Differences in physicochemical properties of water from neighbourhood boreholes and their usefulness in Clarias gariepinus egg hatching

Water parameters and egg hatching success in water from three boreholes within close proximity were investigated. The studies were conducted to ascertain differences in their quality and ability to support Clarias gariepinus egg hatching. The boreholes were tagged 300m, 400m and 330m in relation to their distances from a perennial stream within the vicinity. Temperature and pH were investigated using digital metres. Dissolved oxygen, alkalinity and total hardness were determined using titration method. The water parameters were measured twice a week for 5 weeks. Percentage egg hatching, time to commencement and termination of egg hatching were studied in triplicates. The results obtained showed that pH, Dissolve oxygen (DO), Alkalinity and total hardness were significantly different (P<0.05) among the boreholes, while temperature was not significantly different (P>0.05). Total hardness fluctuated most at 21% coefficient of variation (CV). Egg fertilization success was not significantly different (P>0.05). Percentage egg hatching (68.8%, 92.8% and 87.3% for 300m, 400m and 330m) respectively was significantly different (P<0.05). Higher coefficient of variation in hardness enhanced egg hatching. It could be induced in hatchery operations. Time to commencement (1443, 1453 and 1517) minutes and termination of hatching (1962, 1957 and 2037) minutes were significantly different (P<0.05). Larval survival by day-3 post hatch was significant[y different (P<0.05). The study provided evidence of disparity in water quality among the boreholes and revealed differences in their ability to support Clarias gariepinus egg hatching. These suggest carefulness in choice of borehole water for fish egg hatching regardless of proximity of boreholes.Keywords: Catfish, Propagation, Water and Eg

3D FEM simulation of titanium alloy (Ti6Al4V) machining with harmonic endmill tools

Usually, end milling operations have been carried out using conventional uniform helix tools with fixed helix angles. Thus, many studies have been conducted to study the effects of these tools on the thermomechanical properties of a milling process. Recently, there have been works that point to the benefits of using harmonic endmills. Harmonic endmills consist of cutting edge profiles that have continuously harmonically varying helix angles. The variation is described using a harmonic function of axial position (elevation) of points on the cutting edge. In this work, a 3D finite element simulation using ABAQUS, is carried out for the complex milling process of Titanium alloy Ti6Al4V. The envelope of the harmonic tool is first generated using a set of MATLAB codes and stored in a Standard Triangle Language (.stl) format. The machine tool is introduced into an FEM program which has been designed to provide for dynamic effects, thermo‐mechanical coupling, material damage law and the criterion for contact associated with the milling process. A Johnson‐Cook material constitutive equation which combines the effects of strain hardening, strain softening, and temperature softening is used. To account for the chip separation criterion, the Johnson Cook damage evolution equation is used. The milling process simulation for Ti6Al4V is then carried out. In the end, the stress distribution and the cutting forces are obtained.Projekt DEA

Corrosion properties of tempered medium carbon steel in 1.0 M HCl and homemade vinegar

ABSTRACT. The consumable palm wine has never been used in heat treatment process of steels. This research therefore focuses on the utilization of the consumable palm wine and other palm tree products as quenchants. The mechanical and physical properties of the samples were also evaluated to determine which of the quenchants that influences the hardness and corrosion rate values of medium carbon steel the most. The corrosion test was performed in 1.0 M of HCl solution and homemade vinegar using potentiodynamic polarization method. The results revealed a hardness value of 431, 351, 359 and 265 HB for the samples quenched in palm wine, palm kernel oil, palm oil and as-received, respectively. The corrosion rates of palm oil tempered samples showed more susceptibity to corrosion in HCl solution with a value of 2.261e+003 mil/year. Vinegar offers the highest corrosion rate with a value of 4.017e+002 mil/year for palm wine tempered. The corrosion rate of the as-received samples pulled the lowest values while on the treated samples, palm kernel oil showed the least corrosion rate values.   KEY WORDS: Consumable palm wine, Palm oil, Hardness, Corrosion rate, Austenitization, Quenching   Bull. Chem. Soc. Ethiop. 2022, 36(4), 893-901.                                                               DOI: https://dx.doi.org/10.4314/bcse.v36i4.14                                                     &nbsp

Qualitative and quantitative evaluation of the phytochemical contents in some selected green leafy vegetables in the Eastern part of Nigeria

Background: Leafy vegetables are sources of macro and micronutrients that play major role in maintaining healthy living. Phytochemicals are non-nutrient but bioactive compound with health protecting properties which play a variety of roles such as antioxidants, inhibition of tumor growth, antimutagens, enzyme modulators and free radical scavengers. In this study, the qualitative and quantitative evaluation of the phytochemical contents of “Ahihara” (Corchorus, olitorius), “eriamionu” (Celosia argentea), Tree spinach (Cnidoscolusa conitifolius) and “ugu”(Telfairia occidentalis) consumed in the eastern part of Nigeria was carried out. Methods: Qualitative and quantitative screenings were carried out on the raw, cooked and shade dried leaves to determine the presence of alkaloids, anthocyanin, carotenoid, flavonoid, glycoside, saponin, oxalate and tannins using standard methods. Fisher's Least Significant Difference was used to compare the different means at p < 0.05. Results: The results showed that the plant materials used for this study contain most of the phytochemicals tested for. Alkaloid was found to be present in high amounts in the shade dried vegetable except “ugu” (1.91, 1.32, 1.25 and 0.95g/100g for “Ahihara”, tree spinach, “eriamionu” and “ugu” respectively) while glycoside was absent in “ugu” and tree spinach but present in “Ahihara” and “eriamionu”. “Ahihara” was found to also contain the highest amount of anthocyanin (0.11g/100g). Processing affected the availability of the phytochemicals differently. Shade drying significantly (p<0.05) increased the concentration of all the phytochemicals. Cooking decreased the content of the alkanoid, anthocyanins, flavonoid, glycoside, oxalate and saponin but did not affect the level of carotenoid and tannin. Conclusion: The phytochemicals were present in all the vegetables studied. Of all the treatments, shade drying was observed to be a good processing method as it increased the phytochemical contents of the vegetable

Modified activation process for supercapacitor electrode materials from African maize cob

In this work, African maize cobs (AMC) were used as a rich biomass precursor to synthesize carbon material through a chemical activation process for application in electrochemical energy storage devices. The carbonization and activation were carried out with concentrated Sulphuric acid at three different temperatures of 600, 700 and 800 °C, respectively. The activated carbon exhibited excellent microporous and mesoporous structure with a specific surface area that ranges between 30 and 254 m2·g−1 as measured by BET analysis. The morphology and structure of the produced materials are analyzed through Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Boehm titration, X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. X-ray photoelectron spectroscopy indicates that a considerable amount of oxygen is present in the materials. The functional groups in the activated carbon enhanced the electrochemical performance and improved the material’s double-layer capacitance. The carbonized composite activated at 700 °C exhibited excellent capacitance of 456 F g−1 at a specific current of 0.25 A g−1 in 6 M KOH electrolyte and showed excellent stability after 10,000 cycles. Besides being a low cost, the produced materials offer good stability and electrochemical properties, making them suitable for supercapacitor applications

DEVELOPMENT OF AN INNOVATIVE ELECTROCOAGULATION (EC) REACTOR FOR LEAD REMOVAL FROM EX-MINING POND WATER

Exposure of tin ore and the associated minerals such as galena (PbS), arsenopyrite (FeAsS), chalcopyrite (CuFeS2), stannite (Cu2FeSnS4), teallite (PbSnS2), pyrite (FeS), etc to air during mining might cause the oxidation and dissolution of the minerals which lead to the release of heavy metals to the mining pond. One of such heavy metals is Pb. Ex-mining pond water was reported to contain Pb as high as 69.46 mg/L. Consumption of water containing Pb can cause toxic effects to humans, including brain damage. This is the reason ex-mining pond water is not recommended as drinking water source. The conventional treatment of water does not easily remove Pb from water. A promising and emerging treatment technology for Pb removal is by the application of electrocoagulation (EC). However, the EC process has problem of systematic reactor design, scale-up, among others

DEVELOPMENT OF AN INNOVATIVE ELECTROCOAGULATION (EC) REACTOR FOR LEAD REMOVAL FROM EX-MINING POND WATER

Exposure of tin ore and the associated minerals such as galena (PbS), arsenopyrite (FeAsS), chalcopyrite (CuFeS2), stannite (Cu2FeSnS4), teallite (PbSnS2), pyrite (FeS), etc to air during mining might cause the oxidation and dissolution of the minerals which lead to the release of heavy metals to the mining pond. One of such heavy metals is Pb. Ex-mining pond water was reported to contain Pb as high as 69.46 mg/L. Consumption of water containing Pb can cause toxic effects to humans, including brain damage. This is the reason ex-mining pond water is not recommended as drinking water source. The conventional treatment of water does not easily remove Pb from water. A promising and emerging treatment technology for Pb removal is by the application of electrocoagulation (EC). However, the EC process has problem of systematic reactor design, scale-up, among others

Patterns and clinical outcomes of childhood poisoning presenting to a children’s emergency department in Yenagoa, Nigeria: a 10-year retrospective study

Introduction Background: Childhood poisoning, characterised by exposure to toxic substances, poses a global health concern with variations across regions. Despite the importance of having current information about childhood acute poisoning in our region, there is a noticeable gap in such research in our local context. Regularly reviewing the agents responsible for poisoning in our locale is essential for devising prevention strategies and treatment approaches. This study aimed to examine the patterns and outcomes of childhood poisoning at the Children’s Emergency Department of the Federal Medical Centre, Yenagoa, Bayelsa State, Nigeria.Methods A retrospective cross-sectional study was conducted, analysing cases of childhood poisoning in the Children’s Emergency Ward, presenting from January 2013 to December 2022. Sociodemographic data, types of poisoning agents, home interventions, clinical features and outcomes were extracted from medical records.Results Of 9389 admissions, 81 (0.8%) cases were admitted for childhood poisoning, but only 69 cases were analysed (total n=69). Children aged under 5 years (52.2%) and who were males (59.4%) were mostly involved. Organophosphates (21.7%) and kerosene (20.3%) were common poisoning agents, often accidental (72.5%) and occurring at home (94.2%). Delayed hospital presentation (>2 hours) was common (68.1%). Vomiting (72.5%) and drooling saliva (56.5%) were prevalent symptoms. Hydration (60.9%) was the main hospital intervention, while antidotes were infrequently used (15.9%). Mortality was 8.7%, predominantly due to kerosene ingestion in young children.Conclusion Organophosphate and kerosene poisoning are the most common in this facility. Enforcement challenges persist, emphasising the importance of safe storage practices and improved poison control measures. Addressing resource constraints for antidote availability and increasing awareness are vital for effective management and prevention