Browsing Research articles (Dept of Chemistry) by Issue Date
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Munkombwe N.M. (Elsevier Ltd. www.elsevier.com/locate/phytochem, NaN, 2003)[more][less]
Abstract: Two phenylpropanoid glucosides, 2-O-b-d-glucosyloxy-4-methoxybenzenepropanoic acid and its methyl ester, together with syringin and adicardin were isolated from the stem of Gnidia polycephala and characterized by physical and spectroscopic data. URI: http://hdl.handle.net/10311/275 Files in this item: 2
Phenylpropanoid glycosides.pdf (2.288Mb)Phenylpropanoid glycosides of Gnidia.pdf (155.6Kb) -
Mabaleha, M.B.; Yeboah, S.O. (AOCS Press., NaN, 2004)[more][less]
Abstract: Seed oils from six legume cultivars of Phaseolus vulgaris, grown in the Kingdom of Lesotho, were extracted and their physicochemical properties and FA compositions were determined in order to compare their dietary lipids with those in P. vulgaris cultivars grown in other parts of the world. The oil content of the beans was very low, ranging from 1.5 to 2.0% (w/w). The acid values ranged from 11.0 to 19.2 mg KOH/g, whereas a combination of the PV and the p-anisidine values in Holm’s equation gave oxidation values that ranged from 11.0 to 15.0. Thus, considerable enzymatic hydrolysis and oxidation had taken place in the beans during storage. Iodine values ranged from 80.5 to 92.3 (Wijs method), indicating moderate unsaturation in the oils. However, capillary GC analysis, supported by proton NMR analysis of the FAME, gave a total unsaturation range from 79.67 to 84.24%. The dominant FA were α-linolenic acid (36.47–48.81%) and linoleic acid (20.96–36.10%), with appreciable amounts of palmitic acid (14.33–18.23%). This FA composition pattern is quite similar to the FA distribution reported for low oil-bearing legume seeds. Thus, notwithstanding the different climatic and soil conditions, the general properties of lipids in the southern African legume cultivars were quite similar to those of lipids in P. vulgaris cultivars grown in other parts of the world. The high content of α-linolenic acid in the cultivars of P. vulgaris could very likely play a beneficial role in reducing the risk of coronary heart disease among the large populations consuming them in the southern African region. URI: http://hdl.handle.net/10311/303 Files in this item: 1
Characterization and compositional.pdf (3.533Mb) -
Mapolelo, M.; Torto, N. (Elsevier; www.elsevier.com/locate/talanta, NaN, 2004)[more][less]
Abstract: [Please note that chemical formulae do not display correctly in this abstract]. Sorption properties of baker's yeast cells, characterised as Saccharomyces cerevisiae were evaluated for trace enrichment of metal ions: Cd2+, Cr3+, Cr6+, Cu2+, Pb2+ and Zn2+ from aqueous environments. Metal concentration was determined by flame atomic absorption spectrometry (FAAS). Parameters affecting metal uptake such as solution pH, incubation time, amount of yeast biomass and effect of glucose concentration (energy source) were optimised. Further studies were carried out to evaluate the effects on metal uptake after treating yeast with glucose as well as with an organic solvent. The results showed that trace enrichment of the metals under study with yeast, depends upon the amount of yeast biomass, pH and incubation time. Treatment of yeast cells with 10-20mM glucose concentration enhanced metal uptake with exception to Cr6+, whose metal enrichment capacity decreased at glucose concentration of 60 mM. Of the investigated organic solvents THF and DMSO showed the highest and lowest capacity, respectively, to enhance metal uptake by yeast cells. Trace enrichment of metal ions from stream water, dam water, treated wastewater from a sewage plant and wastewater from an electroplating plant achieved enrichment factors (EF) varying from 1 to 98, without pre-treatment of the sample. pH adjustment further enhanced the EF for all samples. The results from these studies demonstrate that yeast is a viable trace metal enrichment media that can be used freely suspended in solution to achieve very high EF in aquatic environments. URI: http://hdl.handle.net/10311/156 Files in this item: 2
license.txt (1.998Kb)mapolelotortonew.pdf (469.7Kb) -
Erasto, P.; Bojase-Moleta, G.; Majinda, R.T. (Elsevier Ltd. www.elsevier.com/locate/phytochem, NaN, 2004)[more][less]
Abstract: Three new flavonoids-5,7,4'-trihydroxy-6-[1-hydroxy-2-methylbuten-2-yl]isoflavone (isogancaonin C), 7,2'-dihydroxy-4'-methoxyisoflav- 3-ene (bolusanthin III), 6,6'-dihydroxy-4'-methoxy-2-arylbenzofuran (bolusanthin IV), in addition to eight known flavonoids; derrone, medicarpan, genistein, wighteone, lupiwighteone, gancaonin C, 7-hydroxy-4'-methoxyisoflavone and 7,3'-dihydroxy-4'- methoxyisoflavone were isolated from the root wood of Bolusanthus speciosus.The compounds showed strong antimicrobial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Candida mycoderma.The isolated compounds also showed moderate to strong radical scavenging properties against DPPH radical with the highest activities shown by the 2-arylbenzofuran, the isoflav-3-ene and 7,3'-dihydroxy-4'-methoxyisoflavone in decreasing order. URI: http://hdl.handle.net/10311/299 Files in this item: 1
Antimicrobial and antioxidant.pdf (3.228Mb) -
Shoeb, M.; Jaspars, M.; MacManus, S.M.; Majinda, R.R.T.; Sarker, S.D. (Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, NaN, 2004)[more][less]
Abstract: A study focusing on Centaurea cyanus L. (family: Asteraceae alt. Compositae), otherwise known as "cornflower" or "bachelor's button. The seed is purchased from B & T World Seeds sarl, Pauguignan, 34210 Olonzac, France and the voucher specimen (PHSH0002) kept in the Plant and Soil Science Department, University of Aberdeen, UK for testing. The result shows the occurrence of epoxylignans, berchemol (1) and lariciresinol 4-O-b-d-glucopyranoside (2) in the seeds of C. cyanus. URI: http://hdl.handle.net/10311/300 Files in this item: 1
epoxylignans from the seeds.pdf (1.594Mb) -
Goodwin, J.W.; Hughes, R.W.; Reynolds, P.A.; Kwaambwa, H.M. (Elsevier B.V. www.elsevier.com/locate/colsurfa, NaN, 2004)[more][less]
Abstract: A series of well characterised cis-poly(isoprene) (PIP) polymers (Mw = 1180, 8000, 28 300, 31 500, 86 000, 115 000 and 130 000) have been added to dispersions of poly(12-hydroxystearic acid) (PHS) coated poly(methylmethacrylate) (PMMA) particles in dodecane. The ratio of particle size to adsorbed layer was also varied. For a given added polymer molecular weight, the polymer concentration in the continuous phase covered the dilute, semi-dilute and concentrated regimes as defined by the critical concentrations c and c . The viscosity behaviour of latex dispersions with added polymer were similar for all latex/polymer combinations except when polymer Mw = 1180 was added. In the latter case, the effect of adding polymer reduced both the viscosity and shear thinning behaviour. This supports the contention that the lower molecular weight polymer acts more like a diluent than a depletent. The behaviour of the viscosity ratio (the viscosity of the dispersion relative to that of the medium) as a function of polymer concentration increased with an increase in the polymer concentration until some critical concentration (cmax) for all polymers except for a polymer molecular weight 1180 Daltons. The addition of the polymer Mw = 8000 gave the highest viscosity ratio values in the polymer concentration range studied. It was found that the viscosity of all latex/polymer combinations decreased with an increase in temperature. The results suggest that the viscosity behaviour cannot be explained on the basis of a simple steric–elastic model and require a modified theoretical treatment. URI: http://hdl.handle.net/10311/324 Files in this item: 1
Viscosity behaviiour of particles.pdf (4.522Mb) -
Omisore, N.; Adewunmi, C.; Iwalewa, E.; Ngadjui, B.; Watchueng, J.; Abegaz, B.; Ojewole, J. (Elsevier Ltd. www.elsevier.com/locate/jethpharm, NaN, 2004)[more][less]
Abstract: The present studywas undertaken to investigate the antinociceptive and anti-inflammatory activities of the leaf and twig extracts of Dorstenia barteri (Moraceae) in mice. Both the leaf and twig extracts of Dorstenia barteri at 50, 100 and 200 mg/kg showed significant (P < 0.05-0.01) antinociceptive activities in chemical-, mechanical- and thermal-induced pain test models. Intraperitoneal administration of the plant extracts at 50, 100 and 200 mg/kg significantly (P < 0.05-0.01) inhibited carrageenin-induced acute inflammation in oedema paw weight, pulmonary oedema and number of pleural leucocytes in a dose-dependent way. The twig extract was found to be more active than the leaf extract in all the experimental models used. The inhibitory effects of the plant extracts were comparable to those of the reference drugs acetylsalicyclic acid (ASA) and phenylbutazone (PBZ) at 100 mg/kg i.p. The significant reduction in acetic acid-induced abdominal contractions, the decrease in oedema paw weight as well as in the number of leucocytes in the pleural cavity exudates, and the significant increase in the reaction time and pain threshold of mice observed in this study suggest that Dorstenia barteri extracts possess both anti-inflammatory and antinociceptive activities. The present study, therefore, lend pharmacological support to the folkloric uses of Dorstenia barteri extracts in the treatment, control and/or management of arthritis, rheumatism, gout, headache and other forms of body pains in some parts of Africa. URI: http://hdl.handle.net/10311/256 Files in this item: 2
license.txt (1.998Kb) -
Ngadjui, B.; Watchueng, J.; Keumedjio, F.; Ngameni, B.; Simo, I.; Abegaz, B. (Elsevier Ltd. www.elsevier.com/locate/phytochem, NaN, 2004)[more][less]
Abstract: The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,50-di-(2-hydroxy-3-methylbut-3-enyl)-4,20,40-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-30-(2-hydroxy-3-methylbut- 3-enyl)-20,40-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)- 50-(3,3-dimethylallyl)-4,20,40-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 30-(2-hydroxy -3-methylbut-3-enyl)-4,20,40-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. b-Sitosterol and its b-D-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. URI: http://hdl.handle.net/10311/253 Files in this item: 2
license.txt (1.998Kb)Prenylated chalcones, flavone.pdf (3.563Mb) -
Masesane, I.; Steel, P. (Elsevier Ltd; www.elsevier.com/locate/tetlet, June 21, 2004)[more][less]
Abstract: The Diels-Alder adduct of ethyl (E)-3-nitroacrylate and furan provides a versatile template for the stereoselective synthesis of mono and dihydroxylated derivatives of 2-aminocyclohexanecarboxylic acid (ACHC). The hydroxylated ACHC derivatives can be considered to be useful building blocks for B-peptides. URI: http://hdl.handle.net/10311/235 Files in this item: 2
license.txt (1.998Kb)Stereoselective routes to 3-hydroxy.pdf (721.3Kb) -
Chacha, M.; Bojase-Moleta, G.; Majinda, R.R.T. (Elsevier Ltd; http://www.elsevier.com/wps/find/journaldescription.cws_home/273/description, November 20, 2004)[more][less]
Abstract: From the stem wood of Erythrina latissima, two isoflavones and a flavanone were isolated and characterized as 7,3'-dihydroxy-4'-methoxy-5'-(y,y-dimethylallyl)isoflavone (erylatissin A), 7,3'-dihydroxy-6".6"-dimethyl-4".5"-dehydropyrano [2",3":4'.5']isoflavone (erylatissin B), (-)-7,3'-dihydroxy-4'-methoxy-5'-(y,y-dimethylallyl)flavanone (erylatissin C), respectively, in addition to 10 known flavonoids. Structures of these compounds were determined on the basis of their spectroscopic data. These compounds showed antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida mycoderma. The isolated compounds also exhibited weak radical scavenging properties towards DPPH radical. URI: http://hdl.handle.net/10311/216 Files in this item: 2
license.txt (1.998Kb) -
Omisore, N.O.A.; Adewunmi, C.O.; Iwalewa, E.O.; Ngadjui, B.T.; Adenowo, T.K.; Abegaz, B.M.; Ojewole, J.A.; Watchueng, J. (Brazilian Journal of Medical and Biological Research. http://www.scielo.br/scielo.php?pid=0100-879X&script=sci_serial, NaN, 2005)[more][less]
Abstract: Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 μg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 μg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6- prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 μg/ml) > quercitrin (0.244 μg/ml) ≥ bartericin B (0.244 μg/ml) > bartericin A (0.73 μg/ml) > stigmasterol (0.98 μg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 μg/ ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 μg/ ml) and high (EC50 <50 μg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied. URI: http://hdl.handle.net/10311/284 Files in this item: 1
Antitrichomonal and antioxidant.pdf (2.508Mb) -
Ngamga, D.; Yankep, E.; Tane, P.; Bezabih, M.; Ngadjui, B.T.; Fomum, Z.T.; Abegaz, B.M. (Verlag der Zeitschrift fu¨r Naturforschung, Tu¨bingen · http://znaturforsch.com, NaN, 2005)[more][less]
Abstract: Three new isoflavonoids, griffonianone F, G and H were isolated from the seeds of Millettia griffoniana, along with the known prebarbigerone, pseudobaptigenin, pseudobaptigenin methyl ether, tephrosin, dipterixine, odorantine, 7,4’,5’-tetramethoxyisoflavone and isojamaicin. Their structures were assigned on the basis of spectroscopic data and chemical transformations. URI: http://hdl.handle.net/10311/274 Files in this item: 1
Isoflavonoids from Seeds.pdf (1.353Mb) -
Mutanyatta, J.; Bezabih, M.; Abegaz, B.; Dreyer, M.; Brun, R.; Kocher, N.; Bringmann, G (Elsevier Ltd.http://www.elsevier.com/wps/find/journaldescription.cws_home/942/description#description, NaN, 2005)[more][less]
Abstract: From the roots of Bulbine frutescens, the first sulfated phenylanthraquinones were isolated, together with their known sulfate-free analogs. Their structures were elucidated by spectroscopic and chiroptical methods, by acid hydrolysis or by partial synthesis. The new compounds have the usual stereo-orientation at the biaryl axis (i.e., with the acetyl portion above the anthraquinone plane) except for sodium ent-knipholone 60-O-sulfate (and thus, also its hydrolysis product, ent-knipholone), which exhibit an opposite axial configuration. We also describe the first stereoanalysis of natural phenylanthraquinones, some of which were found to be not enantiomerically pure, some even nearracemic. We furthermore, report on the first X-ray structure analysis of a phenylanthraquinone, viz. 40-O-demethylknipholone. URI: http://hdl.handle.net/10311/246 Files in this item: 2
license.txt (1.998Kb) -
Nkoane, B.B.M.; Sawula, G.M.; Wibetoe, G.; Lund, W. (Elsevier www.elsevier.com/locate/jgeoexp, NaN, 2005)[more][less]
Abstract: Plant species that accumulate high levels of metals in proportion to the metal content in the soil are of considerable interest in biogeochemical and biogeobotanical prospecting. This study was aimed at investigating copper and nickel accumulation in the plants Helichrysum candolleanum and Blepharis diversispina, to assess their potential use as mineral indicators in biogeochemical prospecting. Soils and plants were collected from copper–nickel mineralised areas in Botswana. Analyses of the soils and the respective plant parts (roots, stem, leaves and flowers) were carried out using ultrasonic slurry sampling electrothermal atomic absorption spectrometry (ETAAS), which allowed rapid determination of copper and nickel in small amounts of the samples. The metal concentration in the soil was in the range c40 Ag/g–4% (w/w) for Cu and c60 Ag/g–0.3% (w/w) for Ni. The concentration ranges of the elements in the plant parts were c6 Ag/g–0.2% Cu and c3–210 Ag/g Ni. At high soil metal content (greater than 2.5% (w/w) Cu and 0.1% (w/w) Ni), high levels of both nickel and copper were found in the shoots (leaves and flowers) of H. candolleanum. Concentrations as high as 0.2% (w/w) Cu were found in the leaves and flowers of H. candolleanum, indicating hyperaccumulation for this plant. For B. diversispina, the metal concentrations did not exceed 100 Ag/ g for any plant part, for both metals. Both plant species tolerate high concentrations of metals and should therefore be categorized as metallophytes. In order to evaluate metal translocation from the soil to the shoots, metal leaf transfer coefficients (ratio of metal concentration in the leaf to metal concentration in the soil) were calculated. Our data suggest that the two plant species have different metal uptake and transport mechanisms, which needs to be investigated further. The present work also suggests that H. candolleanum may be used as a copper/nickel indicator plant in biogeochemical or biogeobotanical prospecting. URI: http://hdl.handle.net/10311/527 Files in this item: 1
NKOANE2005Indicatorplants.pdf (1.835Mb) -
Simo, I.K.; Ngadjui, B.T.; Abegaz, B.M. (Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, June 18, 2005)[more][less]
Abstract: Dorstenia (Moraceae) is a mainly tropical genus of some 170 species (Mabberley, 1987). There are 23 species in Cameroon where a decoction of the leaves is administered for the treatment of cough, headache and stomach pain (Bouquet, 1969). The genus is made up largely of herbaceous perennials with succulent and non-succulent scrambling rhizomes (Berg et al., 1989). The twigs of Dorstenia angusticornis were collected in February 2002 from Kumba South West Province of Cameroon. Voucher specimen (No 28165/sfcam) is deposited at the National Herbarium Yaounde, Cameroon. URI: http://hdl.handle.net/10311/255 Files in this item: 1
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Ahmad, J.; Ddamba, W.A.A. (Chemic Publishing Co., http://www.asianjournalofchemistry.com/, NaN, 2006)[more][less]
Abstract: The expression for mechanical work obtained in the expansion of a gas commonly used in physical chemistry textbooks is critically examined. The mathematical form of the first law of thermodynamics is arrived at by a procedure that is consistent with the common definition of mechanical work. The treatment is extended to explain the concept of reversible and irreversible work. URI: http://hdl.handle.net/10311/225 Files in this item: 2
license.txt (1.998Kb)Work in thermodynamics.pdf (1.197Mb) -
Evaluation of methods for the isolation, detection and quantification of cyanobacterial hepatotoxinsMsagati, T A M; Siame, B A; Shushu, D D (Elsevier Ltd. www.elsevier.com/locate/aquatox, NaN, 2006)[more][less]
Abstract: Cyanobacterial hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They are extremely stable in water due to their stable chemical structure and can tolerate radical changes in water chemistry, including pH and salinity. Different methods for the extraction and detection of these compounds have been reported. Extraction methods utilizing both aqueous and organic solvent systems have been reported. The detection methods ranging from immunological or biochemical assays such as enzyme linked immunosorbent assays (ELISA) and enzyme activity assays, to chemicals methods such as high performance liquid chromatography (HPLC) and more sophisticated liquid chromatography–mass spectrometry (LC–MS) have been documented as well. We review some important aspects of cyanobacterial hepatotoxins and methods of analysis for these toxins. URI: http://hdl.handle.net/10311/314 Files in this item: 1
Evaluation of methods for the.pdf (12.27Mb) -
Ddamba, W.A.A.; Mokate, O. (Journal of Solution Chemistry., NaN, 2006)[more][less]
Abstract: Densities (ρ) of the binary systems of {difurylmethane+(ethanol or propan-1- ol or butan-1-ol or pentan-1-ol or hexan-1-ol)} have been measured with an Anton Paar DMA 4500 vibrating-tube densimeter over the entire composition range at 298.15K and atmospheric pressure. Excess molar volumes (V E m ) of each binary system were determined and correlated by the Redlich-Kister equation. Limiting (Vi E,∞) and excess partial molar volumes (V E i ) of components of each binary system have been calculated to provide insight into the intermolecular interactions present and the packing efficiencies. The results have been discussed in terms of specific intermolecular interactions, dispersive forces and structural effects. URI: http://hdl.handle.net/10311/318 Files in this item: 1
Volumetric prop.pdf (3.737Mb) -
Nijegorodov, N; Zvolinski, V; Luhanga, P V C; Mabbs, R; Ahmad, J (Elsevier Science Ltd. www.elsevier.com/locate/saa, NaN, 2006)[more][less]
Abstract: The multi-banded fluorescence and laser properties of 11 new amino- and tosylamino derivatives of 2,5-di(phenyl)-1,3,4-oxadiazole and oxadiazole in various solvents at 293K are reported. All the compounds investigated possess intra-molecular hydrogen quasi-bond (IHB) of 4.6–5.2 kcal mol−1 in the ground state. In the excited state they can undergo protolytic dissociation or intra-molecular photon-initiated transfer of proton and reveal anomalous fluorescence which cannot be explained within the framework of the Kasha and Kasha–Vavilov rules. Depending upon the excitation wavelength, solvent, concentration and pH of the medium, the compounds studied show a single, double, triple or even a four-banded fluorescence, which has not been reported earlier. The nature of multi-banded fluorescence is explained in terms of the possible photochromic processes in excited states. Quantum yields and decay times of the different fluorescence bands are reported. Anomalous dependence of quantum yield upon concentration of the solution is observed. Laser properties of the compounds studied are carefully tested. Laser action based on the fluorescence of the so-called bi-radical molecules is reported. Various possible arrangements of singlet and triplet levels of compounds investigated are discussed. URI: http://hdl.handle.net/10311/247 Files in this item: 2
license.txt (1.998Kb)Nijegorodov_SAa65_2006.pdf (2.225Mb) -
Alemaw, B.F.; Chaoka, T.R.; Totolo, O. (Elsevier Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/413/description#description, NaN, 2006)[more][less]
Abstract: The agricultural economic sector of Botswana is limited mainly to range resources-based livestock and pockets of arable farming based on rainfall and limited irrigated agriculture at several places. In this study agricultural sustainability of rain-fed agriculture is investigated in Botswana by considering the Pandamatenga plains as a case study. Daily soil moisture regimes with respect to crop growth cycle were modelled using a water balance model based on 42 years of daily hydroclimatic inputs and corresponding simulated components of soil moisture, evaporation, surface runoff, and deep percolation. Using a sustainability criterion on crop water requirement and soil moisture availability during the cropping periods, it was found that rain-fed agriculture of maize, sunflower, and sorghum crops is sustainable. The relative sensitivity to drought of these crops was also found to conform to the Agromisa recommendations. In the pursuit to explore more IWRM opportunities, through the simulation of the corresponding direct runoff, we have also explored that more water harvesting opportunities exist in order to manage rainfall excesses effectively. URI: http://hdl.handle.net/10311/155 Files in this item: 4
alemaw_chaoka_totolo_06.pdf (2.112Mb)license.txt (1.998Kb)license.txt (1.998Kb)license.txt (1.998Kb)