Length -weight relationship and condition factor in the Polyculture of Clarias and Tilapia in concrete tanks

The experiment was conducted to determine the length weight relationship and condition factor of Clariasgariepinus and Oreochromisniloticus in five different stocking combinations for a period of twelve weeks from 17th July – 9th October, 2009. A total of 1,509 juveniles of C. gariepinus withaverage weight of 24.88g and average length of 14.52cm, and 2,991 juveniles of O. niloticus with average weight of 24.90g and average length of 10.93cm were stocked at 30 fish/m2 in clarias:tilapia ratios of 0:1, 1:0, 1:2, 1:4, and 1:6. The fish were fed at 3% body weight per day (BWD) over a period of 84 days. The monoculture of the two species (Treatments 1 and 2) yielded the lowest growth indices (WG, %WG and SGR), while the performance of clarias at each of the three polyculture systems were higher than those of tilapia. For clarias Treatment 5 (1:6) had the maximum length (17.92±0.37cm) while the monoculture recorded the minimum of 16.60±0.29. The monoculture of tilapia gave the lowest length gain (4.83±0.41cm) while the highest (11.60±0.51cm) for tilapia was recorded in Treatment 4 (1:4). From the regression parameters and the associated statistics (r and SE) for the validation of the models, it is evident that there was a strong positive relationship between length and weight. Even though the relationship was curvilinear there were still higher percentages of regression coefficient in all the treatments and between the species. The SE was also low in all the treatments which further validated the logtransformed models. Therefore, the models are valid for estimating weight of the fishes from the length measurements without necessarily measuring the weight. Stocking ratio of 1:6 should be encouraged for better growth performance.Keywords: Polyculture, length – weight, condition factor, clarias, tilapia, juveniles

Removal of Congo Red Dye from Aqueous Solution using Sugarcane Bagasse and Bambara Groundnut Shell

A methodology involving sugarcane bagasse (SB) and Bambara groundnut shell (BGS) as adsorbents was developed in order to remove the carcinogenic Congo red dye from aqueous medium. The effect of contact time, sorbent dosage, initial concentration and pΗ were investigated. The results showed high efficiency of ≈ 93% and 75% using 4.5g of SB and BGS respectively. The results also indicated that the % removal increases with increase in dye loading concentration, while it decreased with an increase in pΗ of the solution from 4 to 10. From the results, it is possible to conclude that sugarcane bagasse and Bambara groundnut shell are good adsorbents for dye effluent treatment.Keywords: Bambara groundnut shell, Congo red, Sugarcane Bagasse, % Dye Removal

Evaluation of different feeding frequencies on growth performance and feed utilization of Clarias gariepinus (Burchell, 1822). Fingerlings

The experiment was conducted to assess the growth performance and feed utilization of Clarias gariepinus under the feeding frequencies of T1 (twice/day), T2 (thrice/day), and T3 (four times/day) at 3% BWD per day over a period of 56 days. A total of 180 fingerlings with average weight of 2.39±0.19g and average length of 5.02±1.04cm were stocked at 15 fish per plastic container of 35 litres capacity. The highest weight gain recorded at the end of the experiment was 7.39±0.19g in (T3) and the lowest was 5.35±0.31g in (T1). The highest specific growth rate (SGR%) value of 1.19±0.02 was recorded in (T3) and the lowest 1.01±0.03 was recorded in (T1). T3 recorded the highest FCR value of 1.88±1.37, while the lowest value of 8.34±2.12 was obtained in (T1). Therefore, Treatment 3 yielded the best performance in terms of WG, SGR, and FCR and can be recommended for enhanced growth performance and optimum feed utilization.Keywords; Fingerlings, feeding, frequency, growth, performance, utilization

Improved Polymer Flooding in Harsh Environments by Free-Radical Polymerization and the Use of Nanomaterials

High temperature and high salinity (HTHS) and extreme pH conditions can significantly affect the stability of polymers and deteriorate the performance of polymers in enhanced oil recovery (EOR). This work advances polymer flooding in harsh environments on two fronts: engineering polymers with improved temperature tolerance and dispersing suitable nanoparticles in the synthesized polymers to further improve their capabilities to withstand temperature, salinity, and different pH conditions. Different modified acrylamide copolymers (polymers synthesized from two different monomers) and terpolymers (polymers synthesized from three different monomers) are produced via free-radical polymerization, and multiwall carbon nanotubes (MWCNTs) were introduced to obtain aqueous polymer dispersions with unique properties. The conversion, molecular weight, and polydispersity of the co/terpolymers were evaluated by 1 H-NMR and GPC analysis. The interfacial, rheological behavior and stability of the dispersions were investigated under HTHS conditions at various pH values to identify the suitable candidates for EOR applications. The oil recovery performance is examined in a core flooding setup at 85 °C and American Petroleum Institute (API) brine conditions. The polyampholytic terpolymer and polyelectrolyte copolymer containing negative sulfonate groups showed improved viscosity and stability in the presence of MWCNTs in alkaline and saline conditions, respectively. Compared to the pure polymer dispersions, the addition of MWCNTs to polymers improves the oil recovery efficiency at high temperature (85 °C) in the presence of both alkaline pH and API brine conditions yet with a lower pressure drop. This shows great promise for future EOR applications

Tuberculosis In A Nigerian Medium Security Prison

Introduction: Prisons worldwide have been cited as reservoirs for tuberculosis and also an ideal setting for interventions but little is known about the epidemiology and control of tuberculosis in Nigerian Prisons. Objective: To determine the prevalence of tuberculosis, role of prison in its control and the mortality from tuberculosis among prison inmate in Kuje prison, Abuja, Nigeria. Materials and Methods: This study was a retrospective study of cases of tuberculosis in Kuje prison between April, 2004 and December, 2008. Data was collected from their medical records. The inclusion criterion was: (1) Cases of tuberculosis in which the diagnosis was based on clinical history, smear positive test and chest x-ray radiograph. (2) Cases where the treatment of tuberculosis was according to treatment strategy recommended by World Health Organization. Results: A total of forty-eight inmates, aged 20 to 45years, were diagnosed with tuberculosis within the period of interest. The prevalence rate was 2.4%, based on a total prison population of 2002. Majority of cases 93.8% were first detected in Prison and the remaining 6.3% were detected prior to incarceration. Out of the 6.3% diagnosed prior to incarceration, 2.1% and 4.2% of cases have defaulted from DOTS for 2weeks and more than 4weeks respectively. Majority (66.7%) completed the treatment before discharging from prison, 29.2% were discharged from prison at various level of treatment and 4.2% of cases died while on reatment. Those who died were co-infected with HIV Conclusion: It was evident from this study that: The prevalence of tuberculosis in Kuje prison was high, prison has a role in diagnosis and treatment, adherence and treatment outcome were good and the main indicator for mortality was HIV infection. Primary prevention measures specifically targeting prisoners are needed to reduce prevalence of tuberculosis and also to achieve the objectives of National Health Policy on tuberculosis and leprosy. Keywords: Prison, tuberculosis, control, mortalit

Stabilization of Polymer Nanocomposites in High-Temperature and High-Salinity Brines

Stabilization of polymer nanocomposites in aqueous environment with high salinity has been a constant challenge for their applications. This work aimed to improve the stability of graphene oxide (GO) polyacrylamide nanocomposites at high-temperature and high-ionic-strength brines. GO was synthesized via a modified Hummers’ method and the copolymer of acrylamide (COPAM) was obtained via free-radical polymerization. The covalent functionalization of COPAM with the partially reduced GO (rGO) was successfully achieved. 1,3-Propane sultone was used to further functionalize the obtained rGO–COPAM composites to accomplish the zwitterionic character on the rGO–COPAM surface to get a material with excellent temperature stability and dispersibility in the presence of high ionic strength brines. The synthesized materials were characterized by 1H NMR, gel permeation chromatography, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy analysis, and so forth. The thermal stability of the dispersion at 80 °C for 120 days was observed by visual inspection and spectroscopic analysis. The results showed that the zwitterionic polymer produced excellent brine stability with GO nanosheets and suggested promising applications of zwitterionic polyacrylamide–GO systems especially for enhanced oil recovery

Effects of salinity on the onset of elastic turbulence in swirling flow and curvilinear microchannels

Elastic turbulence, which is sensitive to geometry and polymer rheology, has shown great potential for improving the performance of mixing, heat transfer, and even oil recovery. Recent studies showed the importance of the rheological properties of polymer solutions on the onset of elastic turbulence. However, variations of rheological properties based on polymer sensitivities such as salinity and its corresponding effects on the elastic turbulence have not been revealed. This work investigated systematically the effects of salinity on the onset of elastic turbulence in both swirling flow and curvilinear microchannels. The variations of statistical properties, such as probability distribution functions (PDFs) and power spectral density of injected power (PSD), were analyzed for characterization. The onset conditions of elastic turbulence are postponed by high salinity, which is consistent with the mixing performance in a curvilinear microchannel. A salinity independent power-law exponent at a value of −4.3 is observed in a fully developed elastic regime for all polymer solutions. Particularly, the diffusion of fluorescein at a low flow rate in the microchannel is possible due to the existence of a steady secondary flow before the onset of elastic instability

Acute mesenteric ischemia and duodenal ulcer perforation: a unique double pathology

Background: Acute mesenteric ischaemia and duodenal perforation are surgical emergencies with serious consequences. Patients presenting with acute mesenteric ischaemia alone face a high mortality rate as high as 60% whereas those presenting with peptic ulcer perforation the mortality rates range from 6-14%. There are very few reported cases of patients presenting with this dual pathology. Case presentation: We report a unique case of a 53 year old Italian lady who presented with acute mesenteric ischaemia and duodenal perforation. This is the first report of massive bowel ischaemia and duodenal perforation with no apparent underlying common pathophysiology leading to this presentation. Conclusion: Early management in the intensive care unit and appropriate surgical intervention maximised the patient’s chances of survival despite the poor prognosis associated with her dual pathology. The rare pathology of the patient described can be explained by two possible hypotheses: peptic ulcer disease causing duodenal ulceration, which precipitated ischaemic infarction of the small bowel. The second hypothesis is the patient developed a stress related ulcer following ischaemic bowel infarction secondary to arterial thrombosis