Design and construction of an inverter using solar cell as a source of charger

The present study is basically on electricity generation in which solar cell or module is used to power an inverter. This can also be called photovoltaic system, because it consists of solar modules, solar charge controller, 24V.d.c battery and an inverter. Solar modules serve as source of charger through solar charge controller to the battery and inverter are used in converting the direct current into an alternating current for the domestic appliance. This study is very useful in electricity generation especially in a developing country such as Nigeria where there is epileptic power supply. It-’s use is far better than generating set because it needs less maintenance, it does not use fuel, it is not heavy, it is rugged, it does not need an alternating current for its charging and it is noiseless

Response of African Catfish, Clarias gariepinus; (Burchell, 1822) to Diets of African Yam Bean, Sphenostylis stenocarpa Subjected to Two Processing Methods

Response of Clarias gariepinus to diets of African yam bean (Sphenostylis stenocarpa) (AYB) subjected to two processing methods was assessed. Mature AYB was boiled, fermented and processed into meals. Seven diets were formulated to contain 44.07 ±0.48% crude protein and 19.03±0.05 kJ g-1 gross energy respectively. Fishmeal in the diets was substituted with each of the two processed AYB meals at 40%, 45% and 50% levels. Nine fingerlings (initial average weight 1.36±0.02g) were stocked per experimental tank. Experimental diets were fed to triplicate groups of catfish fingerlings at 10% body weight for 56 days. Results showed that specific growth rate (SGR) and protein production value (PPV) were highest at 45% replacement of fermented AYB (3.32±0.20; 49.30±17.94) compared to control (3.17±0.44; 38.89±12.49). Mean values for haematological parameters (PCV, HB, WBC and RBC) significantly increased (P<0.05) above the initial status and control group. Haematological values for fish fed 40% inclusion level of fermented and boiled AYB were the highest. This study shows that AYB processed by fermentation and boiling were effective in enhancing fish growth. However, based on SGR and PPV results Fermented AYB should not be used in Clarias gariepinus diets beyond 45%inclusion level.Key Words: African Catfish, Alternative Protein Sources, African Yam Beans, Haematolog

Preliminary Evaluation of Jackbean (Canavalia ensiformis L.DC) Seed Meal as a Substitute for Fishmeal in diets for Clarias gariepinus (Burchell, 1822)

Jackbean (Canavalia ensiformis) is an under-utilized legume with crude protein content and amino acid profile that make it a potential ingredient in the tropics as substitute for fish meal in fish diets. This study assesses the potentials of Jackbean seed meal (JBSM) for partial replacement of fish meal in diets of Clarias gariepinus. Fishmeal in control diet was replaced progressively (10%, 20% 40% and 60%) by raw JBSM, 30-and 60-minute boiled JBSM. Test fish in each tank were fed 3% of their biomass twice daily for 56 days. Fish fed control diet had the best performance (Specific growth rate 1.6; Feed conversion ratio 1.88: Protein efficiency ratio 1.74). Specific growth ratio and PER of fish groups fed test diets were inversely related to the dietary levels of JBSM. The same trend applied to protein and fat contents of the fish carcass. Feed conversion ratio however had the reverse trend. Fish fed diets with up to 20% fishmeal substituted by 60 minute boiled JBSM had protein content similar to those fed the control diets (

Sciades herzbergii oxidative stress biomarkers: an in situ study of an estuarine ecosystem (São Marcos' Bay, Maranhão, Brazil)

In order to study the effects of environmental contamination on wild fish, sites were sampled in São Marcos' Bay. The first is located near the ALUMAR/ALCOA port, a potentially contaminated area. The second, located near the Coqueiro beach, was used as a reference area. The activity of antioxidant defence catalase (CAT) and glutathione S-transferase (GST) in S. herzbergii was compared with the biometric data and gonadosomatic index (GSI). The result showed that GSI decreased significantly in females (p<0.05) at the contaminated site. The activity of CAT was higher in fish caught at the contaminated site. A significant difference was observed in GST activity in the liver of S. herzbergii in the comparison between fish from the contaminated site and those from the reference site (p<0.05). GSI provides new insights into the nature of the detoxification response in this catfish species because it is not correlated with the enzymes at the potentially contaminated site. We are, therefore, in a position to suggest that the elevated GST/CAT activity might well be related to the reproduction of the animals at the reference site but not at the potentially contaminated site. If that be the case, one may conclude that GST/CAT and GSI are useful biomarkers of aquatic contamination.<br>O objetivo desse trabalho foi estudar os efeitos da contaminação ambiental em peixes amostrados em dois locais da Baía de São Marcos. O primeiro ponto está localizado próximo ao porto da ALUMAR/ALCOA, considerado como uma área potencialmente contaminada. O segundo ponto, situado na praia do Coqueiro, foi usado como uma área de referência. Dados da atividade da enzima de defesa antioxidante catalase (CAT) e da glutationa S-transferase (GST) em S. herzbergii foram comparados com os dados biométricos e o índice gonadossomático (GSI). Resultados mostraram que o GSI diminuiu significativamente em fêmeas (p <0.05) no local contaminado. A atividade da CAT foi mais alta nos peixes do local contaminado. Uma diferença significativa foi observada na atividade de GST de S. herzbergii no local contaminado e no local de referência (p <0.05). GSI possibilitou uma nova abordagem quanto à natureza da resposta de destoxificação nessa espécie de bagre porque este índice não apresentou correlação com as enzimas no local potencialmente contaminado, mas apresentou no local de referência. Assim, sugere-se que a boa correlação da GST/CAT e GSI poderia estar relacionada à reprodução dos animais no local de referência, mas não no local potencialmente contaminado. Se esse for o caso, pode-se concluir que GST/CAT e GSI podem ser utilizados como bons biomarcadores para avaliar contaminação aquática