bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on mechanical properties of titanium alloy drill pipe and application technology
Authors: Yang Xiaoyong , Chen Shichun , Feng Qiang , Zhang Wenhua , Wang Yue
Published: May 2021

With the increasing intensity of oil and gas field exploration and development, oil and gas wells are also drilling into deeper and more complex formations. Conventional steel drilling tools can no longer meet the requirements of ultra-deep, high-temperature and high-pressure wells. The paper first analyzes the advantages of titanium alloy drill pipe based on basic performance of titanium alloy drill pipe. The experimental results show that the basic properties of titanium alloy drill pipes meet the operating standards of the petroleum industry. Then the buckling performance of titanium alloy drill pipe and steel drill pipe is compared, the calculation results show that the buckling performance of titanium alloy drill tools is slightly lower than that of steel drill tools. Secondly, the maximum allowable buildup rate of titanium alloy drill pipe and steel drill tool is studied. The research shows that under the same condition of the drill pipe outer diameter, titanium alloy drill pipe can be used for a smaller curvature radius and greater buildup rate. This advantage of titanium alloy drill pipe makes it more suitable for short radius and ultra-short radius wells. Finally, taking a shale gas horizontal well as an example, with the goal of reducing drill string friction and ensuring drill string stability, a comparative study on the application of titanium alloy drill pipe and steel drill pipe is carried out. The results show that titanium alloy drill pipe has a wider application in the field, and is suitable for operations under various complex working conditions.
Flow Field Simulation and Efficiency Calculation of Muzzle Brake Based on ANSYS Fluent
Authors: Wang Zhen
Published: May 2021

The development of advanced artillery needs to be combined with simulation means, so, traditional calculation method and the flow field simulation method was employed to calculate the efficiency of a largecaliber muzzle brake we designed, and the results achieved by these two methods were 47.8% and 49.3%, respectively. Further, the overpressure value 1 m away from the muzzle was obtained through flow field simulation, and the far-field overpressure value was calculated using blast wave attenuation equations. The result suggests that the blast wave from the designed muzzle brake has little harmful impact. This paper provides an intuitive calculation method of muzzle brake efficiency, also, it provides theoretical support for research of high efficiency muzzle brake and personnel protection onboard.
Photocatalytic degradation of ethyl paraben wastewater by mixed crystal molecularly imprinted TiO2
Authors: Zhang Liangxiao , Zhu Lei , Wang Xun , Tao Xiumei , Liu Xian
Published: May 2021

Using ethyl paraben as the template molecule and n-tetrabutyl titanate as the titanium source, the molecularly imprinted titanium dioxide (MIP-TiO2) photocatalyst was prepared by the sol-gel method. The effects of different pH values, imprinting molecular weights and other factors on the degradation of ethyl paraben were studied, and the materials were analyzed by TEM, XRD, FT-IR and other characterization methods. The results show that the catalyst has a mixed crystal structure in which anatase and rutile ore coexist, and the rutile ore content of MIP-TiO2is calculated to be 78.5%. Catalytic degradation of ethyl paraben by reacting for 40 min under ultraviolet light, the removal rate of ethyl paraben by pure TiO2is 80.74%, and the removal rate of ethyl paraben by MIP-TiO2can reach 96.27%. MIP-TiO2is 15.53% higher than TiO2. MIP-TiO2has imprinting holes, which can target the target pollutants and effectively improve the selectivity of the photocatalyst MIP-TiO2. The selectivity factor of MIP-TiO2is 1.69 times that of TiO2.
Failure Analysis and Protection of Oxygen Corrosion of Reheater Tube in a Power plant
Authors: Yang Chao , Li Xiuneng , Wang Yunan , Sun Mingcheng
Published: May 2021

The failure analysis of reheater tubes were analyzed by means of alloy composition analysis, metallographic structure analysis, mechanical properties analysis and oxide composition analysis. The results showed: The alloy composition meets the requirements of 12Cr1MoV standard. No abnormality was observed in metallographic structure. Mechanical properties qualified. Oxide components are mainly O and Fe. Comprehensive analysis shows that The main reason of reheater tube failure is oxygen corrosion, which caused thinning of the reheater tube wall, leading to leakage accident. Suggestions for subsequent protection are put forward.
Directional Bouncing of Impacting Droplets on Non-Uniform Rough Surfaces with High Temperature
Authors: Sun Kuan , Liu Cong , Feng Shile , Liu Yahua
Published: May 2021

Directional transport of high-temperature droplets enjoys broad application prospects in the fields of drag reduction and heat transfer. In this paper, two adjacent regions with different surface roughness were constructed on 304 stainless steel by laser etching to control the directional movement of high-temperature droplets. It is found that the regions with different surface roughness have different Leidenfrost temperatures, and the Leidenfrost temperature is lower under smaller roughness. When the droplet hits the boundary of the adjacent regions at high temperatures, it will bounce towards the region with larger roughness spontaneously, and the directional bouncing distance tends to first increase and then decrease with the increase of temperature and Weber number. In addition, when the droplet impacts at the boundary of the adjacent regions which have different Leidenfrost temperatures, the two parts of the droplet will be in transition boiling and film boiling respectively. The resulting Young’s force is the main factor that drives the droplets to bounce directionally.
Improving electrochemical corrosion properties of ZE41A magnesium alloy via hydrothermal treatment
Authors: Zhang Yuguang , Zhang Fan , Cheng Qingpeng , Huang Xiuling , Zhang Kai , Wen Guosen , Zhang Chaoxiong
Published: May 2021

ZE41A magnesium alloy was selected as matrix material, using hydrothermal method for the synthesis of the surface coating. The formation of anti-corrosion coatings on the surface of magnesium alloy was investigated in pure water. By adjusting the experimental parameters such as the hydrothermal time (1-3 h) and the hydrothermal temperature (120-160 °C), the generation of the coating on the magnesium alloy surface is regulated. The surface morphologies, composition phase, and corrosion resistance of the hydrothermal conversion coatings were investigated by the method of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical corrosion tests. Results show that prolonged hydrothermal time and increased hydrothermal temperature change the morphologies as well as the chemical compositions of formed coatings from a relative loose structure with few magnesium hydroxides into a fine dense one with higher amount of magnesium hydroxide.
Effect of foliar iron sulfate on the fruit growth and quality of pineapple (Ananas comosus cv. Yellow Mauritius) planted in lateritic soil in Leizhou Peninsula
Authors: Liu ShengHui , Zhu ZhuYing , Zhang YuMei , Wu QingSong , Zhang XiuMei
Published: May 2021

Leizhou Peninsula in South China is facing a serious water shortage problem because of the special regional and geological conditions. As a kind of low water requirement crop, pineapple has been popular in lateritic soil. However, the physical characteristics of Lateritic soil such as too cohesive, impervious, low content of organic matter, and seasonal arid often bring some problem to pineapple cultivation. Seasonal iron deficiency can be easily observed from April to July. The effect of foliar spray of iron sulfate (with concentration of 0, 0.5%, 0.75%, 1%) on the fruit growth and quality of pineapple cv. Yellow Mauritius were studied in this research. Results showed that there were no significant difference (p>0.05) on the fruit weight, longitudinal diameter, transverse diameter among all the treatment. 0.75% treatment increased the fruit weight to 6.08% and decreased crown weight significantly. Both 0.75% and 1% iron sulfate treatment not only enhanced vitamin C extremely significantly, but also improved the aroma quality significantly with the increase of total esters, especially in the content of hexanoic acid methyl ester, 3-(methyl tio) propanoic acid methyl ester and 2-methylbutanoic acid methyl ester. The content of these 3 esters above were all extremely significantly higher than control, which means much stronger pleasant aroma. Hence, 0.75% was the optimal concentration of foliar spray with iron sulfate in pineapple cv. Yellow Mauritius.
Research on Precharge Control Strategy of Modular Multilevel Inverter
Authors: Fang Chuanliang , Chen Guochu
Published: May 2021

This paper mainly introduces the Modular Multilevel Converter (MMC) topology structure, simple analysis of the working principle of MMC, deduced the mathematical model of MMC. The precharging control strategy of MMC sub-module (SM) is studied, and the charging process is divided into uncontrollable charging stage and controllable charging stage. For the uncontrollable charging stage, an improved DC side pre-charging method is proposed, and a five-level simulation model of voltage-type MMC is established in the Matlab/Simulink simulation environment, and the simulation results of the system are comprehensively analyzed.
One-step vapor-pressured induced synthesis of spherical-like Co9S8/N, S-codoped carbon nanocomposites with superior rate capability as lithium-ion-battery anode
Authors: Li Jiayang , Li Zhenwei , Han Meisheng
Published: May 2021

As high theoretical capacity and excellent electrical conductivity, Co9S8 as a promising electrode material in lithium-ion batteries (LIBs) has attracted wide attention. In the present work, a simple vaporpressured induced route is developed for fabricating spherical-like Co9S8/N, S-codoped carbon nanocomposites (Co9S8/NSC), in which Co9S8 nanoparticles with an average size of 100 nm are encapsulated into N, S-codoped carbon matrix, by pyrolysis of mixture of cobalt isooctanoate dissolved into dimethylformamide and thiourea in a sealed vessel for the first time. As anode for LIBs, the Co9S8/NSC shows an excellent reversible capacity, a superior rate performance, and a long cycling stability. For example, a high capacity of 975.3 mA h g-1 can be achieved after 100 cycles at 0.1 A g-1. When cycled at 1 A g-1, it also maintains a high specific capacity of 791.5 mA h g-1 after 1000 cycles. Besides, it also shows a superior rate performance (329.8 mAh g-1 at 20 A g-1). Such superior performances may arise from its structural advantages that the smaller Co9S8 nanoparticles encapsulated into N, S-codoped carbon could enhance active sites, electrical conductivity, and structural stability.
Distribution of TN and TP in Dongchang Lake from Sediment and Non-sediment Water Recharge Based on MIKE21
Authors: Xin Zhiran , Ren Liqing
Published: May 2021

With the continuous increase of urban population, the eutrophication of urban lakes is becoming more and more serious. It is necessary to improve the ecological environment of lakes by water supplement. In this study, TN (total nitrogen) and TP (total phosphorus) of Dongchang Lake before and after water replenishment were sampled and measured, and the hydrodynamic, water quality and sediment MIKE21 models of Dongchang Lake were established. Finally, the variation trend of TN and TP of Dongchang Lake before and after water replenishment of sediment and non-sediment water were simulated, and the following conclusions are drawn: During water replenishment, the TP concentration of each point will rise, and the TP concentration of non-sediment water is higher. After the completion of the water replenishment process, the TP concentration at each point decreases in turn. Under the two water replenishment modes, the difference of TP concentration gradually become narrower, but the TP concentration in non-sediment water is higher. The change trend of TN is similar to that of TP, but after the increase of TN concentration caused by water supply, the concentration of TN remains high in the next few days. This study provides an empirical basis for the development of lake water environment improvement strategies.
Optimization of brandy base wine production technique using ginger pomace
Authors: Chu Bao , Jin Yuhong , Gao Aiying , Wu Shuai
Published: May 2021

In this work, the effects of ginger pomace/water ratio, yeast strain selection, sugar and yeast addition, fermentation temperature on the physicochemical properties and sensory evaluation of ginger brandy and its base wine was investigated to optimize production technique. It was found that the pH and total acidity of ginger brandy base wine were mainly influenced by ginger pomace/water ratio, yeast strain, sugar and yeast addition, fermentation temperature. Gingerol content was mostly affected by ginger pomace/water ratio. The results of electronic nose analysis showed that main aroma components of ginger pomace brandy were mainly affected by ginger pomace/water ratio. In general, the optimized production technique was ginger pomace/water ratio at 1:3, 3# yeast strain, sugar and yeast addition (102 g/L and 0.40 g/L), fermentation temperature (18°C). Ginger brandy base wine made by above technique after second full distillation could produce ginger brandy with typical, strong and balanced ginger aroma, mellow and full-bodied taste, and long aftertaste.
Analysis on Operation Management of Logistics Park in China
Authors: Meng Xiangru , Sun Jianmeng , Wang Haining
Published: May 2021

Since the State Council issued the “Plan for the Adjustment and Revitalization of the Logistics Industry” in 2009, the logistics industry, as the basic and strategic industry in the development of the national economy, has played an increasingly important role in promoting industrial transformation and upgrading and promoting economic development. In order to promote the development of logistics industry, a large number of logistics parks have been built all over the country under the guidance of policies and the promotion of the market. However, after the construction of these logistics parks has been put into operation, There are a series of problems in its development and profit. This paper analyzes the present situation and profit of logistics park in China, and briefly analyzes the main business characteristics of freight hub, production service, port service, trade service and comprehensive service. On this basis, the main problems existing in the existing profit model of logistics park in China are summarized.
Analysis on the Integration Path of “One Belt And One Road” International Railway Transportation Rules
Authors: Guo Ruiqi , Zhang Shuyin , Zhang Zhuangzhi , Wang Kunmin , Cai Yinghui , Yu Changjiang , Wang Zirui
Published: May 2021

With the rapid growth of Sino-European international trade and the ongoing development of “One Belt And One Road”, it can be predicted that the status of railway transportation in the international logistics system will be greatly enhanced, which urges us to further study the rules of international railway freight transportation. At present, the pattern of the rules system of international freight transport by railway is the two conventions of the international cargo association and the international cargo contract. In addition, the existing rules system of freight transport by railway in China also has some problems such as being too administrative, which needs to be reformed urgently. By comparing the contents of the two conventions of international railway freight transport and listing the possible conflicts in the substantive laws of various countries involved in the conventions, this paper designs a set of dispute settlement mechanism for “One Belt And One Road” railway transport, and puts forward some suggestions on the integration of the rules of “One Belt And One Road” international railway freight transport.
Study on Water Exchange and Water Quality Simulation of Macao Airport Expansion Project
Authors: Pengfei Huang , Pei Liu , Wei Xu
Published: May 2021

In this paper, we analyzed the current situation of water pollution sources near Macao airport, established a two-dimensional water exchange and water quality mathematical model near the project, and compared and simulated the reclamation schemes of Macao airport. According to the results of water exchange and COD calculation of water quality, the 80 m channel scheme was remarkably better than the 40 m one in terms of water exchange capacity and the possibility of achieving the water quality target. However, with the increase of channel width, the variation of water exchange rate and half exchange period would slow down. There was no significant difference in water exchange rate, water exchange period and water quality distribution between 80m channel and 120 m channel. The final scheme was to adopt the 80 m channel.
Joint decisions for Cold Chain Cross-border E-commerce with Overseas Warehouse Logistics Outsourcing
Authors: Jiang Ying-Mei , Mou Jin-Jin
Published: May 2021

Considering a two-echelon supply chain consisting of one overseas warehouse logistics provider and one cross-border e-commerce retailer with cold chain products over a finite time horizon, this paper studies the optimal decision-making of logistics pricing, freshness-keeping effort level and cold chain product pricing under the Stackelberg game and the cooperative game, and makes a comparative analysis of the two models. Through two-person cooperative game of transferable payment, it is proved that (1)both the total supply chain profit and individual profit of the two parties are greater than the Stackelberg game;(2) the freshness level is higher than that of the Stackelberg game;(3) the logistics price is lower than that of the Stackelberg game;(4) e-commerce transaction scale (i.e. logistics demand scale) is higher than that of the Stackelberg game; and (5) the retail price of the cold chain product is lower than the Stackelberg game. Numerical results bear out the validity of the theoretical models.
The Effects of Labeling on Environmental Self-identity
Authors: Zheng Li , Tong Zepeng , Sun Yan
Published: May 2021

Labeling refers to the behavior that a person uses specific words to label and tends to describe according to the label. For example, when labeled as “environmentally-conscious”, one will enhance his/her pro-environmental behaviors. Thus that will strengthen his/her environmental self-identity, which, in turn, will promote pro-environmental behaviors. This paper looks into the effects of four labels on pro-environmental behaviors. The study into elephant protection found that negative labels can significantly encourage elephant protection and discourage the consumption of elephant-related products. This research will provide a policy tool for environmental organizations and relevant governmental departments.
Research on the impact of crowd queuing behavior on construction personnel evacuation
Authors: Zeng Meiting , Zhao Daoliang , Yang Li , Lu Yun , Shi Lei , Hu Zhao
Published: May 2021

The evacuation channel is an important way to connect the room and the security exit. This paper studies the impact of queuing behavior on the evacuation of people in the building channel. In this paper, Considering the factors of evacuation channel width, personnel density and speed, queuing form, different queuing queues, etc., using Massmotion software simulation. The research shows that for different queuing methods, the evacuation efficiency of queuing by shares is less affected by the width of the channel, there is a critical channel width for the evenly divided queues, and the evacuation efficiency of the different queuing queues is inconsistent; under different widths, the personnel density and speed have different evacuation efficiency Law of influence. The research in this paper can provide a certain reference for the design of building evacuation.
Bird Strike Risk Control in Meizhou Airport Based on Cascading Failure Model in Coupled Map Lattices
Authors: Qiao Liang
Published: May 2021

The fundamental way to reduce the risk of bird strike is to manage the ecological environment of the airport and its surrounding areas and affect the ecological chain of birds. Based on a comprehensive survey of animal and plant populations in Meizhou airport, an airport ecological chain network is established, and a improved cascading failure model in coupled map lattices is introduced to simulate the robustness and vulnerability of the network. It is found that airport ecological network will be collapsed around five time series one after another under the external attack. It also shows that the network will have a global breakdown under a very small external perturbation value when Solanum indicum L. and Callidium villosulum Fairmaire are deliberately attacked. The simulation results show that if the airport authorities give priority to governance these populations of animals and plants with higher in-degree, it may reduce bird strike risk. The analysis results provide a theoretical basis for airport bird strike prevention.
Site-specific assessment of wind turbine residual life and health status
Authors: Guo Ri Yang , Li Wei , Xia Hui , Feng Jiang Zhe , Ren Huai Hui
Published: May 2021

At present, some 600kW and 750kW wind turbines put into operation earlier in China have exceeded their 20-year design life. For these turbines, the safety, reliability and economy of these turbines are usually evaluated in a reasonable way, so as to formulate life extension or decommissioning strategies to maximize economic benefits. Referring to the current international standards and guidelines, this paper takes a wind farm in South China as an example to evaluate the remaining life and state of the turbines. The external environment data of the met mast is extrapolated to the turbine site, and the load simulation is carried out based on the wind turbine model. The fatigue load set of the turbines under the design load condition and the site-specific load condition is obtained. The possible fatigue damage in the historical operation period is calculated. Combined with the linear damage accumulation theory of Miner, the fatigue of each turbine in the site is obtained by load analogy. The final P90 life is obtained by analyzing the uncertainty factors introduced in the assessment of residual life and health status.
Provenance and tectonic implications of the Yanshi bauxite area in Western Henan, China
Authors: Sun Fengyu , Cao Gaoshe , Zhou Qikai
Published: May 2021

The bauxite layer in Western Henan supplies a large number of bauxite ores and is useful for studying tectonic movement. In this paper, the bauxite samples were selected to carry out LA-ICP-MS detrital zircons U-Pb dating and Hf isotope testing. The results indicated that the detrital zircons with the Early Paleozoic ages were mainly derived from the North Qinling Orogenic Belt. The detrital zircons of the Precambrian age may be derived mainly from the basement of the North China Block and the North Qinling Orogenic Belt. The results of this study support the opinion that the North Qinling Orogenic Belt has been uplifted at ~310 Ma, and the surface of the southern craton has an overall north-dipping topography at this time.
Parameter Effects in the Preparation of Pyrolytic Carbon from Agroforestry Biomass Waste
Authors: Sun Yuxin , Xu Jiaying , He Meixuan , Tang Yixuan , Cao Leichang
Published: May 2021

Traditional fossil fuels are being replaced by pyrolytic carbonization fuel from agricultural and forestry biomass to address the energy shortage crisis and the environmental pollution caused by the massive burning of fossil fuels in recent years. This paper introduces the research progress in the preparation of agriculture and forestry biomass pyrolysis carbonization molding fuel. The advantages and disadvantages of different biomass conversion technology are presented. The effects of different technological parameters on the preparation of pyrolytic carbon from agricultural and forestry biomass waste were reviewed. Agriculture and forestry biomass combustion characteristics and their regularity are analyzed.
Ecological Efficiency Analysis in Zhejiang Province: Based on Improved Super-SBM Model
Authors: Zhu Zeyuan , Liu Sizhan
Published: May 2021

This paper use the super efficiency SBM-DEA model with undesirable outputs to calculate the ecological efficiency of Zhejiang Province from 2001 to 2018, and construct multiple linear regression model that evaluating the influencing factors of ecological efficiency based on it. The ecological efficiency of Zhejiang Province fluctuated and increased during the study period, which was mainly driven by pure technical efficiency. In the multiple regression analysis, it can be concluded that income factors, structural factors and institutional factors have a gradually weakening positive impact on ecological efficiency. This paper argues that Zhejiang Province should make full use of regional advantages, resource advantages and talent advantages on the basis of maintaining the current industrial level. It is advised to vigorously develop high-tech industries, strengthen international communications on knowledge and seek new economic growth points. Finally a higher level of coordination between economic development and ecological protection can be achieved.
The current knowledge of hyperaccumulator plants
Authors: He Yao , Ding Na , Han Mengxuan , Wang Xinshuai , Lin Hua , Yu Guo
Published: May 2021

In recent years, heavy metal pollution in soil has become a serious problem. Remediation technologies have been developed, such as physical remediation, chemical remediation, microbial remediation and other technologies. Among them, phytoremediation has been widely used in practice. In this paper, the present situation of heavy metal pollution in soil in China, the research progress of remediation technology of heavy metal contaminated soil and the remediation of heavy metal contaminated soil by hyperaccumulators are reviewed, to help with follow-up research in this area.
Discuss the abnormal exothermic phenomenon “ cold fusion “
Authors: Liu Yang , Liu DongJie , Zhao JiaXing , Lu Xin
Published: May 2021

The research on cold fusion phenomenon has been in the past 30 years. Based on the research results of the predecessors, this article comprehensively describes the research results of the predecessors on the cold fusion phenomenon, and discusses it theoretically and experimentally. From the perspective of thermodynamics, this paper proposes to charge the palladium wire with hydrogen at low temperature to increase the frequency of abnormal heat generation, and gives a calculation formula for the hydrogen charging rate of the palladium wire. At the same time, a theoretical solution model for the isotope effect on the abnormal heat release phenomenon is proposed.
Assessment of the impacts of building materials on the reduction of CO2 emissions from high-rise commercial buildings in Hong Kong
Authors: Lin Min Qi , Chau Chi Kwan , Xu Meng Yi , Ji Cheng , Feng Xiao Hu
Published: May 2021

Based on data collected in 20 A-level high-rise commercial concrete buildings in Hong Kong, the research successfully established a probability density function model, which is used to describe the carbon emissions profile of a commercial building. Results indicate that the superstructure of a commercial building, on average, had a footprint of 226.65 kg CO2/m2 and 10.6 kg CO2/m2 separately in the material use stage and transportation stages. It also evaluates the carbon emissions of various building elements and divides them into three levels according to the magnitude of their contribution. The results show that upper floor construction and external wall in Tier 1 contribute nearly 80% of emissions and should be of great concern. In addition to the probability density function model, a regression model was also successfully established in the study to predict carbon emissions. Research has shown that building layers and gross floor area can predict carbon emissions per unit area, and there is a positive relationship between the independent variable and the dependent variable. The regression model can help building designers determine design options to reduce carbon emissions in the early stages of design.
Remediation of Mariculture Sediment by Sediment Microbial Fuel Cell
Authors: Zhao Nannan
Published: May 2021

To investigate the removal effect of pollutants in mariculture sediment by sediment microbial fuel cell (SMFC) and its power generation capacity, the effects of external resistance, cathode pH and cathode dissolved oxygen concentration (DO) on the SMFC system were investigated. The results showed that the optimal parameters for SMFC were as follows: external resistance = 1500 Ω, pH = 8.5 and DO = 5 mg·L-1. In these situations, the power generation performance and organic degradation effect were both the best. The maximum output voltages were 585, 606, and 587 mV, respectively; the removal rates of COD in sediment were 75.51%, 84.21% and 86.63%, respectively; and the removal rates of ammonia nitrogen in sediment were 80.34%, 98.91% and 90.24%, respectively. The SMFC system had a certain degradation ability to pollutants such as COD and ammonia nitrogen in the sediment of the marine aquaculture areas, which had a broad application prospect.
Attentional processes and performance in hot humid or dry environments: review, applied recommendation and new research directions
Authors: Robin Nicolas , Coudevylle Guillaume R. , Hue Olivier
Published: May 2021

Many important sporting events are organized in hot ambient conditions. In addition, given the global warming around the world, and because heat also concerns millions of people living in hot-dry and/or hot-humid environments, individuals often perform cognitive and/or cognitivo-motor tasks under heat stress conditions. Hot environment can negatively affect aerobic and high intensity performances and can also negatively influence mental performances and cognitive function as executive functions and attention. This review was realized in order to provide a better understanding of the influence of the heat on cognition as attentional processes. In addition, applied recommendations and strategies (e.g., acclimation, cooling, mental technics), that individuals can use during learning, training or competitions performed in hot environments, are discussed. Finally, new directions in research are proposed.
Musculoskeletal profile of amateur combat athletes: body composition, muscular strength and striking power
Authors: Del Vecchio Luke , Borges Nattai , MacGregor Campbell , Meerkin Jarrod D. , Climstein Mike
Published: May 2021

Background: Previous research highlighted positive musculoskeletal adaptations resulting from mechanical forces and loadings distinctive to impacts and movements with sports participation. However, little is known about these adaptations in combat athletes. The aim of this study was to quantify bone mineral density, lean muscle mass and punching and kicking power in amateur male combat athletes. Methods: Thirteen male combat athletes (lightweight and middleweight) volunteered all physiological tests including dual energy X-ray absorptiometry for bone mineral density (BMD) segmental body composition (lean muscle mass, LMM), muscle strength and striking power, sedentary controls (n = 15) were used for selected DXA outcome variables. Results: There were significant differences (p < 0.05) between combat groups for lumbar spine (+5.0%), dominant arm (+4.4%) BMD, and dominant and non-dominant leg LMM (+21.8% and +22.6%). Controls had significantly (p < 0.05) high adiposity (+36.8% relative), visceral adipose tissue (VAT) mass (+69.7%), VAT area (+69.5%), lower total body BMD (−8.4%) and lumbar spine BMD (−13.8%) than controls. No differences in lower limb BMD were seen in combat groups. Arm lean mass differences (dominant versus non-dominant) were significantly different between combat groups (p < 0.05, 4.2% versus 7.3%). There were no differences in punch/kick power (absolute or relative) between combat groups. 5RM strength (bench and squat) correlated significantly with upper limb striking power (r = 0.57), dominant and non-dominant leg BMD (r = 0.67, r = 0.70, respectively) and total body BMD (r = 0.59). Conclusion: BMD and LMM appear to be particularly important to discriminate between dominant and non-dominant upper limbs and less so for lower limb dominance in recreational combat athletes.
Le tourisme à la Fédération Française de Canoë-Kayak et des sports de pagaie : entre service public et gestion déléguée
Authors: Marsac Antoine
Published: May 2021

Pour les licenciés à la Fédération française de canoë-kayak et des sports de pagaie (FFCK), le tourisme demeure la première activité pratiquée. Pour comprendre la place de ce secteur au sein de la FFCK, les résultats d’une enquête administrée par l’IFOP en 2018 aux adhérents sont croisés avec le traitement thématique de 20 entretiens semi-directifs menés auprès d’élus et de cadres techniques. Si le développement du tourisme reste mitigé dans le projet fédéral qui se focalise en priorité sur la compétition, une offre commerciale apparaît pourtant déterminante pour répondre aux enjeux de l’organisation. Celle-ci nécessite d’externaliser la gestion de sites aux sociétés membres agréées. Il s’agit d’étudier ce mode de gestion déléguée par le partenariat entre la FFCK et ces acteurs à partir du modèle sociologique de Chifflet (2005) (Chifflet, P. (2005). Idéologie sportive et service public en France. Mythe d’un système unifié. Grenoble : PUG.). S’appuyant sur les parties prenantes, ces stratégies sont analysées de la délégation de service public vers la RSO en réinterrogeant les rapports publics-privés.
Menace du stéréotype et force de préhension chez les seniors : le rôle modérateur des traits de personnalité
Authors: Canada Brice , Gigante Darline , Martinent Guillaume , Stephan Yannick
Published: May 2021

Objectif :Cette étude visait à examiner l’effet d’un contexte de menace du stéréotype sur la force de préhension des seniors et le rôle modérateur des traits de personnalité.Méthode :Cent soixante-dix-huit personnes âgées de 60 à 100 ans (M = 77 ans) ont été aléatoirement réparties dans trois conditions expérimentales distinctes : un groupe en condition de menace du stéréotype (n = 57), un groupe en condition de suppression du stéréotype négatif (n = 62), et un dernier groupe ne recevant aucune information stéréotypique (n = 59). Les participants ont répondu à plusieurs questionnaires permettant de mesurer les traits de personnalité, les données sociodémographiques et l’état de santé objectif. Par ailleurs, la force de préhension a été évaluée à l’aide d’un dynamomètre manuel, et mesurée avant et après la mise en place du contexte évaluatif générant l’effet de menace ou de suppression du stéréotype.Résultats :Les analyses de covariances réalisées n’indiquent aucun effet d’interaction significatif entre les traits de personnalité et les conditions expérimentales sur la force de préhension des participants.Discussion :Cette étude semble indiquer que les traits de personnalité ne modèrent pas l’effet de menace du stéréotype sur un des marqueurs du fonctionnement physique des seniors, à savoir la force de préhension.
La gouvernance de la Fédération Française de Tennis entre 1970 et 2020 : entre autonomie et dépendances dans la relation à la sphère publique
Authors: Bayle Emmanuel
Published: May 2021

Dans un modèle d’organisation du sport français fortement soutenu et contrôlé par l’État et plus largement par la sphère publique, la FFT délégataire d’une mission de service public fait à première vue figure d’exception. Elle a en effet construit son modèle économique et d’organisation autour d’un évènement très lucratif : Roland Garros (RG). Au premier abord, il semble qu’elle ait fondé un développement autonome – à défaut d’être indépendant –viaun modèle d’affaire privé singulier lui permettant rapidement de dépendre faiblement de l’État. Cependant, nous montrons que le soutien de la sphère publique a aussi créé en parallèle un régime de dépendances multiples qui a pu soit favoriser soit limiter le développement de la FFT et de ses clubs. Ce constat se retrouve dans deux grandes phases de son développement : la « révolution Chatrier » (1968–1992) et la « période de la maturité » (1993–2020). Ces relations ont entraîné une gouvernance de compromis pour ancrer une stratégie de développement ayant pour objet d’optimiser et de légitimer les soutiens publics. Elles ont aussi été orientées au profit des dirigeants en place. Ces relations ont pu prendre plusieurs formes : réseaux politiques, aides directes et indirectes aux différents niveaux de la pyramide fédérale, influences sur le cadre de gouvernance organisationnelle. Il sera dès lors discuté de ce que révèlent les stratégies d’autonomisation mais aussi d’acceptation et de gestion des dépendances par rapport à la sphère publique : les ambiguïtés et les jeux politiques internes autour de l’image et des passions et de l’écosystème autour du tennis français et de RG dont les dirigeants ont joué pour se maintenir au pouvoir ; les paradoxes entre gestion d’une mission de service public et hyper-commercialisation questionnant la légitimité des aides publiques ; et enfin, la difficulté de transformer et de faire évoluer le modèle gouvernance et la capacité à s’auto-réformer compte tenu des dépendances créées.
Proposition d’un cadre d’analyse systémique de la situation économique et financière des fédérations sportives françaises
Authors: Terrien Mickael , Feuillet Antoine , Bayle Emmanuel
Published: May 2021

Cet article s’intéresse à la situation économique et financière de 76 fédérations françaises sur la période 2012–2017 à travers une analyse factorielle (analyse en composantes principales puis analyse factorielle exploratoire). Les résultats permettent d’établir un cadre d’analyse systémique de la situation économique et financière des fédérations sportives. Il repose sur trois dimensions évaluées chacune par un score unique : dépendance en ressources publiques ; budget financier et attraction de ressources financières ; investissement dans les services. L’exemple des fédérations de karaté et de lutte illustre l’intérêt de ce cadre pour synthétiser un volume important d’informations et comparer facilement leurs niveaux de performance économique et financière. Les résultats permettent, par ailleurs, d’identifier des vecteurs de vulnérabilités financières qui ne sont pas forcément liés à la dépendance envers les subventions directes et indirectes accordées par le ministère des Sports. L’analyse des corrélations entre les variables a enfin mis à jour certains résultats. Ces derniers sont notamment liés à la politique ministérielle de soutien aux fédérations et l’inefficiente stratégie d’allocation des ressources ministérielles, principalement orientée vers les organisations qui en ont le moins besoin.
Ocular Involvement in COVID-19: Conjunctivitis and More
Authors: Rokohl Alexander C. , Grajewski Rafael S. , Matos Philomena A. Wawer , Kopecky Adam , Heindl Ludwig M. , Cursiefen Claus
Published: May 2021

Since the beginning of 2020, SARS-CoV-2, the pathogen of COVID-19, has led to a global pandemic that also affects ophthalmology. Ophthalmologists can be confronted at any time with potentially COVID-19 associated ocular symptoms or manifestations in patients and also become infected through close patient contact. Even without systemic infection, the ocular surface can come into direct contact with aerosols or liquids containing SARS-CoV-2 particles. A smear infection through hand-to-eye contact is also possible. A purely isolated ocular infection has not yet been shown. Rather, it seems that ocular complications occur in the context of a systemic infection. However, ocular symptoms can also be the first symptom of COVID-19. The most common ocular complication of COVID-19 is mild follicular conjunctivitis. Haemorrhagic conjunctivitis, dry eye disease, episcleritis, or retinal involvement can also occur less frequently. There are currently no evidence-based therapy
recommendations for COVID-19 associated diseases of the ocular surface. Artificial tears might be helpful for symptom relief. There is no evidence for antiviral, antibiotic, or anti-inflammatory therapies, but these medications might be used in individual cases. Potential intraocular complications include retinal artery occlusions and haemorrhages, as well as cotton wool spots caused by complement-mediated thrombotic angiopathy. Neuro-ophthalmological complications including Miller-Fisher syndrome or infarct-related central blindness can also occur in very rare cases. Knowledge of potential transmission routes and personal protective equipment is just as essential for each ophthalmologist as a basic knowledge of potential ocular symptoms and complications.
Mechanistic Evaluation of Linalool Effect against Renal Ischemia- Reperfusion Injury in Rats
Authors: Golmohammadi Mohammad-Ghasem , Banaei Shokofeh , Azimian Ehsan
Published: May 2021

Background Kidney ischemia reperfusion (IR) is an important cause of renal dysfunction. The hypoxic conditions in ischemic damage result in the formation of free radicals and apoptotic death of renal cells. We evaluated the renoprotective effects of linalool in IR- induced renal injury.

Methods Wistar rats were divided into three groups of six rats; namely, control group, IR group, and linalool + IR group. The animals were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 24 h reperfusion. Linalool (40mg/kg) was administered before ischemia. After 24h reperfusion, the kidney tissues were obtained for detection of miR-21, HSP 70 and caspase-3 expression levels and histological studies. Also, the blood samples were collected for the measurement of biochemical parameters.

Results IR significantly increased the expression of miR-21, HSP70 and capase-3 and the serum levels of BUN-Cr, ALT, AST and ALP enzymes. Furthermore, histological findings of the IR group confirmed that there were acute tubular necrosis and lymphocyte infiltration in the renal tissues. Treatment with linalool improved the renal function and morphological changes.

Conclusion It seems that linalool could exert a nephroprotective effect via a number of mechanisms in renal IR injury.
Evaluation of Cocoa Bean Shell Antimicrobial Activity: A Tentative Assay Using a Metabolomic Approach for Active Compound Identification
Authors: Rojo-Poveda Olga , Ribeiro Sofia Oliveira , Anton-Sales Cèlia , Keymeulen Flore , Barbosa-Pereira Letricia , Delporte Cédric , Zeppa Giuseppe , Stévigny Caroline
Published: May 2021

Cocoa bean shell is one of the main by-products of chocolate manufacturing and possesses several compounds with biofunctionalities. It can function as an antibacterial agent, and its action is mostly reported against Streptococcus mutans. However, only a few studies have investigated the cocoa bean shell compounds responsible for this activity. This study aimed to evaluate several extracts of cocoa bean shells from different geographical origins and cocoa varieties and estimate their antimicrobial properties against different fungal and bacterial strains by determining their minimal inhibitory concentration. The results demonstrated antimicrobial activity of cocoa bean shell against one of the tested strains, S. mutans. Cocoa bean shell extracts were further analysed via LC-HRMS for untargeted metabolomic analysis. LC-HRMS data were analysed (preprocessing and statistical analyses) using the Workflow4Metabolomics platform. The latter enabled us to identify
possible compounds responsible for the detected antimicrobial activity by comparing the more and less active extracts. Active extracts were not the most abundant in polyphenols but contained higher concentrations of two metabolites. After tentative annotation of these metabolites, one of them was identified and confirmed to be 7-methylxanthine. When tested alone, 7-methylxanthine did not display antibacterial activity. However, a possible cocktail effect due to the synergistic activity of this molecule along with other compounds in the cocoa bean shell extracts cannot be neglected. In conclusion, cocoa bean shell could be a functional ingredient with benefits for human health as it exhibited antibacterial activity against S. mutans. However, the antimicrobial mechanisms still need to be confirmed.
Intraperitoneal Activation of Coagulation and Fibrinolysis in Patients with Cirrhosis and Ascites
Authors: Thaler Johannes , Lisman Ton , Quehenberger Peter , Hell Lena , Schwabl Philipp , Scheiner Bernhard , Bucsics Theresa , Nieuwland Rienk , Ay Cihan , Trauner Michael , Pabinger Ingrid , Reiberger Thomas , Mandorfer Mattias
Published: May 2021

Development of ascites is the most common form of decompensation of cirrhosis. We aimed to investigate the coagulation system in ascitic fluid and plasma of patients with cirrhosis. We determined coagulation parameters and performed clotting and fibrinolysis experiments in ascitic fluid and plasma of thoroughly characterized patients with cirrhosis and ascites (n = 25) and in plasma of patients with cirrhosis but without ascites (n = 25), matched for severity of portal hypertension. We also investigated plasma D-dimer levels in an independent cohort of patients (n = 317) with clinically significant portal hypertension (HVPG ≥ 10 mmHg), grouped according to ascites severity. Ascitic fluid was procoagulant in a clotting assay. The procoagulant potential of ascitic fluid was abolished by depletion of extracellular vesicles from ascitic fluid by filtration or by addition of a tissue factor-neutralizing antibody. Compared with plasma, extracellular vesicle-associated tissue factor activity was high in ascitic fluid, while activities of other coagulation factors were low. The extracellular vesicle-depleted fraction of ascitic fluid induced fibrinolysis, which was prevented by aprotinin, indicating the presence of plasmin in ascitic fluid. Plasma peak thrombin generation and parameters reflecting fibrinolysis were independently associated with the presence of ascites. Finally, plasma D-dimer levels were independently linked to ascites severity in our second cohort comprising 317 patients. In conclusion, coagulation and fibrinolysis become activated in ascites of patients with cirrhosis. While tissue factor-exposing extracellular vesicles in ascitic fluid seem unable to pass the peritoneal membrane, fibrinolytic enzymes get activated in ascitic fluid and may re-enter the systemic circulation and induce systemic fibrinolysis.
Psychomotor Delay in a Child with FGFR3 G380R Pathogenic Mutation Causing Achondroplasia
Authors: Ergoren Mahmut C. , Eren Erdal , Manara Elena , Paolacci Stefano , Tulay Pinar , Sag Sebnem O. , Bertelli Matteo , Mocan Gamze , Temel Sehime Gulsun
Published: May 2021

Achondroplasia (ACH) is a hereditary disorder of dwarfism that is caused by the aberrant proliferation and differentiation of chondrocyte growth plates. The common findings of macrocephaly and facial anomalies accompany dwarfism in these patients. Fibroblast growth factor receptor 3 (FGFR3) gene mutations are common causes of achondroplasia. The current study presents a case of 2-year-old male child patient presenting with phenotypic characteristics of ACH. The interesting finding of the case is the presence of psychomotor delay that is not very common in these patients. Clinical exome sequencing analyzing 4.813 disease causing genes revealed a de novo c.1138G > A mutation within the FGFR3 gene. In conclusion, the mutation confirms the clinical diagnosis of ACH, and it seems to be causing the psychomotor delay in this patient.