106 research outputs found

    Effect of pepper and salt blends on microbial quality of quanta: Ethiopian dried red meat

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    This study was conducted to assess the effect of spice blends varying in salt and pepper concentrations on the microbial quality of Quanta: Ethiopian dried red meat. The experiment had seven treatments: 25% spices, 25% salt, and 50% pepper (T1); 25% spices, 20% salt, and 55% pepper (T2); 25% spices, 15% salt, and 60% pepper (T3); 25% spices, 10% salt, and 65% pepper (T4); 25% spices, 5% salt, and 70% pepper (T5); 100% spices (without salt and pepper), a positive control (T6); a negative control without any added ingredient (T7). Microbiological analyses were performed initially on the raw sliced meat and spice blends, and after application of the treatments on the 10th and 20th days of drying. High initial loads of total bacteria (APC) and Enterobacteriaceae (EC) were observed in the raw meat samples and spice blends and increased over the drying periods (10 and 20 days) in all treatments. No significant difference (p>0.05) was observed among the treatments (T1-T7) for APC and EC at a given drying period and between the drying periods. Salmonella spp. was not detected in any of the seven treatments either on the 10th and 20th days of drying. However, Escherichia coli was detected in six (T1-T6) of the dry meat samples except in T7 both on the 10th and 20th days of drying suggesting that the spice blends served as a source of contamination of the dried meat samples with E. coli. However, the spice blends used in combination with drying were effective in inhibiting the growth of Salmonella species in the dry meat samples. Spices as well as the raw meat used for Quanta preparation should be produced and handled under hygienic conditions to minimize the microorganisms that they harbor

    Experimental Evaluation of Conservation Agriculture with Drip Irrigation for Water Productivity in Sub-Saharan Africa

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    A field-scale experimental study was conducted in Sub-Saharan Africa (Ethiopia and Ghana) to examine the effects of conservation agriculture (CA) with drip irrigation system on water productivity in vegetable home gardens. CA here refers to minimum soil disturbance (no-till), year-round organic mulch cover, and diverse cropping in the rotation. A total of 28 farmers (13 farmers in Ethiopia and 15 farmers in Ghana) participated in this experiment. The experimental setup was a paired ‘t’ design on a 100 m2 plot; where half of the plot was assigned to CA and the other half to conventional tillage (CT), both under drip irrigation system. Irrigation water use and crop yield were monitored for three seasons in Ethiopia and one season in Ghana for vegetable production including garlic, onion, cabbage, tomato, and sweet potato. Irrigation water use was substantially lower under CA, 18% to 45.6%, with a substantial increase in crop yields, 9% to about two-fold, when compared with CT practice for the various vegetables. Crop yields and irrigation water uses were combined into one metric, water productivity, for the statistical analysis on the effect of CA with drip irrigation system. One-tailed paired ‘t’ test statistical analysis was used to examine if the mean water productivity in CA is higher than that of CT. Water productivity was found to be significantly improved (α = 0.05) under the CA practice; 100%, 120%, 222%, 33%, and 49% for garlic, onion, tomato, cabbage, and sweet potato respectively. This could be due to the improvement of soil quality and structure due to CA practice, adding nutrients to the soil and sticking soil particles together (increase soil aggregates). Irrigation water productivity for tomato under CA (5.17 kg m−3 in CA as compared to 1.61 kg m−3 in CT) is found to be highest when compared to water productivity for the other vegetables. The mulch cover provided protection for the tomatoes from direct contact with the soil and minimized the chances of soil-borne diseases. Adapting to CA practices with drip irrigation in vegetable home gardens is, therefore, a feasible strategy to improve water use efficiency, and to intensify crop yield, which directly contributes towards the sustainability of livelihoods of smallholder farmers in the region

    Scaling-up Conservation Agriculture Production System (CAPS) with Drip Irrigation by Integrating MCE Technique and the APEX Model

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    The conservation agriculture production system (CAPS) approach with drip irrigation has proven to have the potential to improve water management and food production in Ethiopia. A method of scaling-up crop yield under CAPS with drip irrigation is developed by integrating a biophysical model: APEX (agricultural policy environmental eXtender), and a Geographic Information System (GIS)-based multi-criteria evaluation (MCE) technique. Topography, land use, proximity to road networks, and population density were considered in identifying potentially irrigable land. Weather and soil texture data were used to delineate unique climate zones with similar soil properties for crop yield simulation using well-calibrated crop model parameters. Crops water demand for the cropping periods was used to determine groundwater potential for irrigation. The calibrated APEX crop model was then used to predict crop yield across the different climatic and soil zones. The MCE technique identified about 18.7 Mha of land (16.7% of the total landmass) as irrigable land in Ethiopia. Oromia has the highest irrigable land in the nation (35.4% of the irrigable land) when compared to other regional states. Groundwater could supply a significant amount of the irrigable land for dry season production under CAPS with drip irrigation for the various vegetables tested at the experimental sites with about 2.3 Mha, 3.5 Mha, 1.6 Mha, and 1.4 Mha of the irrigable land available to produce garlic, onion, cabbage, and tomato, respectively. When comparing regional states, Oromia had the highest groundwater potential (40.9% of total potential) followed by Amhara (20%) and Southern Nations, Nationalities, and Peoples (16%). CAPS with drip irrigation significantly increased groundwater potential for irrigation when compared to CTPS (conventional tillage production system) with traditional irrigation practice (i.e., 0.6 Mha under CTPS versus 2.2 Mha under CAPS on average). Similarly, CAPS with drip irrigation depicted significant improvement in crop productivity when compared to CTPS. APEX simulation of the average fresh vegetable yield on the irrigable land under CAPS with drip irrigation ranged from 1.8–2.8 t/ha, 1.4–2.2 t/ha, 5.5–15.7 t/ha, and 8.3–12.9 t/ha for garlic, onion, tomato, and cabbage, respectively. CAPS with drip irrigation technology could improve groundwater potential for irrigation up to five folds and intensify crop productivity by up to three to four folds across the nation

    Evaluation of CFSR, TMPA 3B42 and ground-based rainfall data as input for hydrological models, in data-scarce regions: The upper Blue Nile Basin, Ethiopia

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    Accurate prediction of hydrological models requires accurate spatial and temporal distribution of rainfall. In developing countries, the network of observation stations for rainfall is sparse and unevenly distributed. Satellite-based products have the potential to overcome this shortcoming. The objective of this study is to compare the advantages and the limitation of commonly used high-resolution satellite rainfall products (Climate Forecast System Reanalysis (CFSR) and Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) 3B42 version 7) as input to hydrological models as compared to sparsely and densely populated network of rain gauges. We used two (semi-distributed) hydrological models that performed well in the Ethiopian highlands: Hydrologiska Byråns Vattenbalansavdelning (HBV) and Parameter Efficient Distributed (PED). The rainfall products were tested in two watersheds: Gilgel Abay with a relatively dense network of rain gauge stations and Main Beles with a relatively scarce network, both are located in the Upper Blue Nile Basin. The results indicated that TMPA 3B42 was not be able to capture the gauged rainfall temporal variation in both watersheds and was not tested further. CFSR over predicted the rainfall pattern slightly. Both the gauged and the CFSR reanalysis data were able to reproduce the streamflow well for both models and both watershed when calibrated separately to the discharge data. Using the calibrated model parameters of gauged rainfall dataset together with the CFSR rainfall, the stream discharge for the Gilgel Abay was reproduced well but the discharge of the Main Beles was captured poorly partly because of the poor accuracy of the gauged rainfall dataset with none of the rainfall stations located inside the watershed. HBV model performed slightly better than the PED model, but the parameter values of the PED could be identified with the features of the landscape

    Study Of Mechanical Alloying Of Sm And Fe

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    Mechanical alloying of Sm and Fe with the composition of SmFe3 was studied using x-ray-diffraction (XRD), Mossbauer, and magnetization measurements. Data taken as a function of milling time for up to 20 h show significant changes occurring during ball milling. The XRD studies show that the initial crystalline Bragg reflections changed to a broad maximum, which is attributed to the formation of an amorphous phase. The initial six-line pattern in the Mossbauer spectrum, characteristic of magnetic ordering, changed to a broad singlet, characteristic of a nonmagnetic material. Magnetization measurements revealed that the coercive field was at its maximum after 5 h of milling and decreased sharply as the milling time increased. The remanent magnetization was at its maximum between 5 and 10 h of milling. The final product of the ball milling, which exhibited the characteristics of an amorphous paramagnetic material in its XRD and Mossbauer spectrum, was studied after heat treatment. The XRD and the Mossbauer spectra of the heat treated alloy show that substantial changes occurred during heat treatment in that sharp Bragg reflections, characteristic of crystalline materials, reappear and the alloy changed from a paramagnetic to a ferromagnetic state. (C) 1997 American Institute of Physics

    Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique

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    Water hyacinth is a well-known invasive weed in lakes across the world and harms the aquatic environment. Since 2011, the weed has invaded Lake Tana substantially posing a challenge to the ecosystem services of the lake. The major factors which affect the growth of the weed are phosphorus, nitrogen, temperature, pH, salinity, and lake depth. Understanding and investigating the hotspot areas is vital to predict the areas for proper planning of interventions. The main objective of this study is therefore to predict the hotspot areas of the water hyacinth over the surface of the lake using the geographical information system (GIS)-based multi-criteria evaluation (MCE) technique. The main parameters used in the multi-criteria analysis were total phosphorus (\u3e0.08 mg L−1), total nitrogen (\u3e1.1 mg L−1), temperature (\u3c26.2 °C), pH (\u3c8.6), salinity (\u3c0.011%), and depth (\u3c6 m). These parameters were collected from 143 sampling sites on the lake in August, December (2016), and March (2017). Fuzzy overlay spatial analysis was used to overlay the different parameters to obtain the final prediction map of water hyacinth infestation areas. The results indicated that 24,969 ha (8.1%), 21,568.7 ha (7.1%), and 24,036 ha (7.9%) of the lake are susceptible to invasion by the water hyacinth in August, December, and March, respectively. At the maximum historical lake level, 30,728.4 ha will be the potential susceptible area for water hyacinth growth and expansion at the end of the rainy season in August. According to the result of this study, the north and northeastern parts of the lake are highly susceptible for invasion. Hence, water hyacinth management and control plans shall mainly focus on the north and northeastern part of Lake Tana and upstream contributing watersheds

    Advances in water resources research in the Upper Blue Nile basin and the way forward: A review

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    The Upper Blue Nile basin is considered as the lifeline for ∼250 million people and contributes ∼50 Gm3/year of water to the Nile River. Poor land management practices in the Ethiopian highlands have caused a significant amount of soil erosion, thereby threatening the productivity of the Ethiopian agricultural system, degrading the health of the aquatic ecosystem, and shortening the life of downstream reservoirs. The Upper Blue Nile basin, because of limited research and availability of data, has been considered as the “great unknown.” In the recent past, however, more research has been published. Nonetheless, there is no state-of-the-art review that presents research achievements, gaps and future directions. Hence, this paper aims to bridge this gap by reviewing the advances in water resources research in the basin while highlighting research needs and future directions. We report that there have been several research projects that try to understand the biogeochemical processes by collecting information on runoff, groundwater recharge, sediment transport, and tracers. Different types of hydrological models have been applied. Most of the earlier research used simple conceptual and statistical approaches for trend analysis and water balance estimations, mainly using rainfall and evapotranspiration data. More recent research has been using advanced semi-physically/physically based distributed hydrological models using high-resolution temporal and spatial data for diverse applications. We identified several research gaps and provided recommendations to address them. While we have witnessed advances in water resources research in the basin, we also foresee opportunities for further advancement. Incorporating the research findings into policy and practice will significantly benefit the development and transformation agenda of the Ethiopian government

    Environmental tracers to evaluate groundwater residence times and water quality risk in shallow unconfined aquifers in sub Saharan Africa

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    In sub-Saharan Africa, shallow aquifer systems are relied on as the main safe and secure water resource available to rural communities. Information on the sustainability and vulnerability of groundwater abstraction is becoming increasingly important as groundwater development increases. As part of the UpGro Consortium Project- Hidden Crisis, 150 hand pumped boreholes (HPBs), ranging between 15 and 101 m depth were investigated to examine the resilience of aquifer systems in the Ethiopian Highlands, and the crystalline basement rocks of Uganda and Malawi. Environmental tracers (chlorofluorocarbons (CFCs), SF6, chloride and the stable isotopes of water), water quality indicators (nitrate and E. coli), and groundwater-level time series data were used to estimate groundwater residence time and recharge at a regional scale (100–10,000 km2) and investigate the risks to water quality and water supply over different timeframes, and geological and climatic environments. Average estimated recharge rates using three different techniques (CFCs, chloride mass balance, water table fluctuation method) were between 30 and 330, 27–110 and 30–170 mm y−1, for sites in Ethiopia, Uganda and Malawi, respectively. These estimates of recharge suggests abstraction from dispersed low-yielding HPBs is sustainable. Comparison of stable isotopes in rainfall and groundwater indicates that there is little evaporation prior to recharge, and recharge events are biased to months with greater rainfall and more intense rainfall events There was a weak correlation between nitrate and CFCs within all three countries, and no correlation between E. coli and CFCs within Ethiopia or Malawi. The presence of E. coli at a large proportion of the sites (Ethiopia = 38%, Uganda = 65% and Malawi = 47%) suggests rapid transit of contaminated surface water into the borehole and its presence in groundwater that has CFC-12 concentrations less than 75 pg kg−1 indicates mixing of very young water with water >40 years old. The rapid transit pathways are most likely associated with damaged HPB headworks and poor construction. In several monitored HPBs, daily drawdown due to pumping, drew the groundwater levels close to the base of the HPB, indicating that these HPBs were located in parts of the aquifer with low permeability, or were poorly designed, offering limited capacity for increased demand. Improved HPB siting and construction, coupled with groundwater level monitoring are required to capitalise on the more resilient groundwater within the shallow aquifers and safeguard adequate and good quality water supply for rural communities
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