Scientific African最新文献

Integrated solar system for green hydrogen production and sustainable AC power generation using digital control 采用数字控制的绿色制氢和可持续交流发电集成太阳能系统

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-12-29 DOI: 10.1016/j.sciaf.2025.e03160

S. YAHYAOUI , A. AZIZ , S. DAHBI , J. BLAACHA , A. MESSAOUDI

Green hydrogen production from solar energy faces critical challenges in power management and system efficiency. This work presents an optimised integrated photovoltaic energy conversion system capable of simultaneously supplying alternating current energy to local loads and producing green hydrogen by water electrolysis. Unlike conventional systems using batteries, the proposed architecture combines a Buck converter controlled by a Perturb-and-Observe algorithm, a Boost converter that stabilises the DC bus at 24 V, and a unipolar pulse width modulation bridge inverter followed by an LC filter to generate a clean sinusoidal voltage with minimal distortion. A cylindrical-electrode electrolyser is directly connected downstream of the Buck converter, where it absorbs excess power, tolerates current and voltage fluctuations, and contributes to stabilising the system which is considered as a key innovation. Experimental tests in Oujda, Morocco, under both stable and highly variable solar irradiance show that the cylindrical electrolyser absorbs up to 85 % of available PV power while maintaining system stability. The system efficiency is 11.7 % which is significantly higher than the 8-9.1 % reported for flat-plate electrolyser systems with battery storage. The proposed system ensures a hydrogen production of 40–60 mL/min with delivering a clean AC power with a total harmonic distortion below 5 %. Overall, the proposed configuration provides an effective alternative for autonomous systems in the African context by adopting a strategy in which the cylindrical electrolyser simultaneously functions as a photovoltaic power adapter and a hydrogen production unit offering a battery-free, cost-effective solution.

太阳能绿色制氢在电源管理和系统效率方面面临严峻挑战。本研究提出了一种优化的集成光伏能量转换系统，该系统能够同时为本地负载提供交流能量，并通过水电解产生绿色氢气。与使用电池的传统系统不同，所提出的架构结合了一个由扰动和观察算法控制的Buck转换器，一个将直流母线稳定在24 V的Boost转换器，以及一个单极脉宽调制桥式逆变器，然后是一个LC滤波器，以产生具有最小失真的干净正弦电压。一个圆柱电极电解槽直接连接到Buck转换器的下游，在那里它吸收多余的功率，容忍电流和电压波动，并有助于稳定系统，这被认为是一个关键的创新。在摩洛哥Oujda进行的稳定和高度可变太阳辐照度的实验测试表明，圆柱形电解槽在保持系统稳定性的同时吸收了高达85%的可用光伏发电。系统效率为11.7%，这是显著高于8- 9.1%的平板电解槽系统与电池存储报告。该系统可确保氢气产量为40-60 mL/min，同时提供清洁的交流电源，总谐波失真低于5%。总的来说，拟议的配置为非洲环境下的自主系统提供了一种有效的替代方案，采用了一种策略，即圆柱形电解槽同时作为光伏电源适配器和氢气生产单元，提供了一种无电池、经济高效的解决方案。

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引用次数: 0

Study of the electronic properties of quantum rings under the influence of the electric field in the presence of two off-center impurities 两种偏离中心杂质存在时电场影响下量子环电子性质的研究

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-12-26 DOI: 10.1016/j.sciaf.2025.e03155

M. El Hadi , M. Hbibi , S. Chouef , R. Boussetta , A. El Moussaouy , O. Mommadi , C.A. Duque

This study examines the electronic properties of a GaAs quantum ring under the influence of external electric fields and donor impurity interactions, utilizing the Finite Difference Method (FDM) and the effective mass approximation. We explore the effects of quantum ring geometry, impurity positioning, and the application of electric fields on the electron–impurity binding energy and the average distance between the electron and the impurities. Our results reveal that the electron–impurity binding energy is strongly influenced by the angular position of the impurities, with stronger interactions observed when the impurities are closer to the symmetry axis of the ring. The application of an external electric field induces the Stark effect, which reduces the binding energy and alters the electron charge distribution. Furthermore, the presence of impurity interactions (

κ = 1

) increases the binding energy, while the absence of impurity interactions (

κ = 0

) leads to weaker binding. The study also shows that the average distance between the electron and impurities is sensitive to the angular position of the impurities and decreases under the influence of an electric field. These findings underscore the crucial role of quantum ring geometry, external fields, and impurity interactions in shaping the electronic properties of nanoscale devices, providing valuable insights for the development of advanced quantum-based technologies.

利用有限差分法（FDM）和有效质量近似，研究了外电场和施主杂质相互作用下GaAs量子环的电子特性。我们探讨了量子环几何形状、杂质定位和电场的应用对电子-杂质结合能和电子与杂质的平均距离的影响。我们的结果表明，电子-杂质结合能受杂质的角度位置的强烈影响，当杂质更接近环的对称轴时，观察到更强的相互作用。外加电场的作用引起了斯塔克效应，它降低了结合能，改变了电子电荷的分布。此外，杂质相互作用（κ=1）的存在增加了结合能，而不存在杂质相互作用（κ=0）导致结合较弱。研究还表明，电子与杂质之间的平均距离对杂质的角度位置很敏感，并且在电场的影响下减小。这些发现强调了量子环几何形状、外场和杂质相互作用在塑造纳米级器件电子特性中的关键作用，为先进量子技术的发展提供了有价值的见解。

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引用次数: 0

A comparative study of estimation methods for the New Sine Topp-Leone Fréchet distribution 新正弦Topp-Leone分布估计方法的比较研究

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-12-18 DOI: 10.1016/j.sciaf.2025.e03142

Amal S. Hassan , Emadeldin I.A. Ali , Hanene Hamdani , Ahmed M. Gemeay , Ahmed W. Shawki , Mohammed Elgarhy

Modeling and fitting complex datasets are crucial domains in various scientific fields. This article presents the sine Topp-Leone Fréchet distribution, a new probability distribution obtained by integrating the Fréchet distribution with the sine Topp-Leone-G family. The suggested model’s most noteworthy feature is its ability to accurately represent a broad variety of hazard rate patterns (such as upside-down, reversed J-shaped, decreasing, and increasing) with just three parameters. Its density may also display unimodal, reversed-J, and right-skewed shapes. We offer a number of statistical properties for the proposed distribution. Using sixteen different estimation approaches, we estimated the parameters of the suggested model and investigated a number of its distributional characteristics. We evaluate the validity of the suggested model and compare the efficacy of various parameter estimates using a Monte Carlo simulation. Numerical analysis shows that the Kolmogorov and second-order left-tail Anderson–Darling estimators exhibit superior efficiency and consistency in a variety of scenarios. They frequently receive the highest overall ranking based on the sum of all performance criteria and consistently produce estimates with low bias and mean squared error. Additionally, we evaluated the suggested distribution’s adaptability using two real-world datasets, demonstrating its remarkable ability to precisely fit the data. According to our findings, the suggested distribution performs better in terms of fit quality than a cotangent Fréchet, odd exponential-logarithmic Fréchet, Topp-Leone Fréchet, odd-generalized exponential inverse Weibull, generalized inverse Weibull distribution, arctan inverse Weibull, new arctan Fréchet, and Fréchet distributions.

复杂数据集的建模和拟合是各个科学领域的关键领域。本文提出了正弦Topp-Leone fracimchet分布，它是将fracimchet分布与正弦Topp-Leone- g族积分得到的一种新的概率分布。所建议的模型最值得注意的特点是，它能够仅用三个参数就准确地表示各种各样的风险率模式（例如倒挂、倒j型、减少和增加）。它的密度也可能显示单峰、反j型和右倾斜的形状。我们为提议的分布提供了一些统计性质。使用16种不同的估计方法，我们估计了所建议模型的参数，并研究了它的一些分布特征。我们评估了所建议的模型的有效性，并使用蒙特卡罗模拟比较了各种参数估计的有效性。数值分析表明，Kolmogorov估计和二阶左尾Anderson-Darling估计在各种情况下都具有较好的效率和一致性。基于所有性能标准的总和，它们经常获得最高的总体排名，并始终如一地产生低偏差和均方误差的估计。此外，我们使用两个真实数据集评估了建议分布的适应性，证明了其精确拟合数据的卓越能力。根据我们的研究结果，建议的分布在拟合质量方面优于余切分布、奇指数对数分布、Topp-Leone分布、奇广义指数逆威布尔分布、广义逆威布尔分布、arctan逆威布尔分布、新arctan frsamet分布和frsamet分布。

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引用次数: 0

Determinants of child survival in Ghana: A multi-level survival analysis of individual and contextual factors 加纳儿童生存的决定因素：个体和环境因素的多层次生存分析

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-12-03 DOI: 10.1016/j.sciaf.2025.e03124

Dieu Donne Yormekpe , Benedicta Osei

This study investigates child survival determinants in Ghana using a multi-level survival analysis of the 2006, 2011 and 2018 Multiple Indicator Cluster Surveys (n=13,125). We employed Cox proportional hazards, parametric accelerated failure time (AFT) and gamma frailty models to assess individual and contextual factors influencing under-five mortality, accounting for unobserved heterogeneity. Key findings reveal a wealth-mortality relationship, with middle-wealth households showing lower mortality (HR=0.60, TR=1.44) compared to low-wealth, while rich households exhibited higher risks (HR=1.84, TR=0.64). Maternal education significantly reduces mortality risk (primary: HR=0.69, TR=1.28; secondary+: HR=0.86, TR=1.12). Institutional deliveries lower mortality by 29%–43% (TR=1.29–1.43). Northern regions (Upper West: HR=2.53, TR=0.50; Northern: HR=2.24, TR=0.56) face elevated risks, reflecting structural disparities. Gamma frailty models revealed a significant frailty variance (

θ > 0

), confirming substantial unobserved heterogeneity across regions and indicating that unmeasured, region-specific factors influence child mortality. The Weibull AFT model provided the best fit (AIC=21,999.45), highlighting early-life mortality risks. The policy implications are clear that interventions must be spatially targeted and move beyond simple wealth stratification, requiring specific environmental and infrastructural improvements tailored to high-risk and economically disparate areas of Ghana.

本研究利用2006年、2011年和2018年多指标类集调查（n=13,125）的多层次生存分析，调查了加纳儿童生存的决定因素。我们采用Cox比例风险、参数加速失效时间（AFT）和γ脆弱性模型来评估影响5岁以下儿童死亡率的个体和环境因素，并解释未观察到的异质性。主要发现揭示了财富与死亡率之间的关系，与低财富家庭相比，中等财富家庭的死亡率较低（HR=0.60， TR=1.44），而富裕家庭的风险较高（HR=1.84， TR=0.64）。孕产妇教育显著降低了死亡风险（初等教育：风险比=0.69，TR=1.28；中等教育：风险比=0.86，TR=1.12）。在医院分娩可使死亡率降低29%-43% （TR= 1.29-1.43）。北部地区（上西部：HR=2.53， TR=0.50；北部：HR=2.24， TR=0.56）风险较高，反映出结构性差异。Gamma脆弱性模型显示出显著的脆弱性方差（θ>0），证实了各地区之间存在大量未观察到的异质性，并表明未测量的区域特异性因素影响儿童死亡率。Weibull AFT模型提供了最佳拟合（AIC=21,999.45），突出了生命早期死亡风险。政策影响很明显，干预措施必须有空间针对性，不能只是简单的财富分层，需要针对加纳高风险和经济差异大的地区进行具体的环境和基础设施改善。

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引用次数: 0

Forecasting temperature data for two counties in California using the stress–strength reliability of the MO q-GEVL distribution: A return level based approach and time series 利用MO q-GEVL分布的应力-强度可靠性预测加州两个县的温度数据：基于回归水平的方法和时间序列

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2026-01-29 DOI: 10.1016/j.sciaf.2026.e03207

Eslam Abdelhakim Seyam , Shimaa Wasfy Sadk , Ibrahim A. Fares , Rasha Abd El-Wahab Attwa

In this article, the stress–strength reliability (

S S R = P (X < Y)

), where both stress

X

and strength

Y

follow a new model called Marshall Olkin’s q extended generalized extreme value linear distribution (

M

-

q GEVL

) under type II progressive censoring, is investigated. The

S S R

estimation is considered using both maximum likelihood estimation (

M L E

) and Bayesian estimation (

B E

). Since the

M L E

equations are extremely complex, a metaheuristic optimization technique called the Whale Optimization Algorithm (WOA) is utilized. The

B E

is considered for both informative and non informative cases using both Linex and square error loss functions. Temperature data from Sacramento and Los Angeles counties in California are also used to demonstrate the proposed statistical methodology, showing that the

M - q G E V L

model provides a better fit than both

q G E V L

and

G E V L

based on lower

S K

,

A I C

, and

B I C

values. Time series analysis, return level, and

S S R

are applied to predict future temperatures, and the results consistently indicate higher predicted temperatures in Los Angeles than in Sacramento.

本文研究了应力X和强度Y都遵循马歇尔奥尔金q扩展广义极值线性分布（M-qGEVL）模型的应力-强度可靠度（SSR=P(X<；Y)）。最大似然估计（MLE）和贝叶斯估计（BE）同时用于SSR估计。由于MLE方程非常复杂，因此使用了一种称为鲸鱼优化算法（WOA）的元启发式优化技术。使用线性误差和平方误差损失函数，考虑了信息和非信息情况下的BE。利用加州萨克拉门托和洛杉矶县的温度数据验证了所提出的统计方法，结果表明，基于较低的SK、AIC和BIC值，M-qGEVL模型比qGEVL和GEVL模型具有更好的拟合效果。利用时间序列分析、回归水平和SSR预测未来气温，结果一致表明洛杉矶的预测气温高于萨克拉门托。

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引用次数: 0

Assessing the influence of smart grids policy and regulatory framework on electricity revenue generation: The case of South Africa 评估智能电网政策和监管框架对发电的影响：以南非为例

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2026-02-15 DOI: 10.1016/j.sciaf.2026.e03264

Oladimeji Joseph Ayamolowo, K. Kusakana

As the world transitions toward a low-carbon economy using digital technologies. Smart grid technologies have been deployed in countries around the world by integrating renewable energy, digital monitoring, and intelligent control systems in a bid to meet the net-zero carbon emission goal while enhancing operational efficiency and revenue collection. This study gives a comprehensive review of the strides made by the South Africa energy sector towards the realization of a smart energy sector. It further investigates the influence of smart grid (SG) policies and regulatory frameworks on electricity revenue generation in South Africa. The research identified Strategic National Smart Grid Vision (2024) and the South African Smart Grids Initiative (SASGI) as central programs by the South African National Energy Development Institute which drives this smart grid transformation. Key research findings reveal that policy alignment and regulatory reforms have improved billing accuracy, reduced non-technical losses, and increased municipal revenues through smart metering and advanced monitoring systems. However, challenges persist in investment, infrastructure modernization, and consumer participation. The study concludes that a robust, well-coordinated regulatory environment and sustained investment are essential to achieving South Africa’s 2030 smart grid targets and fostering a resilient, intelligent energy future.

随着世界向使用数字技术的低碳经济过渡。通过整合可再生能源、数字监控和智能控制系统，智能电网技术已在世界各国部署，以实现净零碳排放目标，同时提高运营效率和收入。本研究全面回顾了南非能源部门在实现智能能源部门方面所取得的进展。它进一步调查了智能电网（SG）政策和监管框架对南非电力收入产生的影响。该研究将战略国家智能电网愿景（2024年）和南非智能电网倡议（SASGI）确定为南非国家能源发展研究所推动智能电网转型的核心项目。主要研究结果表明，政策调整和监管改革提高了计费准确性，减少了非技术损失，并通过智能计量和先进的监控系统增加了市政收入。然而，投资、基础设施现代化和消费者参与方面的挑战依然存在。该研究的结论是，健全、协调良好的监管环境和持续的投资对于实现南非2030年智能电网目标和培育一个有弹性、智能的能源未来至关重要。

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引用次数: 0

Effects of climate change on the dynamics of small Sahelian water bodies over the period 1972-2020: a case study in the Logone-Cameroon floodplain (Lake Chad basin) 1972-2020年气候变化对萨赫勒小水体动态的影响——以龙岗-喀麦隆漫滩（乍得湖盆地）为例

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2026-02-22 DOI: 10.1016/j.sciaf.2026.e03270

Solange Léonie Piih , Guillaume Ewodo Mboudou , André Firmin Bon , Raoul Wappouo

Studies conducted in recent years in the Lake Chad basin indicate a considerable decrease in the lake's surface area, attributed to rainfall deficits observed across Africa for more than 25 years. However, the dynamics of small water bodies remain poorly understood in other parts of the Chad Basin, where ponds play an important role in socio-economic development. The objective of this study was to characterize the spatio-temporal dynamics (1972–2020) of small water bodies in the Cameroonian part of the Lake Chad basin. The work consisted of assessing meteorological drought and processing and supervised classification of 42 satellite imagery coupled with field data. Standardized Precipitation Index (SPI) values ranged from 2.154 to -2.509, illustrating the uniformity of climatic conditions and a rainfall profile with alternating normal (1972–1979), dry (1980–1997), and wet (1998–2020) periods. These climatic conditions lead to contrasting patterns of flooding and drought during different seasons, contributing to distinct dynamics in water surface areas extracted with an overall accuracy of 98.77 % and a Kappa coefficient of 0.97 %. Changes in water surface areas between wet and dry periods indicated significant dynamics with a high risk of flooding and very high vulnerability to drought. Correlation coefficients illustrate the relationship between short-term drought (SPI3) and surface water resources. Wet conditions (> 0.3 km²) control water availability in the dry season, but its sustainability depends on the intensity of external inflows and water pumping. Some ponds showed similar average interannual hydrological conditions with corresponding average climatic conditions. Diffuse behaviors indicate complex dynamics that limit water availability in some areas, sometimes leading to local disturbances. These results improve our understanding of how the Sahelian plains function and can provide guidance on post-flood water use in order to ensure water availability, protect communities, and preserve socio-ecosystems in the face of contemporaneous challenges that are sometimes unavoidable.

近年来在乍得湖流域进行的研究表明，由于在整个非洲观测到超过25年的降雨不足，乍得湖的表面积显著减少。然而，在乍得盆地的其他地区，人们对小水体的动态仍然知之甚少，在这些地区，池塘在社会经济发展中发挥着重要作用。本研究的目的是表征乍得湖流域喀麦隆部分小水体的时空动态（1972-2020）。这项工作包括气象干旱评估和42幅卫星图像加上实地数据的处理和监督分类。标准化降水指数（SPI）值在2.154 ~ -2.509之间，显示了气候条件的均匀性以及正常（1972-1979）、干旱期（1980-1997）和湿润期（1998-2020）交替变化的降水剖面。这些气候条件导致不同季节洪涝和干旱的不同模式，导致水面区域的不同动态，提取的总体精度为98.77%，Kappa系数为0.97%。湿润期和干旱期之间水面面积的变化表明了显著的动态变化，洪水风险高，干旱脆弱性高。相关系数反映了短期干旱（SPI3）与地表水资源之间的关系。湿润条件（0.3平方公里）控制旱季的可用水量，但其可持续性取决于外部流入和抽水的强度。有些池塘的年际水文条件与相应的气候条件相似。扩散行为表明在某些地区限制水可用性的复杂动态，有时导致局部扰动。这些结果提高了我们对萨赫勒平原功能的理解，并可以为洪水后的水资源利用提供指导，以确保水资源的可用性，保护社区，并在面对有时不可避免的当代挑战时保护社会生态系统。

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引用次数: 0

Exploring the apoptosis-inducing potential of Syzygium cimini leaves in cancer treatment; LC-ESI-MS/MS analysis, biological assessments, and computational studies 探讨合欢叶诱导肿瘤细胞凋亡的作用LC-ESI-MS/MS分析，生物学评估和计算研究

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-11-24 DOI: 10.1016/j.sciaf.2025.e03108

Ahmed A. Al-Karmalawy , Mohamed E. Eissa , Rehab F. Taher , Tarek A. Yousef , Arwa Omar Al Khatib , Marwa Sharaky , Radwan Alnajjar , Haidy A. Abbas

This study provides a novel, integrated phytochemical and biological profiling of S. cumini leaves, differentiating it through its computational and experimental focus on the caspase-mediated apoptotic pathway. Herein, sixty-nine (69) compounds were tentatively identified in the methanol extract of Syzygium cumini leaves, with 45 of these compounds found only in the hexane extract. The IC_50s of the methanol extract of Syzygium cumini leaves were recorded towards eight diverse cancer cell lines. The methanol extract showed very strong anticancer activities against MDA-MB-468, HEPG2, and H1299 cancer cells with IC₅₀ values of 13.16, 10.60, and 20.55 µg/mL, respectively. Furthermore, the methanol extract of Syzygium cumini leaves was further examined for its apoptotic potential as a proposed mechanism for its anticancer activity. Interestingly, the expression of the proapoptotic markers (Caspases 3, 6, and 7, and BAX) was upregulated with a fold change of 1.29, 2.02, 1.95, and 3.52, respectively. On the other hand, the expression of anti-apoptotic proteins (MMP2, MMP9, and Bcl-2) was dramatically decreased by 1.78, 1.84, and 2.07-fold change, respectively. Additionally, a molecular docking study against Caspase 6 clarified that kaempferol malonyl-hexoside, kaempferol-O-(p-coumaroyl)-hexoside, and quercetin-O-hexoside-pentoside showed superior docking scores compared to the Co-crystal inhibitor. Moreover, a molecular dynamics simulation for 500 ns was implemented to validate the docking results and confirm the stability of these compounds within the active site of the Caspase 6 enzyme. Additionally, the MM-GBSA calculations and ADME pharmacokinetic properties were evaluated.

本研究提供了一种新的、综合的植物化学和生物学分析，通过计算和实验重点对半胱天冬酶介导的凋亡途径进行了区分。本文初步鉴定了69种化合物，其中45种化合物仅存在于己烷提取物中。记录了芫荽叶甲醇提取物对8种不同癌细胞的ic50。甲醇提取物对MDA-MB-468、HEPG2和H1299癌细胞具有较强的抗肿瘤活性，IC50值分别为13.16、10.60和20.55µg/mL。此外，我们还进一步研究了茴香叶甲醇提取物的细胞凋亡潜力，作为其抗癌活性的可能机制。有趣的是，促凋亡标志物（Caspases 3、6、7和BAX）的表达上调，分别为1.29、2.02、1.95和3.52倍。另一方面，抗凋亡蛋白MMP2、MMP9和Bcl-2的表达分别下降了1.78倍、1.84倍和2.07倍。此外，一项针对Caspase 6的分子对接研究表明，山奈酚丙二酰己糖、山奈酚o-（对香豆醇）己糖和槲皮素o-己糖-戊糖的对接得分高于共晶抑制剂。此外，通过500 ns的分子动力学模拟验证了对接结果，并证实了这些化合物在Caspase 6酶活性位点内的稳定性。此外，还评估了MM-GBSA计算和ADME的药代动力学性质。

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引用次数: 0

Analysis of aquaculture methods, socio-economic benefits, and challenges faced by small-scale fish farmers in Chiredzi Rural District, Zimbabwe 分析津巴布韦奇雷兹农村地区小规模养鱼户的水产养殖方法、社会经济效益和面临的挑战

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2025-12-08 DOI: 10.1016/j.sciaf.2025.e03128

Rodney T Muringai, Walter Musakwa

Aquaculture plays a pivotal role in enhancing food security and socioeconomic development, particularly in rural areas. In the Chiredzi Rural District, aquaculture is expanding rapidly to improve food and nutrition security, while enhancing livelihoods and climate resilience. However, a significant knowledge gap exists regarding aquaculture methods, socio-economic benefits, and challenges faced by small-scale fish farmers in this area. Therefore, this study aimed to analyse the methods used by fish farmers, assess the socio-economic benefits, and identify the challenges they face in the Chiredzi Rural District of Zimbabwe. Data were collected using a mixed-methods approach. A multistage sampling technique was used to select the target wards and the farmers. A semi-structured survey questionnaire was administered to 120 fish farmers in Wards 9 (Twananani), 10 (Batanai) and 11 (Chikombedzi). The findings show that 85 % of farmers use earthen pond systems and mainly cultivate Nile Tilapia. Aquaculture is not profitable in the Chiredzi Rural District, but it contributes to food and nutritional security. The main challenges for fish farmers include adverse weather, disease, and limited technical assistance. To enhance the sustainability and profitability of small-scale aquaculture in Chiredzi Rural District, it is recommended that local government and development partners invest in targeted technical support and climate-resilient infrastructure for fish farmers.

水产养殖在加强粮食安全和社会经济发展方面发挥着关键作用，特别是在农村地区。在Chiredzi农村地区，水产养殖正在迅速扩大，以改善粮食和营养安全，同时提高生计和气候适应能力。然而，在该地区的水产养殖方法、社会经济效益和小规模养鱼户面临的挑战方面存在着重大的知识差距。因此，本研究旨在分析津巴布韦Chiredzi农村地区养鱼户使用的方法，评估其社会经济效益，并确定他们面临的挑战。采用混合方法收集数据。采用多阶段抽样技术选择目标病区和农户。对第9区（Twananani）、第10区（Batanai）和第11区（Chikombedzi）的120名养鱼户进行了半结构化问卷调查。调查结果显示，85%的农民使用土池系统，主要养殖尼罗罗非鱼。在Chiredzi农村地区，水产养殖无利可图，但它有助于粮食和营养安全。养鱼户面临的主要挑战包括恶劣天气、疾病和有限的技术援助。为了提高Chiredzi农村地区小规模水产养殖的可持续性和盈利能力，建议地方政府和发展伙伴为养鱼户提供有针对性的技术支持和气候适应型基础设施投资。

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引用次数: 0

Integration of subsurface and outcrop data to evaluate the mineralogy, geochemistry, and hydrocarbon potentiality of Duwi black shale Formation at Kharga and Dakhla depressions, Western Desert, Egypt 利用地下和露头数据综合评价埃及西部沙漠Kharga和Dakhla凹陷Duwi黑色页岩组矿物学、地球化学和油气潜力

IF 3.3 Q2 MULTIDISCIPLINARY SCIENCES

Scientific African

Pub Date : 2026-03-01 Epub Date: 2026-02-02 DOI: 10.1016/j.sciaf.2026.e03239

Samar R. Soliman , Yasser F. Salama , Ibrahim M. Abd ElGaied , Mohamed I. El-Sayed , Gebely A Abu El-Kheir , Zakaria M. Abd-Allah

The black shale successions in Egypt remain insufficiently investigated, particularly with respect to their geochemical and mineralogical properties. Accordingly, this study presents a comprehensive evaluation of the Cretaceous Duwi Formation in the Kharga and Dakhla depressions of Egypt’s Western Desert through an integrated geological, mineralogical, and geochemical approach. This work is based on several geochemical analyses, such as XRD, XRF, total (sulfur, organic carbon, and carbon), Rock Eval Pyrolysis (RE-P), and Pyrolysis Gas Chromatography that were undertaken on the collected black shale samples. Mineralogical results confirm that smectite and kaolinite are the primary clay components in Mut-Manflout. A strong correlation between major oxides and common trace elements reveals a detrital provenance; by contrast, the elevated chemical index of alteration reflects an intensive degree of weathering within outcrop samples. Geochemical outcomes reveal that the core and outcrop samples remain thermally immature, with TOC fluctuating between 0.19 and 1.59 wt.%, a limit of poor potential within outcrop samples, whereas it ranges from 0.27 to 3.57 wt.%, a limit of excellent potential within core samples. The studied core samples are classified as Type I–II to Type II–III kerogen, representing the reliable limit of the oil-gas-prone area, while the outcrop samples are classified as Type III–IV kerogen, indicating a gas-prone limit. A notable association between TOC level and S₁+S₂ value indicates good generation potential for primary core shale samples; however, reflects a poor category for the outcrop shale samples at the selected sections. Collectively, the findings highlight the Duwi Formation black shales as an underexplored unconventional resource with variable hydrocarbon potential across the Kharga and Dakhla depressions.

埃及的黑色页岩层序仍然没有得到充分的调查，特别是在其地球化学和矿物学性质方面。因此，本研究通过综合地质、矿物学和地球化学方法，对埃及西部沙漠Kharga和Dakhla凹陷白垩纪Duwi组进行了综合评价。这项工作是基于对收集的黑色页岩样品进行的几种地球化学分析，如XRD， XRF，总（硫，有机碳和碳），岩石评价热解（RE-P）和热解气相色谱法。矿物学研究结果表明，蒙脱石和高岭石是穆特-曼脱岩粘土的主要成分。主要氧化物与常见微量元素之间的强相关性揭示了碎屑物源；相比之下，蚀变化学指标的升高反映了露头样品中强烈的风化程度。地球化学结果表明，岩心和露头样品仍保持热未成熟状态，TOC在0.19 ~ 1.59 wt.%之间波动，为露头样品中较差的潜力极限，而在0.27 ~ 3.57 wt.%之间波动，为岩心样品中极好的潜力极限。岩心样品划分为ⅰ-ⅱ型至ⅱ-ⅲ型干酪根，代表了油气倾向区可靠界限；露头样品划分为ⅲ-ⅳ型干酪根，代表了油气倾向区可靠界限。TOC水平与S1+S2值的显著相关性表明原生岩心页岩样品具有良好的生烃潜力；然而，这反映了所选剖面的露头页岩样品类别较差。总的来说，这些发现强调了Duwi组黑色页岩是一种未被开发的非常规资源，在Kharga和Dakhla坳陷具有可变的油气潜力。

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引用次数: 0