bluuebunny/crossref_metadata_2025_split huggingface dataset:
Large Eddy Simulation Studies on Effects of Soot Productivity in a Momentum Dominated Strained Diffusion Jet Flames
Authors: N.H. Mohamed Ibrahim , Udayakumar M. , Balasubramanian Dhinesh , Tran Viet Dung , Truong Thanh Hai , Nguyen Van Nhanh 
Published: September 2022

Abstract
The present numerical study is to determine the soot volume fraction, rate of soot nucleation, rate of coagulation, rate of surface growth, and rate of surface oxidation for flame configurations having the fuel mixture composition of C2H4: H2: N2 (63.4: 4.7: 31.9% by mass) along with air. The Brookes–Moss–Hall and OH oxidation radical is coupled with the combustion and P−1 radiation model. The inputs needed for this numerical study to determine soot volume fraction are maintained the same as the earlier experimental conditions. The hyperbolic function in the governing models is interpolated with quadratic upwind interpolation for convective kinetics, diffusion function with second-order upwind in space, and bounded second-order implicit in time. A suitable pressure implicit method for splitting operators, and a pressure–velocity coupler are also incorporated to evaluate pressure to satisfy continuity. The above governing models are solved using the ILU method with a unity Courant–Friedrichs–Lewy number. It is observed that along the axial direction, the flame with 12,900 s−1 shows higher rate of soot nucleation and rate of soot coagulation compared with the flame having lower strain rate. Also, the highest strain rate flame shows the lowest rate of soot surface growth, and also the rate of soot oxidation is the least.
Acceleration of a Physics-Based Machine Learning Approach for Modeling and Quantifying Model-Form Uncertainties and Performing Model Updating
Authors: Azzi Marie-Jo , Ghnatios Chady , Avery Philip , Farhat Charbel 
Published: September 2022

Abstract
The nonparametric probabilistic method (NPM) for modeling and quantifying model-form uncertainties is a physics-based, computationally tractable, machine learning method for performing uncertainty quantification and model updating. It extracts from data information not captured by a deterministic, high-dimensional model (HDM) of dimension N and infuses it into a counterpart stochastic, hyperreduced, projection-based reduced-order model (SHPROM) of dimension n ≪ N. Here, the robustness and performance of NPM are improved using a two-pronged approach. First, the sensitivities of its stochastic loss function with respect to the hyperparameters are computed analytically, by tracking the complex web of operations underlying the construction of that function. Next, the theoretical number of hyperparameters is reduced from O(n2) to O(n), by developing a network of autoencoders that provides a nonlinear approximation of the dependence of the SHPROM on the hyperparameters. The robustness and performance of the enhanced NPM are demonstrated using two nonlinear, realistic, structural dynamics applications.
Linear Quadratic Regulator Optimal Control of Two-Rotor Wind Turbine Mounted on Spar-Type Floating Platform
Authors: El Beshbichi Omar , Xing Yihan , Chen Ong Muk 
Published: September 2022

Abstract
Interest is steadily growing for multi-rotor wind turbine concepts. This type of wind turbine offers a practical solution for scaling issues of large wind turbine components and for the reduction of costs associated with manufacturing, logistics, and maintenance. However, the literature lacks thorough knowledge of the dynamic performance of multi-rotor wind turbine concepts installed on floating platforms. Previous research studied the dynamic response of a two-rotor wind turbine concept mounted on a spar-type floating platform (2WT). Platform yaw motion is a significant dynamic factor directly caused by differential turbulence intensity experienced by the two hubs coupled with the distribution of thrust loads on the tower structure. Blade-pitch control analysis also showed how the 2WT yaw response is extremely sensitive to the control strategy employed. In this work, a linear quadratic regulator (LQR) is used to design an optimal controller for the 2WT prototype. Three LQR gain schedules corresponding to three operation regions are considered. An in-house tool for the dynamic analysis of multi-rotor floating wind turbines is used for linear state-space extraction and dynamic analysis. The control performance in different load conditions is assessed against the baseline OC3 proportional-integral (PI) control strategy and a PI-P control strategy in a previous article presented by the authors.
A Dynamic Loading Mechanism for a Morphing Winglet
Authors: Buchkazanian Raffi S. , Campos Gabriel H. , Xi Fengfeng (Jeff) 
Published: September 2022

Abstract
A loading mechanism for a variable cant angle morphing winglet is proposed in this paper. The mechanism provides a method of loading a morphing winglet with the simulated aerodynamic lift force by maintaining its application direction always orthogonal to the surface of the winglet throughout the range of motion. The loading mechanism is developed by type synthesis of four-bar linkages through enumeration of prismatic and revolute joints. The final design is a R-P-R-P four-bar linkage modified by merging the middle P-R joint together to form a planar joint named Shark-fin. The shape of Shark-fin is optimized to minimize its weight effect on the overall loading system. A half-scale prototype was built as a reference to address several implementation issues including the neutral loading condition. Afterwards, a full-size dynamic loading mechanism was successfully constructed and implemented to load test a full-size morphing winglet.
Study on Geothermal Heat Exchangers With Nanofluids Containing Ceramic Nanoparticles
Authors: Barua Himel , Sinaki Maryam Younessi , Farhad Siamak 
Published: September 2022

Abstract
A geothermal heat exchanger (GHE) uses geothermal energy for heating or cooling residential places during winter or summer. Two different designs of GHEs, the straight pipe and coiled pipe designs, are evaluated in this study, and the effect of nanofluids as the working fluid is investigated. For this purpose, a mathematical model is developed, validated, and used to predict the temperature gain, heat gain, exergy gain, and pressure loss of the working fluid for different concentrations of additive ceramic nanoparticles of aluminum oxide (Al2O3) and magnesium oxide (MgO) in the working fluid. It is shown that the coiled pipe design has a better performance compared to the straight pipe design for GHEs. It is also shown how the temperature, heat gain, and exergy gain change with increasing the additive nanoparticles into the base fluid, which is water, while the pressure loss does not change significantly. The temperature gain increases about 60% when the volume fraction of nanoparticles in the base fluid reaches 2%. This also helps to improve the natural circulation of working fluid and the GHE may not need a circulating pump to run at low flowrates. It is also shown that the additive MgO nanoparticles are more effective than Al2O3 nanoparticles to improve the GHE performance.
Locating Acoustic Emission Signals Due to Shock Impacts on a Carbon Fiber Sample Using Piezoelectric and Fiber Optic Sensors
Authors: Stepanova L. N. , Kabanov S. I. , Chernova V. V. 
Published: September 2022

Abstract
Comparative tests related to locating acoustic emission (AE) signals due to shock impacts on a T700 carbon fiber sample were carried out. Piezoelectric acoustic emission transducers (AETs) and fiber-optic sensors (FOSs) were installed on the sample, forming rectangular location antennas measuring $$360 \times 280$$ mm. Strikes were delivered with balls weighing 10 and 18.5 g. Antennas consisting of four AET sensors and four FOS sensors and an antenna consisting of two AET sensors and two FOS sensors were organized. When using the antenna containing four FOS sensors, the impact on the sample was produced by a load weighing 530 g dropped from a height of 400 mm. AE signals were recorded by the SCAD-16.10 system with “floating” selection thresholds when the ball was dropped and during its repeated bounces. Then AE signal clusters were formed and recorded during the impact of loads. The arrival times of AE signals to the antenna sensors were calculated using the threshold method, the root mean square (RMS) deviation method and the two-interval method. It is shown that the maximum error in locating AE signals is observed when a steel ball with a diameter of 16 mm is dropped from a height of 300 mm and the minimum error is when using an electronic simulator.
Features of the Operation of a Three-Electrode Electrostatic Microgenerator in the Presence of Collisions between Electrodes
Authors: Dragunov V. P. , Ostertak D. I. , Sinitskiy R. E. , Dragunova E. V. 
Published: September 2022

Abstract
The results of studying the influence of impact interactions on the operation of a three-electrode two-capacitor microelectromechanical transducer (MEMT) and a microgenerator based on it are presented. The operation of the microgenerator in the impact periodic mode is analyzed for two extreme cases, when the movable electrode initially comes into contact with the limiters located on the left (LWC) or right (RWC) walls of the casing. The relationship between the system parameters and the characteristics of the external driving force source, which makes it possible to evaluate the possibility of implementing a periodic impact operation, is obtained. The dependences of the average generated power of the impact microgenerator on the number of collisions and the load are calculated. It is shown that a microgenerator with a three-electrode MEMT, in the case when the movable electrode initially comes into contact with the limiters located on the LWC, develops more power than in the case when the movable electrode initially touches the limiters located on the RWC. The efficiency of the microgenerator in impact and nonimpact modes is compared. It is shown that when using the impact mode, a gain by factors of 2 to 5 in the developed power is possible with a significant decrease of 1 to 2 orders of magnitude of the optimal load resistance compared to using an equivalent impact-free mode. In general, the analysis carried out and the developed approach make it possible to significantly narrow the range of the search for the necessary system parameters at the preliminary design stage and reduce the design time.
Significance of pancreatic duodenal homeobox-1 (PDX-1) genetic polymorphism in insulin secretion in Japanese patients with type 2 diabetes
Authors: Okura Tsuyoshi , Nakamura Risa , Ito Yuichi , Kitao Sonoko , Anno Mari , Endo Satomi , Taneda Natsuka , Matsumoto Kazuhisa , Shoji Kyoko , Okura Hiroko , Matsuzawa Kazuhiko , Izawa Shoichiro , Ueta Etsuko , Kato Masahiko , Imamura Takeshi , Taniguchi Shin-ichi , Yamamoto Kazuhiro 
Published: September 2022

IntroductionPancreatic and duodenal homeobox factor-1 (PDX-1) is an imperative gene for insulin secretion in maturity-onset diabetes of the young 4.PDX-1gene polymorphism was associated with lower first-phase insulin secretion in a genome-wide association study of intravenous glucose tolerance test. It was not associated with type 2 diabetes risk and insulin secretion in a genome-wide oral glucose tolerance test study. However, there have been no reports of overt type 2 diabetes and insulin resistance evaluation using a glucose clamp. We investigatedPDX-1polymorphism, insulin secretion, and insulin resistance in overt type 2 diabetes.Research design and methodsWe performed a meal tolerance test (MTT) and hyperinsulinemic–euglycemic clamping on 63 Japanese subjects, 30 with type 2 diabetes and 33 non-diabetic. We analyzed the rs1124607PDX-1gene polymorphism and defined A/C and C/C as the high-risk group and A/A as the low-risk group.ResultsHOMA-beta (homeostatic model assessment beta-cell function) was significantly lower in the high-risk group than in the low-risk group for all subjects (72.9±54.2% vs 107.0±63.5%, p<0.05). Glucose levels and glucose area under the curve (AUC) were not significantly different between both the risk groups. The insulin levels at 60 and 120 min and the insulin AUC after MTT were remarkably lower in the high-risk group than those in the low-risk group for all subjects (AUC 75.7±36.7 vs 112.7±59.5, p<0.05). High-risk subjects with type 2 diabetes had significantly lower insulin levels at 30 and 60 min and insulin AUC than low-risk subjects. Non-diabetic high-risk subjects depicted significantly lower insulin levels at 120 and 180 min. There were negligible differences in insulin resistance between the risk groups.ConclusionsThese results suggest that thePDX-1genetic polymorphism is crucial for insulin secretion in Japanese patients with type 2 diabetes.
Practical utility of the ACT-FAST triage algorithm from a primary stroke centre perspective
Authors: Tan Shuangyue , Stephens Karen , Gao Lan , Tan Elise , Frost Tanya , Choi Philip M C 
Published: September 2022

Background: Rapid reperfusion in ischaemic stroke with emergent large vessel occlusion (ELVO) reduces morbidity and mortality. Limited distribution of endovascular clot retrieval (ECR) capable comprehensive stroke centres (CSCs) necessitates development of pre-hospital models of care to provide equitable and economical access to reperfusion therapy. We examine the time metrics of the traditional secondary transfer strategy in comparison to the direct bypass strategy and the potential utility of the ACT-FAST prehospital triage algorithm on a large volume Melbourne primary stroke centre (PSC).Method: Retrospective analysis of consecutive patients presenting to a PSC from 1 January 2020 to 31 December 2020. Clinical records were interrogated for ACT-FAST positive patients. Time metrics were established using Google Maps traffic modelling and local/published door-to-needle, door-in-door out and door-to-groin data.Results: 88 patients during the study period were ACT-FAST positive. Of these, 49/88 (56%) cases had ELVO ischaemic strokes, 24/88 (27%) cases had intracranial haemorrhages and the remaining 15/88 (17%) had non ELVO ischaemic strokes or mimics (seizure, complex migraine, etc). 28/88 (32%) cases met indication for and were subsequently transferred to a CSC for consideration of ECR. The modelled median scene to groin time for the direct bypass strategy is 94 min whereas the median scene to groin time for the secondary transfer strategy is 109 min, giving a difference of 15 min.Conclusion: Time savings to groin puncture for the direct bypass strategy is substantially less than previous estimates and suggests that the secondary transfer strategy continues to be a viable pathway for a high efficiency PSC.
‘Is it painful’? A qualitative study on experiences of patients before prostate needle biopsy
Authors: Mao Jinjiao , Dai Yun , Wang Lijuan , Pan Shucheng , Wang Wei , Yu Hongwei 
Published: September 2022

ObjectiveTo assess the experiences and emotional reactions of men prior to receiving a prostate needle biopsy (PNB).DesignThis was a qualitative study involving (1) material research and filter, (2) interviewer training, (3) cognitive semistructured interviews with open-ended questions, (4) data analysis, including translation and back translation and (5) group discussions to determine common themes in the data. All interviews were digitally audio-recorded. The thematic analysis was conducted by repeatedly reading the data manuscript and engaging in group discussion.Setting and participantsA total of 30 participants with suspected prostate cancer (PC) who were scheduled to receive a PNB were interviewed. Eligible participants were Chinese native men aged 51–77 years, and the study was conducted in China between September and December 2020. All participants were informed about the purpose of the study and provided written informed consent.ResultsFour main themes were identified based on the interview content: (1) fear (of pain, adverse effects and bad results), (2) impact of lower urinary tract symptoms (on emotional impact, work and sleeping), (3) inner struggles (relating to hesitation, regret and embarrassment) and (4) lifestyle change (including diet, exercise and receipt of traditional Chinese medicine).ConclusionsThis patient cohort had a low level of knowledge about PC and PNB. Providing additional education about these topics would help to reduce patient fear and anxiety and improve experiences of the procedure.
Effect of transcutaneous electrical acupoint stimulation on bone metabolism in patients with immobilisation after foot and ankle fracture surgery: a randomised controlled trial study protocol
Authors: Guo Shiqi , Zhao Guozhen , Chen Xue-ming , Xue Ying , OuYang Xia-li , Liu Jin-Yi , Huang Yue-ping , Liu Ya-jie , Yao Qin , han li , Zhang Chun-hui , Li Bo , Wang Qi , Zhao Baixiao 
Published: September 2022

IntroductionFracture is a disease with a high incidence worldwide. Foot and ankle fractures are common among fractures of the lower extremities. Foot and ankle fractures usually require surgical fixation and a period of fixed treatment, which can lead to decreased bone density. Although transcutaneous electrical acupoint stimulation (TEAS) is widely used for movement system diseases, there is minimal evidence to show the effectiveness of TEAS on patients after surgical fixation of ankle and foot fractures. This trial aims to evaluate whether TEAS can reduce bone loss in patients with immobilisation after ankle and foot fractures.Methods and analysisA randomised controlled trial will be conducted in which 60 patients will be randomly divided into two groups: (a) the control group will be treated according to the routine procedures of basic orthopaedics treatment; (b) in the treatment group, bilateral SP36, BL23 and ST36 will be performed on the basis of the control group, and the test will be performed for 30 min every other day for a total of 8 weeks. Bone turnover markers will be used as primary outcome. Secondary outcomes are composed of blood phosphorus, blood calcium and bone mineral density. Treatment safety will be monitored and recorded.Ethics and disseminationThis trial is approved by the Ethics Committee of Beijing University of Chinese Medicine (2020BZYLL0611) and the Ethics Committee of Beijing Luhe Hospital (2020-LHKY-055-02), and inpatients who meet the following diagnostic and inclusion criteria are eligible to participate in this study.Trial registration numberChiCTR 2000039944.
Glucocorticoid receptor expression in patients with cardiac arrest in the early period after the return of spontaneous circulation: a prospective observational single-centre study
Authors: Yu Yanan , Tang Ziren , Xie Miaorong , Li Jiabao , Hang Chen-Chen , An Le , Li Chunsheng 
Published: September 2022

ObjectivesRapid changes in glucocorticoid (GC) levels and adrenal insufficiency are related to the development of post-cardiac arrest (CA) syndrome. However, GC receptor (GR) expression changes have not been studied. Hence, this study aimed to investigate the association of early changes in GR expression and prognosis and immune response in patients who experienced CA.DesignProspective observational study.SettingEmergency department.ParticipantsPatients (85) in the early period of return of spontaneous circulation (ROSC) after CA were admitted between October 2018 and October 2019. After a physical examination, age-matched and sex-matched healthy individuals (40) were recruited for the control group.Primary and secondary outcome measuresGR expression and cell counts of circulatory T and B lymphocytes, natural killer cells and regulatory T (Treg) cells were assessed. Plasma total cortisol and adrenocorticotrophic hormone (ACTH) levels were also tested.ResultsAll cell counts were lower, and plasma total cortisol levels were higher (p<0.001) in patients who experienced CA than in the healthy control group. GR expression in Treg cells and CD3+CD4+ T lymphocytes were not significantly different, but the mean fluorescence intensity and GR expression in other cells were lower in patients who experienced CA (p<0.05) than in the healthy control group. ACTH levels were not different. There were no significant differences between survivors and non-survivors.ConclusionsThis study revealed that GR expression and cell counts rapidly decreased, whereas plasma total cortisol levels increased in the early period after ROSC among patients who experienced CA. Our findings provide important information about GR level and function, and immunosuppressive status in these patients. Assessing GR expression in patients who experienced CA may help screening for those who are more sensitive to GC therapy.
SARS-CoV-2 chronological genomic evolution and epidemiology in the Middle East and North Africa (MENA) region as affected by vaccination, conflict and socioeconomical disparities: a population-based cohort study
Authors: Obeid Dalia , Alnemari Rawan , Al-Qahtani Ahmed A. , Alsanea Madain , Alahideb Basma , Alsuwairi Feda , Abdulkarim Maha , Alhamlan Fatimah S. 
Published: September 2022

ObjectiveTo describe the chronological genomic evolution of SARS-CoV-2 and its impact on public health in the Middle East and North Africa (MENA) region.MethodsThis study analysed all available SARS-CoV-2 genomic sequences, metadata and rates of COVID-19 infection from the MENA region retrieved from the Global Initiative on Sharing All Influenza Data database from January 2020 to August 2021. Inferential and ‎descriptive statistics were conducted to describe the epidemiology of SARS-CoV-2.ResultsGenomic surveillance of SARS-CoV-2 in the MENA region indicated that the variants in January 2020 predominately belonged to the G, GR, GH or O clades and that the most common variant of concern was Alpha. By August 2021, however, the GK clade dominated (57.4% of all sequenced genomes), followed by the G clade (18.7%) and the GR clade (11.6%). In August, the most commonly sequenced variants of concern were Delta in the Middle East region (91%); Alpha (44.3%) followed by Delta (29.7%) and Beta (25.3%) in the North Africa region; and Alpha (88.9%), followed by Delta (10%) in the fragile and conflict-affected regions of MENA. The mean proportion of the variants of concern among the total sequenced samples differed significantly by country (F=1.93, P=0.0112) but not by major MENA region (F=0.14, P=0.27) or by vaccination coverage (F=1.84, P=0.176).ConclusionThis analysis of the genomic surveillance of SARS-CoV-2 provides an essential description the virus evolution and its impact on public health safety in the MENA region. As of August 2021, the Delta variant showed a genomic advantage in the MENA region. The MENA region includes several fragile and conflict-affected countries with extremely low levels of vaccination coverage and little genomic surveillance, which may soon exacerbate the existing health crisis within those countries and globally.