http://hdl.handle.net/123456789/1372 Tue, 14 Apr 2026 23:26:38 GMT 2026-04-14T23:26:38Z http://hdl.handle.net/123456789/5986 Existence and uniqueness of periodic solutions for a system of difference equations with finite delay Yankson, Ernest We consider a special class of system of delay diference equations. The fundamental matrix solution together with Floquet theory is used to convert the system of equations into an equivalent summation equation. Fixed point theorems due to Krasnoselski and Banach are then used to show the existence of a unique periodic solution of the system of diference equations 9p:, ill. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/123456789/5986 2015-01-01T00:00:00Z http://hdl.handle.net/123456789/5974 Cobweb model with buffer stock for the stabilization of tomato prices in Ghana Anokye, Martin; Oduro, Francis T. In this paper a linear cobweb model is developed to study the phenomenon of commodity price fluctuations and then a buffer stock incorporated into the model to stabilize the price of fresh tomatoes in Ghana. The model performed on the assumptions that fresh tomatoes have no equal substitutes, and that there is no foreign competition and also no exogenous shocks needed to generate price fluctuations. The analysis detected that the slope of the demand function of price was smaller than the slope of the supply function of price curve implying that the price and quantity supplied of the fresh tomatoes would oscillate around a fixed price and quantity and also spiral outward. The “Keep Supply at Average” (KSA) buffer scheme achieved price and quantity stability in the short run. The mean price of the scheme was GH¢17.31, very close to actual price mean of Gh¢ 13.40 in the first 16 quarters. The standard deviation of the scheme price also dropped to 1.2 from 9.13 during price stabilization compared to 14.60 of actual price mean. In the long run the scheme price went up to Gh¢ 18.22, an increase of Gh¢ 0.91 and it is clear that in long run buffer system will fail unless the average supply is reviewed regularly. The scheme price trend equation indicated that with the implementation of the buffer scheme, the average quarterly price of fresh tomatoes increased by only 0.05 11p:, ill. Wed, 16 Jan 2013 00:00:00 GMT http://hdl.handle.net/123456789/5974 2013-01-16T00:00:00Z http://hdl.handle.net/123456789/5970 Assessment of microbiological safety of tiger nuts (Cyperus esculentus L.) in the Cape Coast Metropolis of Ghana Nyarko, Hubert. D.; Tagoe, Daniel. N. A.; Aniweh, Yaw. The microbiological safety of tiger nut (Cyperus esculentus L.), a popular tuber eaten in the fresh uncooked state in Ghana was assessed from three major markets in the Cape Coast Municipality to ascertain their microbiological safety in relation to bacterial contamination. A study of 24 samples of 8 each from the markets divided into two batches were analyzed by surface-washing in Phosphate Buffered Water (PBS) only and PBS plus 1% Sodium hypochlorite. Serial dilutions were made and required volumes (0.1ml) of test samples were dispensed separately into sterile Petri dishes and pour plated with Plate Count Agar (PCA) for enumeration of colonies. MacConkey and Uriselect agars were used for enteric bacteria and species identifications. Mean Total Viable Count (TVC), Mesophilic Aerophilic Count (MAC), and Coliform Count (CC) on PCA using PBS only ranged between 2.54 ×105- 8.22×105;1.87×105-5.44×105 and 9.44×102- 3.32×103CFU/g respectively whilst that of PBS plus 1% Sodium hypochlorite ranged between 1.51×102-1.35×103; 2.52×103-1.06×103 and 4.86×10 18.69×10 1 CFU/g respectively. There was marked significant differences p-(0.0319; 0.0267; and 0.0104) between PBS only and PBS plus 1% Sodium hypochlorite for TVC, MAC and CC respectively. Seven different bacteria species isolated were made up of Bacillus spp. And Escherichia coli (18.9%) each; Enteroccoccus spp. (16.2%); Pseudononas aeruginosa and Staphylococcus aureus (13.5%) each, Streptococcus spp. (10.8%) and Enterobacter cloacae (8.1%). This study looks at the levels and nature of microbial contaminations of tiger nut retailed in the Cape Coast Metropolis, and the possible means of reducing such contamination 7p:, ill. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/123456789/5970 2011-01-01T00:00:00Z http://hdl.handle.net/123456789/5966 Antimicrobial examinations of cymbopogon citratus and adiatum capillus-veneris used in Ghanaian folkloric medicine Nyarko, Hubert D.; Barku, Victor Y. A.; Batama, Joseph The antimicrobial activity and Minimal Inhibitory Concentration (MIC) of the extracts of Cymbopogon citratus and Adiatum capillus-veneris were evaluated against four bacteria (Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumonia, Pseudomonas aeruginosa, and a fungus (Candida albicans). These plants are used in Ghanaian folk medicine to treat infections of microbial origin. The antibacterial and antifungal activities were tested using agar diffusion technique. The ethanol extracts of the two plants showed appreciable antimicrobial and antifungal activity against Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumonia and Candida albicans with MIC of 0.78mg/ml and 12.5mg/ml for C. citratus and A. capillus-veneris respectively. However, the aqueous extract of Cymbopogon citratus showed no activity against the tested organs but that of Adiatum capillus-Veneris had activity against Proteus mirabilis and Klebsiella pneumonia. All the plants show different kinds of phytochemicals. The phytochemical investigation revealed the presence of sugars, flavanoids, triterpenoids, and steroids for A. capillus-veneris and flavonoids, anthraquinones, alkaloids, saponins, phenols and steroids for C.citratus. Statistical analysis using student t-test showed no statistical difference between MICs of the two plants and chloramphenicol 7p:, ill. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/123456789/5966 2012-01-01T00:00:00Z