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Journal of Earth Science 2024年

作者： FLORES Daniel Germán OCA?A Raúl emmanuel MELIáN Edgardo ORTEG Andrés ESPER ANGILLIERI María Yanina PITTALUGA María Alejandra CIGEOBIO (CONICET-UNSJ) Av.José I.de la Roza y Meglioli Gabinete de Geología Ambiental， INGEO， Universidad Nacional de San Juan， Av.José I.de la Roza y Meglioli

The Monte Desert is characterized by a great diversity of landforms created with fluvial， alluvial which the vegetation patterns are related to. The present work has the following objectives: 1: determine whether topographical attributes， surface characteristics， soil properties and vegetation patterns vary between alluvial landforms， and 2: define whether morphometric， soil and surface properties influence vegetation patterns along alluvial landscape. Morphometric data were obtained by processing a 5 m digital elevation model. The coverage of rock fragments， fine sediments and mulch was quantified. Observations and descriptions of the soil profiles were restricted to the uppermost 50 cm. Vegetation properties were calculated using a Point Quadrat Method. The relationship between variables was evaluated through multivariate statistical analysis. The main results show the presence of 45 plant species distributed in 19 families， where shrubs are dominant. The wind effect， topographic wetness and dissection of the landscape are limiting factors of diversity. The coverage of superficial rock fragments influence vegetation coverage through the distribution and availability of rainwater. Furthermore， the different soil textures reveal that the silt content favors an increase in vegetation coverage. The presence of V horizon could condition the installation and development of vegetation in the early stages of growth.

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Investigation of Carbonation of Concrete Based on Crushed Sand and Admixtures

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Journal of Minerals and Materials Characterization and Engineering 2024年第5期12卷 247-264页

作者： Jacques Herve Koung à Bediang emmanuel Elat Assoua Moukete Paul Djomou Djonga Michel Mbessa Laboratory of Civil and Mechanical Engineering Department of Civil Engineering National Advanced School of Engineering of Yaounde 1 Yaounde Cameroon Laboratory of Mechanics and Materials of Civil Engineering Department of Civil Engineering CY Cergy Paris University Paris France Department of Textile and Leather Engineering National Advanced School of Engineering of Maroua Maroua Cameroon Department of Civil Engineering National Advanced School of Public Works National Advanced School of Engineering of Yaounde 1 Yaounde Cameroon

Carbonation is a natural aging process that occurs in all types of concrete. One of its primary implications is the acceleration of steel corrosion caused by the phenomena of depassivation. The goal of this research is to investigate the carbonation of quarry sand-based concrete. The concrete is made of 100% crushed sand 0/6.3, gravel 8/15, and 15/25 from the Arab Contractor quarry in Nomayos, Cameroon, with CEM II B-P 42.5 R from CIMENCAM (Cimenteries du Cameroun). The study employed two admixtures: one with a dual superplasticizing and reducing action (Sikamen) and another with a water-repellent effect (Sika liquid). Carbonation was performed on concrete samples at the following dates: 0, 7, 14, 28, 56, 90, 180 days, one year, and six months. Carbonated concrete (CC) and non-carbonated concrete (NCC) samples are compared in terms of their physical attributes and mineralogical characteristics. The results of this investigation reveal that after more than a year and six months of carbonation, porosity decreases and permeability increases. Despite the high fineness modulus of quarry sand, the compressive strength of quarry sand-based concrete is satisfactory. Carbonation depth is relatively high on some dates, exceeding the minimal cover value for concrete reinforcement. Sikament additive increases concrete compactness and durability while decreasing permeability. Sika water repellant mixes with the lime in cement to generate complimentary crystallizations that block the mortar’s capillaries, making it watertight.

关键词： Carbonation Concrete Crushed Sand Sikamant Water-Repellent

Variation in Yellow Root Cassava (Manihot esculentus Crantz) Genotypes and Phenotypic Relationship for Selected Postharvest and Morphological Traits

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Agricultural Sciences 2024年第9期15卷 993-1008页

作者： Suffian Mansaray Prince emmanuel Norman Joseph Sherman-Kamara Isata Kamanda Kadiatu Nannah Serry Post-Harvest and Nutrition Sierra Leone Agricultural Research Institute (SLARI) Tower Hill Freetown Sierra Leone Department of Agriculture Engineering School of Technology Njala University Njala Campus Bo Sierra Leone Germplasm Enhancement and Seeds System Sierra Leone Agricultural Research Institute (SLARI) Tower Hill Freetown Sierra Leone

This study evaluated the variation in yellow root cassava (Manihot esculentus Crantz) genotypes and phenotypic relationship for selected postharvest and morphological traits. The trial was established at the Njala Agricultural Research Centre experimental site, Njala, during 2017/2018 cropping season in a randomized complete block design with three replications. Findings showed that the higher the total carotene content (TCC) in yellow flesh cassava genotypes, the longer the rate of postharvest physiological deterioration (PPD). Genotypes TR-0051-TCC/17 and TR-0012-TCC/17 recorded higher TCC (18.9 µg/g and 13.6 µg/g) and longer rate of PPD (4.29 and 3.14), respectively. Genotypes TR-0051-TCC/17, TR-0016-TCC/17, TR-0028-TCC/17, TR-0012-TCC/17 and TR-0020-TCC/17 had the highest TCC values of 18.9 µg/g, 16.09 µg/g, 14.72 µg/g, 13.6 µg/g and 11.23 µg/g with corresponding higher color chart values of 6, 6, 6, 5, and 6, respectively. This suggests the direct dependence of TCC on the root parenchyma color intensity in yellow flesh cassava genotypes. Findings also show a direct relationship between morphological and postharvest traits in yellow flesh cassava genotypes that could be exploited for the genetic improvement of cassava for increased shelf life, nutrition and related quality traits, as well as conservation and utilization of the crop.

关键词： Cassava Variability Regression Correlation Postharvest and Morphological Traits

Hydrochemistry of Groundwater in the Rice Cultivation Area of Maga: Analysis of the Mineralization Process

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Journal of Geoscience and Environment Protection 2024年第9期12卷 370-387页

作者： emmanuel Aguiza Abaï Hugues Pahimi Prosper Samba Koukouare Guillaume Ewodo Mboudou Auguste Ombolo Department of Industrial Security Quality and Environment National Advanced School of Mines and Petroleum Industries University of Maroua Kaele Cameroon School of Chemical Engineering and Mineral Industries University of Ngaoundere Ngaoundere Cameroon Department of Hydrocarbons Exploitation Mao National Higher Petroleum Institute NDjamena Chad Department of Hydraulics and Water Management National Advanced School of Engineering of Maroua University of Maroua Maroua Cameroon Department of Rural Engineering Higher Institute of Agriculture Forestry Water and Environment University of Ebolowa Ebolowa Cameroon

The use of groundwater for drinking water supply to the population is increasingly practiced in the rice cultivation area of Maga. However, there is a lack of knowledge about the hydrochemical characteristics of this water due to a lack of quality control. This study aims to contribute to the understanding of mineralization processes in order to establish the hydrochemical profile of the water in the area. The methodological approach consisted of collecting fifteen water samples from wells and boreholes during six campaigns for physicochemical analysis, and studying them through methods of interpreting hydrochemical data. The analysis results show that these waters are moderately mineralized. The water facies are mainly of the bicarbonate sodium and potassium type, as well as the bicarbonate calcium and magnesium type. Calculation of saturation indices demonstrates that evaporite minerals show lower degrees of saturation than carbonate minerals, with gypsum, anhydrite, and halite being in a highly undersaturated state. The mineralization of groundwater originates from the dissolution of surrounding rocks on the one hand, and anthropogenic activities involving exchanges between alkalis (Na+ and K+) in the aquifer and alkaline earth (Ca2+ and Mg2+), resulting in the fixation of alkaline earth and the dissolution of alkalis.

关键词： Hydrochemistry Mineralization Groundwater Maga

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玻璃体腔注射药物前结膜囊培养结果分析

中华眼底病杂志 2024年第9期40卷 687-692页

作者：任新军柯屹峰谭亮章 emmanuel Eric Pazo 栗勇涛李筱荣天津医科大学眼科医院、眼视光学院、眼科研究所、国家眼耳鼻喉疾病临床医学研究中心、天津市分中心、天津市视网膜功能与疾病重点实验室天津300384

目的观察玻璃体腔注射(IVI)前不同方式预防感染后结膜囊微生物培养阳性率的变化差异。方法前瞻性病例对照研究。2021年7月至2023年12月于天津医科大学眼科医院IVI中心接受IVI药物治疗的眼底疾病患者1200例纳入研究。按照IVI前3、1 d抗... 详细信息

目的观察玻璃体腔注射(IVI)前不同方式预防感染后结膜囊微生物培养阳性率的变化差异。方法前瞻性病例对照研究。2021年7月至2023年12月于天津医科大学眼科医院IVI中心接受IVI药物治疗的眼底疾病患者1200例纳入研究。按照IVI前3、1 d抗生素眼液点眼(前3 d、前1 d)、治疗前不使用抗生素眼液(前0)和IVI前3 min、30 s聚维酮碘(PVI)眼局部消毒将患者随机分为6组:前3 d抗生素+3 min PVI组、前1 d抗生素+3 min PVI组、前0+3 min PVI组、前3 d抗生素+30 s PVI组、前1 d抗生素+30 s PVI组、前0+30 s PVI组,每组均为200例。IVI前进行结膜囊微生物采样培养,比较各组阳性率差异。多组间比较采用单因素方差分析;计数资料比较采用χ2检验。结果1200例患者中,男性566例,女性634例;年龄(62.59±13.44)岁。糖尿病、高血压分别为397、482例。IVI次数(2.35±2.34)次。IVI前结膜囊培养阳性64例。各组患者年龄(F=1.468)、性别构成比(χ^(2)=2.876)、糖尿病例数(χ^(2)=10.002)、高血压例数(χ^(2)=6.019)、IVI次数(χ^(2)=4.507)、结膜囊细菌培养阳性率(χ^(2)=6.272)比较,差异均无统计学意义(P>0.05)。以IVI前抗生素应用时长为分层因素,不同IVI前抗生素应用时长组结膜囊培养阳性率比较,差异无统计学意义[χ^(2)=0.414,P=0.520,合并比值比(OR)=0.819,95%可信区间(CI)0.493~1.360]。以PVI应用时长为分层因素,不同PVI消毒时间组结膜囊培养阳性率比较,差异无统计学意义(χ^(2)=0.000,P=1.000,合并OR=1.000,95%CI 0.503~1.988)。结论IVI前0.5%PVI作用30 s可达到抑制结膜囊微生物菌落生长的作用;IVI前眼局部抗生素眼液的应用不能降低结膜囊细菌阳性率。

关键词：玻璃体腔注药结膜囊微生物培养聚维酮碘眼内炎

Study of Some Biodemographic Parameters of Caryedon serratus Olivier (Coleoptera: Chrysomelidae) Insect Pest of Tamarind (Tamarindus indica Lin.) Fruit, in Burkina Faso

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Advances in Entomology 2024年第2期12卷 67-77页

作者： Kilo Francine Marina Ki Koï Wenceslas Kam emmanuel Kabore Antoine Sanon Zakaria Ilboudo Laboratoire d’Entomologie Fondamentale et Appliqué e (LEFA) UFR/SVT Universit&eacute Joseph KI-ZERBO Ouagadougou Burkina Faso Institut Supé rieur du D&eacuteveloppement Durable Universit&eacute de Fada N’gourma Fada N’gourma Burkina Faso

The lack of food security leads us to turn to the riches of the forest, namely non-timber forest products (NTFP) and timber forest products (TFP). In Burkina, these products are a source of income for families, improving their living conditions. Tamarindus indica L. that is a NFTP, is widely used in both rural and urban areas. Unfortunately, tamarind is subject to attack by Caryedon serratus. Its biological activity begins on the fruit before the harvest. The aim of our study is to evaluate some biodemographic parameters of the insect pest C. serratus Olivier. First100 healthy T. indica pods were placed in contact with ten pairs of C. serratus for 24 hours. 25 pods, each carrying a maximum of two eggs, were divided into five batches of 5 pods. Then a pair of C. serratus aged less than 24 h was placed in contact with 4 healthy pods for 24 h. Every day, the pair was removed and transferred to another box containing 4 new healthy pods. A total of 20 replicates were performed. The results showed that C. serratus has an average lifespan of 14 days. However, the female (16 days) lived longer and laid an average of 34 eggs during her lifetime. The egg-laying period lasted 14 days, the number of eggs increased until reaching a maximum peak on the 4th day. C. serratus has an embryonic development time of 3 days and an emergence rate of 66.63%. However, the weight of males and females differed significantly (p = 0.0108). We found an intrinsic rate of natural increase of 0.12 and a population doubling time was 5.68 days. These results have enabled us to gain a better understanding of its development cycle and its capacity for regeneration. This allows us to implement control strategies for better stock protection.

关键词： Biodemographic Parameters Stock Caryedon serratus Tamarindus indica

The COVID-19 Pandemic: Present or Gone, Where Do Adolescents Stand?

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Advances in Infectious Diseases 2024年第2期14卷 374-386页

作者： Ifueko Enadeghe Ayebo Sadoh emmanuel U. Eyo-Ita Phillip O. Abiodun Department of Child Health University of Benin Teaching Hospital Benin City Nigeria Institute of Child Health University of Benin Benin City Nigeria

Introduction: The initial global response to the SARS-CoV-2 pandemic focused on adults as adolescents mainly had subclinical infections. Adolescents, however, could transmit the virus and hence be a risk to the elderly, young children and immunocompromised. Adolescents are also at risk of long-term complications. This study sought to determine the prevalence of antibodies to SARS-CoV-2 among adolescents in Southern Nigeria, and to determine the association between SARS-CoV-2 seropositivity and age, gender, socioeconomic class, school type and nutritional status. Methods: This descriptive cross-sectional study was carried out in Edo state of southern Nigeria. We recruited 270 in-school adolescents aged 10 - 19 years. A WHO-adapted, pre-tested questionnaire was used to obtain data on participant history and risk factors. The questionnaire was interviewer-administered. Adolescents whose parents gave consent were recruited through a multi-stage randomized sampling method. Capillary blood for the assay was collected and analysed using a lateral-flow immunoassay device. The primary outcome was serostatus of the study. The positive predictors of serostatus were finally determined using a multiple logistics regression model. Statistical significance was set at p Results: The seroprevalence of SARS-CoV-2 was 45.9%. IgM antibodies were found in 5.6% of participants. Older adolescents had higher seropositivity rates than younger adolescents (2 = 8.101, p = 0.017). There was no association between gender and seropositivity. Adolescents in public schools were more likely to be seropositive than those in private schools (2 = 25.242, p = 0.001). A higher seroprevalence was noticed among study participants in the lower socioeconomic class (x2 = 6.928, p = 0.031), and those in overcrowded classes. (2 = 79.303, p = 0.001). Conclusion: This study showed a high seroprevalence of SARS-CoV-2 among in-school adolescents. Behavioural change communication on SARS-CoV-2, vaccination of adole

关键词： Pandemic Adolescents Seroprevalence COVID-19

Physicochemical and Thermal Properties of Some Key Tropical Sawdust Woods for Energy Production

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Journal of Sustainable Bioenergy Systems 2024年第1期14卷 1-22页

作者： Davy Fiwa Kaoke Yann Le Brech emmanuel Talla Anthony Dufour Patrick Mountapmbeme Kouotou Department of Chemical Engineering School of Chemical Engineering and Mineral Industries University of Ngaoundere Ngaoundere Cameroon National Advanced School of Engineering of Maroua University of Maroua Maroua Cameroon Laboratory of Reactions and Process Engineering University of Lorraine-France Nancy France Higher Institute of Agriculture Wood Water and Environment University of Ebolowa Ebolowa Cameroon

In South Saharan countries, 85% of the population uses biomass as a primary energy source. Cameroon presents one of the highest biomass energy and sawmills produce important sawdust resources which are not used and are burnt in piles leading to significant air toxic emissions. Therefore, we have to valorize industrially these available sawdusts. This study focuses on the physicochemical and thermochemical analysis of Ayous, Sapelli and Tali sawdust. The proximate and ultimate analysis, particle size, structural composition, as well as heavy metal content and calorific value were determined. In addition, the thermogravimetric mass losses were also estimated. The results showed that high water contents (24% - 41%) were recorded in the raw sawdust, and the thermal treatment reduced these contents from 78% to values in the range of 4% - 9%. The values for ash and volatile matter content were respectively between 0.25% - 0.74% and 68% - 76%. The LHV is higher in Ayous (17.5 MJ/kg) and Sapelli (16.8 MJ/kg) than that of Tali (15.7 MJ/kg). The concentration of heavy metals is very low in each species. Extractives are more present in Tali (16.06%) than in the other sawdusts. Pyrolysis of sawdust shows the typical decomposition of hemicellulose (270˚C - 325˚C), cellulose (325˚C - 400˚C) and lignin (200˚C - 550˚C) with a maximum loss of 75% at 370˚C and the melting point is 320˚C. The results of the sawdust parameters determined in the paper can be valorized to reduce pollutants emissions by developing the efficiency and effectiveness of biomass energy processes and promoting the use of biomass as a sustainable alternative to traditional fossil fuels.

关键词： Wood Sawmills Sawdust Combustion Energy

Climatic and non-climatic factors driving the livelihood vulnerability of smallholder farmers in Ahafo Ano North District,Ghana

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Regional Sustainability 2024年第3期5卷 24-39页

作者： Frank BAFFOUR-ATA Louisa BOAKYE Moses Tilatob GADO Ellen BOAKYE-YIADOM Sylvia Cecilia MENSAH Senyo Michael KWAKU KUMFO Kofi Prempeh OSEI OWUSU emmanuel CARR emmanuel DZIKUNU Patrick DAVIES Department of Environmental Science Kwame Nkrumah University of Science and TechnologyKumasiAK-039-5028Ghana Department of Meteorology and Climate Science Kwame Nkrumah University of Science and TechnologyKumasiAK-039-5028Ghana

Smallholder farmers in Ahafo Ano North District,Ghana,face multiple climatic and non-climatic *** study assessed the factors contributing to the livelihood vulnerability of smallholder farmers in this district by household surveys with 200 respondents and focus group discussions(FGDs)with 10 *** Mann–Kendall trend test was used to assess mean annual rainfall and temperature trends from 2002 to *** relative importance index(RII)value was used to rank the climatic and non-climatic factors perceived by *** socioeconomic characteristics affecting smallholder farmers’perceptions of climatic and non-climatic factors were evaluated by the binary logistic regression *** showed that mean annual rainfall decreased(P>0.05)but mean annual temperature significantly increased(P<0.05)from 2002 to 2022 in the *** key climatic factors perceived by smallholder farmers were extreme heat or increasing temperature(RII=0.498),erratic rainfall(RII=0.485),and increased windstorms(RII=0.475).The critical non-climatic factors were high cost of farm inputs(RII=0.485),high cost of healthcare(RII=0.435),and poor condition of roads to farms(RII=0.415).Smallholder farmers’perceptions of climatic and non-climatic factors were significantly affected by their socioeconomic characteristics(P<0.05).This study concluded that these factors negatively impact the livelihoods and well-being of smallholder farmers and socioeconomic characteristics influence their perceptions of these ***,to enhance the resilience of smallholder farmers to climate change,it is necessary to adopt a comprehensive and context-specific approach that accounts for climatic and non-climatic factors.

关键词： Smallholder farmers Livelihood vulnerability Climate change Socioeconomic characteristics Food security Ghana

Study of Rice Husks and Expanded Polystyrene Composites for Construction Applications

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Open Journal of Civil Engineering 2024年第3期14卷 456-468页

作者： Edem Chabi Valéry Kouandété Doko Sena Peace Hounkpè Paul Damien Amadji emmanuel Olodo Laboratory of Rural Engineering School of Rural Engineering National University of Agriculture Ketou Benin Laboratory of Applied Energy and Mechanics (LEMA) Polytechnic School of Abomey-Calavi University of Abomey-Calavi Abomey-Calavi Benin Department of Civil Engineering Higher National School of Public Works (ENSTP) National University of Sciences Technologies Engineering and Mathematics Abomey Benin

In the current context of environmental challenges, this study focuses on developing innovative and eco-friendly composites using rice husk and recycled expanded polystyrene. This dual-responsibility approach valorizes a by-product like rice husk, often considered waste, and reuses polystyrene, a plastic waste, thereby contributing to CO2 emission reduction and effective waste management. The manufacturing process involves dissolving recycled polystyrene into a solvent to create a binder, which is then mixed with rice husk and cold-compacted into composite materials. The study examines the impact of two particle sizes (fine and coarse) and different proportions of recycled polystyrene binder. The results show significant variations in the mechanical characteristics of the composites, with Modulus of Rupture (MOR) values varying from 2.41 to 3.47 MPa, Modulus of Elasticity (MOE) ranging from 223.41 to 1497.2 MPa, and Stiffness Coefficient (K) from 5.04 to 33.96 N/mm. These characteristics demonstrate that these composites are appropriate for various construction applications, including interior decoration, panel claddings, and potentially for furniture and door manufacturing when combined with appropriate coatings. This study not only highlights the recycling of agricultural and plastic waste but also provides a localized approach to addressing global climate change challenges through the adoption of sustainable building materials.

关键词： Rice Husk Recycled Expanded Polystyrene Eco-Friendly Composites Waste Valorization Sustainable Construction