EFFECTS OF MOISTURE CONTENTS AND TEMPERATURE ON THE THERMAL PROPERTIES OF SOME NERICA VARIETIES RELEVANT TO ITS PROCESSING

The thermal properties of NERICA (New Rice for Africa) was investigated on differing moisture content levels and temperatures. The NERICA varieties studied includes; FARO 44, FARO 52, FARO 57, FARO 60 and FARO 61. The variety samples were later categorized into two; NERICA Raw-Paddy and NERICA Parboiled-Milled samples. The thermal properties studied were; thermal conductivity, specific heat, and thermal diffusivity. The thermal conductivity and the specific heat were determined using the thermal conductivity probe method and a digital scanning calorimeter, respectively. The thermal diffusivity was determined from the obtained results of the specific heat and the thermal conductivity. Results indicated that, increase in moisture content and temperature results to increase in the specific heat, thermal conductivity and thermal diffusivity of NERICA varieties and these ranged from 4.245 to 39.976 kJ/kgoC; 0.042 to 1.403 W/moC; and 1.236 x 10-5 to 5.933 x 10-5 m2/s respectively for NERICA Raw-Paddy and 7.033 to 81.657 kJ/kgoC; 0.067 to 1.876 W/moC; and 1.413 x 10-5 to 5.219 x 10-5 m2/s respectively for NERICA Parboiled-Milled. Bulk density decreased with an increase in moisture contents and temperature and the obtained results ranged from 760.3 to 698.7 kg/m3 for NERICA Raw-Paddy and 720.4 to 652.4 kg/m3 for NERICA Parboiled. Regression analysis were carried out on the thermal properties of NERICA varieties and moisture content, and there was positive correlation between the parameters. There were significant effects of moisture content (p < 0.05) on all the parameters studied

CONCENTRATION OF HEAVY METALS IN THE SOIL AND PLANTS AROUND WASTE DUMPSITES IN ENUGU METROPOLIS, NIGERIA

Aims: The purpose of this project is to find the concentration of heavy metals in the topsoil and the plant around the waste dumpsite from Enugu municipal solid disposal sites. Methodology and Results: There was a collection of soil samples from four designated public municipal solid waste dumpsites in Enugu metropolis. The soil samples were collected at 10m intervals from the centre location point of each dumpsite at a constant depth. The sample collection design include centre (0 m) of the dumpsites, 10, 20, and 30m. However, the control sample was 65m away from the centre of dumpsites at the same depth. Plant samples were taken just at the centre (0m), and control measures were at 65m distance away from each dumpsite. The Goat grasses harvested were taken to the lab to determine and analyse heavy metals intake from the soil. These samples were analysed using atomic absorption spectrophotometer (AA320N) model. On the average, high concentrations of Zn, Fe, Mn, Cu, and Pb found in the soil samples collected at the centre of the dumpsites were 141.70, 121.5, 75.53, 70.33 and 64.53 mg/kg respectively. The results were statistically analysed and had significant effects between the samples (p < 0.05). Conclusion, significance, and impact study: The heavy metals studied were within the acceptable or permissible limit by WHO and FAO. However, the plant intake of zinc at Presidential that was beyond the maximum permissible level of 163.45 mg/kg Zn compared with FAO and WHO standard of 50 mg/kg

Determination of toxic elements, rare earth elements and radionuclides in coal fly ash, products and waste

Philosophiae Doctor - PhDCoal fly ash has been studied extensively to understand the environmental impacts associated with its disposal, management and reuse. Although several beneficiation processes have been proposed, there has been little or no emphasis on the environmental safety of such processes, products and wastes. Elemental analysis has revealed that toxic elements and radionuclides are present in coal fly ash. Rare earth elements (REE) such as La, Ce and Y are also present in significant amounts in coal fly ash. The aims of this study were to determine the total elemental composition of coal fly ash using different analytical techniques; to validate the application potentials of fly ash beneficiation processes in terms of their environmental safety; and to valorise coal fly ash with a view of recovering REE either by concentrating or leaching the REE in the coal fly ash, products or waste from the beneficiation processes. The beneficiation processes studied were treatment of acid mine drainage (AMD) with fly ash; and the synthesis of geopolymer from fly ash. The fresh fly ash sample used in this study was collected directly from the hoppers at Matla power station and the AMD sample was collected from Carletonville goldmine. A total of 54 major, trace and REE were accurately determined in the ash using different analytical techniques. It was shown that the elemental content of Matla fly ash was of the same order as the SRM NIST coal fly ash 1633b. The comparative study of the four analytical techniques established that ENAA can accurately determine the major, minor and trace elements; that XRF is best suited for the determination of the major and minor elements, whilst the LA ICP-MS is reliable for trace elements determination. The solid residue (AMD/FA) resulting from the AMD interaction with fly ash was characterized with fly ash and the results compared. The results revealed that the amounts of La (141.09 ± 3.85 mg/kg), Ce (27.45 ± 2.04 mg/kg), and Nd (63.73 ± 0.05 mg/kg) in AMD/FA residue was considerably higher than their average abundance in the earth crust that varies from 66 mg/kg in Ce and 40 mg/kg in Nd to 35 mg/kg in La. The results also showed that the AMD/FA residue contained As (11.39 ± 1.21 mg/kg), Cd (3.77 ± 0.02 mg/kg), Cr (72.43 ± 1.27 mg/kg), Hg (10.50 ± 0.85 mg/kg), Ni (124.15 ± 1.6 mg/kg) and Pb (22.46 ± 1.43 mg/kg) which are potentially harmful if leached in to the environment in excessive amounts

Chemical, physical and morphological changes in weathered coal fly ash : a case study of brine impacted wet ash dump

>Magister Scientiae - MScFly ash is the major waste material produced by power plants in the combustion of coal to generate electricity. The main constituents of fly ash are Si, Al, Fe and Ca with smaller amount of S, Mn, Na, K, and traces of many other elements such as Co, Cd, As, Se, Zn, Mo, Pb, B, Cu and Ni. Fly ash is usually disposed either by dry or wet disposal methods. These disposal methods have raised major environmental concerns due to the potential leaching of chemical species from the ash heap by ingress of rainfall and brine used to transport the fly ash to the dam. This study focuses on the changes in chemical composition, morphology and mineral phases due to weathering, of coal fly ash co-disposed with brine over 20 years at Sasol Secunda ash dump in Mpumalanga Province, South Africa. The design and operation of the Secunda ash dump presupposes that the ash dump may act as a sink for the salts which originated from chemicals used for normal operation in the plants. The majority of these salts come from the brines generated during desalination and raw water regeneration. The aim of this study is to ascertain if the ash dump could serve as a sustainable salt sink.Samples were drawn along the depth of two drilled cores (S1 and S3) from the weathered Secunda ash dump and analysed in conjunction with the fresh (unweathered) Secunda fly ash taken from the fly ash hoppers for comparative analysis. Scanning electron microscopy (SEM), X-ray diffractive (XRD) and X-ray fluorescence (XRF) spectrometry were employed to obtain a detailed morphological, mineralogical and bulk chemical composition of all the samples. Pore water analysis was used to determine the pH, EC and moisture content of fly ash samples. A five step sequential chemical extraction procedure was used to establish the geochemical association of particular elements with various mineral phases. The total acid digestion test was also used to determine the total elemental compositions of the Secunda fly ash samples. The SEM results showed that the fly ashes consist of irregular and numerous spherically shaped particles. Changes (encrustations, etchings and corrosion) in the morphologies of the weathered ash particles were also observed. The XRD results revealed quartz, mullite, lime and calcite as the major mineral phases. Other minerals identified in very minor quantities in the drilled Secunda ash core that were dried prior to analysis were halite, kaolinite, nitratine, bassanite, microline. and hydrophitte. These phases may have formed during sample handling. XRF investigation revealed that the major oxides present in the dumped ash samples were SiO₂, A₂2O₃, CaO, Fe₂O₃, MgO, Na₂O, TiO₂ and the minor elements present were K₂O, P₂O₅, SO₃ and MnO. The sum of the mean values of the % composition of SiO₂, Al₂O₃, and Fe₂O₃ was 70.19 %, and 72.94 % for the two drilled ash core samples (S1 and S3) respectively, and 78.67 % for the fresh ash which shows the significant alteration of the Si, Al and Fe content in the ash matrix over time. The fly ash is classified as Class F using the ASTM C 618 standards. The loss on ignition (LOI) which is an indication of unburned carbon or organic content was 4.78 %, 13.45 % and 8.32 % for the fresh ash, drilled ash cores S1 and S3 respectively. The high LOI values for the drilled ash cores could indicate high hydrocarbon content in the ash dump because of co-disposal practises where hydrocarbon waste are included in the brine stream for disposal on the ash. While the ash samples from the surface appeared dry, moisture content (MC) analysis showed that there is considerable water entrained in the fly ash dump. The fresh ash MC was 1.8 % while core S1 ranged from 41.4 – 73.2 %; core S3 ranged from 21.7 – 76.4 %. The variations in the MC values can be attributed to uneven flow paths due to inconsistent placement conditions or variations in ambient weather conditions during placement. The fresh fly ash (n=3) had a pH of 12.38±0.15, EC value of 4.98±0.03 mS/cm and TDS value of 2.68±0.03 g/L, the pH of the drilled ash core S1 (n=35) was 10.04 ±0.50, the EC value was 1.08±0.14 mS/cm and the TDS value was 0.64 ±0.08 g/L. Core S3 (n=66) had pH of 11.04±0.09; EC was 0.99 ±0.03 and TDS was 0.57 ± 0.01. The changes in pH values can be attributed to the dissolution and flushing out from the dump basic alkaline oxides like CaO and MgO These variations in pH values shows that the fly ash is acidifying over time and metal mobility can be expected under these conditions. The large decrease of EC in the drilled ash cores S1 and S3 compared to the fresh ash indicated a major loss of ionic species over time in the ash dump. The sequential extraction scheme revealed that the elements Al, Si, Ca, Mg, Ba, Sr, Fe, Mn, Na, K, As, Pb, Cr, Mo, Cu, Ni and Zn are present in Secunda fresh and weathered fly ash and are partitioned between the water soluble, exchangeable, carbonate, iron and manganese, and residual fractions of the coal fly ash. It also showed that the trace elements As, Pb, Cr, Mo, Cu, Ni and Zn do not show permanent association with particular mineral phases as a continuous partitioning between different mineral phases was observed in the weathered drilled core. Generally, all the elements had the highest concentration in the residual fraction. But it was evident that the labile phase (water soluble, exchangeable and carbonate fractions) had fairly high concentrations of Si (± 6.5 %), Al (± 6.5 %), Ca (±10 %), Mg (± 5.5 %), Ba (± 7.5 %),Sr (± 7.5 %), Na (± 12 %) and K (± 12 %) for the Secunda drilled ash core (S1 and S3) and fresh fly ash samples. This indicates that these species can leach easily upon water ingress and could pose a danger to the environment. Na and K had the highest concentrations leached out in the labile phase in all the ash samples. The amount of Na leached out of the drilled Secunda ash core in the labile phase was 13.21 % of 18584.26 mg/kg in the five geochemical phases of core S1; and 9.59 % of 11600.17 mg/kg in the five geochemical phases of core S3 while the fresh Secunda fly ash leached out 11.28 % of 16306.30 mg/kg of Na in the five geochemical phases. This study provided significant insight into the pore water chemistry, morphology, mineralogy and chemical composition and the elemental distribution pattern of the major and trace elements in the Secunda fly ash and weathered drilled Secunda ashm core S1 and S3. Though results from XRF analysis and the sequential extraction scheme shows that Na, K, S, Ca and Mg were slightly captured from the co-disposed brine by the Secunda fly ash, these species were however released in the labile phase. Hence there was no significant retention of these species in the ash dump. The amount of these species retained in the weathered ash were (0.26 % and 0.55 %) for Na, (0.02 % and 0.34 %) for K, (0.08 % and 0.06 %) for S, (0.94 % and 0.01 %) for Ca and (0.37 % and 0.96 %) for Mg in drilled ash cores S1 and S3 respectively. This poor retention of Na K, S, Ca and Mg which are major components of Sasol Secunda brine in the drilled ash cores S1 and S3 clearly shows the unsustainability of the Secunda fly ash dump as a salt sink

Responsible Consumption Behaviour: A Framework for Acquisition, Use & Disposal of Computers

Green IT has been identified as a contributing factor in maintaining a green environment. However, past studies have focused mainly on Green IT practised by IT vendors or organizations rather than by individual consumers. Malaysia is a developing nation with high computer penetration. Almost every citizen is owns several computers, from desktops, tablet PCs, laptops, notebooks to smartphones. This contributes to unsustainable computer production, consumption, and disposal patterns. Greenhouse gas (GHG) emission resulting from computer life cycles can be reduced if individuals acquire, use, and dispose computers in a responsible manner. Hence, this study investigates the antecedents of individuals’ responsible consumption behaviour. A research framework was developed through integrating several theories, i.e. Theory of Planned Behaviour, Value-Belief-Norm, and Theory of Interpersonal Behaviour. This study contributes to existing knowledge in the fields of information systems, consumer research, and sustainability, through the development of a theoretical framework that identifies the key factors that influence responsible consumption behaviour. The findings will enable policy makers to design programmes that could influence behavioural change and stimulate responsible consumption behavior, in order to prevent further degradation of the natural environment

Determination of the rheological characteristics of some varieties of new rice for Africa (NERICA) relevant to its processing

The pasting properties of some NERICA (New Rice for Africa) varieties were determined using the rapid visco-analytical machine (RVA). The studied varieties include FARO 44, FARO 52, FARO 57, FARO 60, and FARO 61. The parameters assessed include the pasting temperature, peak time, peak or maximum viscosity, hot paste viscosity or trough, cold paste or final viscosity, breakdown, and setback. Results obtained indicated that the pasting characteristics of NERICA varieties studied exhibited good pasting behavior. Results showed that peak viscosity, final viscosity, hot paste viscosity, breakdown, and setback ranged from 30.83 to 85.17 RVU; 62.21 to 167.13 RVU; 25.83 to 76.88 RVU; and 5.01 to 8.29 RVU; and 31.38 to 81.96 RVU, respectively. There were significant effects of moisture content and temperature (p < 0.05) on all parameters studied. These generated results of the pasting characteristics of NERICA will be extremely useful in determining their suitability in food and other relevant industries

A Review of Traditional Methods of Conflict Resolution from a Nigerian-African-Perspective

Westernisation and globalization have almost eroded this culture and left in their trail an alien culture of conflict resolution which, in most cases, is at variance with our African ethics and cultural values. The replacement of our grand African methods of conflict resolution with the European methods of conflict resolution has particularly done harm rather than good to our group cohesion as one Nigeria, and generally to our group cohesion as Africans. There is doubtless the fact that an alien culture of conflict resolution on an African soil necessarily undermines our history as one black people, our philosophy as a communal entity and our belief that peace and unity of the collective supersedes the selfish interests of a select few who seek to benefit from conflict. Our history of ethnic clashes, insurgencies and the rise of crime in our African societies attest to the fact that in matters of conflict resolution, Nigerians and indeed Africans have employed the wrong methods, bereft of our African spirit of unity and peace in preference to unrests, upheavals and wars. It is against this backdrop that this paper explored our traditional methods of conflict resolution and made recommendations. In doing this, the paper looked at what conflict is, causes of conflict in Africa, principles of conflict resolution, methods of conflict resolution by the major ethnic nationalities in Nigeria, the use of proverbs rhetoric and folklores in conflict resolution and common methods of conflict resolution in Africa. The paper concluded the discourse with a summary and made some recommendations on the way forward

Improving Surgical Skills of OBGYN Residents through Partnership with Rural Hospitals: Experience from Southeast Nigeria

Background: surgical burden of disease is enormous in sub-Saharan Africa where conditions amenable to surgery also contribute to high maternal mortality ratio in the region. Training of specialists in Obstetrics and Gynaecology must include acquisition of requisite surgical skills. Aim: To evaluate the impact of clinical rotations at rural hospitals on the clinical knowledge, and surgical and administrative skills of residents in Obstetrics and Gynaecology. Subjects and Methods: This was a cross-sectional study using mixed methods involving resident doctors in Obstetrics and Gynaecology at the Federal Teaching Hospital, Abakaliki, Nigeria who had undergone rural postings. Information was obtained from consented residents (June 2013 to February 2015) using a questionnaire and focused group discussion. Data was analyzed using Epi info (CDC, Atlanta USA). Results: Thirty-four questionnaires (89.5%) were analyzed; 70.6% were junior residents. Junior residents had a 900% and 460% rise in the rates of emergency and elective caesarean sections they performed, and had similar increases with regard to gynaecological procedures. Senior residents had a 100% and 80% rise in performance of total abdominal hysterectomy and myomectomy respectively. Seventy-five percent of all the residents believed that their surgical skills improved tremendously while 87.5% of the senior residents believed their administrative skills greatly improved also. Conclusion: Residents in Obstertics and Gynaecology at the Federal Teaching Hospital Abakaliki believed that supervised clinical rotations in rural hospitals offered them an opportunity to improve on their clinical knowledge and surgical skills. We advocate an objective assessment of the skills and knowledge of the residents against the claimed subjective improvement.Keywords: Clinical and surgical skills, Rural posting, Resident

Effect of post-infection vaccination on immune status of Newcastle disease-infected chicken

This study investigated the response of chicks infected with velogenic Newcastle disease virus (NDV) to Newcastle disease vaccine - NDV-I2. A total of 90 day-old cockerel chicks were used for this study. At three weeks of age, the chicks were randomly separated intotwo equal groups of 45 chicks designated A and B. After separation, Group A chicks were vaccinated with NDV-I2 vaccine intraocularly, while Group B chicks were not vaccinated. At six weeks of age, Groups A and B chicks were further randomly separated into sub groups A1, A2, A3 and B1, B2, B3 of 15 chicks each respectively. After separation, chicks in subgroups A2, A3, B2, and B3 were exposed to chicks infected with NDV. Upon manifestation of clinical infections, chicks in subgroups A2 and B2 were revaccinated with NDV-I2 vaccine, while subgroups A3 and B3 were not vaccinated. Percentage morbidity was 42.86, 64.29, 100 and 92.86 % for subgroups A2, A3, B2 and B3 respectively, while percentage mortality was 14.29, 50, 100 and 71.43 % in subgroups A2, A3, B2 and B3 respectively. This study showed that vaccination of previously vaccinated chicks during Newcastle disease outbreak protects the chicks and reduces both morbidity and mortality significantly. Keywords: Cockerels, Newcastle disease, Vaccination, Revaccination, Geometric mean titre, Morbidity, Mortalit