Combining Remote Sensing and Space-Time Analysis for Desertification Monitoring in the Semiarid Dryland of Nigeria

Desertification has been identified as the resultant effect of dryland loss. Desertification is catalysed by anthropogenic modifications and variations in environmental/climatic conditions. The situation in Nigeria is further exacerbated by the growing demand for land by the population. To this effect, this study performed a space-time analysis of vegetative cover between 2001 and 2020 to unravel patterns and trends across the semiarid region of the dryland system in Nigeria. The dynamics during the rainy season (May and September) were examined using the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) dataset subjected to space-time analysis. Generalised Difference Vegetation Index (GDVI) was computed to the power of 2 to quantify vegetative cover across the study area. The results showed that the average of the GDVI ranges between -0.40 and 0.94, with a standard deviation of 0.11. Time series cluster analysis revealed that there are two temporal clusters: (1) no statistically significant trend (Statistics= 1.33, p-value = 0.18) and (2) statistically significant downtrend (Statistics = -2.37, p=0.02), with cluster 1 covering 95% of the areas examined. The most dominant (97% of the area) emerging space-time pattern was cold-spots (persistent, diminishing, sporadic, oscillating, and historical types). In conclusion, most of the areas showed no definite temporal pattern of vegetation pattern during the period, while more than 90% of the areas have witnessed a decline in vegetative cover. There is a need for a more coordinated approach to desertification control, constant monitoring is pertinent while new approaches to restoring degraded land are recommended

Dual Layer Monolith ATR of Pyrolysis Oil for Distributed Synthesis Gas Production

We have successfully demonstrated a novel reactor technology, based on BASF dual layer monolith catalyst, for miniaturizing the autothermal reforming of pyrolysis oil to syngas, the second and most critical of the three steps for thermochemically converting biomass waste to liquid transportation fuel. The technology was applied to aged as well as fresh samples of pyrolysis oil derived from five different biomass feedstocks, namely switch-grass, sawdust, hardwood/softwood, golden rod and maple. Optimization of process conditions in conjunction with innovative reactor system design enabled the minimization of carbon deposit and control of the H2/CO ratio of the product gas. A comprehensive techno-economic analysis of the integrated process using in part, experimental data from the project, indicates (1) net energy recovery of 49% accounting for all losses and external energy input, (2) weight of diesel oil produced as a percent of the biomass to be ~14%, and (3) for a âÂÂdemonstrationâ size biomass to Fischer-Tropsch liquid plant of ~ 2000 daily barrels of diesel, the price of the diesel produced is ~$3.30 per gallon, ex. tax. However, the extension of catalyst life is critical to the realization of the projected economics. Catalyst deactivation was observed and the modes of deactivation, both reversible and irreversible were identified. An effective catalyst regeneration strategy was successfully demonstrated for reversible catalyst deactivation while a catalyst preservation strategy was proposed for preventing irreversible catalyst deactivation. Future work should therefore be focused on extending the catalyst life, and a successful demonstration of an extended (> 500 on-stream hours) catalyst life would affirm the commercial viability of the process

Microchannel Reactor System Design & Demonstration For On-Site H2O2 Production by Controlled H2/O2 Reaction

We successfully demonstrated an innovative hydrogen peroxide (H2O2) production concept which involved the development of flame- and explosion-resistant microchannel reactor system for energy efficient, cost-saving, on-site H2O2 production. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for controlled direct combination of H2 and O2 in all proportions including explosive regime, at a low pressure and a low temperature to produce about 1.5 wt% H2O2 as proposed. In the second phase of the program, as a prelude to full-scale commercialization, we demonstrated our H2O2 production approach by ‘numbering up’ the channels in a multi-channel microreactor-based pilot plant to produce 1 kg/h of H2O2 at 1.5 wt% as demanded by end-users of the developed technology. To our knowledge, we are the first group to accomplish this significant milestone. We identified the reaction pathways that comprise the process, and implemented rigorous mechanistic kinetic studies to obtain the kinetics of the three main dominant reactions. We are not aware of any such comprehensive kinetic studies for the direct combination process, either in a microreactor or any other reactor system. We showed that the mass transfer parameter in our microreactor system is several orders of magnitude higher than what obtains in the macroreactor, attesting to the superior performance of microreactor. A one-dimensional reactor model incorporating the kinetics information enabled us to clarify certain important aspects of the chemistry of the direct combination process as detailed in section 5 of this report. Also, through mathematical modeling and simulation using sophisticated and robust commercial software packages, we were able to elucidate the hydrodynamics of the complex multiphase flows that take place in the microchannel. In conjunction with the kinetics information, we were able to validate the experimental data. If fully implemented across the whole industry as a result of our technology demonstration, our production concept is expected to save >5 trillion Btu/year of steam usage and >3 trillion Btu/year in electric power consumption. Our analysis also indicates >50 % reduction in waste disposal cost and ~10% reduction in feedstock energy. These savings translate to ~30% reduction in overall production and transportation costs for the $1B annual H2O2 market

Effect of Myristica fragrans Houtt. Seed (Nutmeg) on Helicobacter pylori induced gastritis in albino rats: in vitro and in vivo studies

The anti-Helicobacter pylori (H. pylori) activities of dichloromethane and methanol extracts of Myristica fragrans Houtt. seed (nutmeg) was studied to authenticate traditional use in gastrointestinal disorder. Anti-H. pylori activities using the agar dilution method was investigated in 39 strains of H. pylori comprising 38 clinical isolates and a standard strain. Bactericidal studies were done by the viable counting technique. The effect of 500 mg/kg and 250 mg/kg body weight of the methanol extract of nutmeg on H. pylori-induced gastritis and colonization was investigated in albino rats. The minimum inhibitory concentration (MIC) was 6.25 mg/mL while the minimum bactericidal concentration (MBC) ranged from 6.25 mg/mL to 100 mg/mL. Bacterial density score of the gastric mucosa reduced from 5.0 ± 7.07 x 108 to 1.6 ± 1.4 x 104 and 3.45 ± 1.4 x 104 CFU/mL (mean ± SD, p < 0.05) after treatment with 500 mg/kg body weight and Ofloxacin 400 mg/kg respectively. Analysis of variance (ANOVA) tested the effect of the groups on the treatment days and revealed a significant difference between the treatments at p< 0.05. The results of these studies have proven the activities of Myristica fragrans Houtt. seed on H. pylori - induced gastritis in albino rats.Keywords: Crude extracts, susceptibility testings, bactericidal studies, bacterial inoculation, histopathological examinations

Parental concern, self-efficacy and school environment as predictors of academic achievement of adolescents with hearing impairment in Lagos State

This study investigated parental concern, self-efficacy and school environment on academic achievement of adolescents with hearing impairment in Lagos State. Descriptive survey research design was adopted for this study. The sample consisted of ninety nine (99) students drawn from Junior and Senior Secondary Schools students in Lagos State. A self-constructed questionnaire tagged “parental concern, self-efficacy and school environment on academic achievement of adolescents with hearing impairment questionnaire (PCOSSAWHIQ)” and Achievement test on English Language extracted from West Africa Examination Council (WAEC) were used for data collection.. Data were analyzed using Pearson Product Moment Correlation and Analysis of Variance (ANOVA). The study revealed that there is significant relationship between parental concern and academic achievement of adolescents with hearing impairment, there is significant relationship between self-efficacy and academic achievement of adolescents with hearing impairment, there is significant relationship between school environment and academic achievement of adolescents with hearing impairment and there is significant joint contribution of parental concern, school environment self-efficacy and gender on academic achievement. Counselling programmes should be organized for adolescents in order to make the adolescents develop high self-efficacy and excel academically. School counsellors should work with other special educators to meet the developmental needs of all adolescent students with the inclusion of special needs.Keywords: Parental concern, Self-efficacy, School environment, Academic achievement, Adolescence with Hearing Impairmen

CFD SIMULATIONS OF GAS AND LIQUID SLUGS FOR TAYLOR FLOW IN A MICROCHANNEL

ABSTRACT The rapid development of microfabrication techniques creates new opportunities for applications of microchannel reactor technology in chemical reaction engineering. The extremely large volume-to-surface ratio and the short transport path in microchannels enhance heat and mass transfer dramatically and hence provide many potential opportunities in chemical process development and intensification. Multiphase reactions involving gas/liquid reactants with a solid as a catalyst are ubiquitous in the chemical and pharmaceutical industries, and the hydrodynamics play a prominent role in reactor design and performance. For gas/liquid two-phase flow in a microchannel, the Taylor slug flow regime is the most commonly encountered flow pattern, therefore the present study deals with the numerical simulation of gas and liquid slugs in a microchannel. A T-junction microchannel (empty or packed) with varying cross-sectional width (0.25, 0.5, 0.75, 1, 2 and 3 mm) served as the model micro-reactor, and a finite volume based commercial CFD package, FLUENT, was adopted for the numerical simulation. The gas and liquid slug lengths at various operating conditions were obtained and found to be in good agreement with the literature data. Keywords: Taylor flow; Liquid and gas slugs; Microchannel; Numerical simulation INTRODUCTION The microchannel reactor has many advantages over conventional macroreactors. With its small transverse dimensions (submillimeter), the microchannel reactor possesses extremely high surface to volume ratios, and consequently exhibits enhanced heat and mass transfer rates. Scale-up for high throughput is achieved by simple replication of microreactor units; which eliminates costly reactor redesign and pilot plant experiments, thus shortening the development time from laboratory to commercial production. There are numerous potential applications for microchannel reaction technology in chemical and biological engineering, which are suitable for various types of reactions, from thin-wall reactors, membrane reactors to packed bed reactors, and from single phase reactions to multiphase reaction

Environmental Impacts of Sand Dredging in Awoyaya, Lagos State, Nigeria

The research analysed the environmental impacts of sand dredging in Awoyaya, Lagos State. Water and soil samples were collected from three different locations in the study area. The results of water analysis reveals that average pH of water is 6.16, the average temperature of water is 27.55?C, the average chloride of water is 0.11mg/l, the average turbidity of water is 118ppm, the average sulphate of water is 45.67ppm, the average total dissolve solid in water is 98.3mg/l, the average total suspended solid in water is 114.1mg/l, the average total solid of water is 213ppm, the average iron present in water is 0.07ppm, and the average Zinc present in water is 0.015ppm. The results of the physiochemical and geochemical parameters of soil show that the average pH of soil is 7.78, the average organic carbon, organic matter, nitrogen and phosphorous of soil are 0.42%, 0.72%, 0.05%, and 10.73% respectively and the average values of SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O present in the soil are 80.97%, 1.64%, 1.33%, 1.55%, 1.00%, 0.20%, 0.21%, 0.15 respectively. The analysis carried out shows that the dredging in Awoyaya has little impact on water and soil in the dredging area. Keywords: Environmental impact, Turbidity, Temperature, Organic Carbon, Organic Matter, Total dissolved solid, total solid, total suspended solid

Corporate Entrepreneurship, HRM Practices and Firm Performance

AIn modern business dynamics, firm growth and sustainability significantly depends on corporate entrepreneurship (CE) and entrepreneurship (E) practices. Because of their significance, we have examined the direct and indirect effect of corporate entrepreneurship (CE) and entrepreneurship (E) on firm performance (FP) in SMEs of Nigeria. We have used a sample of 387 for collecting the data non-randomly. The tool we used for collecting the data was a close-ended questionnaire, which we adapted from earlier studies. The authors have used Smart PLS for statistical analysis. We found that corporate entrepreneurship (CE), entrepreneurship (E), and human resource management (HRM) affects firm performance (FP). We also found that HRM practices also have a significant link with corporate entrepreneurship (CE), entrepreneurship (E), and firm performance (FP). The results also suggest that entrepreneurship (E) and corporate entrepreneurship (CE) mediates HRM practices and firm performance (FP). The above findings were consistent with the view that HRM practices are an essential component of an organization. HRM activities besides conventional functions also promote entrepreneurial (E) behaviour and organizational outcomes. Thus, the HRM department must continuously revisit the policies and procedures to ensure that they are aligned with the changing environment. Entrepreneurial (E) and corporate entrepreneurial (E) orientation support an environment that encourages employees to participate in decision making, which enhances employees’ sense of belonging and promote a positive attitude towards work.Keywords: Corporate entrepreneurship, entrepreneurship, practices, firm performance, Nigeri

Antimicrobial activities and the Bactericidal Kinetics of Allium ascalonicum Linn. (Whole plant) against standard and clinical strains of Helicobacter pylori: Support for Ethnomedical Use

Helicobacter pylori are the causative agents of gastroduodenal disorders, such as peptic ulcer, acute gastritis and even stomach cancer. It is believed to infect over half the world’s population. Recently, there have been cases of chemotherapy – failures and emergence of resistant strains. This necessitated the search for more active drugs. Crude n-hexane and methanol extracts were used to screen Helicobacter pylori ATCC 43504 and forty-two other clinical isolates of Helicobacter pylori, using the agar diffusion method in Mueller-Hinton agar supplemented with 5% defibrinated horse blood. The strains were incubated in a microaerophilic incubator, and it was observed that the standard strain and twenty-eight out of the forty-two clinical strains were susceptible to the methanol extract with the diameter of zone of inhibition ranging from 10 + 0.00 to 20 + 0.00 mm at test concentrations of 100 mg/mL to 200 mg/mL. The minimum inhibitory concentrations of susceptible strains ranged between 100 mg/mL to 200 mg/mL. The kill kinetics showed that at 4×MIC, equivalent to the minimum bactericidal concentration (MBC), the methanol extract of Allium ascalonicum gave 96-98% and 100% kill of the organisms within the contact time of 6 and 24 hours respectively. The n-hexane fraction did not show any inhibitory potential against any of the strains. Phytochemical screening of the extract showed the presence of alkaloids, saponins, flavonoids, essential oil and cardiac glycosides. Anthraquinones, tannins and terpenoids were not detected. The presence of these secondary metabolites and the observed activity of Allium ascalonicum provide a scientific rationale for the use of this plant in folk medicine in Nigeria and other parts of the world. Keywords: Allium ascalonicum, Helicobacter pylori, antimicrobial activities, bactericidal kinetic