bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Breed Differences in Known and New Fescue Toxicosis Associated Phenotypes in Charolais-and Hereford-Sired Crossbred Beef Cows
Authors: Lucas Kayla M. , Koltes Dawn A. , Meyer Laura R. , Tucker John D. , Hubbell Donald S. , Powell Jeremy G. , Apple Jason K. , Koltes James E.
Published: September 2021

Beef cattle phenotypes are affected by the consumption of toxic fescue. Toxic fescue’s impact is dependent on heat stress and breed composition, with genetic variability for robustness to toxin exposure believed to exist within and across breeds. The study objective was to characterize the effect of fescue toxicosis across breeds for known and novel heat and fescue stress-associated phenotypes. One-hundred crossbred fall-calving Charolais- and Hereford-sired cows of parities 1–3 were allocated to graze either toxic fescue (n = 50), non-toxic fescue (n = 25), or a rotation between toxic and non-toxic fescue (n = 25) for 156 days. Phenotypes impacted by breed (genetics) included hair coat score (p < 0.0001), hair reduction/shedding rate (p < 0.05), rectal temperature (RT) (p < 0.0001), vaginal temperature (p < 0.05), serum phosphorus concentration (p < 0.02) and respiration rate (RR) (p < 0.003). Cows on toxic fescue experienced reduced hair shedding efficacy (p < 0.0001), higher vaginal temperatures (p < 0.0001), increased systolic blood pressure (p < 0.04), increased RR (p < 0.0001) and reduced average daily gain (p < 0.0001), compared to cows grazing non-toxic fescue. Calves born from cows with higher RT during the last third of gestation had higher RT at weaning (p < 0.02), indicating potential physiological effects of in utero heat stress. The study indicates that beef cows exhibit variable responses to toxic fescue within and across breeds which may impact future calf phenotypes.
Effect of Palpable Udder Defects on Milk Yield, Somatic Cell Count, and Milk Composition in Non-Dairy Ewes
Authors: Zeleke Mandefrot M. , Kenyon Paul R. , Flay Kate J. , Aberdein Danielle , Pain Sarah J. , Peterson Sam W. , Ridler Anne L.
Published: September 2021

In non-dairy ewes, udder defects hinder the survival and weight gain of their pre-weaned lambs. The objectives of this study were to determine the effects of palpable udder defects on milk yield, somatic cell count (SCC), and milk composition in non-dairy Romney ewes. Ewes with a history of udder defects or normal udders were selected for the study. Of a total of 48 ewes that lambed, 30 ewes reared at least one lamb, and were milked six times, once weekly, for the first six weeks of lactation. Udder halves were palpated and scored at each milking event. Multivariate linear mixed models examined the impacts of udder defects on udder-half and whole-udder milk yield, SCC, and milk composition (fat, protein, lactose, total solids, and solids non-fat (SNF)). Across the six examinations, 24.7% of the total 352 udder-half examinations were observed to be defective. Udder halves that were defective at least once produced on average 57.9% less (p < 0.05) milk than normal udder halves, while normal udder halves with a contralateral defective half yielded 33.5% more (p < 0.05) milk than normal udder halves. Successive occurrence of both hard and lump udder defect categories in an udder-half, udder defect detection early in lactation, and a high frequency of udder defect detection were all associated with udder-half milk yield loss (p < 0.05). At the whole-udder level, no differences in milk yield (p > 0.05) were observed between those with one udder-half defective and both normal udder-halves. However, udders in which one udder half was categorised as hard but progressed to lump and remained as lump until 42 days of lactation produced less (p < 0.05) milk compared with normal udders. With the exception of SNF, there were no significant associations (p > 0.05) between milk composition parameters and udder defect. Overall, these findings emphasise the importance of udder health in non-dairy ewes and the potential effect of udder defects on their lambs.
The Quest for Genes Involved in Adaptation to Climate Change in Ruminant Livestock
Authors: Passamonti Matilde Maria , Somenzi Elisa , Barbato Mario , Chillemi Giovanni , Colli Licia , Joost Stéphane , Milanesi Marco , Negrini Riccardo , Santini Monia , Vajana Elia , Williams John Lewis , Ajmone-Marsan Paolo
Published: September 2021

Livestock radiated out from domestication centres to most regions of the world, gradually adapting to diverse environments, from very hot to sub-zero temperatures and from wet and humid conditions to deserts. The climate is changing; generally global temperature is increasing, although there are also more extreme cold periods, storms, and higher solar radiation. These changes impact livestock welfare and productivity. This review describes advances in the methodology for studying livestock genomes and the impact of the environment on animal production, giving examples of discoveries made. Sequencing livestock genomes has facilitated genome-wide association studies to localize genes controlling many traits, and population genetics has identified genomic regions under selection or introgressed from one breed into another to improve production or facilitate adaptation. Landscape genomics, which combines global positioning and genomics, has identified genomic features that enable animals to adapt to local environments. Combining the advances in genomics and methods for predicting changes in climate is generating an explosion of data which calls for innovations in the way big data sets are treated. Artificial intelligence and machine learning are now being used to study the interactions between the genome and the environment to identify historic effects on the genome and to model future scenarios.
Flunixin Meglumine Enhanced Bone Fracture Healing in Rabbits Associated with Activation of Early Collagen Deposition and Enhancement of Vascular Endothelial Growth Factor Expression
Authors: Elgendy Mohamed , Elsayad Gamal , Seleim Magdi , Abdo Walied , Baty Roua S. , Elmahallawy Ehab Kotb , Atiba Ayman
Published: September 2021

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used postoperative analgesics, antipyretics, and anti-inflammatories, and they help prevent blood clotting. However, most NSAIDs delay bone healing. This study was aimed to investigate bone healing in a rabbit animal model by assessing the ability of flunixin meglumine (FM) and ketoprofen to induce fracture healing by examining histology, radiological changes, and vascular endothelial growth factor (VEGF) immunostaining during bone healing. For this purpose, 24 New Zealand rabbits were assigned to three groups: the control group, the FM group, and the ketoprofen group. Our results revealed that there were no intraoperative complications, and all surviving rabbits achieved full-weight bearing. Significant periosteal reaction and callus formation were confirmed at 2 postoperative weeks. Interestingly, FM enhanced callus formation, bone union, and remodeling in the FM group compared to the control and ketoprofen groups. FM enhanced bone healing through early collagen deposition and marked angiogenesis process activation by increasing the expression of VEGF. Our findings demonstrated, for the first time, the potential imperative action of FM in the bone healing process rather than other NSAIDs in animals.
Sperm Repository for a Breeding Program of the Eastern Oyster Crassostrea virginica: Sample Collection, Processing, Cryopreservation, and Data Management Plan
Authors: Yang Huiping , Huo Yuanzi , Yee Jayme C. , Rikard Scott , Walton William C. , Saillant Eric
Published: September 2021

The Eastern oyster Crassostrea virginica (Family Ostreidae) is one of the most important fishery and aquaculture species in the U.S. and is a keystone species for coastal reefs. A breeding program was initiated in 2019 to support the fast-growing aquaculture industry culturing this species in the Gulf of Mexico. Oysters from 17 wild populations in embayment along the U.S. Gulf of Mexico coast from southwest Florida to the Matagorda Bay, Texas were used as broodstock for the program to maximize genetic diversity in the base population. A sperm repository of the broodstock was established to support the breeding project. The goal of this study was to demonstrate the sperm sample collection, processing, cryopreservation, and the data management plan involved in the establishment of a sperm germplasm repository of base populations. The supporting objectives were to: (1) develop a data management plan for the sperm repository; (2) streamline the procedure for sample collection, processing, and cryopreservation; (3) incorporate sperm quality analysis into the procedure, and (4) archive the cryopreserved samples as a repository for future use in the breeding program. This sperm repository included a total of 102 male oysters from the 17 collection sites (six oysters per site). A data management plan was developed with six categories, including sample collection, phenotype, fresh sperm, genotype, cryopreservation, and post-thaw sperm, as guide for data collection. Sperm collection was accomplished by strip spawn, and fresh sperm production, motility, and fertility were recorded for quality analysis. Cryopreserved sperm samples were sorted, labelled, archived, and stored in liquid nitrogen for future use. Post-thaw motility (1–30%) and plasm membrane integrity (15.34–70.36%) were recorded as post-thaw quality parameters. Overall, this study demonstrated a streamlined procedure of oyster sperm collection, processing, and cryopreservation for establishing a sperm repository that can serve as a template for construction of oyster germplasm repositories for breeding programs.
Redox Balance in Male Infertility: Excellence through Moderation—“Μέτρον ἄριστον”
Authors: Symeonidis Evangelos N. , Evgeni Evangelini , Palapelas Vasileios , Koumasi Dimitra , Pyrgidis Nikolaos , Sokolakis Ioannis , Hatzichristodoulou Georgios , Tsiampali Chara , Mykoniatis Ioannis , Zachariou Athanasios , Sofikitis Nikolaos , Kaltsas Ares , Dimitriadis Fotios
Published: September 2021

Male infertility, a relatively common and multifactorial medical condition, affects approximately 15% of couples globally. Based on WHO estimates, a staggering 190 million people struggle with this health condition, and male factor is the sole or contributing factor in roughly 20–50% of these cases. Nowadays, urologists are confronted with a wide spectrum of conditions ranging from the typical infertile male to more complex cases of either unexplained or idiopathic male infertility, requiring a specific patient-tailored diagnostic approach and management. Strikingly enough, no identifiable cause in routine workup can be found in 30% to 50% of infertile males. The medical term male oxidative stress infertility (MOSI) was recently coined to describe infertile men with abnormal sperm parameters and oxidative stress (OS), including those previously classified as having idiopathic infertility. OS is a critical component of male infertility, entailing an imbalance between reactive oxygen species (ROS) and antioxidants. ROS abundance has been implicated in sperm abnormalities, while the exact impact on fertilization and pregnancy has long been a subject of considerable debate. In an attempt to counteract the deleterious effects of OS, urologists resorted to antioxidant supplementation. Mounting evidence indicates that indiscriminate consumption of antioxidants has led in some cases to sperm cell damage through a reductive-stress-induced state. The “antioxidant paradox”, one of the biggest andrological challenges, remains a lurking danger that needs to be carefully avoided and thoroughly investigated. For that reason, oxidation-reduction potential (ORP) emerged as a viable ancillary tool to basic semen analysis, measuring the overall balance between oxidants and antioxidants (reductants). A novel biomarker, the Male infertility Oxidative System (MiOXSYS®), is a paradigm shift towards that goal, offering a quantification of OS via a quick, reliable, and reproducible measurement of the ORP. Moderation or “Μέτρον” according to the ancient Greeks is the key to successfully safeguarding redox balance, with MiOXSYS® earnestly claiming its position as a guarantor of homeostasis in the intracellular redox milieu. In the present paper, we aim to offer a narrative summary of evidence relevant to redox regulation in male reproduction, analyze the impact of OS and reductive stress on sperm function, and shed light on the “antioxidant paradox” phenomenon. Finally, we examine the most up-to-date scientific literature regarding ORP and its measurement by the recently developed MiOXSYS® assay.
Reactive Oxygen Species and Antioxidative Defense in Chronic Obstructive Pulmonary Disease
Authors: Taniguchi Akihiko , Tsuge Mitsuru , Miyahara Nobuaki , Tsukahara Hirokazu
Published: September 2021

The respiratory system is continuously exposed to endogenous and exogenous oxidants. Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways, leading to the destruction of lung parenchyma (emphysema) and declining pulmonary function. It is increasingly obvious that reactive oxygen species (ROS) and reactive nitrogen species (RNS) contribute to the progression and amplification of the inflammatory responses related to this disease. First, we described the association between cigarette smoking, the most representative exogenous oxidant, and COPD and then presented the multiple pathophysiological aspects of ROS and antioxidative defense systems in the development and progression of COPD. Second, the relationship between nitric oxide system (endothelial) dysfunction and oxidative stress has been discussed. Third, we have provided data on the use of these biomarkers in the pathogenetic mechanisms involved in COPD and its progression and presented an overview of oxidative stress biomarkers having clinical applications in respiratory medicine, including those in exhaled breath, as per recent observations. Finally, we explained the findings of recent clinical and experimental studies evaluating the efficacy of antioxidative interventions for COPD. Future breakthroughs in antioxidative therapy may provide a promising therapeutic strategy for the prevention and treatment of COPD.
Cystine and Methionine Deficiency Promotes Ferroptosis by Inducing B-Cell Translocation Gene 1
Authors: Cho Il-Je , Kim Doyeon , Kim Eun-Ok , Jegal Kyung-Hwan , Kim Jae-Kwang , Park Sang-Mi , Zhao Rongjie , Ki Sung-Hwan , Kim Sang-Chan , Ku Sae-Kwang
Published: September 2021

Ferroptosis is a type of programmed necrosis triggered by iron-dependent lipid peroxidation. We investigated the role of B-cell translocation gene 1 (BTG1) in cystine and methionine deficiency (CST/Met (−))-mediated cell death. CST/Met (−) depleted reduced and oxidized glutathione in hepatocyte-derived cells, increased prostaglandin-endoperoxide synthase 2 expression, and promoted reactive oxygen species accumulation and lipid peroxidation, as well as necrotic cell death. CST/Met (−)-mediated cell death and lipid peroxidation was specifically inhibited by pretreatment with ferroptosis inhibitors. In parallel with cell death, CST/Met (−) blocked global protein translation and increased the expression of genes associated with the integrated stress response. Moreover, CST/Met (−) significantly induced BTG1 expression. Using a BTG1 promoter-harboring reporter gene and siRNA, activating transcription factor 4 (ATF4) was identified as an essential transcription factor for CST/Met (−)-mediated BTG1 induction. Although knockout of BTG1 in human HAP1 cells did not affect the accumulation of reactive oxygen species induced by CST/Met (−), BTG1 knockout significantly decreased the induction of genes associated with the integrated stress response, and reduced lipid peroxidation and cell death in response to CST/Met (−). The results demonstrate that CST/Met (−) induces ferroptosis by activating ATF4-dependent BTG1 induction.
AI-Powered Service Robotics for Independent Shopping Experiences by Elderly and Disabled People
Authors: Ghazal Mohammed , Yaghi Maha , Gad Abdalla , El Bary Gasm , Alhalabi Marah , Alkhedher Mohammad , El-Baz Ayman S.
Published: September 2021

Through human development and technological expansion, it has become apparent that the potential lies within each individual to have an essential part in the transcendence of society and the community. People less privileged than others may need more strength and determination to surpass their current resources to overcome normal and natural obstacles in order to simulate an environment where productivity and creativity exist. This paper aims to study an approach that will assist the elderly and people of determination in one of the most essential activities practiced by individuals: shopping. The study focuses on facilitating the acquirement of items from shelves and skipping the cashier line. The proposed system is a service robot supported by a robotic arm and a linear actuator as a lifting mechanism, controlled by a remote joystick to help the elderly or disabled people reach items on high shelves. The scanning system is based on barcode detection, using transfer learning. The network was designed using YOLOv2 layers connected to TinyYOLO as feature extraction layers. This network has proven to be the most practical, with 86.4% accuracy and real-time operation with 27 FPS in comparison to using the YOLOv2 layers with DarkNet or VGG19 as feature extraction layers. An anti-theft system is integrated into the robot to improve the reliability of the self-checkout feature. The system uses computer vision GMM and Kalman filter for item detection inside the cart, and the item is validated to be the one that has been scanned, using SURF for structural features, HSV for color, and load-sensors mounted to the base of the cart to measure the item’s weight.
Applications of FFTA–HFACS for Analyzing Human and Organization Factors in Electric Misoperation Accidents
Authors: Lin Chuan , Xu Qifeng , Huang Yifan
Published: September 2021

Human and organizational factors (HOFs) play an important role in electric misoperation accidents (EMAs), but research into the reliability of human factors is still in its infancy in the field of EMAs, and further investment in research is urgently required. To analyze the HOFs in EMAs, a hybrid method including the Human Factors Analysis and Classification System (HFACS) and fuzzy fault tree analysis (FFTA) was applied to EMAs for the first time in the paper. HFACS is used to identify and classify the HOFs with 135 accidents, reorganized as basic events (BEs), intermediate events (IEs), and top event (TE), and develop the architecture of fault tree (FT). Fuzzy aggregation is employed to address experts’ expressions and obtain the failure probabilities of the BEs and the minimal cut sets (MCSs) of the FT. The approach generates BEs failure probabilities without reliance on quantitative historical failure statistics of EMAs via qualitative records processing. The FFTA–HFACS model is applied for quantitative analysis of the probability of failure of electrical mishaps and the interaction between accident risk factors. It can assist professionals in deciding whether and where to take preventive or corrective actions and assist in knowledgeable decision-making around the electric operation and maintenance process. Finally, applying this hybrid method to EMAs, the results show that the probability of an EMAs is 1.0410 × 10−2, which is a risk level that is likely to occur and must be controlled. Two of the most important risk factors are habitual violations and supervisory violation; a combination of risk factors of inadequate work preparation and paralysis, and irresponsibility on the part of employees are also frequent errors.
Emergency Planning for UAV-Controlled Crowd Evacuations
Authors: Alhindi Afnan , Alyami Deem , Alsubki Aziza , Almousa Razan , Al Nabhan Najla , Al Islam A. B. M. Alim , Kurdi Heba
Published: September 2021

One of the most challenging problems during disasters involving crowds is pedestrian evacuation. It is very important in such situations to improve survival rates by getting all or most of the people out in the shortest possible time. Technological intervention through augmenting the evacuation process using an unmanned aerial vehicle (UAV) exhibits great potential in improving survival rates, but the exploration of this method is still in its infancy. Therefore, this study explores the potential of utilizing UAVs for crowd management during emergency evacuations. We conducted a rigorous study, using a simulation model featuring four UAVs and differing numbers of pedestrians, with use of two UAV guidance approaches: partial guidance and full guidance. The experimental results suggest that exploiting UAVs in crowd evacuation and following the partial guidance approach can lead to a more efficient evacuation process.
Acoustic Word Embeddings for End-to-End Speech Synthesis
Authors: Shen Feiyu , Du Chenpeng , Yu Kai
Published: September 2021

The most recent end-to-end speech synthesis systems use phonemes as acoustic input tokens and ignore the information about which word the phonemes come from. However, many words have their specific prosody type, which may significantly affect the naturalness. Prior works have employed pre-trained linguistic word embeddings as TTS system input. However, since linguistic information is not directly relevant to how words are pronounced, TTS quality improvement of these systems is mild. In this paper, we propose a novel and effective way of jointly training acoustic phone and word embeddings for end-to-end TTS systems. Experiments on the LJSpeech dataset show that the acoustic word embeddings dramatically decrease both the training and validation loss in phone-level prosody prediction. Subjective evaluations on naturalness demonstrate that the incorporation of acoustic word embeddings can significantly outperform both pure phone-based system and the TTS system with pre-trained linguistic word embedding.
A Novel Dual-Wavelength Method for Evaluating Temperature Effect in Fiber-Optic SPR Sensors
Authors: Su Ning , Luo Wei , Wang Liusan , Zhang Zhengyong , Wang Rujing
Published: September 2021

The temperature effect is one of the critical factors to induce the resonance wavelength shift in fiber-optic surface plasmon resonance (SPR) sensors, which leads to the inaccuracy measurement of refractive index (RI) in practical applications. In this study, a novel dual-wavelength method is presented for fiber-optic SPR sensors to measure the changes of RI and temperature simultaneously in real time. A typical model of an SPR-based fiber optical sensor is constructed for theoretical analysis of temperature effect. Both the thermo-optic effect in the fiber core and phonon–electron scattering along with electron–electron scattering in the metal layer are studied systematically in the theoretical model. The linear and independent relationship, about the dependence of defined output signals on the RI and temperature, is validated by a theoretical calculation in specific dual wavelengths. A proof-of-concept experiment is conducted to demonstrate the capability of the presented dual-wavelength technique. The experimental results indicate that the presented dual-wavelength method is technically feasible and can be applied for practical application. Since the presented method only depends on the full advantages of the transfer spectrum data, it can be applied directly to the conventional single-channel fiber-optic SPR without any specific design structure of the sensor probe. The proposed method provides a new way to detect the RI under different thermal conditions and could lead to a better design for the fiber-optic SPR sensors.
Scrum VR: Virtual Reality Serious Video Game to Learn Scrum
Authors: Mayor Jesus , López-Fernández Daniel
Published: September 2021

Education is crucial for the growth of society, and the usage of effective learning methods is key to transmit knowledge to young students. Some initiatives present Virtual Reality technologies as a promising medium to provide active, effective, and innovative teaching. In turn, the use of this technology seems to be very attractive to students, making it possible to acquire knowledge through it. On the other hand, agile methodologies have taken an essential role within information technologies and they are key in Software Engineering education. This paper combines both areas and presents prior research about Virtual Reality experiences with educational purposes and introduces a serious VR video game that aims to promote the learning of agile methodologies in Software Engineering education, specifically the Scrum methodology. This application tries to bring students closer to their first days of work within a software development team that uses the Scrum methodology. Two evaluation processes performed with university teachers and students indicate that the developed video game meets the proposed objectives and looks promising.
Woodworking Tool Wear Condition Monitoring during Milling Based on Power Signals and a Particle Swarm Optimization-Back Propagation Neural Network
Authors: Dong Weihang , Xiong Xianqing , Ma Ying , Yue Xinyi
Published: September 2021

In the intelligent manufacturing of furniture, the power signal has the characteristics of low cost and high accuracy and is often used as a tool wear condition monitoring signal. However, the power signal is not very sensitive to tool wear conditions. The present work addresses this issue by proposing a novel woodworking tool wear condition monitoring method that employs a limiting arithmetic average filtering method and particle swarm optimization (PSO)-back propagation (BP) neural network algorithm. The limiting arithmetic average filtering method was used to process the power signal and extracted the features of the woodworking tool wear conditions. The spindle speed, depths of milling, features and tool wear conditions were used as sample vectors. The PSO-BP neural network algorithm was used to establish the monitoring model of the woodworking tool wear condition. Experiments show that the proposed limiting arithmetic average filtering method and PSO-BP neural network algorithm can accurately monitor the woodworking tool wear conditions under different milling parameters.
Insight on Knowledge, Risk Perception and Practices to Prevent the Spread of COVID-19: A Cross-Sectional Study among Italian University Students
Authors: Licata Francesca , Oliverio Alessandra , Di Gennaro Gianfranco , Nobile Carmelo Giuseppe Angelo , Bianco Aida
Published: September 2021

Addressing adherence to non-pharmaceutical interventions among young adults represents a public health priority since this age group did not directly experience a health risk from COVID-19. The study aims were to investigate the level of knowledge, risk perception and practices to prevent the spread of COVID-19 among undergraduate university students in Southern Italy. This cross-sectional study was conducted between the 1st and 31st of July 2020. An anonymous and structured questionnaire was sent via institutional email. Among the 1323 sampled students, more than two-thirds gave the correct answer to all the knowledge statements. Good knowledge about COVID-19 showed a positive association with those studying medical or life sciences majors. Almost two-fifths (38.5%) of the sample declared to have quite a bit/extreme fear of falling ill with COVID-19 and it was significantly more likely among females and those with good knowledge. Only 30.2% of the students did not touch their face mask while using it. Moreover, practicing respiratory etiquette was more likely among females, among respondents with higher levels of fear of falling ill with COVID-19 and among those who exhibited good knowledge about COVID-19. The study insights will be valuable for the ongoing mitigation of the current pandemic especially with regard to the correct use of face masks.
Photocatalytic Phenol Degradation by Silica-Modified Titanium Dioxide
Authors: Eddy Diana Rakhmawaty , Ishmah Soraya Nur , Permana Muhamad Diki , Firdaus M. Lutfi , Rahayu Iman , El-Badry Yaser A. , Hussein Enas E. , El-Bahy Zeinhom M.
Published: September 2021

Titanium dioxide (TiO2) has been widely applied as a photocatalyst for wastewater treatment due to its high photocatalytic activity and it can remove various harmful organic pollutants effectively. Under heated system, however, TiO2 is prone to agglomeration that decrease its abilities as a photocatalyst. In order to overcome the agglomeration and increase its thermal resistance, addition of silica (SiO2) as supporting material is proposed in this research. Silica or silicon dioxide can be extracted from natural resources such as beach sand. Here, we report the application of a composite photocatalyst of TiO2/SiO2 to remove phenolic compounds in wastewater. The photocatalyst was synthesized by adding SiO2 from beach sand onto TiO2 through impregnation methods. The results of the X-ray diffraction (XRD) showed that TiO2 was present in the anatase phase. The highest crystallinity was obtained by TiO2/SiO2 ratios of 7:1. SEM results showed that the shape of the particles was spherical. Further characterizations were conducted using Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, and a particle size analyzer (PSA). By using the optimized condition, 96.05% phenol was degraded by the synthesized photocatalyst of TiO2/SiO2, under UV irradiation for 120 min. The efficiency of the TiO2/SiO2 is 3.5 times better than commercial TiO2 P25 for the Langmuir–Hinshelwood first-order kinetic model.
Assessment of Stocking Activities on the Native Brown Trout Populations from Nestos River (Southern Balkans) Inferred by mtDNA RFLP and Sequencing Analyses
Authors: Giantsis Ioannis A. , Sapounidis Argyrios , Koutrakis Emmanouil , Apostolidis Apostolos P.
Published: September 2021

Alien fish introductions, conducted towards the ichthyofauna enhancement in local drainages, have been occasionally proved harmful for the indigenous freshwater fish populations. The present study was designed to assess the impact of stocking activities, carried out in the past decades with fingerlings originating from Acheloos river hatcheries, on the native trout (Salmo sp.) populations of Nestos River, Greece. Trout specimens collected from several tributaries of Nestos River and were analyzed by means of PCR-RFLP and sequencing targeting the mitochondrial ND5-ND6 genes and the entire control region, respectively. It should be mentioned that trouts from Acheloos mainly belong to the marmoratus mitochondrial DNA (mtDNA) lineage, while the autochthonous trouts from Nestos belong to the Adriatic lineage. Both methodologies demonstrated that most samples from the three tributaries located at the lower part of Nestos constitute offspring of the fingerlings transferred from Acheloos hatcheries. Therefore, these tributaries have been strongly affected by stocking activities with a potential complete loss of their autochthonous trout. On the other hand, it seems that trout populations from higher altitude tributaries have not been affected by stockings. Hence, efforts should be undertaken in order to prevent the prevalence of the non-indigenous translocated Salmo in higher altitude tributaries, in conjunction with a management plan designed for the total trout populations from the area, speaking of which it has been recently included to the National Park of Rodopi Mountains.
Accuracy and Wear Evaluation of the Customized Zirconia Guided Sleeves
Authors: Chen Yu-Feng , Pan Chin-Yun , Chen Yung-Chung , Du Je-Kang , Lan Ting-Hsun
Published: September 2021

This in vitro study investigated the accuracy and wear conditions of three drill sleeve distances (0.01, 0.02, and 0.03 mm) for 3D-guided stents in simulated clinical dental implant surgery. Fifteen sets of upper and lower partially edentulous epoxy tooling board models with four edentulous first molar sites were prepared in a Nissin Simple Manikin II and set on a dental chair. Sixty computer-aided design and computer-aided manufacturing (CAD/CAM) designed and guided stents with three drill sleeve distances were prepared in this study. The maximum height (Sz) of the wear roughness of drills, maximum deviation, and drilling time were observed. The highest maximum horizontal deviations were observed at the upper first molar (0.48 ± 0.12 mm, p < 0.001). The highest maximum vertical and angular deviations were observed at the lower left first molar (1.08 ± 0.35 mm and 5.61° ± 1.21°, respectively, p < 0.001). Only angular deviation significantly differed among the three drill sleeve distances (p = 0.046); the 0.03 mm distance exhibited the maximum angular deviation (3.92° ± 1.87°). The bigger drill sleeve distance (0.03 mm) was associated with more wear roughness (8.70 ± 2.29 µm) of the drills. Guided stents with varying drill-sleeve distances (0.01, 0.02, and 0.03 mm) exhibited no significant difference in preparation drilling time and abrasive wear. In practice, the optimal drill sleeve distance for single-type CAD/CAM-guided stents of dental implantation was 0.01 mm.
Analysis of Carrier-Based Aircraft Catapult Launching Based on Variable Topology Dynamics
Authors: Chen Hu , Fang Xingbo , Nie Hong
Published: September 2021

The catapult process of a carrier-based aircraft includes multiple links such as catapult tensioning, separation of the holding rod, dragging and running, separation of the catapult and drag shuttle, and free running. The connection relationships between the front landing gear of the carrier-based aircraft and other related components in each link are different, therefore, it is necessary to adjust the topological relationships of the dynamic model in real time, when solving the catapult dynamics of a carrier-based aircraft. In this paper, a dynamic model of the multibody system of the catapult take-off is established, and a variable topology solution is carried out for the dynamic model by adjusting dynamic augmentation equations; in addition, a dynamic analysis of a carrier-based aircraft catapult and take-off process is carried out. A catapult dynamics model and variable topology solution method were established, which solved the changes at the moment of the restraining rod separation, catapult rod separation, and catapult tackle during the aircraft catapult take-off. After the restraining rod was separated from the front landing gear, the catapult force was transmitted to the rear strut, which instantly increased the load of the rear strut by 238.5 kN. In addition, after the carrier-based aircraft reached the end of the catapult’s stroke, the catapult rod was separated from the catapult tow shuttle then unloaded, and the load of the rear strut was reduced from 486.2 kN to −20.3 kN. Under the protruding effect of the nose gear, the pitch angle of the carrier-based aircraft increased rapidly from −0.93° and reached 0.54° when the carrier-based aircraft rushed out of the deck.
An Artificial Intelligence–Assisted Design Method for Topology Optimization without Pre-Optimized Training Data
Authors: Halle Alex , Campanile Lucio Flavio , Hasse Alexander
Published: September 2021

Engineers widely use topology optimization during the initial process of product development to obtain a first possible geometry design. The state-of-the-art method is iterative calculation, which requires both time and computational power. This paper proposes an AI-assisted design method for topology optimization, which does not require any optimized data. An artificial neural network—the predictor—provides the designs on the basis of boundary conditions and degree of filling as input data. In the training phase, the so-called evaluators evaluate the generated geometries on the basis of random input data with respect to given criteria. The results of those evaluations flow into an objective function, which is minimized by adapting the predictor’s parameters. After training, the presented AI-assisted design procedure generates geometries that are similar to those of conventional topology optimizers, but require only a fraction of the computational effort. We believe that our work could be a clue for AI-based methods that require data that are difficult to compute or unavailable.
Mechanical Properties and Microstructure of Shotcrete under High Temperature
Authors: Liu Guoming , Zhao Jipeng , Zhang Zhixue , Wang Chenglong , Xu Qianqian
Published: September 2021

High temperature is recognized as one of the extreme environments in the application of shotcrete which significantly deteriorate the performance of shotcrete. This paper reviews the mechanical properties and microstructure of shotcrete under high temperature. First of all, this paper reviews the cause of formation of high ground temperature. Based on these causes, the author establishes a heat transfer model with a spiral shape by introducing a multidimensional morphological formula into the heat conduction process. Then, the paper reviews the influence of high temperature on the mechanical and micro properties of shotcrete, the cooling technology under high temperature, and the optimization research technology of shotcrete. The author discusses the influence of high temperature on the thermal parameters and the deformation of shotcrete from the perspective of thermodynamics. Multiple studies have shown that the irregular movement and disorderly overlapping of molecules in the shotcrete caused by the high temperature environment result in the premature termination of the hydration reaction of cement in shotcrete. Finally, the author suggests the challenges of high-temperature shotcrete in term of the process structure, performance optimization, and application in special engineering fields. The research in this paper intends to give guidance to those conducting shotcrete research under high temperature, and to promote the further development of shotcrete technology.
Effects of Recycled Fine Glass Aggregates on Alkali Silica Reaction and Thermo-Mechanical Behavior of Modified Concrete
Authors: Abalouch Ibtissam , Sakami Siham , Elabbassi Fatima-Ezzahra , Boukhattem Lahcen
Published: September 2021

The objective of this work is to develop a new composite material by substituting sand with recycled waste glass (RWG). Different volume percentages of RWG varying from 0 to 50% were incorporated into concrete, with maximum size that did not exceed 1.25 mm. The microscopic characterization by scanning electron microscopy SEM-EDS and optical microscopic test, as well as the durability against alkali silica reaction (ASR) test, were performed respectively to visualize the morphology and assess the damage caused by ASR. Furthermore, the mechanical and thermophysical properties measurements were carried out. The results of microscopic characterization showed the presence of cracks inside a minority of glass particles due to ASR, and ASR test indicated that expansion activity remained well below the limit expansion value of 0.15%. The obtained results also showed that, at 28 and 90 days of curing, compressive strength increased respectively by up to 1.63% and 29% for 20% of the incorporated RWG volume rate in concrete; however, beyond this rate it diminished receptively by 30% and 3.2%. This improvement with curing age was attributed to pozzolanic reaction. Regarding density, it reduced by around 5%. Furthermore, thermal conductivity and thermal effusivity decreased respectively by 36% and 8.06% at dry state and they dropped respectively by 44% and 21.28% at saturated state, related to reference concrete RC. It is therefore feasible to substitute high amount of natural sand with RWG to obtain new composite that may be successfully used as structural material in construction building.
Non-Linear Dynamic Analysis of Drill String System with Fluid-Structure Interaction
Authors: Wang Rongpeng , Liu Xiaoqin , Song Guiqiu , Zhou Shihua
Published: September 2021

In this research, the non-linear dynamics of the drill string system model, considering the influence of fluid—structure coupling and the effect of support stiffness, are investigated. Using Galerkin’s method, the equation of motion is discretized into a second-order differential equation. On the basis of an improved mathematical model, numerical simulation is carried out using the Runge—Kutta integration method. The effects of parameters, such as forcing frequency, perturbation amplitude, mass ratio and flow velocity, on the dynamic characteristics of the drill string system are studied under different support stiffness coefficients, in which bifurcation diagrams, waveforms, phase diagrams and Poincaré maps of the system are provided. The results indicate that there are various dynamic model behaviors for different parameter excitations, such as periodic, quasi-periodic, chaotic motion and jump discontinuity. The system changes from chaotic motion to periodic motion through inverse period-doubling bifurcation, and the support stiffness has a significant influence on the dynamic response of the drill string system. Through in-depth study of this problem, the dynamic characteristics of the drill string can be better understood theoretically, so as to provide a necessary theoretical reference for prevention measures and a reduction in the number of drilling accidents, while facilitating the optimization of the drilling process, and provide basis for understanding the rich and complex nonlinear dynamic characteristics of the deep-hole drill string system. The study can provide further understanding of the vibration characteristics of the drill string system.
Cohesive Subgraph Identification in Weighted Bipartite Graphs
Authors: Liu Xijuan , Wang Xiaoyang
Published: September 2021

Cohesive subgraph identification is a fundamental problem in bipartite graph analysis. In real applications, to better represent the co-relationship between entities, edges are usually associated with weights or frequencies, which are neglected by most existing research. To fill the gap, we propose a new cohesive subgraph model, (k,ω)-core, by considering both subgraph cohesiveness and frequency for weighted bipartite graphs. Specifically, (k,ω)-core requires each node on the left layer to have at least k neighbors (cohesiveness) and each node on the right layer to have a weight of at least ω (frequency). In real scenarios, different users may have different parameter requirements. To handle massive graphs and queries, index-based strategies are developed. In addition, effective optimization techniques are proposed to improve the index construction phase. Compared with the baseline, extensive experiments on six datasets validate the superiority of our proposed methods.
Influence of Blade Wrap Angle on the Hydrodynamic Radial Force of Single Blade Centrifugal Pump
Authors: Tan Linwei , Yang Yongfei , Shi Weidong , Chen Cheng , Xie Zhanshan
Published: September 2021

To investigate the effect of blade wrap angle on the hydrodynamic radial force of a single blade centrifugal pump, numerical simulation is conducted on the pumps with different blade wrap angles. The effect of the wrap angle on the external characteristics and the radial force of a single blade centrifugal pump was analyzed according to the simulation result. It is found that, with the increase of the blade wrap angle, the head and efficiency of the single blade centrifugal pump are improved, the H-Q curve becomes steeper, and the efficiency also increased gradually, while the high-efficiency area is narrowed. The blade wrap angle has a great effect on the radial force of the single blade centrifugal pump. When the blade wrap angle is less than 360°, the horizontal component of the radial force is negative and the value is reduced with the increase of the wrap angle of the blade. When the wrap angle is larger than 360°, the horizontal component of the radial force is positive and the value increases with the increase of the wrap angle. Under part-loading conditions, the radial force of the single blade pump is significantly reduced with the increase of the blade wrap angle. When the wrap angle is smaller than 360°, the radial force decreases with the flow rate increase. In the condition that the wrap angle is larger than 360°, the radial force increases with the flow rate increase.
Experimental Investigation of Particle Size Degradation and Plugging Efficiency of Three Granular Lost Circulation Materials
Authors: Alhaidari Saleh A. , Alarifi Sulaiman A.
Published: September 2021

This work delineates a comprehensive study of one of the main problems that contributes towards nonproductive time (NPT) in a drilling operation, which is lost circulation. The focus of this study was to investigate the performance of walnut, graphite, and marble, which are three widely used and industry-available granular lost circulation materials (LCMs). Additionally, the study aimed to establish a particle size selection guideline for better operational performance and plugging efficiency. Four water-based carrier fluid systems (water–bentonite mix, water–polymer mix, and two polymer–salt systems) were tested with the LCMs in this study. Dry and wet particle size degradation studies were conducted on all the LCMs with the different carrier fluid systems to study their compatibility and efficiency. The effect of the carrier fluid type was proven to be significant only on marble particles size degradation; walnut and graphite were not affected by the carrier fluids and showed consistent size degradation performance with all fluids. The results of this work led to newly developed particle size selection guidelines to enhance plugging efficiency—guidelines that are custom-made for each material by taking into consideration the rate of the degradation and type of material and by correlating the findings with fracture width. Applying this method of investigation to the current lost circulation management practice can help resolve many lost circulation incidents by effectively and efficiently selecting the appropriate LCM.
Landslides Triggered by the May 2017 Extreme Rainfall Event in the East Coast Northeast of Brazil
Authors: Espinoza Nikolai S. , dos Santos Carlos A. C. , Silva Madson T. , Gomes Helber B. , Ferreira Rosaria R. , da Silva Maria L. , Santos e Silva Cláudio M. , de Oliveira Cristiano P. , Medeiros João , Giovannettone Jason , Amaro Venerando E. , Santos Celso A. G. , Mishra Manoranjan
Published: September 2021

Given the increasing occurrence of landslides on the East Coast Northeast of Brazil (ECNEB), it is essential to understand its conditions and triggering factors because meteorological anomalies triggered by a landslide will threaten life and property in the region. In this sense, this research aimed to diagnose the meteorological conditions that triggered landslides in the ECNEB in May 2017, evaluate the terrain’s intrinsic conditions using elevation, slope, and susceptibility parameters and determine critical precipitation thresholds for the city with the highest number of landslide risk areas in the region. A dynamic downscaling experiment was carried out using the Regional Climate Model (RegCM) to verify the ability of this model to represent rainfall over the ECNEB. The results from the intrinsic factors showed that the ECNEB is highly susceptible to landslides with various high-risk sectors for landslides to the population. The extreme rainfall event was associated with the convergence of humidity at low levels over the ocean, which contributed to landslides in the ECNEB, mainly in the State of Pernambuco, where 67 landslides were registered. The RegCM numerical simulation underestimated the high daily rainfall signal seen on the Tropical Rainfall Measuring Mission satellite. It is suggested that sensitivity tests can be performed using other physical parameters to find the best model configuration for the ECNEB. This work recommends that exploring the relationship between precipitation and landslides will provide objective criteria for assessing risk areas by contributing to the predictability of disasters in this region.