a permanent magnet (PM) slotless brushless DC motor, the material permeability will no longer be a constant value, and the neglected magnetic saturation model used for motor optimization will no longer be applicable. And considering that the increase in motor torque will lead to a high temperature rise of the winding, therefore, an electromagnetic heat coupling model applicable to the occurrence of magnetic saturation in the motor is established, and the model is utilized in combination with the particle swarm algorithm to enhance the maximum output torque of the motor. Firstly, a 100 W, 16,400 r/min high-speed PM slotless DC brushless motor is taken as the object of study, and its electromagnetic–thermal coupling model is established to derive the analytical equations for the electromagnetic torque with respect to the split ratio, the thickness of the stator yoke, the PM thickness, and the copper loss. Secondly, based on the modeling, the motor was optimized using a particle swarm algorithm to maximize the output torque and minimize the copper loss. Finally, a prototype was fabricated and verified with the prototype through no-load and load experiments. The difference between the theoretical maximum output torque and the experimental maximum output torque is less than 8%. The results show that this method can effectively predict the maximum output torque of the motor in the case of magnetic saturation, and the model is suitable for increasing the maximum output torque of slotless brushless DC motors under space constraints.
Innovative High-Induction Air Diffuser for Enhanced Air Mixing in Vehicles and Personalized Ventilation Applications
Authors: Bode Florin Ioan , Joldos Titus Otniel , Sirbu Gabriel Mihai , Danca Paul , Cosoiu Costin , Nastase Ilinca
Published: June 2024

Thermal comfort is very important for the well-being and safety of vehicle occupants, as discomfort can elevate stress, leading to distracted attention and slower reaction times. This creates a riskier driving environment. Addressing this, high-induction air diffusers emerge as a significant innovation, enhancing indoor environmental quality (IEQ) by efficiently mixing cool air from the heating ventilation and air conditioning (HVAC) system with the cabin’s ambient air. This process ensures uniform airflow, diminishes temperature discrepancies, prevents draft sensations, and boosts overall air quality by improving air circulation. In addition to enhancing thermal comfort in vehicles, the novel air diffuser also offers significant potential for personalized ventilation systems, allowing for individualized control over airflow and temperature, thereby catering to the specific comfort needs of each occupant. This study introduces a novel air diffuser that demonstrates a 48% improvement in air entrainment compared to traditional diffusers, verified through Ansys Fluent simulations and laser Doppler velocimetry (LDV) measurements. At a fresh airflow rate of 31.79 m3/h, the total air entrainment rate at 0.6 m for the standard air diffuser is 73.36 m3/h, while for the innovative air diffuser, it is 109.26 m3/h. This solution has the potential to increase the level of thermal comfort and air quality within vehicles, and also signals potential applications across various enclosed spaces, underscoring its importance in advancing automotive safety and environmental standards.
Analytical Prediction of the Thermal Behavior of Semiconductor Power Devices from Room-Temperature I–V Measurements
Authors: Ress Sandor , Farkas Gabor , Rencz Marta
Published: June 2024

The thermal characterization of power devices is an inevitable task in the industry. Thermal transient testing is one of the major tools for this characterization, as it is not only capable of giving information about the actual thermal parameters but may also reveal the root cause of potential device failures. The testing may occur on single packages or modules on a dedicated standard test bench, or “in situ”, in an actual assembly. The testing process itself is very fast in both cases, on the order of seconds, but the transient measurement needs to be preceded by a calibration step to determine the temperature dependence of a temperature-sensitive parameter (TSP) of the semiconductor device. This may require a long time, as the device has to be measured at many stabilized temperatures, which in the case of power devices may take hours. It also has to be considered that, especially in “in situ” measurements, reaching the highest device temperatures of power devices may even damage other parts of the surrounding electronics. Moreover, the temperature distribution inside a module will be different at calibration time than during operation with the same junction temperature, as bond wires and copper traces do not reach the chip temperature in the latter case. This paper presents a methodology that can be used to replace the lengthy measurement of one parameter at many temperatures with a fast single I–V characteristics measurement at room temperature. Physics-based calculations assign a unique temperature-sensitive parameter to each item of interest in the system. After the presentation of the theoretical background, the usability of the method is demonstrated by verifying measurements on silicon power devices.
Calculation Method of Three-Phase Productivity of Horizontal Well in Water-Bearing Condensate Gas Reservoir
Authors: Zhang Yufeng , Chen Yefei , Xu Anzhu , He Jun , Luo Erhui , Liu Yunyang , Zeng Xing , Jiang Luyang
Published: June 2024

Condensate gas reservoirs are a special kind of reservoir because of the presence of multiphase flow in their production. The accurate calculation of the multiphase flow productivity in horizontal wells is of great significance for reservoir development. In this study, the total pseudopressure and the equivalent total flow are defined to solve the multiphase nonlinear problem in the oil–gas–water three-phase control flow equation, and to establish a three-phase productivity equation considering the non-Darcy effect. It provides a solution for the three-phase productivity calculation of horizontal wells in water-bearing condensate gas reservoirs. The example verification and error analysis of three horizontal wells, except for the gas production error of Well Y3 and the average error of the production data of other gas wells, is below 4%. The fitting effect of Well Y2 is better than that of the other two horizontal wells, and the average error of the oil, gas, and water phases is below 3%. This method provides a practical and simple engineering tool for the analysis of the productivity of condensate gas reservoirs considering multiphase flow.