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A hybrid solar-biogas system for post-COVID-19 rural energy access

CLEAN ENERGY 2024年第1期8卷 84-99页

作者： Overen, Ochuko K. Obileke, Kechrist Meyer, Edson L. Makaka, Golden Apeh, Oliver O. Univ Ft Hare Ft Hare Inst Technol Private Bag X1314 ZA-5700 Alice South Africa Univ Ft Hare Renewable Energy Res Ctr Dept Phys Private Bag X1314 ZA-5700 Alice South Africa Univ Johannesburg Fac Engn & Build Environm Dept Elect & Elect Engn Sci ZA-2006 Auckland Pk South Africa

Solar home systems for rural electrification are often designed with a limited energy supply, which presents a drawback for the technology. Furthermore, uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks. Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable electricity access to underserved rural communities while achieving waste management. Therefore, this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities. A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study. The findings show that the daily household energy consumption was 6.6 kWh, equivalent to 206.40 kWh/month. A 1.2-kWp and 1.2-m3 hybrid solar-biogas system was found to adequately power the house. Financially, the total initial investment cost of the system was $5777.20 with a net present value of $6566.78, net profit of $4443.6, a payback period of 14 years and 8 months, and a levelized cost of energy of $0.21/kWh; these include a 60% initial investment and maintenance costs subsidy. Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system. The study successfully revealed the design, specifications and upscaling mechanism of the proposed hybrid solar-biogas system. More research is required to unveil the efficacy of the system, the performance gap and the perception of the technology by the beneficiaries. A hybrid solar-biogas system is designed for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities. A parametric research approach is used to specify the desired household load and the hybrid system sizi

关键词： energy access sustainable rural development clean energy waste management post-COVID-19 recovery plan SOUTH-AFRICA ELECTRIFICATION BATCH

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Lithostratigraphy,Sedimentology,and Provenance of the Balfour Formation(Beaufort Group) in the Fort Beaufort-Alice Area,Eastern Cape Province,South Africa

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Acta Geologica Sinica(English Edition) 2009年第5期83卷 902-916页

作者： David KATEMAUNZANGA Cornelis Janse GUNTER Council for Geoscience PretoriaSouth Africa Geology Department University of Fort HareAliceSouth Africa

The Balfour Formation has a pronounced lithological variation that is characterized by alternating sandstone- and mudstone-dominated members. The sandstone-dominated Oudeberg and Barberskrans Members are composed of lithofacies that range from intraformationai conglomerates to fine-grained sediments, whereas the mudstone-dominated members （Daggaboersnek, Elandsberg, and Palingkloof） are dominated by the facies Fm and FI. Petrography, geochemistry, and a paleocurrent analysis indicated that the source rock of the Balfour Formation was to south east and the rocks had a transitional/dissected magmatic arc signature. The sandstones-rich members were deposited by seasonal and ephemeral high-energy, low-sinuous streams, and the fine-grained-rich members were formed by ephemeral meandering streams. The paleoclimates have been equated to present temperate climates; they were semiarid becoming arid towards the top of the Balfour Formation. This has been determined by reconstructing the paleolatitude of the Karoo Basin, geochemistry, paleontology, sedimentary structures, and other rock properties, like color.

关键词： Balfour Formation Karoo Supergroup Beaufort Group lithostratigraphy sedimentology provenance Permo-Triassic

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Euclea undulata Thunb.:Review of its botany,ethnomedicinal uses,phytochemistry and biological activities

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Asian Pacific Journal of Tropical Medicine 2017年第11期10卷 1030-1036页

作者： Alfred Maroyi Medicinal Plants and Economic development(MPED)research centre Department of BotanyUniversity of Fort HarePrivate Bag X1314Alice 5700South Africa

Euclea undulata(E. undulata) is traditionally used for the treatment of body pains, chest complaints, cough, diabetes, diarrhoea, headaches, heart diseases and toothaches in southern Africa. This study was aimed at reviewing the botany, ethnopharmacology and biological activities of E. undulata in southern Africa. Results presented in this study are based on review of literature using search engines such as Science Direct, Springerlink,Scopus, Pub Med, Web of Science, Bio Med Central and Google Scholar. Herbal medicine is prepared from the decoctions of the roots, bark and leaves, and extracts of these plant parts have demonstrated anticholinesterase, anti-inflammatory, antimicrobial, antimycobacterial, antiplasmodial, antioxidant and hypoglycaemic activities. Multiple classes of phytochemical compounds such alkaloids, diterpenes, fatty acids, flavonoids, glycosides, naphthoquinones, phenolics, phytosterols, reducing sugars, saponins and tannins have been isolated from the species. E. undulata has a lot of potential as herbal medicine in tropical Africa, and advanced research is required aimed at correlating its medicinal uses with the phytochemistry and pharmacological properties.

关键词： Complementary and alternative medicine Euclea undulata Ethnopharmacology Southern Africa Traditional medicine

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Antioxidant, antibacterial and phytochemical properties of two medicinal plants against the wound infecting bacteria

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Asian Pacific Journal of Tropical Biomedicine 2017年第9期7卷 817-825页

作者： Idowu Jonas Sagbo Anthony Jide Afolayan Graeme Bradley Department of Botany University of Fort HarePrivate Bag X1314Alice 5700South Africa Department of Biochemistry and Microbiology University of Fort HarePrivate Bag X1314Alice 5700South Africa

Objective: To investigate the antioxidant, antibacterial and phytochemical properties of ethanol extracts of Brachylaena elliptica and Brachylaena ilicifolia against wound infecting bacteria normally found in diabetic ***: The in vitro antioxidant activity of the two plants extracts were investigated spectrophotometrically using 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt, hydrogen peroxide(H_2O_2) and ferric reducing power. The antibacterial assay and minimum inhibitory concentration(MIC) was determined using the agar dilution method against five bacteria strains using amoxycillin and ciprofloxacin as positive control. The phytochemical analyses(tannins,total phenol, flavonoids, flavonols, proanthocyanidin, alkaloids and saponins) were assessed using standard ***: The ethanol extract of both plants exhibited strong antioxidant activities in some cases when compared to the standards(vitamin C and BHT). The antibacterial activity of both plants showed an appreciable broad spectrum activity against these wound pathogens with MIC value ranges between 0.3 mg/m L and 5 mg/m L. Tannins,phenols, flavanols, proanthocyanidins and alkaloids content of B. ilicifolia were significantly higher than those in B. elliptica. However, there were no significant differences in the flavanoid content of both plants ***: These results indicated that the ethanol leaf extracts of these plants have antioxidant and antibacterial activity against the tested bacteria possibly due to the presence of bioactive compounds and therefore could be used as alternative therapy against wound infection caused by these bacteria in diabetic patients.

关键词： Diabetes mellitus Antioxidant Phytochemical Brachylaena elliptica Brachylaena ilicifolia Wound

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Anti-inflammatory activity of the essential oils of Cymbopogon validus(Stapf) Stapf ex Burtt Davy from Eastern Cape, South Africa

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Asian Pacific Journal of Tropical Medicine 2016年第5期9卷 415-419页

作者： Pamela Rungqu Opeoluwa Oyedeji Benedicta Nkeh-Chungag Sandile Songca Oluwatobi Oluwafemi Adebola Oyedeji Department of Chemistry Faculty of Science and Agriculture University of Fort Hare Department of Biological and Environmental Sciences Faculty of Natural Sciences Walter Sisulu University Department of Chemical and Physical Sciences Faculty of Natural Sciences Walter Sisulu University Department of Applied Chemistry Faculty of Sciences University of Johannesburg

Objective: To evaluate the essential oil composition and the anti-inflammatory activity of Cymbopogon validus(C. validus) leaves and flowers. Methods: A total of 300 g of fresh or dry(leaves and flowers) of C. validus were cut into small pieces and subjected to hydro-distillation method for approximately 5 h using the Clevenger apparatus. The extracted essential oils were then used for testing the anti-inflammatory activity. The anti-inflammatory activity was evaluated by using egg-albumin induced paw edema. Results: The extracted oils had the following yields 2.2% for fresh leaves, 2.0% for dry leaves and 2.4% v/w for dry flowers. GCMS results revealed that the oils contained artemisia ketone(37.5%), linalool(3.2%-29.6%), northujane(4.4%-16.8%), verbenone(13.5%), naphthalene(1.7%-9.6%), δ-cadinene(0.5%-8.1%), hedycaryol(5.4%-7.6%) and α-eudesmol(6.5%-6.7%) as the major constituents. C. validus essential oils showed significant(P<0.05) anti-inflammatory effects from the first 30 min after albumin injection compared to aspirin which had a later onset of effect. Conclusions: The findings of this study show that the essential oil extracted from C. validus fresh or dry leaves and flowers have anti-inflammatory properties; that might be associated with the major components and the minor components found in the essential oils.

关键词： Cymbopogon validus Essential oils Anti-inflammation Artemisia ketone Linalool Egg albumin-induced edema

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Antibacterial and antioxidant activities of hydroalcoholic stem bark extract of Schotia latifolia Jacq

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Asian Pacific Journal of Tropical Medicine 2011年第12期4卷 952-958页

作者： Sunday Oyewole Oyedemi Anthony Jide Afolayan School of Biological Sciences University of Fort HareAlice 5700South Africa

Objective:To investigate the antibacterial and antioxidant activities of hydroalcoholic extract of Scholia latifolia（***） bark commonly used in South Africa traditional medicine for the treatment of various ***:The antibacterial test and MIC was determined by using agar well diffusion and dilution methods respectively against eight strains of bacteria. The total phenol,proanthocyanidin and flavonoid contents of *** were assessed using Standard *** antioxidant activity of the extract was evaluated using ferric reducing power and the free radical scavenging activity against 1.1-diphenyl-2-picrylhydrazyl（DPPH）, 2.2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid（ABTS）,nitric oxide（NO）,hydrogen peroxide（H2O2） and lipid oxidation（LO）.Results:The antibacterial activity demonstrated an appreciable effect against all the gram positive bacteria at MIC between 0.016 and 10 mg/ml. while that of gram negative bacteria was above 10 mg/*** plant extract exhibited high concentration of proanthocyanidin[（300.00±0.10） mg CE/g].followed by flavonoid[（12.46±0.04 mg） TE/g]and phenol[（1 l.06±0.03） mg QE/g]***,the extract at 0.5 mg/mL scavenges ***.H2O2.LO and NO by 87.55%.89.47%.77.15%.86.48%and 77.75%of the radicals *** reducing power was also found to be concentration dependent Conclusions: Our data suggest that *** extract has antibacterial and antioxidants activity and thus could be used as alternative therapv against antibiotic resistance bacteria and to prevent man) radical related diseases.

关键词： Scotia latifolia Polyphenols Antioxidant activity Free radicals Antibacterial

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Evaluation of acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. in Wistar rats

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Journal of Integrative Medicine 2018年第5期16卷 335-341页

作者： Jeremiah Oshiomame Unuofin Gloria Aderonke Otunola Anthony Jide Afolayan Medicinal Plants and Economic development research centre Department of BotanyUniversity of Fort Hare

Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000 and 5000 mg/kg） and subacute （200, 400 and 600 mg/kg） toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. Results： In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degen- eration. Conclusion： These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.

关键词： Vemonia mespilifolia Less Biochemical parameters Acute toxicity Hematological parameters Subacute toxicity

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Geochemical Evaluation of the Permian Ecca Shale in Eastern Cape Province, South Africa:Implications for Shale Gas Potential

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Acta Geologica Sinica(English Edition) 2018年第3期92卷 1193-1217页

作者： Christopher BAIYEGUNHI Kuiwu LIU Nicola WAGNER Oswald GWAVAVA Temitope L.OLONINIYI Department of Geology University of Fort Hare Department of Geology University of Johannesburg

Shale gas has been the exploration focus for future energy supply in South Africa in recent time. Specifically, the Permian black shales of the Prince Albert, Whitehill, Collingham, Ripon and Fort Brown Formations are considered to be most prospective rocks for shale gas exploration. In this study,outcrop and core samples from the Ecca Group were analyzed to assess their total organic carbon(TOC), organic matter type, thermal maturity and hydrocarbon generation potential. These rocks have TOC ranging from 0.11 to 7.35 wt%. The genetic potential values vary from 0.09 to 0.53 mg HC/g,suggesting poor hydrocarbon generative potential. Most of the samples have Hydrogen Index(HI) values of less than 50 mg HC/g TOC, thus suggesting Type-Ⅳ kerogen. Tmax values range from 318℃ to601℃, perhaps indicating immature to over-maturity of the samples. The vitrinite reflectance values range from 2.22% to 3.93%, indicating over-maturity of samples. Binary plots of HI against Oxygen Index(OI), and HI versus Tmax show that the shales are of Type II and mixed Type Ⅱ-Ⅲ *** on the geochemical data, the potential source rocks are inferred as immature to over-matured and having present-day potential to produce gas.

关键词： geochemistry organic matter type thermal maturity hydrocarbons Ecca Group South Africa

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Variations in Isochore Thickness of the Ecca Sediments in the Eastern Cape Province of South Africa,as Deduced from Gravity Models

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Acta Geologica Sinica(English Edition) 2016年第5期90卷 1699-1712页

作者： Christopher BAIYEGUNHI Oswald GWAVAVA School of Computational Sciences Faculty of Science and AgricultureUniversity of Fort Hare

Gravity modelling was carried out along five profiles that traverse the Eastern Cape Province of South Africa in order to determine the depositional surface and isochore thickness of the Ecca *** models of the subsurface rock density reveal that the Ecca Group has a maximum vertical thickness of about 3215 ± 160 *** maximum depositional surface（elevation）above sea level for the Ecca sediments is about 500 m,whilst the depth below sea level reaches about10000 *** of the isochore thickness maps with the depositional surfaces shows that the sediments in the basement highs were subsided,deformed,eroded and deposited in the basement *** basement highs served as the source area（s） for the sediments in the basement lows,thus basement highs are characterized with thin sediment cover whilst the lows have thick sediment cover.

关键词： ediment isochore thickness depositional surface Ecca Group basement highs and lows

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Decomposition of Surface-Applied and Soil-Incorporated Bt Maize Leaf Litter and Cry1Ab Protein During Winter Fallow in South Africa

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Pedosphere 2014年第2期24卷 251-257页

作者： A.KAMOTA P.MUCHAONYERWA P.N.S.MNKENI Department of Crop Science Bindura University of Science Education School of Agricultural Earth and Environmental SciencesUniversity of KwaZulu-Natal Department of Agronomy University of Fort Hare

Unintended effects of genetic modification on chemical composition of Bt maize leaf litter may have impacts on its decomposition. In most agricultural systems in South Africa, maize litter is either left on the soil surface or incorporated into the soil during tillage. A litterbag experiment, using leaf litter of three maize hybrids （DKC80-12B, DKC80-10 and DKC6-125）, was carried out at the University of Fort Hare research Farm, South Africa, to determine the effects of genetic modification on decomposition of maize leaf litter when left on the soil surface under field conditions between July and November, the normal fallow period, in 2008. Another litterbag experiment was conducted at the University of Fort Hare research Farm and Zanyokwe Irrigation Scheme, South Africa, using leaf ~itter of two maize hybrids genetically modified with the erylAb gene （MONS10）, DKC75-15B and PAN6Q-3OSB, and their corresponding near isolines, CRN3505 and PAN6Q-121. The degradation of CrylAb protein in the litter, both surface-applied and soil-incorporated, was also investigated. Decomposition of Bt maize litter was similar to that of non-Bt maize litter both when applied on the surface and when incorporated into soil. Soil-incorporated litter, as well as its CrylAb protein, decomposed faster than that applied on the surface. The leaf litter C：N ratios of PAN6Q-308B and PAN6Q-121 were similar throughout the study, whereas those of DKC75-15B and CRN3505 declined by similar amounts during a 12-week period. These findings suggested that decomposition of leaf litter of Bt maize, with the MON810 event, was not affected by maize genetic modification, and that the CrylAb protein broke down together with plant leaf litter during the winter fallow regardless of whether the litter was applied on the soil surface or incorporated into soil.

关键词： genetic modification litterbag experiment maize hybrid MON810 event protein degradation

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