Effects of Na2Cr2O7 Inhibitor on the Corrosion Potential Response of Steel Reinforced Concrete in Saline Medium

Electrochemical monitoring method of the open circuit potential was used to investigate the effect of the concentrations of Na2Cr2O7 on the corrosion potential response of steel reinforced concrete in sodium chloride medium. In the study, five different concentrations of Na2Cr2O7 admixtures were employed in a system of replicated samples of steel-reinforced concrete specimens partially immersed in 3.5% NaCl to simulate marine and saline environments. Forty days measured responses from these were subjected to the statistical analyses of the Normal and the Weibull distribution functions and tested using the Kolmogorov-Smirnov goodness of fit criteria. Results obtained from the analyses identified 4 g Na2Cr2O7 with optimal averaged potential response inhibition performance by the Normal model which showed better agreements in its models of Na2Cr2O7 potential test data than that obtained from the Weibull model of the same data. These bear pertinent implications on the need for suitability studies of appropriate statistical distribution for studying performance of corrosion inhibitors even as suggestions were proffered for addressing results conflicts among replicates of steel reinforced concrete samples employed

A Study of the Effect of Electrode Gap on the Production of Hydrogen from Aluminium/Copper Fuel Cell

In this work, we investigated the effects of electrode gap spacing on the amount of hydrogen produced in Aluminium/Copper Fuel Cell and its efficiency. Aluminium/Copper materials were used as the electrodes because of their high performance in the electrolyser systems while Potassium Hydroxide (KOH) was used as electrolyte. 10% concentration of potassium hydroxide was used throughout the experiment. The electrode spacing of 5mm and 10mm were used. It was observed from the graph that 5mm electrode spacing produced maximum efficiency of 29.7% and 10mm electrode spacing produced 17.7% efficiency. This implied that hydrogen production was highly dependent on electrode gap distance. The smaller the gap between the pair of electrodes, the more hydrogen was produced and the more efficient is the system

METHODS OF ASTM G16 AND CONFLICTS IN CORROSION TEST DATA: CASE STUDY OF NANO2 EFFECTIVENESS ON STEEL-REBAR CORROSION

In this paper, applications of the methods of ASTM G16 for addressing inherent conflicts in laboratory measurements of corrosion test data were studied, using the inhibiting effect of NaNO2 on the corrosion of concrete steel-rebar for the case study. For this, electrochemical monitoring techniques were employed for studying effectiveness of different concentrations of NaNO2 admixture in replicated concrete samples immersed in NaCl and in H2SO4 media for an experimental period of sixty-eight days. The corrosion test data from this experimental setup were subjected to the probability density fittings of the Normal and the Weibull functions as well as to significance testing methods of ASTM G16-99 R04 specifications. Results identified 10g (0.1208M) NaNO2 admixture with optimal inhibition efficiency model, η = 88.38±4.62%, in the saline/marine simulating environment and the 8 g (0.0966M) NaNO2 admixture with optimum effectiveness, η = 13.51±83.48%, in the acidic environment. The techniques of ASTM G16 adequately identified and addressed conflicting effectiveness from the test data of NaNO2 admixtures in the studied test environments

Peer tutoring – assisted instruction, parent supportiveness and student locus of control – as determinants of academic achievement in senior secondary school mathematics

The study investigated the effect of peer tutoring-assisted instruction, parent supportiveness and students locus of control on achievement in Senior Secondary Mathematics. It adopted a non-randomized pretest posttest control group design in a quasi experimental setting. It involves 300 senior secondary II students from six coeducational secondary schools in Odogbolu and Ijebu – Ode Local Government Areas of Ogun State Nigeria. The data collected were analysed using analysis of Covariance (ANCOVA). The findings revealed that there was significant main effect of treatment (peer tutoring) on mathematics achievement, it also revealed a significant interaction effect of treatment and parent supportiveness on achievement in mathematics. The three way interaction was founded not to be significant. The implication and recommendations were made. African Journal of Educational Studies in Mathematics and Sciences Vol. 2(1) 2004: 9-1

Application of Bio-Treatment Agent for Waste Water Remediation using Moringa Olifera Seed powder

This study is aimed at determining the efficacy of using Moringa oleifera seed powder (MOSP) in wastewater treatment process (domestic and industrial). The effectiveness of MOSP was evaluated on the microbial and physiochemical characteristics of water. The experimental results of the properties of the treated and untreated water samples from industrial and domestic water sources revealed significant improvement after treatment with MOSP. The findings observed that generally, Moringa oleifera seeds treated both industrial and domestic waste water well as an alternative to commercial coagulating agents.  The study, therefore recommended that Moringa oleifera seed powder be utilized in industries and homes for the treatment of waste water and re-use. In addition, these processes are environmentally friendly and offer a wide variety of other benefits, such as reducing costs, reducing the generation of by-products, and providing greater biodegradability

Putting context to numbers : a geotechnical risk trajectory to cost overrun extremism

The study investigates the cause of the unusually high cost overruns experienced in highway project delivery in the tropical wetland setting of the Niger Delta region of Nigeria. This is in view of the extensive literature supporting the link between geology, the lack of geotechnical best practices and cost overruns. An empirical profiling of cost overrun research further reveals the predominance of mono-method studies based on survey methods, correlative analysis and archival data modelling techniques, all of which are underlain by positivism. The study argues that such positivist philosophies, although methodologically valid, cannot adequately explain and provide in-depth understanding of the contextual cost overrun drivers in highway organisations., Using a robust and thoughtfully designed mix of methods, the paper examines the contribution of geotechnical risks to cost overruns experienced in highway project, and demonstrates the relevance of context in cost overrun research. Cost overrun data from documentary sources for 61 completed highway projects in the Niger Delta are gathered and analysed, revealing an average value of 216%, with extreme cases, ranging up to 1925% of budgeted cost. To uncover the intrinsic contextual drivers, 16 interviews were conducted with participants from the three highway agencies in the region, responsible for the execution of the sampled highway projects. Adopting a geotechnical narrative, the data is thematically analysed, deductively and inductively. The results of the analysis identified that poor project governance, management and procurement practices, have inhibited the competent management of geotechnical risk, creating a propensity for extreme cost overruns on the highway projects. The study submits the phenomenon of cost overruns in public infrastructure projects is underlain by a complexity of contextual social constructs, which would have been overlooked in positivists studies. Cost overrun research therefore, needs to be contextually and numerically anchored. Keywords: Context, Cost overruns, Highway projects, Mixed methods, Social Construct

Increased Prevalence of Activated Protein C Resistance During Pregnancy may Implicate Venous Thrombo Embolic Disorders as a Common Cause of Maternal Mortality in Nigeria

Background: Acquired resistance to protein C in pregnancy has been established as one of the factors associated with thromboembolic phenomenon, an important cause of maternal mortality and morbidity.Objectives: To establish the mean levels of PCA ratio (measure of protein C resistance) of among our pregnant women since maternal mortality rate of the country is on the increase despite efforts to reduce this trend.Materials and Methods: A prospective study was carried out in a tertiary institution in Enugu State, Southeastern Nigeria over the 7 months period from May 2010 to November 2010. Two hundred pregnant women and 50 non pregnant female controls were recruited and PCA ratio, (coagulometric assay) were determined. Results: There was a non significant difference between the mean and standard deviation PCA ratio of the female non pregnant controls and pregnant women in 2nd trimester 4.32±0.4 and 4.30±0.4 respectively. A significant difference was noted between the controls and pregnant women in 3rd trimester 4.32±0.4 and 3.87±0.5 respectively also between the pregnant women in their 2nd and 3rd trimester 4.30±0.4 and 3.87±0.5 respectively.Conclusion: There is increased protein resistance C in our pregnant women. This may implicate thromboembolic disorders as one of the leading causes of increase maternal mortality despite a downward trend in the prevalence of post partum haemorrhage.Keywords: Acquired protein C resistance, maternal mortality, pregnancy, post partum hemorrhage, thromboembolic disorder

Acidosis Activation of the Proton-Sensing GPR4 Receptor Stimulates Vascular Endothelial Cell Inflammatory Responses Revealed by Transcriptome Analysis

Acidic tissue microenvironment commonly exists in inflammatory diseases, tumors, ischemic organs, sickle cell disease, and many other pathological conditions due to hypoxia, glycolytic cell metabolism and deficient blood perfusion. However, the molecular mechanisms by which cells sense and respond to the acidic microenvironment are not well understood. GPR4 is a proton-sensing receptor expressed in endothelial cells and other cell types. The receptor is fully activated by acidic extracellular pH but exhibits lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To delineate the function and signaling pathways of GPR4 activation by acidosis in endothelial cells, we compared the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. The results demonstrated that acidosis activation of GPR4 in HUVEC substantially increased the expression of a number of inflammatory genes such as chemokines, cytokines, adhesion molecules, NF-κB pathway genes, and prostaglandin-endoperoxidase synthase 2 (PTGS2 or COX-2) and stress response genes such as ATF3 and DDIT3 (CHOP). Similar GPR4-mediated acidosis induction of the inflammatory genes was also noted in other types of endothelial cells including human lung microvascular endothelial cells and pulmonary artery endothelial cells. Further analyses indicated that the NF-κB pathway was important for the acidosis/GPR4-induced inflammatory gene expression. Moreover, acidosis activation of GPR4 increased the adhesion of HUVEC to U937 monocytic cells under a flow condition. Importantly, treatment with a recently identified GPR4 antagonist significantly reduced the acidosis/GPR4-mediated endothelial cell inflammatory response. Taken together, these results show that activation of GPR4 by acidosis stimulates the expression of a wide range of inflammatory genes in endothelial cells. Such inflammatory response can be suppressed by GPR4 small molecule inhibitors and hold potential therapeutic value

Inequities in Telemedicine Use Among Patients With Stroke and Cerebrovascular Diseases: A Tricenter Cross-sectional Study

BACKGROUND AND OBJECTIVES: In response to the COVID-19 pandemic, outpatient stroke care delivery was rapidly transformed to outpatient evaluation through video (VTM) and telephone (TPH) telemedicine (TM) visits around the world. We sought to evaluate the sociodemographic differences in outpatient TM use among stroke patients. METHODS: We conducted a retrospective chart review of outpatients evaluated at 3 tertiary stroke centers in the early period of the pandemic, 3/16/2020 through 7/31/2020. We compared the use of TM by patient characteristics including age, sex, race/ethnicity, insurance status, stroke type, patient type, and site. The association between TM use and patient characteristics was measured using the relative risk (RR) from a modified Poisson regression, and site-specific effects were controlled using a multilevel analysis. RESULTS: A total of 2,024 visits were included from UTHealth (n = 878), MedStar Health (n = 269), and Columbia (n = 877). The median age was 64 [IQR 52-74] years, and 53% were female. Approximately half of the patients had private insurance, 36% had Medicare, and 15% had Medicaid. Two-thirds of the visits were established patients. TM accounted for 90% of total visits, and the use of TM over office visits was primarily associated with site, not patient characteristics. TM utilization was associated with Asian and other/unknown race. Among TM users, older age, Black race, Hispanic ethnicity, and Medicaid insurance were associated with lower VTM use. Black (aRR 0.88, 95% CI 0.86-0.91, DISCUSSION: In our diverse cohort across 3 centers, we found differences in TM visit type by race and insurance early during the COVID-19 pandemic. These findings suggest disparities in VTM access across different stroke populations. As VTM remains an integral part of outpatient neurology practice, steps to ensure equitable access are essential

Inequities in Telemedicine Use Among Patients With Stroke and Cerebrovascular Diseases: A Tricenter Cross-sectional Study

BACKGROUND AND OBJECTIVES: In response to the COVID-19 pandemic, outpatient stroke care delivery was rapidly transformed to outpatient evaluation through video (VTM) and telephone (TPH) telemedicine (TM) visits around the world. We sought to evaluate the sociodemographic differences in outpatient TM use among stroke patients. METHODS: We conducted a retrospective chart review of outpatients evaluated at 3 tertiary stroke centers in the early period of the pandemic, 3/16/2020 through 7/31/2020. We compared the use of TM by patient characteristics including age, sex, race/ethnicity, insurance status, stroke type, patient type, and site. The association between TM use and patient characteristics was measured using the relative risk (RR) from a modified Poisson regression, and site-specific effects were controlled using a multilevel analysis. RESULTS: A total of 2,024 visits were included from UTHealth (n = 878), MedStar Health (n = 269), and Columbia (n = 877). The median age was 64 [IQR 52-74] years, and 53% were female. Approximately half of the patients had private insurance, 36% had Medicare, and 15% had Medicaid. Two-thirds of the visits were established patients. TM accounted for 90% of total visits, and the use of TM over office visits was primarily associated with site, not patient characteristics. TM utilization was associated with Asian and other/unknown race. Among TM users, older age, Black race, Hispanic ethnicity, and Medicaid insurance were associated with lower VTM use. Black (aRR 0.88, 95% CI 0.86-0.91, DISCUSSION: In our diverse cohort across 3 centers, we found differences in TM visit type by race and insurance early during the COVID-19 pandemic. These findings suggest disparities in VTM access across different stroke populations. As VTM remains an integral part of outpatient neurology practice, steps to ensure equitable access are essential