Emissions Characterization and Particle Size Distribution from a DPF-Equipped Diesel Truck Fueled with Biodiesel Blends

Biodiesel may be derived from either plant or animal sources, and is usually employed as a compression ignition fuel in a blend with petroleum diesel (PD). Emissions differences between vehicles operated on biodiesel blends and PD have been published previously, but data do not cover the latest engine technologies. Prior studies have shown that biodiesel offers advantages in reducing particulate matter, with either no advantage or a slight disadvantage for oxides of nitrogen emissions. Literature also suggests that diesel engine exhaust particle number emissions are dominated by nucleation mode particles (NMPs) if present, while the mass emissions are dominated by accumulation mode particles (AMPs). This thesis describes a recent study on the emissions impact and exhaust particles size distribution and composition, under steady state condition, of a 2007 medium heavy duty diesel truck (MHDDT) fueled with two biodiesel blends, B20A and B20B, and PD. The truck was tested in a chassis dynamometer laboratory using three steady state driving cycles. The cycles include vehicle run at 20 mph for 30 minutes (MD1), 32 mph for 30 minutes (MD2) and 50 mph for 20 minutes (MD3). Emissions were measured using a full exhaust dilution tunnel equipped with a subsonic venturi and secondary dilution for PM sampling. A fast particle spectrometer (DMS 500) was used to measure the particle number concentration and size distribution from the vehicle exhaust.;The study showed that emissions were more speed dependent than fuel type. For any given cycle, the differences in CO2 and NOx tailpipe emissions produced by the PD, B20A and B20B were statistically insignificant with variations of between 0.5-1.4%, and 0.5-3.4%, respectively at 95% confidence level. The results further showed that, for MD2, CO2 emissions produced were lowest with corresponding highest fuel economy (miles per gallon (mpg) of fuel consumed). The NOx emissions produced for B20A and B20B were slightly higher than those of PD, except for MD2. Generally, low particulate matter (PM) emissions were produced from the test results due to the truck diesel particulate filter (DPF). The carbon monoxide (CO) and hydrocarbon (HC) emissions were also low, with HC being difficult to quantify as a result of oxidation in the DPF.;Analysis of the exhaust particle data showed that, for all of the driving modes, the exhaust particles existed in two distinct modes with the particle number concentration dominated by the NMPs for all three test fuels. The particle mass concentration, dominated by the AMPs, substantially correlated with the pattern observed in the gravimetric PM mass emissions measurement. It was observed that factors such as DPF loading, dilution conditions (temperature, humidity) that are not fuel related strongly affected particle size formation especially in the NMP range. It was also observed that the total exhaust particle number concentration and the geometric mean diameter (GMD) increased with propulsion power. However, the GMD values were typically in the range of 25-40 nm for all driving modes and fuel type combinations. This is further confirmation that exhaust particles were dominated by nanoparticles that have been reported to cause respiratory diseases and other health effects in humans

University Education and the Challenges of Development in African Society

The importance of education can never be under-played in any society as it is the most potent weapon left to man in order to transform, change and liberate himself and the society from the slavery of ignorance and backwardness. This is done in order to attain rapid development in all ramifications. The epistemic foundation for the establishment of higher institutions (universities) has been devoted to the production of knowledge and cultural reproduction through the ages. It should be known from the outset that universities are moulded on the foundation and systemic structure of the Western ideologies. But there are salient barriers towards the pursuit of higher education in Africa, which are multi-faceted and multi-dimensional. The thrust of this paper, then, will be to examine the challenges higher education has in Africa, which hinders its process of producing a body of knowledge that will elevate the human conditions and posit it for all-round development. Therefore, the methodology shall be purely analytic in nature

Educational building conditions and the health of users

In order to maintain a healthy learning environment, diagnosis and management of defects in the educational facility are paramount. The preliminary results of the ongoing research reported here seek to identify defects associated with educational buildings and their effects on the health of polytechnic students and staff in Nigeria. A questionnaire survey, including 34 defects based on a post-occupancy evaluation (POE) was used to establish relationships with the health of polytechnic students and staff. Two hundred (200) respondents were randomly selected based on their schools (faculty) within Lagos State Polytechnic. Descriptive and inferential statistics were used for analysis of the collected data. The results of the study indicate that defects such as plumbing and dampness problems, cobwebs and dust, are prominent in the institution. Also the relationship between building conditions (defects) and health problems was established, with the predictors of the health problems. Based on the findings, it is important for designers and managers of facilities within tertiary institutions to develop and implement design and maintenance policies targeted at minimizing the likelihood of plumbing, dampness, electrical, cobweb and dust problems in educational buildings due to the health risks induced by the defects. It is evident that effective maintenance schedules and policies should be put in place to ensure that facilities are not left to decay before replacement

A case of acute megakaryoblastic leukaemia (FAB M7), a rare type of acute myeloid leukemia (AML), in a teenager

Acute Megakaryoblastic Leukaemia (AML, M7) is a rare type of acute myeloid leukemia (AML) evolving from primitive megakaryoblasts. It accounted for 1.2% of newly diagnosed AML according to Eastern Cooperative Oncology Group (ECOG) trials between 1984 and 1997. Patients may present with a broad variety of symptoms including low-grade fever, easy bruising, and life-threatening conditions. We report a rare case of AML, M7 in a 19-year-old lady who presented with weakness and fatigue. She was diagnosed as a case of AML, M7 on the basis of peripheral blood finding, bone marrow examination report, radiological findings and immunophenotyping

Evaluation of CD4+ T Cells in HIV Patients Presenting with Malaria at the University of Ilorin Teaching Hospital Nigeria

CD4 count is an important immunological marker of disease progression in HIV seropositive patients. This study was carried out to determine the effect of malaria or fever of unknown origin on the population of CD4+ T lymphocytes of HIV seropositive patients attending the highly active antiretroviral therapy (HAART) clinic of the University of Ilorin Teaching Hospital, Ilorin, Nigeria. 36 subjects were selected for this study. Ongoing history of fever was used as a case definition for malaria and malaria was confirmed from microscopic examination of thick and thin film of blood sample obtained from the patients during presentation with fever. The CD4 count was evaluated during presentation of fever and post-fever using flow cytometry. There was significant decrease in CD4 count of the patients. However, upon classifying the patients into 2 groups - those that returned to the clinic after a week and those that returned after a month - a significant increase in CD4 count was noticed in the group that returned after a week, while a significant decrease was noticed in the group that returned after a month (at p value of 95%). Further classification of the patients based on presence of malaria parasite, and body temperature resulted in varying effects on CD4 count post-fever (in the general group, 27 were positive for malaria parasites. Of these 27, there was an increase in CD4 count in 9 (33.3%). However in the group that returned after a week, all 6 (100%) that were positive for malaria parasites showed increase in CD4 count. Five (26.3%) of the 19 patients that had body temperature within the range of 35.5-37.4^o^C showed an increase in CD4 count, while 7 (41.2%) the 17 patients that had body temperature of 37.5^o^C and above showed an increase in CD4 count. The results led to the conclusion that while some components of the immune response to malaria could strengthen the immune system of HIV seropositive patients by increasing their CD4 count, other components will suppress their immunity by decreasing their CD4 count, accelerating the progression to AIDS

OPTICAL PROPERTIES OF GALLIUM PHOSPHIDE (GaP)

Optical properties of Gallium Phosphide (GaP) have been investigated by means of Kramers Kronig method. Optical properties such as refractive index, extinction coefficient, dielectric constant, transmittance, absorption coefficient, reflectance, reflection coefficient and optical conductivity are presented in the energy range 1.03 «¤?? 6.01eV. The calculated optical properties of GaP indicate promising device applications such as the design of optoelectronic devices, electronic and photonic devices

Spatial Variability of Soil Morphorlogical and Physico-Chemical Properties in Ladoke Akintola University of Technology Cashew Plantation, Ogbomoso.

To study the spatial variability of soil morphological, physical and chemical properties in the Cashew plantation of Ladoke Akintola University of Technology, Ogbomoso, Oyo State of Nigeria eight profile pits were dug, described and examined. The result of the analysis and the variability grouping put colour value in AP and B1 as least variable. Stoniness (AP) and structure (AP and B1) were moderately variable properties. Colour (AP, B1 B2 and B3), structure (B2 and B3), stoniness (B1, B2 and B3), concretion (AP B1, B2 and B3) and boundary forms (B1, B2 and B3) have extremely variable properties. pH (H2O and KCl), Na+ base saturation were least to variable. Fe2+, cu 2+, Mg2+, k+, CEC, Ex. Acidity, extractable Mn2+ , organic carbon (g/kg), organic matter (g/kg), and available phosphorus were extremely variable soil properties.The available moisture of soil was very low thus water holding capacity (WHC) and wilting point (WP) of the soil was very low. .The gravel content of the land was high at the surface and reduced down the slope... Bulk density parameter of the land was very high at the surface. The land was very low in plant nutrients, this result show that the soil of the cashew plantation is highly variable and that management techniques that would be flexible enough to carter for the variation noticed should be adopted, such as organic fertilizer application

Determination of selected heavy metals in inland fresh water of lower River Niger drainage in North Central Nigeria

The concentrations of some ferruginous ore associated heavy metals were determined in freshwater from River Niger. Water samples were collected from both upstream and downstream along the mainstream drainage channel, traversing past the steel production industry Ajaokuta between 2003 and 2005. The water samples were digested according to standard methods and tested for Cadmium (Cd), Manganese (Mn), Chromium (Cr), Nickel (Ni), Cupper (Cu), Zinc (Zn) and Lead (Pb) using Unicam 969atomic absorption spectrophotometer. The mean concentrations (mg/L) of heavy metals were: Mn, 3.85 ± 0.93; Zn, 2.72 ± 0.57; Cu, 2.17 ± 0.73; Cr, 2.08 ± 1.27; Ni, 0.78 ± 0.12; Cd, 0.05 ± 0.02; Pb, 0.03 ± 0.02. Theconcentration of Mn, 1.74 to 8.37 mg/L; Cu, 0.58 to 4.50 mg/L; Cd, 0.02 to 0.13 mg/L were variable and inundating. The variations in heavy metal levels between sampling stations were not significant (P >0.05) with relative standard deviation from 2% for Cd and Pb to 12.7% for Cr. The order of dispersion (2 to 14%) showed that the measured metals are nearly homogenously distributed in the water with Cr, Mn, Cu and Zn having the highest concentration variations in the water samples. The concentrations of the evaluated heavy metals were within the guideline levels for freshwaters, and did not appear to have significant negative impact on the water quality.Key words: Heavy metals, freshwater, concentrations, quality, variation, distribution

Theoretical Modelling Of Thermal-Hoop Stress Around The Tooth Of A Spur Gear In A Filler Machine

The study employed the finite element method to develop a validated theoretical model to investigate the distribution of thermal hoop stress around the teeth of a spur gear operating in a filler machine. Three cases of temperature distribution along the radius of a gear tooth were assumed and investigated. The outcome showed that the maximum effective stress occurs at the tip of the gear tooth and decreased circumferentially deep into the gear material. The results also demonstrated that a nonlinear distribution of the temperature around the gear teeth makes the gear material susceptible to penetrating stress and therefore increase the tendency of fatigue failure

Cassava Waste Management and Biogas Generation Potential in Selected Local Government Areas in Ogun State, Nigeria

Agricultural products such as cassava produce huge amounts of waste when processed into consumable goods. The waste generated is generally considered to contribute largely to environmental pollution. This study therefore investigates the waste management practice that is adopted by cassava processors in Ogun State, Nigeria. Five local government areas (LGAs) dominant in processing cassava were selected for the study on the basis of spatial location distribution, landmass, and population. The survey involved the use of structured questionnaires administered to cassava processors of the selected LGAs. The Statistical Package for Social Sciences (SPSS) software application and descriptive statistics were used for data analysis. Results of the analysis show that the majority (70%) of the cassava processors are females. Cassava peel constitutes 10% of the waste produced, of which 91% is heaped at refuse dumps in most communities. Results also reveal that 86.3% of cassava residues are used for animal feeds. Other findings show that the peels, when dried, are used as biofuel for cooking and there is a significant potential for biogas production. From the data captured from respondents during the study, most processors are willing to pay for an improved waste management system. The study therefore recommends the proper waste management of cassava waste to minimize environmental pollution