10 research outputs found
The evaluation of an improved method of monitoring energy consumption used in the heating of industrial buildings
The prospects for various forms of energy continue to engage the thoughts
and pens of many people concerned with our future prosperity. The
vulnerability of forecasts on energy especially those concerned with
oil, to political, military and general economic activity, or lack of
it highlights the importance of energy to practically everything we do. [Continues.
Assessment of the Impacts of Climate Variability on Hydropower Generation
Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at Ī± = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed that the amount of rainfall received during both dry and wet seasons has been decreasing. Positive trend was observed in both average annual maximum and minimum temperature series at Ī± = 0.1 with Z = 1.73 and Ī± = 0.001 with Z= 4.04, respectively and a positive slope for both. Analysis of regime shift at a 5% significant level showed that, rainfall in the New Pangani falls from 1980 to 2014 experienced two decreasing shifts both occurring in the last 15 years of analysis with a percentage of change of more than 10%. This strongly confirms climate variability in the study area. The study shows that hydropower generation depends strongly on the river inflow to the dam (r = 0.98) while changes in temperature do not affect the functioning of the hydropower plant as depicted by the weak linear relationship between temperature, rainfall (r = 0.085) and power generation (r = -0.082). It can be concluded, therefore, that river discharge variability in catchment has an adverse impact on hydropower generation in hydropower plant. 
Heavy metals and cyanide distribution in the villages surrounding Buzwagi gold mine in Tanzania
The study aimed at assessing the levels of heavy metals and cyanide in water and sediments in villages surrounding Buzwagi gold mine, both during wet and dry seasons. Ā A total of 56 samples of water (28 from each season) and 44 samples of sediments (22 from each season) were collected from the wells in the area and were analyzed for total cyanide and heavy metals.Ā The total cyanide was analyzed spectrophotometrically whilst the heavy metals were analyzed by an Inductively Coupled Plasma (ICP). The Pb and Fe levels in water were found to exceed 10 Āµg/L and 2000 Āµg/L respectively, the World Health Organization (WHO) limits for drinking water in some wells. It was therefore concluded that the water is not safe for drinking. The concentrations of cyanide and most of the heavy metals in sediments (except Cd and Hg which were below the detection limit) were higher in the wells closest to the Tailing Storage Facility (TSF) than the wells which are far from the TSF showing that the contamination to the water is due to mining activities. Furthermore concentrations of most of the parameters in sediments were higher in dry than in wet season. It was recommended that the water contamination should be prevented by having a regular inspection of the TSF liner so as to ensure zero discharge and that the alternative source of water should be provided to the mining communities. Key Words: Heavy metals pollution, Total cyanide, ground water pollution and Ā mining.
Isolation and Characterization of Micro-organisms with Industrial Importance From Sisal Bole Rots
Investigation of microorganisms naturally acclimatized to Agave hybrid H 11648 (sisal bole rot) was conducted, with the aim of isolating and characterizing Aspergillus niger strains for industrial use. Microorganism were identified morphologically and then confirmation made by polymerase chain reaction (PCR). Results showed the existence of four major groups, listed in order of abundances as follows; Aspergilli (36.0Ā±0.8) %, Penicillin (28.0Ā±0.1) %, Yeast (15.0Ā±1.6) %and Fusarium (10.0Ā±0.12) %. The main groups of Aspergilli strains were A. nidulans, A. tamari and A. niger in ratios (3:2:2), respectively. Several endo-spore forming non-enteric gram (-) rods and coccid bacteria identified by API20 NE identification systemincluded,Brevundimonas diminuta sp, Shewanella putrefaciens sp, Brevundimonas vesicularis sp and Pasteurella sp. Results showed that sisal bole rot stems hosts a high bio-diversity of microorganism species other than A. niger. Exploitation of the individual strains is recommended. This could eventually produce strains forprecursors of industrially and therapeutically metabolites
Solid Waste Management in Africa: Governance Failure or Development Opportunity?
Waste management is a social, economic, and environmental problem facing all African countries. If the 2030 Agenda for sustainable development is to be achieved, sustainable waste management approaches must be an environmental and public health imperative deserving political priority. Current reasons for the poor management of waste in Africa, include, amongst others, weak organizational structures; lack of appropriate skills; inadequate budgets; weak legislation; lack of enforcement; low public awareness; corruption, conflict; political instability; and lack of political will. At the heart of the problem, is a failure in governance. However, through these gaps, many social and technological innovations have emerged. Innovations that recognize the opportunity that waste provides as a secondary resource. Diverting waste away from dumpsites and landfills towards reuse, recycling and recovery can improve the livelihoods of thousands of informal waste reclaimers, while also creating new jobs and business opportunities for the continent. Reintroducing secondary resources such as polymer, fiber, metals and nutrients back into local value chains has the potential to strengthen manufacturing economies and reduce the economic burden on product imports. Bringing waste under control in Africa and unlocking the opportunities that āwasteā provides as āresourceā will require immediate intervention by government, business and civil society
Greenhouse gas emissions and energy balances of jatropha biodiesel as an alternative fuel in Tanzania
This paper evaluates GHG emissions and energy balances (i.e. net energy value (NEV), net renewable energy value (NREV) and net energy ratio (NER)) of jatropha biodiesel as an alternative fuel in Tanzania by using life cycle assessment (LCA) approach. The functional unit (FU) was defined as 1 tonne (t) of combusted jatropha biodiesel. The findings of the study prove wrong the notion that biofuels are carbon neutral, thus can mitigate climate change. A net GHG equivalent emission of about 848 kg tā1 was observed. The processes which account significantly to GHG emissions are the end use of biodiesel (about 82%) followed by farming of jatropha for about 13%. Sensitivity analysis indicates that replacing diesel with biodiesel in irrigation of jatropha farms decreases the net GHG emissions by 7.7% while avoiding irrigation may reduce net GHG emissions by 12%. About 22.0 GJ of energy is consumed to produce 1 t of biodiesel. Biodiesel conversion found to be a major energy consuming process (about 64.7%) followed by jatropha farming for about 30.4% of total energy. The NEV is 19.2 GJ tā1, indicating significant energy gain of jatropha biodiesel. The NREV is 23.1 GJ tā1 while NER is 2.3; the two values indicate that large amount of fossil energy is used to produce biodiesel. The results of the study are meant to inform stakeholders and policy makers in the bioenergy sector
Steam pretreatment of pine (Pinus patula) wood residue for the production of reducing sugars
The study explores the production of reducing sugars from Pinus patula wood residual chips based on steam pretreatment technology. The severity of the steam pretreatment was altered by using two levels of temperature and time and three levels of sulphur dioxide impregnation. The results show that the efficiency of enzymatic hydrolysis depends on the severity of steam pretreatment. On a given cellulose content, the reducing sugar yield increased from 29% (15.6 g/L) under the mildest steam pretreatment conditions (180 Ā°C, 1.5% SO 2 ) to 91% (42.3 g/L) under the most severe steam pretreatment conditions (225 Ā°C, 3% SO 2 ). In all cases, the enzymatic hydrolysis yield is dependent on enzyme accessibility to the cellulose chains, as the steam pretreatment severity strongly affects biomass fragmentation
Solvent-Free MgO-Functionalized Mesoporous Catalysts for Jatropha Oil Transesterification
A convenient solvent-free technique was employed in the functionalization of Micelle-Templated Silica using Cashew Nut Shell Liquid (MTS-CNSL) as a template and magnesium nitrate as a precursor salt. Magnesium oxide species was highly dispersed in MTS-CNSL by manually grinding the precursor salt and the as-synthesized mesoporous silica followed by calcination. The resultant modified mesoporous silicas MgO/MTS-CNSL were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR, N2 adsorption/desorption), and scanning electron microscopy/energy dispersive X-ray (SEM/EDX). MgO/MTS-CNSL (30) having small specific surface area of 16.7ām2/g and larger pore volume of 0.02ācm3/g, presented higher activity of 81.45% for jatropha oil under optimized conditions (200Ā°C, 4āh, 36 : 1 methanol : oil ratio, 500ārpm, and 6% wt of catalyst). This method of catalyst development has an advantage of being highly energy- and time-efficient