Chemical narcosing of fish in northern Cross River

Chemical narcosing of fish was found to be one of the fishing techniques used for harvesting fish stocks in the northern Cross River, Cross River State, Nigeria. The preparation of the fish poison is described. The ichthyotoxic plants used for the fish poisoning were identified and Derris elliptica recommended to be used for the development of piscicides for the removal of unwanted fish in the fish farm

Design, manufacture and spin test of high contact ratio helicopter transmission utilizing Self-Aligning Bearingless Planetary (SABP)

A 450 hp high ratio Self-Aligning Bearingless Planetary (SABP) for a helicopter application was designed, manufactured, and spin tested under NASA contract NAS3-24539. The objective of the program was to conduct research and development work on a high contact ratio helical gear SABP to reduce weight and noise and to improve efficiency. The results accomplished include the design, manufacturing, and no-load spin testing of two prototype helicopter transmissions, rated at 450 hp with an input speed of 35,000 rpm and an output speed of 350 rpm. The weight power density ratio of these gear units is 0.33 lb hp. The measured airborne noise at 35,000 rpm input speed and light load is 94 dB at 5 ft. The high speed, high contact ratio SABP transmission appears to be significantly lighter and quieter than comtemporary helicopter transmissions. The concept of the SABP is applicable not only to high ratio helicopter type transmissions but also to other rotorcraft and aircraft propulsion systems

Theoretical basis for convective invigoration due to increased aerosol concentration

The potential effects of increased aerosol loading on the development of deep convective clouds and resulting precipitation amounts are studied by employing the Weather Research and Forecasting (WRF) model as a detailed high-resolution cloud resolving model (CRM) with both detailed bulk and bin microphysics schemes. Both models include a physically-based activation scheme that incorporates a size-resolved aerosol population. We demonstrate that the aerosol-induced effect is controlled by the balance between latent heating and the increase in condensed water aloft, each having opposing effects on buoyancy. It is also shown that under polluted conditions, increases in the CCN number concentration reduce the cumulative precipitation due to the competition between the sedimentation and evaporation/sublimation timescales. The effect of an increase in the IN number concentration on the dynamics of deep convective clouds is small and the resulting decrease in domain-averaged cumulative precipitation is shown not to be statistically significant, but may act to suppress precipitation. It is also shown that even in the presence of a decrease in the domain-averaged cumulative precipitation, an increase in the precipitation variance, or in other words, andincrease in rainfall intensity, may be expected in more polluted environments, especially in moist environments. A significant difference exists between the predictions based on the bin and bulk microphysics schemes of precipitation and the influence of aerosol perturbations on updraft velocity within the convective core. The bulk microphysics scheme shows little change in the latent heating rates due to an increase in the CCN number concentration, while the bin microphysics scheme demonstrates significant increases in the latent heating aloft with increasing CCN number concentration. This suggests that even a detailed two-bulk microphysics scheme, coupled to a detailed activation scheme, may not be sufficient to predict small changes that result from perturbations in aerosol loading

Technological status and development prospects of small-scale fishing crafts in Nigerian coastal water

A study of fishing crafts was conducted in some coastal states of Nigeria to elucidate findings on the existing crafts as the baseline for further developments. Based on the technical designs, three types of fishing crafts were identified; planked, dug-out and half dug-out canoes. The planked canoes have the largest cubic number and dug-out canoes the least. At loadwater line, the ratio of freeboard to draft was 2 : 1 for planked canoes, indicating reserved buoyancy. Trim of planked canoe is by stern; the beam-length ratio for dug-out canoes showed high drag. Most of the sea-going canoes have U-shaped bottom hull profile capable of withstanding the rigours of surf landing and displayed good stability against longitudinal water wave. Gunwale and thwarts provided respectively the longitudinal and transverse strength of planked and half dug-out canoes. With its characteristics 'weight low down' construction, planked canoe represent the climax of small scale fishing crafts developments in Nigerian coastal waters. It's only draw back is durability. Further improvement in this canoe should be aimed at increasing the hull size and stiffness, water tightness of deck by coating, caulking, fastening, increasing level of motorization and installation of deck working equipments. Experimental design and use of fibre glass, aluminium and ferrocement hulls, together with improved planked canoe is highly advocate

Development of an Orbital Receiver for Low-Frequency Radio Energy from the Planet Jupiter Final Report

Development of radio receiver for Pioneer F/G Asteroid-Jupiter spacecraf

Women Of Nashville: A Magazine

Short essay about the origin of Women Of Nashville: A Magazin

Development of spunlaced nonwoven filters from PAN, PPS and PI fibres for industrial use

The aim of this work was to produce filter fabrics suitable for high temperature and other conditions encountered in coal power plants using the spunlacing manufacturing technique. Polyacrylonitrile (PAN), polyphenylene sulfide (PPS) and polyimide (PI) fibres being combined suitable for this purpose, each at three aerial density of (440, 500 and 560 g/m2) and each at three water jet pressures of (60, 80 and 90 bars) were produced. The effect of changing these on the fabric air permeability, tensile strength and filtration properties were investigated and optimized. For this purpose, the Box-Behnken experimental design (BBD) was considered the best and therefore used. The PPS/PI fabrics were found to consistently have the highest air permeability, tensile strength and filtration performance, followed by the PPS fabrics and the PAN fabrics. As could be expected, an increase in area weight and water jet pressure generally resulted in a decrease in air permeability irrespective of the fabric types, this being due to the increased number of fibres and therefore greater fibre surface area and entanglement respectively. For fabric tensile strength, the effects of varying fabric area weight and water jet pressure were not so straight forward. For cross direction (CD) an increase in water jet pressure resulted in an increase tensile strength whereas in the machine direction (MD) there was a decrease when the water jet pressure was increased. The filtration efficiency and dust holding capacity of the fabrics were found to be around 96% and 211g/m2, respectively, with the exception of the PPS (500 g/m2 80 bar) fabrics. Increasing the amount of dust being fed to the fabric during each loading cycle, it caused an increase in pressure drop, as the fabrics became increasingly clogged forming a cake layer