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Experimental evaluation of eco-friendly flocculants prepared from date palm rachis

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Journal of Environmental Sciences 2010年第10期22卷 1539-1543页

作者： Ramzi Khiari Sonia Dridi-Dhaouadi Chadlia Aguir Mohamed Farouk Mhenni research unity of Applied Chemistry & Environment Department of Chemistry

Sodium carboxymethylcellulose （CMCNa） is an anionic water soluble polyelectrolyte widely used in many industrial sectors including food, textiles, papers, adhesives, paints, pharmaceuticals, cosmetics and mineral processing. CMCNa was produced by chemical modification of cellulose, and represents many advantages： natural, renewable, non-toxic and biodegradable. In this study, different kinds of CMCNa, prepared from an agricultural waste date palm rachis, were tested as eco-friendly flocculants for drinking water treatment and their performances as flocculants in turbidity removal enhancement were assessed. The prepared materials were characterized by the degree of substitution （DS） and polymerisation （DP）. The study of the effect of some experimental parameters on the coagulation-flocculation performance, using the prepared materials combined with aluminium sulphate （as coagulant）, showed that the best conditions for turbidity treatment were given for pH 8, coagulant dose 20 mg/L, flocculant concentration of 100 mg/L and stirring velocity （during the flocculation step） of 30 r/min. Under the optimum conditions, the turbidity removal using CMCNa, prepared from raw material, was about 95%. A comparison study between the flocculation performance of a commercial anionic flocculant （A100PWG： polyacrylamide） and that of the prepared CMCNa showed that the performance of the waste-based flocculant with a DS of 1.17 and a DP of 480 was 10% better than that achieved by the commercial one.

关键词： carboxymethylcellulose flocculants date palm rachis flocculation process

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Exploring the Factors Associated with 12-Month Non-Return to Work among Motorcyclists Involved in Road Accidents

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Open Journal of Preventive Medicine 2024年第1期14卷 1-16页

作者： Yolaine Glèlè-Ahanhanzo Donatien Daddah Alphonse Kpozehouen Bella Hounkpè Dos Santos Moussiliou N. Paraiso Multidisciplinary research unity for Road Crashes Prevention (ReMPARt) Department of Epidemiology and Bio-Statistics Regional Institute of Public Health University of Abomey-Calavi Ouidah Benin Regional Direction of Health Lokossa Benin Regional Direction of Health Abomey-Calavi Benin Health Promotion Department Regional Institute of Public Health Ouidah Benin

Introduction: Motorcyclists bear a disproportionate burden of morbidity and mortality from road accidents. In addition, the consequences of these accidents affect the ability of victims to return to work. This study aimed to determine the prevalence and factors associated with non-return to work among surviving motorcyclists involved in road accidents 12 months after the event. Materials and Methods: It was a cross-sectional study conducted using data from a cohort of motorcyclists involved in accidents and recruited in five hospitals in Benin from July 2019 to January 2020. The dependent variable was non-return to work 12 months after the accident (yes vs no). The independent variables were categorized into two groups: baseline and 12-month follow-up variables. Logistic regression was used to determine the factors associated with non-return to work at 12 months among the participants. Results: Among the 362 participants, 55 (15.19%, 95% CI = 11.84 - 19.29) had not returned to work 12 months after the accident. Risk factors for non-return to work identified were: smoking (aOR = 4.41, 95% CI = 1.44 - 13.56, p = 0.010), hospitalization (aOR = 2.87, 95% CI = 1.14 - 7.24, p Conclusion: The prevalence of non-return to work at 12 months was high among surviving motorcyclists involved in road accidents in Benin. Integrated support for patients based on identified risk factors should effectively improve their return to work.

关键词： Road Accident Return to Work Motorcyclists Hospital Mental Health Cohort Benin

Factors Associated with Voluntary Cosmetic Depigmentation in Schools in the Collines Department (Benin)

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Journal of Cosmetics, Dermatological Sciences and Applications 2024年第2期14卷 174-187页

作者： Bayédjè Evrard Koutchoro Georgia Damien Barikissou Coovi Nonwanou Ignace Tokpanoude Elvire Sègnon Eurydice Djossou Idohou Olakounlé Sarafath Christiane Koudoukpo Aguemon Badirou unity of Public Health Faculty of Health Sciences University of Abomey-Calavi Abomey-Calavi Benin Department of Public Health Teaching and Research Unit in Community Health and Epidemiology Faculty of Health Sciences University of Abomey-Calavi Abomey-Calavi Benin Dermatology Department Departmental University Hospital Center of Borgou and Alibori Parakou Benin

Skin depigmentation is a worrying practice that is gaining popularity, particularly among young girls. However, this practice poses health risks. It also reflects a negative view of black skin color. This was a cross-sectional study carried out between April and May 2023 which involved 1039 female students from schools and universities in the Collines department selected by stratified sampling. Data was collected during a face-to-face interview using a questionnaire providing information on the demographic, socio-cultural, and economic characteristics of the girls. The depigmentation products used were identified as well as the complications caused by the use of these products. Statistical analysis made it possible to calculate the frequencies and logistic regression made it possible to identify the factors associated with depigmentation. The prevalence of depigmentation among the girls surveyed was 78.2%. The main products used were soaps based on mercurial derivative and hydroquinone (21.6%) and lotions based on hydroquinone and corticosteroids (75.7%). The factors associated with the practice of depigmentation were the ethnicity of the respondents (OR = 2.52;95% CI = [0.47 - 13.33], p = 0.001);the average monthly income of the parents (OR = 3.26;95% CI = [1.71 - 6.09], p = 0.003);the opinion of the respondents on depigmentation (OR = 2.48;95% CI = [0.84 - 7.3], p < 0.001) and the value given to light skin versus black skin (OR = 3.41;95% CI = [2.32 - 5.01], p < 0.001). In conclusion, the prevalence of depigmentation among the girls surveyed is high. Consequently, reinforced awareness measures and stricter control of bleaching products are imperative to address this high prevalence of the phenomenon.

关键词： Voluntary Depigmentation Cosmetic Depigmentation Factors Associated Students Collines Department Benin

research on Virtual Assembly System for Industrial Robots Based on unity3D

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Journal of Harbin Institute of Technology(New series) 2024年

作者： Junyi Ouyang Dezhang Xu The College of Artificial Intelligence， Anhui Polytechnic University Wuhu Anpu Robot Industry Technology research Institute

To address the challenges of insufficient visualization in the industrial robot assembly operation system and the limitation of visualizing only geometric attributes of physical properties， a method is proposed for constructing an industrial robot assembly system based on virtual reality technology. Focusing on the shaft hole assembly， the mechanical characteristics of the industrial robot shaft hole assembly process are analyzed and a dynamic model is established for shaft hole assembly operations. The key elements of virtual assembly operations for industrial robots are summarized and a five-dimensional model is proposed for industrial robot virtual operations. Utilizing the unity3D engine based on the 5-D model for industrial robot virtual operations， an industrial robot shaft hole assembly system is developed. This system enables virtual assembly operations， displays physical attributes， and provides valuable references for the research of virtual systems.

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What is the Role of Gravity,Turbulence and Magnetic Fields in High-mass Star Formation Clouds?

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research in Astronomy and Astrophysics 2024年第6期24卷 21-27页

作者： An-Xu Luo Hong-Li Liu Guang-Xing Li Sirong Pan Dong-Ting Yang School of Physics and Astronomy Yunnan UniversityKunming 650091China South-Western Institute for Astronomy research Yunnan UniversityKunming 650500China

To explore the potential role of gravity,turbulence and magnetic fields in high-mass star formation in molecular clouds,this study revisits the velocity dispersion–size(σ–L)and density–size(ρ–L)scalings and the associated turbulent energy spectrum using an extensive data *** sample includes various hierarchical density structures in high-mass star formation clouds,across scales of 0.01–100 *** observeσ∝L^(0.26)andρ∝L^(-1.54)scalings,converging toward a virial equilibrium state.A nearly flat virial parameter–mass(α_(vir)-M)distribution is seen across all density scales,withα_(vir)values centered around unity,suggesting a global equilibrium maintained by the interplay between gravity and turbulence across multiple *** turbulent energy spectrum(E(k))analysis,based on theσ–L andρ–L scalings,yields a characteristic E(k)∝k^(-1.52).These findings indicate the potential significance of gravity,turbulence,and possibly magnetic fields in regulating dynamics of molecular clouds and high-mass star formation therein.

关键词： ISM:clouds stars:formation stars:kinematics and dynamics

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Single-atom catalysts for the electrochemical reduction of carbon dioxide into hydrocarbons and oxygenates

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Carbon Energy 2024年第3期6卷 64-117页

作者： Karl Adrian Gandionco Juwon Kim Lieven Bekaert Annick Hubin Jongwoo Lim Department of Chemistry Seoul National UniversitySeoulRepublic of Korea research Group Electrochemical and Surface Engineering(SURF) Department of Materials and ChemistryVrije Universiteit BrusselBrusselsBelgium

The electrochemical reduction of carbon dioxide offers a sound and economically viable technology for the electrification and decarbonization of the chemical and fuel *** this technology,an electrocatalytic material and renewable energy-generated electricity drive the conversion of carbon dioxide into high-value chemicals and carbon-neutral *** the past few years,single-atom catalysts have been intensively studied as they could provide near-unity atom utilization and unique catalytic ***-atom catalysts have become one of the state-of-the-art catalyst materials for the electrochemical reduction of carbon dioxide into carbon ***,it remains a challenge for single-atom catalysts to facilitate the efficient conversion of carbon dioxide into products beyond carbon *** this review,we summarize and present important findings and critical insights from studies on the electrochemical carbon dioxide reduction reaction into hydrocarbons and oxygenates using single-atom *** is hoped that this review gives a thorough recapitulation and analysis of the science behind the catalysis of carbon dioxide into more reduced products through singleatom catalysts so that it can be a guide for future research and development on catalysts with industry-ready performance for the electrochemical reduction of carbon dioxide into high-value chemicals and carbon-neutral fuels.

关键词： electrocatalysis electrochemical CO_(2)reduction hydrocarbons oxygenates single-atom catalysts

Global Dynamics of a Delayed HIV-1 Infection Model with Cell-to-cell Transmission, Humoral Immunity and Immune Impairment

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Acta Mathematicae Applicatae Sinica 2024年

作者： Rui XU An-li XUE Chen-wei SONG Complex Systems research Center Shanxi University School of Mathematical Sciences Shanxi University

In this paper, an HIV-1 infection model with intracellular delay, humoral immunity and immune impairment is investigated, in which both virus-to-cell infection and cell-to-cell transmission are *** basic reproduction ratio is calculated and the existence of feasible equilibria is established. By analyzing the distributions of roots of the corresponding characteristic equations, the local asymptotic stability of each of feasible equilibria is established. With the help of appropriate Lyapunov functionals and LaSalle’s invariance principle, it is proved that if the basic reproduction ratio is less than unity, the infection-free equilibrium is globally asymptotically stable, and the virus is eventually eliminated; if the basic reproduction ratio is greater than unity, the chronic-infection equilibrium is globally asymptotically stable. Finally, numerical simulations are carried out to illustrate the effects of some parameters on HIV-1 infection dynamics.

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unity of Knowing and Doing

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China Today 2024年第7期73卷 71-73页

作者： CUI WEIFANG Confucius research Institute

Chinese President Xi Jinping has emphasized the unity of knowing and doing on a number of occasions,saying that knowing is the premise,while doing is putting knowledge to work,and these two ideas have a mutually reinforcing *** of knowing and doing is a key concept in ancient Chinese *** on knowing and doing can be traced back to the pre-Qin period(before 221 B.C.).

关键词： relationship. mutually doing

Impact of Beekeeping on the Wild Bee Diversity in Northern Ivory Coast(West Africa)

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research in Ecology 2024年第1期6卷 6-13页

作者： Drissa Coulibaly Mouhamadou Koné Yalamoussa Tuo Kolo Soro Kouakou Hervé Koua Department of Animal Biology Biological Sciences UnityUniversity Peleforo Gon CoulibalyBP 1328KorhogoIvory Coast Biosciences unity Department of ZoologyAnimal Biology and EcologyUniversity Felix Houphouët-Boigny22 BP 1611 Abidjan 22Ivory Coast

In Ivory Coast,beekeeping takes an important place among the major economic *** contributes to improv-ing the population’s livelihoods thanks to its derived products which are honey,propolis,wax and royal ***-ever,the installation of honey bee hives could put pressure on wild bee species,which often live ***,these wild bees are excellent pollinators of cultivated and wild *** study aimed to assess the effect of honey bee hives on the diversity of wild *** methodology approach consisted of capturing bees in three different plots inside the forest fragment of the botanical garden located at the University Peleforo Gon *** first plot was chosen approximately from 10 m to an apiary containing ten *** two other plots were chosen to be 200 m and 400 m from the apiary,*** were captured once a month for three months using pan traps(UV—blue,yellow and white).A total of 17 bee species belonging to three families(Apidae,Megachilidae and Halictidae)were *** furthest plot from the apiary was the most diverse(H’=2.49)and that near the apiary was the least diverse(H’=0.11).Only,two wild bee species,Hypotrigona *** Thrinchostoma petersi,persisted inside the plot nearby the apiary where honey bees were most *** furthest plots from the apiary seem to have the highest diversity of wild *** findings are very relevant because they can be used for the policies of conservation of wild bees and the management of beekeeping activities.

关键词： Honey bee Apiary Hive Conservation Korhogo