HOST PLANTS OF THE COTTON MEALYBUG, PHENACOCCUS SOLENOPSIS TINSLEY (HOMOPTERA: PSEUDOCOCCIDAE) IN THREE SELECTED TOWNS OF NIGERIA, AND ITS INFESTATION PATTERN

Reconnaissance surveys were carried out for field infestation of Phenacoccus solenopsis Tinsley from 2006 to 2010 in seventy five (75) vegetable gardens located in three (3) towns– Ogbomoso, Abeokuta and Ibadan in Nigeria. No cotton mealybug infestation was observed in Abeokuta and Ibadan, but twenty four (24) plants in 16 different families were observed as its hosts in Ogbomoso area. Of the 24 species, weeds constituted 45.8%, vegetables 29.1%, herbs 12.5%, cereals 4.2%, fruit trees 4.2% and pulse 4.2% each. Infestations started on the abasial leaf surface and advanced to the mid-ribs, petiole, young and succulent stems and buds. Corchorus olitorius and Amaranthus hybridus were the most susceptible of the trialled plant species with heavy root infestation in addition to that of the leaf. On heavily infested plants, certain ants were found together with P. solenopsis; on cowpea however, Aphis craccivora and the ants formed a complex with the mealybug on the flower buds. Of the three towns surveyed, P. solenopsis could be said to be restricted to backyard gardens around Ogbomoso at the moment. However, a nation-wide survey is very necessary now to determine the current status of the mealybug in Nigeria.Â

Nutritional Evaluation of Honey Bee Slum gum Meal as Replacement for Maize in the Feed of Growing Rabbits

As part of the efforts in developing alternative feed ingredients for feeding rabbits a feeding trial was conducted to investigate the nutritional potential of Honey Bee slum gum meal (HBSM) on the performance characteristics of growing rabbit. Thirty (30) growing rabbit of 7 weeks of age were weight-balanced and divided into three (3) dietary treatment groups of 10 rabbit each in a completely randomized designed experiment. Diet 1 had 0% inclusion of HBSM while 25 and 50% maize in diets 2 and 3 were replaced by HBSM respectively. Rabbits received feed and water ad libitum during the 12 weeks of the experiment. The final weights decrease linearly (P<0.05) as the level of inclusion increases (1663.20g 1630.00g and 1458.40g for rabbits on treatments 1, 2 and 3 respectively). Rabbit on diets 1 and 2 had higher (P<0.05) daily weight gains (13.59g and 13.15 respectively) compared with rabbits on diet 3 (11.1g). The digestibility of nutrients were not affected (P>0.05) by the dietary treatments. The values obtained for final weight, carcass weight, abdominal fat, kidney, liver and lungs were significantly (P<0.05) affected by dietary treatment. HBSM can be used as an alternative for substituting maize in growing rabbits diets up of 25% beyond which depression in performance is observed. Key words: Honey slum gum meal, Digestibility, Final weight, growing rabbits

IMPACTS OF COAGULANTS ON QUALITY OF SOFT CHEESE PRODUCED FROM COW-SOY MILK BLENDS

Production of cheese at household level involved the use of different locally produced coagulants which include alum, Sodom apple and fermented maize liquor. Their effects on quality of cheese made from blends of cow-soy milk are sparse. This work investigated effect of coagulants on soft cheese produced from cow soy blends. Soft cheese samples were produced from cow-soy milk blends (90:10%). The cheese was coagulated using three locally available coagulants {juice of Sodom apple (Calotropis procera), aqueous solution of Potassium alum and fermented maize liquor}. Samples were analysed for yield, pH, proximate and mineral contents. Microbial analysis and sensory attributes were also determined. The yield obtained ranged from 38.7 to 39.0%. Highest yield was obtained from Sodom apple coagulated cheese sample. Cheese produced using fermented maize liquor had the highest pH (6.07) while Sodom apple and alum coagulated cheese had the pH values of 6.83 and 6.97, respectively.  The moisture contents of the produced cow-soy cheese ranged from 70.4 to 73.57%. The protein content of the cheese samples coagulated with alum had the highest (12.97%) in all the samples. There was no fiber in all the cheese samples produced. Calcium contents obtained from the three samples ranged between 171.67 and 185.00 mg/100 g. The iron content of cheese coagulated with fermented maize liquor (3.63 mg) was significantly (p < 0.05) higher than that of alum coagulated (3.23 mg/100 g) and Sodom apple coagulated cheese (3.33 mg/100 g). Higher microbial load was recorded in cheese samples coagulated with FML. The sensory attributes of the cheese samples varied with different coagulants. This indicates that the type of coagulant used in cheese-making has effect on the yield, pH some nutritional and sensory attributes of cheese

Investigation of household refrigerator system with varied capillary tube length

Abstract : In this paper, the performance of R600a was investigated in a household refrigerator originally designed to work with R134a using varied capillary tube length (1.0, 1.15, 1.30 and 1.45 m). The refrigerator was instrumented with four thermocouples at the inlet and outlet of the major components. Also, two pressure gauges were connected to the compressor to measure the suction and discharge of the compressor. The experimental results were used to evaluate the performance of the system. The results showed that at optimal capillary tube length the COP and cooling capacity of R600a in the system increased with 45% and 4.2% respectively and the power consumption reduced with 25% using 1.30 m varied capillary tube length compared to R134a. Conclusively, R600a can serve as a retrofit in the household refrigerator systems originally designed to work with R134a refrigerant

Experimental performance of LPG refrigerant charges with varied concentration of TiO2 nano-lubricants in a domestic refrigerator

This article present an experimental investigation of varied mass charges of Liquefied Petroleum Gas (40 g, 50 g, 60 g and 70 g) enhanced with varied TiO2 nanoparticle/mineral oil concentrations (0.2 g/L, 0.4 g/L and 0.6 g/L nanolubricants) in a R134a compressor of a domestic refrigerator. Performance tests investigated at steady state included: pull down time, power consumption, compressor power input, cooling capacity and coefficient of performance (COP). Analysis was based on temperature and pressure readings obtained from appropriate gauges attached to the test rig. Refrigerant property characteristics were obtained using Ref-Prop NIST 9.0 software. Results obtained showed almost equal evaporator air temperatures and reduction in power consumption for all tested nano-lubricant concentrations except at 70 g charge of LPG using 0.6 g/L nano-lubricant. Furthermore, the lowest compressor power input was found to be 21 W and obtained using 70 g of LPG with either of 0.2 g/L or 0.4 g/L nano-lubricants. At 70 g of LPG using 0.6 g/L concentration of nano-lubricant, highest cooling capacity index of 65 W was obtained while the highest COP of 2.8 was obtained with 40 g charge of LPG using 0.4 g/L concentration of nanolubricant. In conclusion, LPG-TiO2 nano-lubricant mixture works safely and efficiently in domestic refrigerators without modification of capillary tube length, but requires adequate optimization

Retrograde Assemblages in the Muscovite-Biotite Gneiss of Oluyole Southwestern Nigeria, an Indication of Shear-Zone Environment

Petrographic and whole-rock geochemical study of biotite-muscovite gneiss was determined in order to interpret the metamorphic evolution of the Basement Complex of Southwestern, Nigeria. The gneiss shows a millimetric banding, and in some cases the quartzo-feldspathic bands running up to 10 cm. The gneiss has mineral assemblage biotite + plagioclase + quartz + garnet + K-feldspar + muscovite + chlorite + ilmenite ±titanite. Chlorite occurs along cleavage planes of biotite, and in some cases forms reaction rims around porphyroblasts of garnet. K-feldspar crystals are surrounded by muscovite. Titanite crystals are sub-idioblastic to xenoblastic in form, and have inclusions of ilmenite. Titanite, where present, occurs in close association with biotite and opaque minerals (ilmenite). Also, titanite forms a reaction rim around apatite. Mylonitic texture, fine-grained matrix of mica and quartz ribbons were observed. In addition, there is stretching of the quartz crystals. The SiO2 content is greater than 60 wt %, while CaO ranges from 3.05-6.91 wt %. The M1 foliation comprise of mineral biotite some of which are included in the opaque mineral, M2 represents the metamorphism which gave rise to porphyroblasts of ilmenite, while the M3 gave rise to foliations that forms a wraparound structure on the porphyroblasts of ilmenite. The last metamorphism gave rise to retrograde minerals; chlorite, titanite, and muscovite. The study suggests that this area of the Basement Complex has been subjected to multiple deformations, as well as multiple episodes of metamorphism. The structures observed are similar to those associated with shear zone environment

ASSESSMENT OF CHEMICAL AND ANTINUTRITIONAL PROPERTIES OF BREAKFAST MEAL PREPARED FROM BLENDS OF BANANA AND AFRICAN YAM BEAN

Banana (Musa sapientus) and African yam bean (Sphenostylis stenocarpa) are nutritional food sources that are valuable industrially even in consideration for a balanced nutrition. This research work evaluates the production of breakfast meal from blends of Banana and African yam bean (AYB). Banana and AYB were mixed in the ratio 90:10, 80:20, 70:30 and 100:0 (control) for the production of breakfast meal. Crude protein, ash, crude fiber, fat and carbohydrate content of mixtures were determined using the AOAC methods. Vitamins, minerals and anti-nutrient composition of the breakfast meal were determined using standard methods and data were analyzed using Analysis of Variance (ANOVA). Sensory attributes were determined using 9-point hedonic scale by forty panelists. The results of the proximate analysis showed that protein ranged from 5.41-11.26%, fat content (1.97-4.56%), carbohydrate (72.71-79.89%), fiber (0.39-0.57%), ash (3.23-3.97%) and moisture content (7.86-8.20%). Oxalate (8.73-4.38%) decreased with increase in AYB inclusion. Tannin values ranged from 17.09-26.73% and phytate ranged from 11.59-46.77%. The sensory evaluation by the panelists shows that the product was widely accepted. Samples 100:0 and 90:10 were mostly preferred in terms of colour, texture, taste, crispiness, sweetness, flavour, appearance and general acceptability. Hence, the fortification of banana flakes with AYB can be encouraged as a breakfast meal

EXPERIMENTAL STUDY OF LPG AND R134a REFRIGERANTS IN VAPOR COMPRESSION REFRIGERATION

Natural refrigerants, such as hydrocarbons, have been renewed in recent years as a result of the environmental problems associated with chlorofluorocarbon (CFC) and hydro-chlorofluorocarbon (HCFC) refrigerants. Due to the depletion of the ozone layer and global warming effects, synthetic refrigerants are being gradually phased out in accordance with the international protocols that aim to protect the environment. A refrigerator designed to work with R134a was used for this experiment, liquefied petroleum gas (LPG) which consists of 60% propane (R290) and 40% butane (R600) was compared with R134a refrigerant in a vapor compression refrigerator with a total volume of 62 L. The experiments were carried out using different charges of 40, 60, 80, and 100 g for R134a and LPG refrigerants, the charges were measured with a digital charging scale. The K-type thermocouples were used to measure the temperatures at the inlet and outlet of the four major components (evaporator, compressor, condenser, and expansion device) of the refrigeration system. The system was instrumented with two pressure gauges at the inlet and outlet of the compressor for measuring the suction and discharge pressures. The results obtained were used to determine the thermodynamic properties of the refrigerants using Refprop, version 9. The results obtained showed that the design temperature and pull-down time set by the International Standard Organisation (ISO) for a refrigerator were achieved with LPG earlier than with R134a. The coefficient of performance (COP) of the system increases by 9.5% and the power consumption is reduced by 12%, when compared with R134a. Therefore, LPG can successfully substitute R134a in domestic refrigerator

Dataset and ANN model prediction of performance of graphene nanolubricant with R600a in domestic refrigerator system

Abstract: This work evaluated the steady state performance of R600a in the base lubricant and graphene nanolubricant. The mea- suring instruments required and their uncertainties were provided, step by step method and procedures for prepara- tion of graphene nanolubricant concentration and substitut- ing it with the base lubricant in domestic refrigerator system are described. The system temperatures data was captured at the inlet and outlet of the system components. Also, the pressures data was recorded at the compressor inlet and out- let. The data was recorded for 3 h at 30 min interval at an ambient temperature of 27 °C. The experimental dataset, Ar- tificial Neural Network (ANN) training and testing dataset are provided. The artificial intelligence approach of ANN model to predict the performance of graphene nanolubricant in do- mestic refrigerator is explained. Also, the ANN model pre- diction statistical performance metrics such as Root Mean Square Error (RMSE) and Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE) and coefficient of determination (R 2 ) are also provided. The data is useful to researchers in the field of refrigeration and energy efficiency materials, for replacing nanolubricant with the base lubricant

Professional development in teaching and learning for early career academic geographers: Contexts, practices and tensions

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Geography in Higher Education on 16th May 2011, available online: doi: 10.1080/03098265.2011.563380This paper provides a review of the practices and tensions informing approaches to professional development for early career academic geographers who are teaching in higher education. We offer examples from Britain, Canada, Nigeria and the USA. The tensions include: institutional and departmental cultures; models that offer generic and discipline-specific approaches; the credibility of alternative settings for professional development in teaching and learning; the valuing of professional development and of teaching in academic systems of reward and recognition; and the challenges of balancing professional and personal life. We summarize concepts of good practice and suggest opportunities for future research