Unsteady flow and heat transfer in periodic complex geometries for the transitional flow regime

Diesel engines are facing significant challenges with upcoming changes in emissions standards. In general, meeting the increased emission standards will require a larger fraction of the engine heat rejection to occur in the vehicle cooling system. For certain applications, the surface geometry must also be such that it resists particulate fouling, precluding common interrupted surfaces such as louvered fins. Although acceptable continuous surface geometries such as bumped fin geometries are in use, the impacts of changing the parameters of this geometry are unknown. This study investigates the transport characteristics of bumped fins in the transitional flow regime using unsteady multi-dimensional solutions of the incompressible Navier-Stokes equations --Abstract, page iv

Effects of management and nutrition on semen quality of beef bulls

The calf crop represents the only source of animal income from the beef cow herd. Infertility or sterility in the bull can cause either reduction or complete loss of income from the herd for a given year. Thus two factors become important: 1. A study of those semen qualities which may predict the probability of a bull\u27s fertility. 2. The avoidance of nutritional and management factors which might decrease bull fertility. Semen quality and characteristics have, in a number of studies, shown varying degrees of correlation to fertility. Since these characteristics will vary even between ejaculates from the same bull, they cannot be expected to give more than an estimation of the animal\u27s fertility. The actual fertility can be proved only by breeding trials. Nevertheless, the study of these semen qualities and characteristics currently form the only basis for rapid prediction of the potential fertility of the bull. It also follows that a study of the influences which different types of management or nutrition may have on bull semen quality allow a rapid method of estimating the effect that management or nutrition might have upon the fertility of the bull. At the Tennessee Experiment Station, several management-nutrition regimes have been developed for beef bulls. It was the purpose of this study to determine the effects of these nutrition regimes on the semen collected by electroejaculation from Hereford, Polled Hereford, and Angus bulls. Conception rate studies were not made

Radioimmunoassay for bovine luteinizing hormone (BLH)

Recent progress in immunological techniques has revealed the possibility for more sensitive methods for assaying protein hormones. A radioimmunoassay technique has been developed for the detection and direct measurement of physiological levels of human pituitary luteinizing hormone in blood plasma. The radioimmunoassay is based on the competition between 131I-labeled hormone and unlabeled hormone for anti-bodies to the hormone. The separation of free hormone from antibody-bound hormone is achieved by precipitation using antibody to Y-globulin of an animal in which the antihormonal serum was produced. This study was initiated to develop the radioimmunoassay technique which could be used to measure physiological levels of bovine LH directly from blood without concentration or purification. The assay was used to measure the variation of luteinizing hormone in the blood of four cows during the estrual cycle. The average levels of the hormone was less than 1.5 mug. equivalents of the standard (NIH-LH-B5) per ml. of serum during diestrus but increased 10 to 20 fold during estrus. The concentra-tion of the hormone in the blood increased sharply in the early stages of estrus and decreased rapidly in the late stage of estrus. The results indicated that the procedures can be used to measure the luteinizing hormone activity in 1 ml. of blood

Impact of water hyacinth (Eichhornia crassipes) on fish catch in the lower Taylor Creek area of Bayelsa State

The aim of the study was to access the impact of water hyacinth, Eichhornia crassipes on fish catch in the lower Taylor Creek area of Bayelsa State. The experimental approach involved the division of the creek into new stations: infested and non-infested at the littoral zone. Subsequently, the deployment of six Malian traps with dimensions of 70cm diameter and 80cm height were set in each station for a period of six months using groudnut cake as bails. Furthermore, fish caught were counted and identified into families and species. From results, fish species composition obtained from the stations were a total of 9 families and 15 species. However, it was observed that the water hyacinth infested area had the lowest fish catch while the non-infestated area had the highest number of fish catch for both dry and wet season. It is therefore concluded that the invasion of Eichhornia crassipes impacted on fish population and composition

Review of crude oil pollution effects on fish and fisheries of Nigerian waters

This paper reviews some adverse effects of crude oil pollution on fish and fisheries in Nigerian waters. The main causes of spillage include blowout, sabotage, corrosion of pipeline, equipment malfunction, operations/maintenance error etc. There are spillage records from 1976 to 1997 with respect to the yearly oil spill incidents, the sizes of spill in relation to the ecological operational areas and the causes of oil spills in relation to sources of oil spill within oil operation. Based on the observation from the analyses of the spillage reports, several steps were recommended in order to reduce the incident of crude oil spillage in Nigeria petroleum industry for the safety of our fragile water bodies and the fisheries resources stock in them

Mesh size selectivity of multifilament gill net at Fakun village, north of Lake Jebba

Studies on the mesh size selectivity of multifilament gill net at Fakun village North of Lake Jebba were carried out. Four different sizes (76mm, 101mm, 126mm and 177mm) of multifilament nets were used in the construction of the gill net with hanging ratio 0.5 each. Daily catch from the nets were examined for seven weeks. The fish caught comprised of nine (9) species, belonging to six (6) families. The result of analysis of variance of the number of species caught showed significant difference (P<0.05) among the different sizes of the gill net. The catch mean weight for each mesh size (76mm, 101mm, 126mm and 177mm), was 266.91, 285.54, 305.10 and 349.02 respectively. Also the relative percentage of number of species caught by each of the mesh size was 39.48% for 76mm, 23.58% for 101mm, 22.44% for 126mm and 14.48% for 177mm, which depicts the selectivity in the catch of the gill nets in this experiment

Quasi Multiplication and K-groups

This is the publisher's version, also available electronically from http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9001075&fileId=S1446788712000584We give a negative answer to the question raised by Mart Abel about whether his proposed definition of K0 and K1 groups in terms of quasi multiplication is indeed equivalent to the established ones in algebraic K-theory

Effect of two fishing baits on catch composition of two traditional fishing traps in the upper Nun River, Niger Delta, Nigeria

The effect of two fishing baits on the catch composition of two traditional fishing traps were investigated between January and December, 2011 in the Upper Nun Rivers, Niger Delta. The traps were set at the littoral zone of the river, baited with Groundnut cake and fresh palm fruit. The Malian trap baited with Groundnut cake caught the highest number (31) of fish species with Species Diversity index of 1.00, while Ikara trap without bait caught the least number of fish species with Species Diversity Index of 0.32. The dominant species in the catches of the traps baited with Groundnut Cake were Synodontis sorex (15.45%), Synodontis clarias (10.57%), Clarias gariepinus (8.54%) and Hetcerobranchus bidorsalis (6.50%) in the small mesh sized Malian traps, while the large mesh sized Malian trap, synodontis sorex (9.05%), synodontis clarias (10.55%), Clarias gariepinus (6.03%) and Distichodus brevipinis (6.50%) were dominant. Mormyrus deliciosus was only caught in Malian trap. In both traps baited with fresh palm fruit, Heterobrancus bidorsalis, Clarias gariepinus, Oreochromis niloticus and Tilapia zilli dominated the catches. Traps not baited were dominated by Clariids. A significant difference was also observed in the weights of fish caught with different baits. The results from this study revealed that, groundnut cake is more efficient than fresh palm fruit as bait in catching freshwater fish

Assessing the Nature of Science Views of Singaporean Pre-Service Teachers

Despite the many developments in the teaching of science, an aspect that continues to be neglected appears to be the character and nature of science (NOS). This is becoming especially important in the light of recent developments in pedagogy, as, for example, more teachers adopt constructivist methodologies and computing technology enables simulations that may blur the lines between models and reality. From the literature, it is known that teachers\u27 modern NOS conceptions, though not a sufficient condition for transmission of modern NOS views, is necessary. In this study, pre-service teachers\u27 NOS conceptions are assessed with an adapted Views of the Nature of Science (VNOS) instrument, originally designed by Lederman, Abd-El-Khalick, Bell, and Schwartz (2002). The modified instrument is an eight-item, open ended questionnaire – designed to elicit descriptive responses to common NOS misconceptions. Responses were analysed into coded categories of ‘informed, ‘uninformed, and ‘ambiguous’. It was found that a significant proportion of teachers possessed uninformed views. Some implications for teaching and teacher education are presented in this paper for discussion