Pore-scale analyses of heterogeneity and representative elementary volume for unconventional shale rocks using statistical tools

We express our appreciations to the Petroleum Technology Development Fund, Nigeria (PTDF), for funding this work.Peer reviewedPublisher PD

Electrochemical corrosion behaviour of austenitic stainless steel (type 304) in dilute hydrochloric acid solution

The effect of sodium chloride concentrations on the electrochemical corrosion behaviour of austenitic stainless steel (type 304) in dilute HCl solution at ambient temperature was studied with the aid of potentiodynamic polarization technique. Results show that increase in concentration of sodium chloride causes a proportionate increase in corrosion rate in 2M HCl solution. At 5M HCl, progressive increase in sodium chloride concentration initially resulted in sharp increase in corrosion rate before decreasing proportionately. Observation reveals that at a threshold concentration increase in sodium chloride concentration does not result in increase in corrosion rate and it was found that the addition of chloride ion destroyed the protective passive film on the surface and increased the corrosion current density. The kinetics of dissolution in the acid chloride solution resulting in pitting and general corrosion was also studied

Effects of Lysine Supplementation on Performance Characteristics and Mineral Retention of Broiler Chickens Fed Raw Benne Seed Based Diets

The objective of the study was to determine the effects of raw benne seed (RBS, Sesamum indicum) with or without lysine supplementation on the performance characteristics and mineral retention of broiler chickens. The feeding trial lasted for 56 days. One hundred and forty unsexed day old broiler chicks (Marshall strain) were used for the study. RBS was incorporated into the diets at 15% and 30% levels and supplemented with 0%, 0.25% and 0.5% of lysine, respectively. Average weekly feed intake in birds fed the control diet and 15% RBS based diet supplemented with 0.25 % and 0.5% lysine were not significantly different, but significantly (

Molecular Characterization of Successive Yeasts Strains and their Optimal Invertase Producing Conditions in Fresh Palm Wine (Raphiahookeri) Obtained from Lagos, Nigeria

Saccharomyces cerevisiae is known to produce invertase. However, molecular characterization of successive yeast strains and their optimal invertase producing conditions in Nigerian Raphiahookeri has not been documented. In this study, molecular characterization of successive yeast strains and their optimal invertase producing conditions in fresh palm wine (Raphiahookeri) obtained from Lagos, Nigeria was evaluated. To achieve this, sequencing of 18S rDNA was carried out following DNA extraction from the yeast isolates. Invertase production within 5-day period was also monitored at different conditions for the yeast strains. The physicochemical parameters investigated include pH, optical density, titratable acidity, sugar concentration and alcohol content. Out of the 21isolates obtained, 18 were identified by 18S rDNA to beS. cerevisiae, while 3 were Penicillium chrysogenum, Blumeriagraminissp. Tritici and Fusarium culmorum. Thefungal population density decreased from 1.01 x 107 to 0.9 x 105CFU/ml. The pH and sugar concentration decreased with increase in age of the wine ranging from 6.05-3.33 and 3.70-1.10mg/100ml respectively. The optical density, titratable acidity and alcohol content increased with time and ranged from 0.454-0.904, 0.266-0.412 % and 0.920-5.640 % respectively. All isolates produced invertase optimally at pH 6, 30°C after 48 h incubation with S. cerevisiae CP006433.1 having the highest production (1.745U/ml).The results highlight the effect of fermentation conditions on the survival and invertase production of yeast strains in Nigerian palm wine

Influence of Operation Parameters on Metal Deposition in Bright Nickel-plating Process

Bright nickel deposits were electrolytically applied on steel in the nickel Watts bath. The effect of some operational parameters on metal deposition in bright nickel plating was investigated. The investigation indicated that the weight of bright nickel deposited on metal during the process of electroplating was affected by plating temperature, voltage, current density, plating bath pH and plating time. The study established that the deposition of best bright nickel was obtained at a plating temperature of 56 oC, current density of 6 A/dm2 and plating time of 18 minutes. Brightener is used in applications requiring outstanding appearance with minimum thickness of applied nickel plating. It can also be used for heavy deposit applications because it exhibits unparalleled ductility and low stress. Brightener was used in this study to determine the best nickel plating in the process. Boric acid was added for fixing the bath pH. The compositions of the brightener and nickel solution used are included in the tex

Changes in the visceral functions of Plasmodium berghei-infected and-uninfected rats following administration of artemether.

The effects of artemether (12.5, 25.0 and 50.0 mg/kg per day, i.m.), administered to different groups of Plasmodium berghei‐infected and ‐uninfected adult Wistar rats for 1 week, were investigated. The parameters evaluated were the feeding, drinking and urinating patterns of the rats and these were compared with those of rats that received normal saline. Artemether caused a significant dose‐dependent reduction in food consumption of both P. berghei‐infected and ‐uninfected rats (P < 0.05). Food intake in infected rats was reduced by approximately 7 g/24 h. This reduction in food intake was further reduced during drug treatment with artemether. Artermether also reduced food intake in uninfected rats. The food consumption of rats that received 12.5 and 25.0 mg/kg artemether was restored after stopping treatment, in contrast with rats that received 50.0 mg/kg, in which the significant reduction in food consumption persisted 1 week after drug administration. During treatment with artemether, the water intake of infected rats was significantly lower than that of uninfected rats in the 12.5 mg/kg artemether‐treated group, but was significantly higher in infected rats than in uninfected rats dosed with 25.0 and 50.0 mg/kg artemether. For all doses of artemether tested, a significant increase in urine output was observed in infected rats during treatment and 1 week after treatment, whereas in uninfected rats a significant increase in urine output was observed only following 25.0 and 50.0 mg/kg artemether 1 week after drug administration. The present study confirms the anorexic activity of a high dose of artemether in both P. berghei‐infected and ‐uninfected rats. It also indicates that high doses of the drug could cause impaired renal function in rats and that the significant increase in urine output could also be due to other effects of artemether, namely those on thirst, anti‐diuretic hormone output and the osmotic pressure of the blood

Changes in some biochemical parameters of kidney functions of Plasmodium berghei infected rats administered with some doses of artemether

This study aimed at determining changes in urine concentrations of sodium (Na+) and potassium (K+) of Plasmodium berghei infected rats during a week of intramuscular administration of artemether (12.5 to 50.0 mg/kg/day) and one week thereafter. Their concentrations and that of creatinine and urea in the plasma were also determined at the end of the study. The observed changes were related to the effects of artemether on the kidneys of the rats. The urine levels of the two electrolytes decreased significantly during treatment (P< 0.05). One week post-treatment with 12.5 mg/kg of artemether, the urine concentrations of the electrolytes increased to values that were not significantly different from that of day 0. At 25 and 50 mg/kg, their urine concentrations still remained significantly lower than day 0 values (P< 0.05). Plasma concentrations of the electrolytes one week post-treatment increased, but they were only significant at 25 mg/kg for K+. A significant increase in the plasma level of creatinine was observed at all the doses of the drug at one week post-treatment. A dose-dependent degeneration of the renal tissue of all the experimental rats was also observed. We concluded that high doses of artemether caused progressive degeneration of the renal tissue of P. berghei infected rats

Effects of artemether on biochemical markers of liver function in Plasmodium berghei-infected and non-infected rats

This study aimed at determining changes in plasma activities of some enzymes and concentrations of plasma organic constituents which are often used in the assessment of liver functions in uninfected rats (UNR) and Plasmodium berghei infected rats (INR), following a week of intramuscular administration of artemether (12.5 to 50.0 mg/kg/day). The observed changes were related to the effects of artemether on the liver of the rats. At all the doses tested, the plasma concentrations of total and conjugated bilirubin increased significantly in both INR and UNR. A significant decrease in the plasma concentrations of glucose was also observed in UNR. The levels of cholesterol were significantly higher in INR than UNR. Plasma glutamate oxaloacetate transaminase (GOT) activity was significantly increased in both categories of rats, but more significantly in INR. The activity of plasma glutamate pyruvate transaminase (GPT) increased significantly at 12.5 and 25.0 mg/kg only in UNR, while a significant increase was observed at 50.0 mg/kg in the INR. Photomicrograph of the liver revealed progressive tissue damage which was more pronounced in INR than UNR. We concluded that high doses of artemether are toxic to the liver of both infected and uninfected rats

Effects of artemether on the plasma and urine concentrations of some electrolytes in rats

This study was carried out to determine the changes in the urine levels of sodium (Na+), potassium (K+), and calcium (Ca 2+) of rats during a week of intramuscular administration of artemether (12.5 to 50.0 mg/kg/day), another one week thereafter and their concentrations in the plasma at the end of the study. At 12.5 and 25.0 mg/kg of artemether, urine Na+ concentration was significantly increased throughout the study (p< 0.05), except on Day 7 (at 12.5 mg/kg) and Day 11 (at 25.0 mg/kg), when it was not significantly different from the control. At 12.5 mg/kg of the drug, urine K+ concentration was significantly increased throughout the study (p< 0.05). Artemether caused no significant changes in urine Ca 2+ concentration in the control rats as well as those that received 12.5 and 25.0 mg/kg of artemether. Progressive and significant reductions in the urine concentrations of all the electrolytes at 50.0 mg/kg of artemether were observed. Their concentrations in the plasma were also significantly reduced at this dose of the drug. A dose-dependent degeneration of the renal tissue of all the experimental rats was also observed. We concluded that high doses of artemether caused progressive degeneration of the renal tissue of rats, inability of the damaged kidneys to concentrate urine, which manifested as excessive water loss and electrolyte depletion