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Optimization of body configuration and joint-driven attitude stabilization for transformable spacecraft under solar radiation pressure

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Astrodynamics 2024年第1期8卷 47-60页

作者： Yuki Kubo Toshihiro Chujo Institute of Space and Astronautical Science Japan Aerospace Exploration AgencyKanagawa252-5210Japan department of Mechanical Engineering Tokyo Institute of TechnologyTokyo152-8550Japan

The solar sail is one of the most promising space exploration systems due to its theoretically infinite specific impulse achieved through solar radiation pressure(SRP).Recently,researchers have proposed“transformable spacecraft”capable of actively reconfiguring their body configurations using actuatable *** spacecraft,if used similarly to solar sails,are expected to significantly enhance orbit and attitude control capabilities owing to their high redundancy in control degrees of ***,controlling them becomes challenging due to their large number of inputs,leading previous researchers to impose strong constraints to limit their potential control *** study focuses on novel attitude control techniques for transformable spacecraft under *** developed two methods,namely,joint angle optimization to obtain arbitrary SRP force and torque,and momentum damping control driven by joint angle *** proposed methods are formulated in a general manner and can be applied to any transformable spacecraft comprising front faces that can predominantly receive the SRP on each *** validity of our proposed method is confirmed through numerical *** study contributes to making most of the high control redundancy of transformable spacecraft without the need for expendable propellants,thus significantly enhancing the orbit and attitude control capabilities.

关键词： solar sail transformable spacecraft attitude-joint coupled motion attitudestabilization

Role of albumin-bilirubin score in non-malignant liver disease

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World Journal of Gastroenterology 2024年第9期30卷 999-1004页

作者： Shi-Xue Xu Fan Yang Nan Ge Jin-Tao Guo Si-Yu Sun department of Gastroenterology Engineering Research Center of Ministry of Education for Minimally Invasive Gastrointestinal Endoscopic TechniquesShengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

The albumin-bilirubin(ALBI)score,which was proposed to assess the prognosis of patients with hepatocellular carcinoma,has gradually been extended to other liver diseases in recent years,including primary biliary cholangitis,liver cirrhosis,hepatitis,liver transplantation,and liver *** ALBI score is often compared with classical scores such as the Child-Pugh and model for end-stage liver disease scores or other noninvasive prediction *** is widely employed because of its immunity to subjective evaluation indicators and ease of obtaining detection *** increasing number of studies have confirmed that it is highly accurate for assessing the prognosis of patients with chronic liver disease;additionally,it has demonstrated good predictive performance for outcomes beyond survival in patients with liver diseases,such as decompensation *** article presents a review of the application of ALBI scores in various non-malignant liver diseases.

关键词： Albumin-bilirubin score Liver cirrhosis Primary biliary cholangitis Hepatitis Liver transplantation Liver injury

From macroautophagy to mitophagy:Unveiling the hidden role of mitophagy in gastrointestinal disorders

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World Journal of Gastroenterology 2024年第23期30卷 2934-2946页

作者： Duo-Lun Gao Meng-Ran Lin Nan Ge Jin-Tao Guo Fan Yang Si-Yu Sun department of Gastroenterology Engineering Research Center of Ministry of Education for Minimally Invasive Gastrointestinal Endoscopic TechniquesShengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

In this editorial,we comment on an article titled“Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases”,which was published in a recent issue of the World Journal of *** focused on the statement that“autophagy is closely related to the digestion,secretion,and regeneration of gastrointestinal cells”.With advancing research,autophagy,and particularly the pivotal role of the macroautophagy in maintaining cellular equilibrium and stress response in the gastrointestinal system,has garnered extensive ***,the significance of mitophagy,a unique selective autophagy pathway with ubiquitin-dependent and independent variants,should not be *** recent decades,mitophagy has been shown to be closely related to the occurrence and development of gastrointestinal diseases,especially inflammatory bowel disease,gastric cancer,and colorectal *** interplay between mitophagy and mitochondrial quality control is crucial for elucidating disease mechanisms,as well as for the development of novel treatment *** the pathogenesis behind gastrointestinal diseases and providing individualized and efficient treatment for patients are subjects we have been *** article reviews the potential mechanism of mitophagy in gastrointestinal diseases with the hope of providing new ideas for diagnosis and treatment.

关键词： Mitophagy Gastrointestinal diseases Parkin Autophagic receptor Colorectal cancer Gastric cancer Inflammatory bowel disease

Acceptability of Immunization against COVID-19 by the Populations of the Kasenga State Health Area in the Uvira Health Zone, DR Congo

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Journal of Immune Based Therapies, Vaccines and Antimicrobials 2024年第3期13卷 33-46页

作者： Derrick Bushobole Akiba Eric Amuri Madabali Robert Bushambale Fataki Abel Asende Luhendama Jacques Mutono Matongo Faustin Bukuru Mudage Christian Banyakwa Mitunda Saili Stay Mushobekwa Michel Byaombe Wa Ngene Martin Longolongo Kiza Paulin Mulogoto Rushanika Emmanuel Nirambo Rujanjika Henry Manya Mboni Criss Koba Mjumbe department of Public Health Higher Institute of Medical Techniques of Uvira (ISTM-Uvira) South Kivu DR Congo department of Laboratory techniques Higher Institute of Medical Techniques of Uvira (ISTM-Uvira) South Kivu DR Congo Nursing Science Sector Higher Institute of Medical Techniques of Uvira (ISTM-Uvira) South Kivu DR Congo department of Public Health University of Lubumbashi Lubumbashi DR Congo department of Pharmaceutical techniques University of Lubumbashi DR Congo department of Pharmaceutical techniques Higher Institute of Medical Techniques of Uvira (ISTM-Uvira) South Kivu DR Congo

Introduction: COVID-19 was an emerging disease putting all public health systems in countries around the world in a state of emergency. To be able to prevent its spread and morbidity and mortality, several appropriate strategies were necessary, such as vaccination. The latter has been the subject of controversy. The objective of the present study is therefore to evaluate the factors associated with the acceptance of this vaccine within the population of the Kasenga State Health Area. A result which will shed light on future strategies to be put in place for possible new vaccines. Methodology: Is a prospective and analytical cross-sectional study conducted over a period of approximately 1 month from January 5 to February 5, 2024. A survey questionnaire in Kobotoolbox was useful for collecting data. STATA software was very important for us in analyzing the data collected. Results: Prevalence of vaccination against COVID-19 among the population of the Kasenga State Health Area is 37.5% (28.4 - 45.6). The study revealed that reluctance is observed among most of the population for different reasons, including, first and foremost, the deliberate aspect of not wanting to take the vaccine (46.6%) and rumors that this antigen is dangerous and harmful (32.9%). 72.5% of respondents believe that the COVID-19 vaccine is a fabrication, unhealthy and that the disease itself never existed. The study proved that there was a statistical relationship between age (p = 0.001) and adherence to vaccination. And the refusal of respondents to recommend the vaccine to loved ones was a factor associated with non-adherence to vaccination (OR = 7.901, 95% IC [3.028 - 20.615], p = 0.000). Conclusion: Vaccination against COVID-19 was not well accepted by the population of the study site. Raising public awareness and involving community leaders and political-administrative authorities, which has not been done well, would play an important role in the good perception of the disease, of the vaccine

关键词： COVID-19 Vaccination Kasenga State Health Area Associated Factors Uvira Health Zone City of Uvira

Heat Transfer Enhancement of the Absorber Tube in a Parabolic Trough Solar Collector through the Insertion of Novel Cylindrical Turbulators

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1279-1297页

作者： Yasser Jebbar Fadhil Fluiful Wisam Khudhayer department of Electrical techniques Al-Mussaib Technical InstituteAl-Furat Al-Awsat Technical UniversityBabilIraq department of Physics Collage of ScienceUniversity of KerbalaKarbalaIraq department of Energy Engineering Collage of Engineering/Al-MusayabUniversity of BabylonBabilIraq

This study includes an experimental and numerical analysis of the performances of a parabolic trough collector(PTC)with and without cylindrical *** PTC is designed with dimensions of 2.00 m in length and 1.00 m in *** related reflector is made of lined sheets of aluminum,and the tubes are made of stainless steel used for the absorption of *** have an outer diameter of 0.051 m and a wall thickness of 0.002 ***,used as a heat transfer fluid(HTF),flows through the absorber tube at a mass flow rate of 0.7 kg/*** dimensions of cylindrical turbulators are 0.04 m in length and 0.047 m in *** are performed using the ANSYS Fluent 2020 R2 *** PTC performance is evaluated by comparing the experimental and numerical outcomes,namely,the outlet temperature,useful heat,and thermal efficiency for a modified tube(MT)(tube with novel cylindrical turbulators)and a plain tube(PT)(tube without novel cylindrical turbulators).According to the results,the experimental outlet temperatures recorded 63.2°C and 50.5°C for the MT and PT,*** heat gain reaches 1137.5 Win the MT and 685.8 Win the *** to the PT collector,the PTC exhibited a(1.64 times)higher efficiency.

关键词： Parabolic trough collector turbulators absorber tube ANSYS thermal efficiency

A Transient-Pressure-Based Numerical Approach for Interlayer Identification in Sand Reservoirs

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Fluid Dynamics & Materials Processing 2024年第3期20卷 641-659页

作者： Hao Luo Haibo Deng Honglin Xiao Shaoyang Geng Fu Hou Gang Luo Yaqi Li Tight Oil and Gas exploration and Development Project department PetroChina Southwest Oil and Gas Field CompanyChengdu610051China Energy College Chengdu University of TechnologyChengdu610059China

Almost all sandstone reservoirs contain interlayers. The identification and characterization of these interlayers iscritical for minimizing the uncertainty associated with oilfield development and improving oil and gas *** interlayers outside wells using identification methods based on logging data and machine learning isdifficult and seismic-based identification techniques are expensive. Herein, a numerical model based on seepageand well-testing theories is introduced to identify interlayers using transient pressure data. The proposed modelrelies on the open-source MATLAB Reservoir Simulation Toolbox. The effects of the interlayer thickness, position,and width on the pressure response are thoroughly investigated. A procedure for inverting interlayer parametersin the reservoir using the bottom-hole pressure is also proposed. This method uses only transient pressuredata during well testing and can effectively identify the interlayer distribution near the wellbore at an extremelylow cost. The reliability of the model is verified using effective oilfield examples.

关键词： Sand reservoir interlayer identification transient pressure analysis numerical well test

A hybrid machine learning approach based study of production forecasting and factors influencing the multiphase flow through surface chokes

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Petroleum 2024年第2期10卷 354-371页

作者： Waquar Kaleem Saurabh Tewari Mrigya Fogat Dmitriy A.Martyushev department of Industrial and Manufacturing Engineering The Pennsylvania State University department of Data Sciences Gyan Ganga Institute of Technology and Sciences department of Petroleum and geo-Engineering Rajiv Gandhi Institute of Petroleum Technology Jais department of Oil and Gas Technologies Perm National Research Polytechnic University

Surface chokes are widely utilized equipment installed on wellheads to control hydrocarbon flow *** correlations have been suggested to model the multiphase flow of oil and gas via surface ***, substantial errors have been reported in empirical fitting models and correlations to estimate hydrocarbon flow because of the reservoir's heterogeneity, anisotropism, variance in reservoir fluid characteristics at diverse subsurface depths, which introduces complexity in production data. Therefore,the estimation of daily oil and gas production rates is still challenging for the petroleum ***, hybrid data-driven techniques have been reported to be effective for estimation problems in various aspects of the petroleum domain. This paper investigates hybrid ensemble data-driven approaches to forecast multiphase flow rates through the surface choke(viz. stacked generalization and voting architectures), followed by an assessment of the impact of input production control ***, machine learning models are also trained and tested individually on the production data of hydrocarbon wells located in North Sea. Feature engineering has been properly applied to select the most suitable contributing control variables for daily production rate forecasting. This study provides a chronological explanation of the data analytics required for the interpretation of production data. The test results reveal the estimation performance of the stacked generalization architecture has outperformed other significant paradigms considered for production forecasting.

关键词： Machine learning Tree-based methods Stacking ensemble Multiphase flow Data analytics Wellhead choke variables

Characteristics of Gold and Its Mineralization Style in the Boulon Djounga Eastern Perimeter of Liptako Mining Company (Central Southwestern Niger)

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Natural Resources 2024年第1期15卷 28-50页

作者： Gambo Ranaou Noura Kamayé Tourba Karimou Dia Hantchi Bouba Hassane Moussa Konaté department of geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger department of geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger

The Boulon Djounga eastern perimeter is part of the Tiawa operating permit of the Société des Mines du Liptako (SML), located in the central southwestern part of Liptako (Niger). In this study, we used field data, Reverse Circulation (RC) surveys and chemical analyzes of gold to determine the characteristics of gold and its mineralization style. The eastern perimeter of Boulon Djounga is represented by a succession of metabasalts and metasediments both intersected by intrusions of quartz and dolerite dykes, and covered by sandstone and clayey rocks. Gold is present in low contents (0.00 - 0.30 ppm) in the sedimentary cover and in medium (0.30 - 1.00 ppm) or high contents (1.00 - 4.534 ppm) in the metasediments, and in the gray quartz veins and locally in the volcanics. It exists in a disseminated state or in a concentrated state in the surrounding areas in the form of discrete grains associated with sulphurous minerals (pyrite: FeS2, chalcopyrite: CuFeS2 or arsenopyrite: FeAsS). The presence of gold in the quartz veins, and the NE-SW and NW-SE orientations of the ore bodies suggest that the eastern Boulon Djounga gold mineralization would be established during a late magmatic extensive phase.

关键词： Liptako Gold Mineralization Metasediments-Volcanics Quartz Veins Sulphurous Minerals Niger

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

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Nuclear Science and techniques 2024年第7期35卷 126-136页

作者： Yuan-Qiao Li Min Lin Li-Jun Xu Rui Luo Yu-He Zhang Qian-Xi Ni Yun-Tao Liu China Institute of Atomic Energy Beijing102413China National Key Laboratory for Metrology and Calibration techniques Beijing102413China department of Radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)<0.070 for the comparison of each source,and the uncertainty results of the GUM were all lower than those of the ***,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

关键词： Surface emission rate Monte Carlo method Metrology Probability distribution function Dead time Low-energy loss correction Least-squares method