A review of diseases associated with cage culture systems: diagnosis and control in smale scale fish farming

Fish cage culture is a rapid aquacultural practice of producing fish with more yield compared to traditional pond culture. Several species cultured by this method include Cyprinus carpio, Orechromis niloticus, Sarotherodon galilaeus, Tilapia zilli, Clarias lazera, C. gariepinus, Heterobranchus bidorsalis, Citharinus citharus, Distochodus rostratus and Alestes dentes. However, the culture of fish in cages has some problems that are due to mechanical defects of the cage or diseases due to infection. The mechanical problems which may lead to clogged net, toxicity and easy access by predators depend on defects associated with various types of nets which include fold sieve cloth net, wire net, polypropylene net, nylon, galvanized and welded net. The diseases problems are of two types namely introduced diseases due to parasites. The introduced parasites include Crustaseans, Ergasilus sp. Argulus africana, and Lamprolegna sp, Helminth, Diplostomulum tregnna: Protozoan, Trichodina sp, Myxosoma sp, Myxobolus sp. the second disease problems are inherent diseases aggravated by the very rich nutrient environment in cages for rapid bacterial, saprophytic fungi, and phytoplanktonic bloom resulting in clogging of net, stagnation of water and low biological oxygen demand (BOD). The consequence is fish kill, prevalence of gill rot and dropsy conditions. Recommendations on routine cage hygiene, diagnosis and control procedures to reduce fish mortality are highlighte

Influence of Compression Stresses on Timber Potentials of Plantation Grown Eucalyptus camaldulensis Denhn in North-Western Nigeria

A study was conducted on the influence of compression stresses on timber potentials of plantation grown E. camaldulensis (Denhn) in North-western Nigeria, with a view to finding an alternative to the over exploited rainforest species. Five 20 year old trees each from Sokoto, Kebbi and Zamfara states were selected and felled for the study. These were cut into top, middle and bottom regions. A total of 225 samples were cut for laboratoryanalysis according to BS881:74 standard procedures. Laboratory analysis was carried out at Forestry Research Institute of Nigeria (FRIN), Ibadan, using Universal Testing Machine (UTM). ANOVA was used to analyze the data and mean separation was done using Duncanfs New Multiple Range Test. Results of the study revealed overall mean compression stress values of 51.85 N/mm2 and 5.00 N/mm2 parallel (//g) and perpendicular („¨g) to grain respectively. ANOVA showed that differences between means in compression stress perpendicular to grain were highly significant while region/location interaction also revealed significant differences. Similarly, location/region and tree/region interactions were highly significant. It is recommended that E. camaldulensis be added in to the list of exploitable species in North-western Nigeria as it provides suitable alternative to species hitherto exploited and that further research should be carried out on wood in service to study the peculiarities of timber behaviour under actual service conditions.Keywords: Compression, stress, timber, parallel, perpendicular, grain and plantatio

Comparative Adsorption Of Crude Oil Using Coconut Shell And Coconut Shell Activated Carbon

Coconut shell (CS) and Coconut Shell Activated Carbon (CSAC) as effective adsorbents for removal of crude oil were examined in this work through batch experiments. Variation in adsorption efficiencies was observed with respect to adsorbate loading, adsorbent loading, contact time, temperature, rotational speed, and pH of the mixture. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used to study the adsorption of the crude oil for both adsorbents, and it was observed that the mechanism of adsorption was of a multi- molecular-layer in nature. Fourier Transform infrared (FTIR) spectroscopy analyses were also carried out on the two adsorbents, before and after adsorption. The results indicated the presence of crude oil component functional groups on the two adsorbents. Optimum values of the six variable parameters for CS and CSAC adsorption were obtained using design of experiments (DOE). Optimum crude oil removal with CS was 51.32% at pH of 6.9, 49.18°C, mixed for 52.35 minutes at a speed of 347.50 rpm, using 3.76 g absorbent on a 0.06 g/L adsorbate mixture, while 91.25% removal was observed when CSAC was used at optimum pH of 6.2, 62.93°C, mixed for 70.12 minutes at a speed of 482.50 rpm, using 4.26 g absorbent on a 0.07 g/L adsorbate mixture. The enhanced effect from CS activation was justified statistically using ANOVA and Bonferroni-Holm Posthoc significance test, confirming that CS and CSAC are useful for crude oil adsorption

National Civil Aviation Policy Implementation in Nigeria: An Empirical Study

The study examined the various programmes put in place by the Ministry of Aviation towards the implementation of government policy on civil aviation and assessed the extent of implementation of the national civil aviation policy in line with the set goals and objectives in Southwestern Nigeria. The study utilized primary and secondary sources of data. Primary data were collected through the administration of questionnaire and conduct of in-depth interviews. In all, 193 copies of questionnaire were administered to the staff of Nigerian Civil Aviation Authority (NCAA); Federal Airports Authority of Nigeria (FAAN); Nigerian Airspace Management Agency (NAMA) and Accident Investigation Bureau (AIB) in the three selected States (Lagos, Oyo and Ondo) of Southwestern Nigeria. In-depth interviews were conducted on eight Directors in the four aviation agencies to complement data obtained through questionnaire. Secondary data were sourced from books, official publications, academic journals, newspapers, magazines and internet materials. Data collected were analysed using simple percentages, frequency counts, mean values, and rank. The results showed that adequate personnel training (84%) and the development of institutional infrastructures for aviation agencies (76%) were programmes put in place by the Ministry of Aviation towards the implementation of civil aviation policy. On the extent of implementation, the study however revealed that, technical personnel were not adequately trained for professionalism and efficiency in air operations (with a mean value of 3.582) and all necessary equipment, technologies and institutional infrastructures were inadequately provided to civil aviation departments and agencies to prevent and counter new and emerging threats (with a mean value of 3.144). The study concluded that government policy on civil aviation in Southwestern had been poorly implemented to date. Keywords: Assessment, Trade Development, Implementation, Government  Policy, Civil Aviation DOI: 10.7176/JLPG/88-26 Publication date: August 31st 201

Treatment outcomes in a rural HIV clinic in South Africa: Implications for health care

Objective: To assess the treatment outcomes of an HIV clinic in rural Limpopo province, South Africa.Methods: A retrospective cohort study involving medical records review of  HIV-positive patients initiated on antiretroviral treatment (ART) was conducted from December 2007 to November 2008 at Letaba Hospital. Data on socio-demographic characteristics, CD4 counts, viral loads (VLs), opportunistic infections, adverse effects of treatment, hospital admissions, and patient retention at 6, 12, 24, and 36 months on ART were collected. Analysis included descriptive statistics, chi-square and t-tests.Results: Of 124 patient records sampled, the majority of patients were female (69%), single (49%), unemployed (56%), living at least 10 km from the hospital (52.4%), and were on treatment at 36 months (69%). Approximately 84% of patients achieved viral suppression (VLs < 400 copies/mL) by 6 months of ART and the mean CD4 count increased from 128 at baseline to 470 cells/mm3 at 24 months. There was a mean weight gain of 5.9 kg over the 36 months and the proportion of patients with opportunistic infections decreased from 54.8% (n = 68) at baseline to 15.3% (n = 19) at 36 months. Although the largest improvements in CD4, VLs, and weights were recorded in the first 6 months of ART, viral rebound became evident thereafter. Of all variables, only age < 50 years and being pregnant were significantly associated with higher VLs (p = 0.03).Conclusion: Good treatment outcomes are achievable in a rural South African ART clinic. However, early viral rebound and higher VLs in pregnancy highlight the need for enhanced treatment adherence support, especially for pregnant women to reduce the risk of mother to child transmission

A table mounted device for cracking dika nut (Irvingia gabonensis)

A simply designed machine for cracking dika nut was fabricated. The nut is fed by hand inbetween a toggle mechanism comprising of the slider and a fixed block. Fracture mechanism was based on the deformation characteristics of dried dika nut under uni-axial compression. When actuated, the slider compresses the nutshell to failure along its line of symmetry. The experimental machine gave 100% cracking efficiency but with 24% kernel breakage in cracking sun-dried dika nut at 6.6% moisture content (w.b). The machine provides a viable and effective technique for safe dika kernel extraction

Design, fabrication and testing of a cassava pelletizer

This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% wb), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (wb) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h

Teaching protocol exchanges over cellular air interface

International audienceThe evolutionary path taken by cellular standards to the current and future standards is incomplete without fully understanding the older standards. The comprehension of the GSM standard, specifically the procedures for protocols exchange over the air interface will help students understand radio resource allocation procedures in GPRS and UMTS, and will ultimately assist future communication engineers to be able to design and solve problems related to these cellular standards. In this paper we describe the novel architecture of our teaching software, developed and programmed in Java. We present all the user interfaces and show how it can be used to assist in teaching, by presenting how the Mobile station and the GSM/GPRS network exchange data frames over the air interface with their associated protocols. Finally the uniqueness of this teaching tool was proved from the stand point of our modular architecture

Deformation and Dehulling of Sponge Gourd (Luffa aegyptiaca) Seeds

This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min−1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 m