Effects of powdered glass as an admixture in cement concrete block

This paper investigated the effects of glass usage in finely divided form on the properties of cement concrete. The powdered glass was used as admixture, replacing cement in the concrete production process. The sourced glass were washed and dried for some days. The dried glass was then crushed into smaller pieces before grinding to finely divided form. Replacement of cement with powdered glass was done at 0-10% with 2% increment by weight of cement. Using a design mix of 1:2:4, with a constant water cement ratio of 0.6, the workability of fresh specimens were determined using the slump height procedure. The specimens were then poured in 150x150x150mm steel moulds and left for 24 hours. The hardened concrete specimens were cured by complete immersion in water for 7, 14, 21 and 28 days. The result showed that workability increases with increase in admixture content. It further revealed that the compressive strength increases with admixture addition to about 4% powdered glass addition. The compressive strength at 6% addition of powdered glass was also higher than that of the conventional concrete. Thus replacement can be done to about 6% addition of powdered glass by weight of cement. The models developed from the study corroborated well with experimental values as high coefficient of determination values were obtained. The models can thus, be used to predict the compressive strength of powdered glass-cement concrete.Keywords: Admixture, Cement Concrete, Compressive Strength, Slump, Powdered Glas

Effect of low density polyethylene as bitumen modifier on some properties of hot mix asphalt

In Nigeria today, polyethylene or water sachet is a major environmental pollutant, a nonbiodegradable material. The usefulness of this pollutant (polyethylene) in the highway industry was investigated by studying its effects on some selected properties of Hot Mix Asphalt, such as, bulk density, stability and flow of the asphalt concrete mix. Specimen preparation was done using Marshall Mix design procedure. The optimum binder content was determined as 5.20% and three samples each for five variations of polyethylene content (2%, 4%, 6%, 8% and 10%) by weight of optimum binder content. It was observed from the study, that the stability and density of asphalt increased with polyethylene content, while a linear reduction in the flow and penetration values was observed with polyethylene content. The optimum modifier content value of 8% by weight of the optimum bitumen content. Models were also developed whose predictive values corroborated well with experimental values with acceptable coefficient of correlation values. Bitumen modified with polyethylene improved the engineering properties of asphalt which therefore means that usage of this waste product in the asphalt production for roadwork is an effective and economical way of managing this waste.Keywords: Polyethylene, modifier, asphalt, bitume

Determinants of Volume of POME Generation in Palm Oil Mills for Planning Wastewater Recovery in Biogas Energy Development

Wastewater volume is a necessary prerequisite for planning transformation to valuable resource and averting environmental degradation. This study investigated the dynamics of POME volume generation in palm oil mills in relation to types of fresh fruit bunches (FFBs), seasons, milling scales and volume of crude palm oil (CPO) produced in ADAPALMS and catchment communities, Ohaji/Egbema LGA, Imo State. The eight catchment communities of ADAPALMS were categorised into three strata in relation to the number of small-scale mills in each community (1-5mills, 6-10mills, and 11-15mills). In each stratum, a community was randomly sampled. A total of nine small-scale mills were sampled from the three sampled communities (Ohoba, Amafor and Etekwuru) in proportion to the average number of mills in each stratum. The lone medium and large scale mill (ADAPLAMS) in the study area represented the other scales of milling. For small and medium scale mills, the volume of POME generated was measured from the dimensions of the vessels where POME was stored, while that of large scale mill was obtained from industrial records. Data was analysed using multiple linear regression of SPSS. The volume of POME generated is significantly related to milling scales and volume of CPO produced (p< 0.01); R2=0.788. Within small scale mills, the volume of POME is significantly related to types of FFBs (p< 0.01), different small milling scales (p< 0.05), and volume of CPO produced (p< 0.01); R2=0.762. Thus, these independent variables are the principal determinants of POME volume generation in the area. The result has implication on the necessity of predictive models in managing the dynamics of POME volumes for efficient recovery and transformation of the wastewater to bioenergy

Addendum of 2MW Wind Turbine to A Power with Directly-Driven Permanent Magnet Generation System

In recent years, wind turbine has become an acceptable alternative energy generation, because of the environmental and economic benefits. Notwithstanding more research works still need to be done to reduce wind turbine installation complexity, enhance profitability and reliability especially in developing countries like Nigeria. This paper presents the modeling and analysis of a 2MW variable-speed directly-driven permanent magnet synchronous generator (PMSG), Wind energy conversion system (WECS). The objective is to optimize the power captured from the wind, ensure optimum efficiency for power generation and reduce system hardware count. The mathematical model for the permanent magnet synchronous wind turbine and its power control algorithms are modified by removing the speed sensors. Further, enhancement was achieved by utilizing wind speed forecasts as the starting speed. A modified Field Orientation Control FOC and voltage orientation control VOC scheme were developed for the system using matlab Simulink CAD application. The Simulation results of the model for various changes in wind speed utilizing average wind speed data of Mmaku in Awgu local government area of Enugu state Nigeria. The developed system ability to ‘smoothen’ the power, voltage output and operates at the optimum coefficient of performance between the cut in speed of 3m/s and 12m/s without wind sensor is found to be promising, Key words: wind turbine, variable-speed, permanent magnet, synchronous generator, efficiency DOI: 10.7176/JETP/9-3-04 Publication date:March 31st 201

Exhaustive Exercise Training Enhances Aerobic Capacity in American Alligator (\u3ci\u3eAlligator Mississippiensis\u3c/i\u3e)

The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, ventricular and skeletal muscle masses and haematocrit. Compared to sedentary control animals, alligators regularly trained for 15 months on a treadmill (run group) or in a flume (swim group) exhibited peak oxygen consumption rates higher by 27 and 16%, respectively. Run and swim exercise training significantly increased ventricular mass (~11%) and haematocrit (~11%), but not the mass of skeletal muscles. However, exercise training did not alter CS or LDH activities of skeletal muscles. Similar to mammals, alligators respond to exercise training by increasing convective oxygen transport mechanisms, specifically heart size (potentially greater stroke volume) and haematocrit (increased oxygen carrying-capacity of the blood). Unlike mammals, but similar to squamate reptiles, alligators do not also increase citrate synthase activity of the skeletal muscles in response to exercise

In vitro effects of metals and pesticides on dehydrogenase activity in microbial community of cowpea (Vigna unguiculata) rhizoplane

Effects of heavy metals and pesticides on cowpea (Vigna unquiculata) rhizoplane microbial community  were assessed in vitro via dehydrogenase activity. The microbial community was exposed to various concentrations of heavy metals and pesticides in a nutrient broth-glucose-2,3,5-triphenyl chloride (TTC) medium. At 0.2 mM, iron and cadmium stimulated the dehydrogenase activity of the microbialcommunity. For all the metal ions, there was progressive inhibition with each successive increase in the concentration of metal ion, reaching near 100% at 0.6, 0.8, 1.2, 0.12 and 12 mM for cobalt, cadmium,iron, mercury and nickel, respectively. Between 0.2 and 0.4 mM, zinc sharply inhibited dehydrogenase activity and at concentration above 0.4 mm, inhibition of dehydrogenase activity became lesspronounced. The order of toxicity is Hg2+ > Co2+ > Cd2+ > Zn2+ > Fe2+ > Ni2+. The herbicides Cotrazine (Atrazine 80W) and Northrin®10EC stimulated dehydrogenase activity of the microbial community at 0.2% and inhibited it at higher concentrations. The median inhibitory concentrations (IC50s) of Cotrazine(Atrazine 80W) and Northrin®10EC were 0.552 ± 0.028 and 0.593 ± 0.051%, respectively. The dehydrogenase activity varied significantly (p < 0.05) with the type and concentrations of metals orpesticides. The result indicates that the heavy metals and pesticides are potentially toxic to V. unquiculata root surface microorganisms. In soil, this toxicity may affect nitrogen fixation processes and by extrapolation affect crop yield

Incidence and pattern of injuries among residents of a rural area in South-Western Nigeria: a community-based study

<p>Abstract</p> <p>Background</p> <p>Despite the high incidence of infectious diseases in developing countries, injuries still contribute significantly to the health burden. There are few reports of rural, community-based injury surveys in Nigeria. This study describes the incidence and pattern of injuries among the residents of a rural area in South-Western Nigeria.</p> <p>Methods</p> <p>It was a community based cross-sectional study. Two of six census areas were randomly selected and all households in the two areas visited. Information on the sociodemographic characteristics, individual injury events and outcomes was obtained with a questionnaire. Data were analyzed using SPSS version 11.</p> <p>Results</p> <p>Information was obtained on the 1,766 persons in 395 households. Fifty-nine injuries were recorded by 54 people, giving an injury incidence of 100 per 1,000 per year (95% CI = 91.4–106.9). Injury incidence among <30 years was 81.6 per 1,000 per year (95% CI = 62.3–83.1); and 126 per 1,000 per year (95% CI = 98.2–137.4) for those ≥ 30 years (p = 0.013). Injury incidence for females was 46 per 1,000 per year; and 159 per 1,000 per year (p = 0.000) for males. A significantly higher proportion of males (5%) sustained injury compared to females (2%) (p = 0.043). Falls and traffic injures, 15 (25%) each, were the leading causes of injury; followed by cuts/stabs 12 (21%), and blunt injuries, 9 (15%). Traffic injuries were the leading cause of injuries in all age groups except among the 5–14 years where falls were the leading cause of injury. In thirty-four (58%) of those injuries, treatment was at a hospital/health centre; while in two (3%), treatment was by untrained traditional practitioners. Thirty-nine (66%) of the injuries were fully recovered from, and 19 (32%) resulted in disability. There were 2 fatalities in the 5-year period, one (2%) within the study period.</p> <p>Conclusion</p> <p>Injuries were common in Igbo-Ora, though resultant disability and fatality were low. Males and those aged ≥ 30 years had significantly higher proportions of the injured. Falls and traffic injuries were the most commonly reported injuries. Appropriate interventions to reduce the occurrences of injuries should be instituted by the local authorities. There is also need to educate the community members on how to prevent injuries.</p

Predictors of Antibiotics Co-prescription with Antimalarials for Patients Presenting with Fever in Rural Tanzania.

Successful implementation of malaria treatment policy depends on the prescription practices for patients with malaria. This paper describes prescription patterns and assesses factors associated with co-prescription of antibiotics and artemether-lumefantrine (AL) for patients presenting with fever in rural Tanzania. From June 2009 to September 2011, a cohort event monitoring program was conducted among all patients treated at 8 selected health facilities in Ifakara and Rufiji Health and Demographic Surveillance System (HDSS).It included all patients presenting with fever and prescribed with AL. Logistic regression was used to model the predictors on the outcome variable which is co-prescription of AL and antibiotics on a single clinical visit. A cohort of 11,648 was recruited and followed up with 92% presenting with fever. Presumptive treatment was used in 56% of patients treated with AL. On average 2.4 (1 -- 7) drugs was prescribed per encounter, indicating co-prescription of AL with other drugs. Children under five had higher odds of AL and antibiotics co-prescription (OR = 0.63, 95% CI: 0.46 -- 0.85) than those aged more than five years. Patients testing negative had higher odds (OR = 2.22, 95%CI: 1.65 -- 2.97) of AL and antibiotics co-prescription. Patients receiving treatment from dispensaries had higher odds (OR = 1.45, 95% CI: 0.84 -- 2.30) of AL and antibiotics co-prescription than those from served in health centres even though the deference was not statistically significant. Regardless the fact that Malaria is declining but due to lack of laboratories and mRDT in most health facilities in the rural areas, clinicians are still treating malaria presumptively. This leads them to prescribe more drugs to treat all possibilities