Packer test is one of the commonly applied methods in determination of hydraulic conductivity particularly in low permeability fractured rock mass. Originally, hydraulic conductivity is defined in Lugeon units which correspond to 1 litre per minute per meter of intake section less than 10 atmospheres of pressure. Since the test is applied under different pressures, which gives the opportunity to observe the hydraulic behaviour of the rock under different stresses. Calculations of hydraulic conductivity for each step of pressure usually give different value of hydraulic conductivity. Selection of a representative hydraulic conductivity value therefore becomes an issue. The arithmetic mean is the commonly accepted value, without justifying its representativeness. In this paper, about 75 packer tests conducted at 17 core wells at different depth with 3.5 m long test sections using double packer were evaluated. The tests are conducted at five pressures that run in three increasing and two decreasing pressures according to the recommendation of Houlsby. Hydraulic conductivity was calculated for every pressure step and evaluated to find a representative value using different methods. The representative values found by different methods is then compared. Results indicate that the arithmetic mean has good correlation with all the methods in particular it is nicely correlated with the modified Lugeon analysis for hydrogeological investigations with a correlation value of R 2 =0.91. Therefore, it is concluded that the uncertainty associated with the use of the simple arithmetic mean is within an acceptable range of error. Keywords: Hydrogeology; Lugeon Value; Packer test; Permeability.
{"title":"Use of Packer Test Results in Hydrogeological Characterization: A Comparison of Calculation Methods for a Representative Value","authors":"Fethangest Weldemariyam Tesema, M. Ekmekci","doi":"10.4314/MEJS.V11I1.4","DOIUrl":"https://doi.org/10.4314/MEJS.V11I1.4","url":null,"abstract":"Packer test is one of the commonly applied methods in determination of hydraulic conductivity particularly in low permeability fractured rock mass. Originally, hydraulic conductivity is defined in Lugeon units which correspond to 1 litre per minute per meter of intake section less than 10 atmospheres of pressure. Since the test is applied under different pressures, which gives the opportunity to observe the hydraulic behaviour of the rock under different stresses. Calculations of hydraulic conductivity for each step of pressure usually give different value of hydraulic conductivity. Selection of a representative hydraulic conductivity value therefore becomes an issue. The arithmetic mean is the commonly accepted value, without justifying its representativeness. In this paper, about 75 packer tests conducted at 17 core wells at different depth with 3.5 m long test sections using double packer were evaluated. The tests are conducted at five pressures that run in three increasing and two decreasing pressures according to the recommendation of Houlsby. Hydraulic conductivity was calculated for every pressure step and evaluated to find a representative value using different methods. The representative values found by different methods is then compared. Results indicate that the arithmetic mean has good correlation with all the methods in particular it is nicely correlated with the modified Lugeon analysis for hydrogeological investigations with a correlation value of R 2 =0.91. Therefore, it is concluded that the uncertainty associated with the use of the simple arithmetic mean is within an acceptable range of error. Keywords: Hydrogeology; Lugeon Value; Packer test; Permeability.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V11I1.4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43799762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In a series of research articles El-khorazaty, Horne and Suchindran have showed how one can derive for any given population indirectly various childbearing and Bongaart fertility-inhibiting indices using only given information on the ASFRs, and the mathematical and regression models suggested by them. Very recently Bongaart revised his old model and suggested a set of new revised formulae to estimate various fertility-inhibiting indices. Following El-Khorazaty and Horne it is aimed to show in the present paper how one can derive various Bongaart revised fertility-inhibiting indices from the given information on various childbearing indices which were further seen derived from the only given information on TFR and a set of regression models that were earlier suggested by the first author and it is shown that the present study succeed in giving meaningful estimates for India its States, UTs, and Districts. Various regression models referring to estimation of childbearing indices used in this study were developed earlier by Ponnapalli using the state level time series of ASFRs overtime of the SRS of India and Horne et al., mathematical model. The regression models used in indirect estimation of the fertility-inhibiting indices from the TFR and also from the childbearing indices were developed by Ponnapalli using the Bongart indices of the DHS surveys earlier given by Bongaart in his revised recent study. Keywords: Fertility; Childbearing indices; Indirect Estimation; Bongaart Indices; ASFRs; TFR; TF; India
{"title":"Regression Estimation of Bongaart Indices from the Childbearing Indices: A Study of India/States/Districts","authors":"K. M. Ponnapalli, Akash Kumar","doi":"10.4314/MEJS.V11I1.7","DOIUrl":"https://doi.org/10.4314/MEJS.V11I1.7","url":null,"abstract":"In a series of research articles El-khorazaty, Horne and Suchindran have showed how one can derive for any given population indirectly various childbearing and Bongaart fertility-inhibiting indices using only given information on the ASFRs, and the mathematical and regression models suggested by them. Very recently Bongaart revised his old model and suggested a set of new revised formulae to estimate various fertility-inhibiting indices. Following El-Khorazaty and Horne it is aimed to show in the present paper how one can derive various Bongaart revised fertility-inhibiting indices from the given information on various childbearing indices which were further seen derived from the only given information on TFR and a set of regression models that were earlier suggested by the first author and it is shown that the present study succeed in giving meaningful estimates for India its States, UTs, and Districts. Various regression models referring to estimation of childbearing indices used in this study were developed earlier by Ponnapalli using the state level time series of ASFRs overtime of the SRS of India and Horne et al., mathematical model. The regression models used in indirect estimation of the fertility-inhibiting indices from the TFR and also from the childbearing indices were developed by Ponnapalli using the Bongart indices of the DHS surveys earlier given by Bongaart in his revised recent study. Keywords: Fertility; Childbearing indices; Indirect Estimation; Bongaart Indices; ASFRs; TFR; TF; India","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V11I1.7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45363090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human’s unwise and ineffective exploitation behavior has caused losses of the vital natural resources, soil and water, which will definitely leave the future of the next generation in jeopardy. As a result of human intervention and natural causes most lakes in Ethiopia are shrinking in size while others are showing increase in volume. The intensive exploitation, beyond its regeneration rate, of the Lake Haramaya for water supply and agricultural purposes by the community within and outside its catchment boundary has led to its extinction. Although, some studies have been conducted on land use/land cover dynamics, the focus given to quantification of temporal variability lake surface area and the impact of weather variability on the lake water was inadequate. Hence, this study was conducted with the prime objective of mapping/quantifying the temporal lake surface area fluctuation using time series remote sensing images and investigating the impact of weather/climate variability on the lake. After acquiring Landsat images of the years 1985, 1995, 2003, 2010 and 2016 over the dry Haramaya Lake basin (path/row 166/54), the Modified Normalized Difference Water Index (MNDWI) and the Normalized Difference Vegetation Index (NDVI) were used for enhancing and extracting the open water surface of the lake. All of the enhanced images display a trend of decreasing lake surface water area with an average shrinkage of 23.6% between the year 1985 and up to its disappearance. After 2000 the lake surface area shrinkage was at its maximum which has a direct relation with the occurrence of dry weather as a result of relatively higher temperature and low rainfall between the years 2000 to 2003. Keywords: Haramaya Lake; Image enhancement; Fluctuation; MNDWI; NDVI; Ethiopia
{"title":"Analysis of Surface Area Fluctuation of the Haramaya Lake using Remote Sensing Data","authors":"Kbrom Ambachew Gebrehiwot, Abebe Fanta Bedie, Mehari Gidey Gebrewahid, Birhanu Kindishih Hishe","doi":"10.4314/MEJS.V11I1.9","DOIUrl":"https://doi.org/10.4314/MEJS.V11I1.9","url":null,"abstract":"Human’s unwise and ineffective exploitation behavior has caused losses of the vital natural resources, soil and water, which will definitely leave the future of the next generation in jeopardy. As a result of human intervention and natural causes most lakes in Ethiopia are shrinking in size while others are showing increase in volume. The intensive exploitation, beyond its regeneration rate, of the Lake Haramaya for water supply and agricultural purposes by the community within and outside its catchment boundary has led to its extinction. Although, some studies have been conducted on land use/land cover dynamics, the focus given to quantification of temporal variability lake surface area and the impact of weather variability on the lake water was inadequate. Hence, this study was conducted with the prime objective of mapping/quantifying the temporal lake surface area fluctuation using time series remote sensing images and investigating the impact of weather/climate variability on the lake. After acquiring Landsat images of the years 1985, 1995, 2003, 2010 and 2016 over the dry Haramaya Lake basin (path/row 166/54), the Modified Normalized Difference Water Index (MNDWI) and the Normalized Difference Vegetation Index (NDVI) were used for enhancing and extracting the open water surface of the lake. All of the enhanced images display a trend of decreasing lake surface water area with an average shrinkage of 23.6% between the year 1985 and up to its disappearance. After 2000 the lake surface area shrinkage was at its maximum which has a direct relation with the occurrence of dry weather as a result of relatively higher temperature and low rainfall between the years 2000 to 2003. Keywords: Haramaya Lake; Image enhancement; Fluctuation; MNDWI; NDVI; Ethiopia","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V11I1.9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48310371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Kahsay, Tesfamichael Gebreyohannes, Fethanegest Woldemariyam Tesema, Tesfa-alem Gebreegziabher Emabye
Groundwater is a vital source of water for domestic and agricultural activities in Raya valley due to non-perennial flow of surface water.Thus the present study aims to evaluate the groundwater quality and assess its suitability for drinking and irrigation purposes. A total of 137 groundwater samples were examined for various physico-chemical parameters to evaluate the quality and suitability of groundwater for the intended purposes. Piper-Hill diagram was adapted to infer hydro-geochemical facies and water types. The suitability of groundwater for drinking purpose was evaluated by comparing the analytical results of different water quality parameters to the Ethiopian standard as well as World Health Organization Standards (WHO, 2006). Salinity, sodicity and related parameters were considered to evaluate the suitability of the groundwater for irrigation use. The dominant water types are magnesium bicarbonate and sodium-calcium bicarbonate.The hydrochemistry of the groundwater changes from Mg-Ca-HCO 3 dominance at the foot of volcanic hills to Ca-Mg-Na-HCO 3 and Ca-Na-Mg-HCO 3 at the valley floor. On the basis of total hardness, 46 % of the water samples in Raya valley fall in the very hard water class whereas, based on TDS values 95% of the water samples are found to be permissible for drinking. With the exception of three constituents (Mg 2+ , Ca 2+ and K + ), all other analyzed constituents in groundwater are within the established standards of Ethiopia. Water suitability for irrigation indicates that the groundwater fall in the range of good to permissible, however, higher salinity, magnesium hazard and low permeability index restricted its suitability in southeastern parts of the study area. Keywords: Water quality; SAR; Irrigation and drinking suitability; Raya Valley; Ethiopia
由于地表水的非常年流动，地下水是Raya河谷家庭和农业活动的重要水源。因此，本研究旨在评价地下水水质，评价其饮用和灌溉的适宜性。共对137个地下水样本进行了各种物理化学参数检查，以评估地下水的质量和适用性。采用Piper-Hill图来推断水文地球化学相和水类型。通过将不同水质参数的分析结果与埃塞俄比亚标准和世界卫生组织标准进行比较，评估了地下水是否适合饮用(世卫组织，2006年)。考虑了盐度、碱度及相关参数来评价地下水的灌溉适宜性。主要的水类型是碳酸氢镁和碳酸氢钠钙。地下水水化学由火山山脚下的Mg-Ca-HCO 3为主转变为谷底的Ca-Mg-Na-HCO 3和Ca-Na-Mg-HCO 3为主。根据总硬度，拉雅河谷46%的水样属于极硬水，而根据TDS值，95%的水样可饮用。除了三种成分(Mg 2+， Ca 2+和K +)外，所有其他分析的地下水成分都在埃塞俄比亚的既定标准范围内。研究区东南部地下水适宜灌溉范围为“好”至“准”，但盐度高、镁危害大、渗透系数低制约了其适宜灌溉。关键词:水质;特别行政区;灌溉饮用适宜性;莱雅谷;埃塞俄比亚
{"title":"Evaluation of Groundwater Quality and Suitability for Drinking and Irrigation Purposes Using Hydrochemical Approach: The Case of Raya Valley, Northern Ethiopia","authors":"G. Kahsay, Tesfamichael Gebreyohannes, Fethanegest Woldemariyam Tesema, Tesfa-alem Gebreegziabher Emabye","doi":"10.4314/MEJS.V11I1.5","DOIUrl":"https://doi.org/10.4314/MEJS.V11I1.5","url":null,"abstract":"Groundwater is a vital source of water for domestic and agricultural activities in Raya valley due to non-perennial flow of surface water.Thus the present study aims to evaluate the groundwater quality and assess its suitability for drinking and irrigation purposes. A total of 137 groundwater samples were examined for various physico-chemical parameters to evaluate the quality and suitability of groundwater for the intended purposes. Piper-Hill diagram was adapted to infer hydro-geochemical facies and water types. The suitability of groundwater for drinking purpose was evaluated by comparing the analytical results of different water quality parameters to the Ethiopian standard as well as World Health Organization Standards (WHO, 2006). Salinity, sodicity and related parameters were considered to evaluate the suitability of the groundwater for irrigation use. The dominant water types are magnesium bicarbonate and sodium-calcium bicarbonate.The hydrochemistry of the groundwater changes from Mg-Ca-HCO 3 dominance at the foot of volcanic hills to Ca-Mg-Na-HCO 3 and Ca-Na-Mg-HCO 3 at the valley floor. On the basis of total hardness, 46 % of the water samples in Raya valley fall in the very hard water class whereas, based on TDS values 95% of the water samples are found to be permissible for drinking. With the exception of three constituents (Mg 2+ , Ca 2+ and K + ), all other analyzed constituents in groundwater are within the established standards of Ethiopia. Water suitability for irrigation indicates that the groundwater fall in the range of good to permissible, however, higher salinity, magnesium hazard and low permeability index restricted its suitability in southeastern parts of the study area. Keywords: Water quality; SAR; Irrigation and drinking suitability; Raya Valley; Ethiopia","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":"1 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V11I1.5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70566300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abijata-Shalla Soda Ash Share Company in the central Main Ethiopian Rift is producing soda ash (Na 2 CO 3 )by evaporating brine water from Abijata Lake. A study was undertaken to assess the challenges associated with the mining practices and quality of soda ash. Presently, 5000t of soda ash is produced annually with a grade of about 90% against the expected 20,000t with 97% grade. During fieldwork, a geological map is prepared and collected soil, trona, soda ash and water samples for chemical analysis. Water samples were collected from the lake and from different evaporation ponds. Soil samples were collected around the ponds and soda ash samples from the processing plant. All the samples were analyzed for major cations and anions in addition to pH and other parameters. The field and laboratory data suggest that the mining method, pond design, and the timing of transfer of brine water from one pond to another are the major challenges that are affecting the quality of soda ash. New pond design is suggested with minor modification to the existing design which is expected to increase the grade close to 97% Na 2 CO 3 . Keywords: Abijata-Shalla Lakes; Brine water; Evaporation; Trona; Soda Ash; Ethiopia.
{"title":"Associated with Quality of Soda Ash, Abijata Lake, Central Main Ethiopian Rift, Ethiopia","authors":"Berihu Gidey, B. Konka","doi":"10.4314/MEJS.V11I1.8","DOIUrl":"https://doi.org/10.4314/MEJS.V11I1.8","url":null,"abstract":"Abijata-Shalla Soda Ash Share Company in the central Main Ethiopian Rift is producing soda ash (Na 2 CO 3 )by evaporating brine water from Abijata Lake. A study was undertaken to assess the challenges associated with the mining practices and quality of soda ash. Presently, 5000t of soda ash is produced annually with a grade of about 90% against the expected 20,000t with 97% grade. During fieldwork, a geological map is prepared and collected soil, trona, soda ash and water samples for chemical analysis. Water samples were collected from the lake and from different evaporation ponds. Soil samples were collected around the ponds and soda ash samples from the processing plant. All the samples were analyzed for major cations and anions in addition to pH and other parameters. The field and laboratory data suggest that the mining method, pond design, and the timing of transfer of brine water from one pond to another are the major challenges that are affecting the quality of soda ash. New pond design is suggested with minor modification to the existing design which is expected to increase the grade close to 97% Na 2 CO 3 . Keywords: Abijata-Shalla Lakes; Brine water; Evaporation; Trona; Soda Ash; Ethiopia.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V11I1.8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43946082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents detection of plastic landmines and characterization of subsurface and the target using ground penetrating radar (GPR) measurements. The inverse transmission line (TL) modeling approach is used to analyze the characteristics of practical GPR system operating above non-uniform ground. The modeling approach considers the presence of surface roughness, natural clutter, targets and soil moisture. With this model, the time domain signature of electromagnetic (EM) propagation can be assessed. The inverse TL modeling is applied to estimate the characteristic parameters (such as conductivity, magnetic permeability and permittivity) of the subsurface and buried plastic landmines. TL modeling is applied to obtain the reverse solution of the electromagnetic equations. Different scenarios were considered and test signals of the B-scan data are used to test the effectiveness of the method. Simulations of the real data analysis showed the effectiveness of the model and its application to target detection and characterization of the subsurface. Performance of the modeling is analyzed using receiver operating characteristic (ROC) analysis of the four hypotheses and it has found that 99.5% detection has achieved as the cost of 12% of false alarm. Keywords : Dielectric properties; EM wave propagation; GPR; Parameter estimation; Inverse transmission line.
{"title":"Inverse Transmission Line Modeling of GPR for Landmine Detection and Subsurface Parameter Estimation","authors":"G. T. Tesfamariam","doi":"10.4314/MEJS.V10I2.2","DOIUrl":"https://doi.org/10.4314/MEJS.V10I2.2","url":null,"abstract":"This paper presents detection of plastic landmines and characterization of subsurface and the target using ground penetrating radar (GPR) measurements. The inverse transmission line (TL) modeling approach is used to analyze the characteristics of practical GPR system operating above non-uniform ground. The modeling approach considers the presence of surface roughness, natural clutter, targets and soil moisture. With this model, the time domain signature of electromagnetic (EM) propagation can be assessed. The inverse TL modeling is applied to estimate the characteristic parameters (such as conductivity, magnetic permeability and permittivity) of the subsurface and buried plastic landmines. TL modeling is applied to obtain the reverse solution of the electromagnetic equations. Different scenarios were considered and test signals of the B-scan data are used to test the effectiveness of the method. Simulations of the real data analysis showed the effectiveness of the model and its application to target detection and characterization of the subsurface. Performance of the modeling is analyzed using receiver operating characteristic (ROC) analysis of the four hypotheses and it has found that 99.5% detection has achieved as the cost of 12% of false alarm. Keywords : Dielectric properties; EM wave propagation; GPR; Parameter estimation; Inverse transmission line.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V10I2.2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45296015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A cross-sectional study was conducted at Mekelle from November 2013 to March 2014 on the basis of questionnaire survey with the main objective of determining the prevalence of taeniasis in human. It also estimates the cost of taeniasis treatment in Mekelle town. A retrospective data on human taeniasis was collected from health centers and inventory of Pharmacy shops in Mekelle town. Out of the total 75 respondents, 46 (61.3%) had contracted Taenia (T) saginata infection and there was significant difference (p<0.05) with religious groups and different levels of raw meat consumers (P=0.000). An-overall prevalence of human taeniasis was 0.56% (193/34, 310). An inventory of pharmacy shops revealed a total of 22,412 adult taeniacidal drug doses worth 95,700 Eth. Birr (4958.5 USD) were sold during the year 2012-2013. Based on the response of pharmacists at 48 different pharmacy shops, 40 (83.33%) were from rural areas as compared to urban dwellers(16.7%). Niclosamide and Prazequantel are the only drugs used for treatment of human taeniasis in the study area and Niclosamide was preferred over Prazequantel. Taeniasis is resulted by consumption of raw beef. Therefore, due attention is needed to spread mass awareness in public and there is strict need for routine meat inspection. Keywords : Health centers; Pharmacy shop; Prevalence; Taeniasis; Mekelle, Ethiopia.
{"title":"Retrospective Study on Prevalence of Human Taeniasis in Mekelle, Tigray, Ethiopia","authors":"Mekonen Yemane, Ashwani Kumar","doi":"10.4314/mejs.v10i2.9","DOIUrl":"https://doi.org/10.4314/mejs.v10i2.9","url":null,"abstract":"A cross-sectional study was conducted at Mekelle from November 2013 to March 2014 on the basis of questionnaire survey with the main objective of determining the prevalence of taeniasis in human. It also estimates the cost of taeniasis treatment in Mekelle town. A retrospective data on human taeniasis was collected from health centers and inventory of Pharmacy shops in Mekelle town. Out of the total 75 respondents, 46 (61.3%) had contracted Taenia (T) saginata infection and there was significant difference (p<0.05) with religious groups and different levels of raw meat consumers (P=0.000). An-overall prevalence of human taeniasis was 0.56% (193/34, 310). An inventory of pharmacy shops revealed a total of 22,412 adult taeniacidal drug doses worth 95,700 Eth. Birr (4958.5 USD) were sold during the year 2012-2013. Based on the response of pharmacists at 48 different pharmacy shops, 40 (83.33%) were from rural areas as compared to urban dwellers(16.7%). Niclosamide and Prazequantel are the only drugs used for treatment of human taeniasis in the study area and Niclosamide was preferred over Prazequantel. Taeniasis is resulted by consumption of raw beef. Therefore, due attention is needed to spread mass awareness in public and there is strict need for routine meat inspection. Keywords : Health centers; Pharmacy shop; Prevalence; Taeniasis; Mekelle, Ethiopia.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/mejs.v10i2.9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43610478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Presence of toxic heavy metals in the environment is of great concern due to their persistence in nature and chronic adverse effects on human health and the environment. Present paper tries to evaluate the efficiency of cactus leaves ( Opuntia f. indica ) and activated carbon made from acacia etbiaca as an adsorbent for the removal of heavy metal pollutants such as cadmium, lead and chromium from water. Adsorption properties such as size, dose, initial concentration and time of contact for cadmium, lead and chromium were studied through batch method. Before removing the toxic heavy metals (Cd, Pb and Cr), the fresh unpeeled cactus leaves (adsorbent) and activated carbon were washed with distilled water to eliminate the turbidity and smell from fresh unpeeled cactus. To describe the equilibrium isotherms, the experimental data were analyzed by the Langmuir and Freundlich isotherm models. Thus, the Freundlich model gave the best correlation with the experimental data. Therefore, the findings indicated that the cactus and activated carbon made locally from acacia etbiaca were found to be effective and low-cost alternative adsorbents for the removal of toxic heavy metals from industrial effluents. The preparation method allowed the use of these materials by local industries for effective remediation of pollution by removing heavy metals from their effluents. Keywords : Cactus leaves; Acacia etbiaca ; Heavy metals; Adsorption, Industrial effluents; Water purification.
{"title":"The Efficiency of Cactus Leaves and Wood Charcoal as a Potential Low-Cost Adsorbent for Removal of Toxic Heavy Metals from Industrial Effluents","authors":"A. Gebrekidan, A. Halefom","doi":"10.4314/MEJS.V10I2.3","DOIUrl":"https://doi.org/10.4314/MEJS.V10I2.3","url":null,"abstract":"Presence of toxic heavy metals in the environment is of great concern due to their persistence in nature and chronic adverse effects on human health and the environment. Present paper tries to evaluate the efficiency of cactus leaves ( Opuntia f. indica ) and activated carbon made from acacia etbiaca as an adsorbent for the removal of heavy metal pollutants such as cadmium, lead and chromium from water. Adsorption properties such as size, dose, initial concentration and time of contact for cadmium, lead and chromium were studied through batch method. Before removing the toxic heavy metals (Cd, Pb and Cr), the fresh unpeeled cactus leaves (adsorbent) and activated carbon were washed with distilled water to eliminate the turbidity and smell from fresh unpeeled cactus. To describe the equilibrium isotherms, the experimental data were analyzed by the Langmuir and Freundlich isotherm models. Thus, the Freundlich model gave the best correlation with the experimental data. Therefore, the findings indicated that the cactus and activated carbon made locally from acacia etbiaca were found to be effective and low-cost alternative adsorbents for the removal of toxic heavy metals from industrial effluents. The preparation method allowed the use of these materials by local industries for effective remediation of pollution by removing heavy metals from their effluents. Keywords : Cactus leaves; Acacia etbiaca ; Heavy metals; Adsorption, Industrial effluents; Water purification.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V10I2.3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42182821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water deficit at later growth stages (terminal drought) is a major abiotic factor limiting productivity of crops in northern Ethiopia. Varietal selection is among sustainable solutions to curb the problem. In line with this, a study was conducted in Tigray region, northern Ethiopia during 2011 and 2012 main cropping seasons to investigate the phenotypic diversity in tef varieties for developmental plasticity under severe water stress. Fifteen tef varieties were tested under late season water stress. Deferred/delay sowing time by two weeks was applied to expose the varieties to water stress. Soil and crop data were collected and analyzed. The varieties have shown significant ( p<0.001 ) interaction with the imposed stresses both for days to maturity and panicle length. Varieties such as DZ-01-974, DZ-01-899, DZ-cr-358 and Berkayi tend to tolerate the effect of terminal drought by shortening their maturity time, which is referred as drought escape. In contrast, varieties like DZ-01-99, DZ-01-358 and AbatNech have significantly reduced in length of their panicle. This is the actively transpiring part during later growth stage, without significant yield loss. This phenotyping for developmental plasticity has indicate that the tef employ escaping and reduction of evaporative surfaces to overcome the severe effects of terminal drought. To tailor varieties that better suit for drought prone farming systems. Such drought-adaptive traits should be targeted in breeding programs. Keywords: Tef; Delayed planting; Maturity; Panicle; Drought escape and avoidance; Ethiopia.
{"title":"Developmental plasticity: a phenological mechanism to endure later stage water deficit stresses in tef [Eragrostis tef (Zucc.) Trotter] varieties","authors":"D. Mengistu","doi":"10.4314/MEJS.V10I2.5","DOIUrl":"https://doi.org/10.4314/MEJS.V10I2.5","url":null,"abstract":"Water deficit at later growth stages (terminal drought) is a major abiotic factor limiting productivity of crops in northern Ethiopia. Varietal selection is among sustainable solutions to curb the problem. In line with this, a study was conducted in Tigray region, northern Ethiopia during 2011 and 2012 main cropping seasons to investigate the phenotypic diversity in tef varieties for developmental plasticity under severe water stress. Fifteen tef varieties were tested under late season water stress. Deferred/delay sowing time by two weeks was applied to expose the varieties to water stress. Soil and crop data were collected and analyzed. The varieties have shown significant ( p<0.001 ) interaction with the imposed stresses both for days to maturity and panicle length. Varieties such as DZ-01-974, DZ-01-899, DZ-cr-358 and Berkayi tend to tolerate the effect of terminal drought by shortening their maturity time, which is referred as drought escape. In contrast, varieties like DZ-01-99, DZ-01-358 and AbatNech have significantly reduced in length of their panicle. This is the actively transpiring part during later growth stage, without significant yield loss. This phenotyping for developmental plasticity has indicate that the tef employ escaping and reduction of evaporative surfaces to overcome the severe effects of terminal drought. To tailor varieties that better suit for drought prone farming systems. Such drought-adaptive traits should be targeted in breeding programs. Keywords: Tef; Delayed planting; Maturity; Panicle; Drought escape and avoidance; Ethiopia.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V10I2.5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46366342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alemtsehay Tsegay, A. Kidane, G. Tesfay, Girmay Kahsay, B. Abrha, J. Aune
Intensive tillage is a major sustainability concern in cereal dominated cropping systems in the drylands of Tigray, Ethiopia. Hence, on-farm trials were conducted to investigate the yield and economic advantage of reduced tillage and intercropping for two seasons. A factorial experiment in a complete randomized block design was carried out at Adigudom located in Hintalo-Wajirat district in South-Eastern Tigray in 2014 (rain-fed) and 2015 (irrigated). The experiment consisted of four tillage frequencies (zero, one, two and four) and three types of cropping systems (sole maize, sole soybean and maize-soybean intercropping) in three/four replications. Maize, variety “Melkassa 2”, and soybean, variety “Awassa 91” were used. Grain and biomass yields, and harvest index of both crops were analysed. Yield advantage of intercropping was evaluated using land equivalent ratio (LER) and partial budget analysis was used for the financial evaluation. The grain and biomass yields of both crops were significantly increased (p<0.05) as the tillage frequencies increased from zero to four in both seasons but the frequent tillage with sole cropping was not economically viable as the two times tillage with maize-soybean intercropping gave 126% greater net benefit compared to the four times tillage sole maize, which is practiced by farmers in the study area. The net benefit was strongly influenced by the main effects of tillage and intercropping in both seasons (p<0.001) and by their interaction in 2014 (p<0.05). Significantly higher LER (1.87-2.12) was recorded from maize-soybean intercropping over sole cropping in all the tillages and both seasons. Hence, two alternative options are suggested that farmers could apply in the drylands of Tigray: (i) keeping the sole cropping culture of maize production, and reducing number of tillages from 4 to 2 that would give 374%and 705% Marginal Rate of Return (MRR), respectively, under the rainfed and irrigated conditions compared to zero tillage sole maize; or (ii) intercropping maize with soybean and reducing tillage frequency from 4to 2 that would give 608% and 585% MRR in the respective growing seasons, compared to zero tillage maize-soybean intercropping. Taking these results into account, two times tillage combined with maize-soybean intercropping can be a good option in dryland areas of Tigray to achieve higher total intercrop yield at a low cost and larger LER. Moreover, reduced tillage can minimize soil degradation and benefit farmers with poor access to draft power or female-headed households constrained with labour for ploughing. Keywords : Tillage; Intercropping; Maize; Soybean; Tigray; Ethiopia. Please find erratum for this article here: https://dx.doi.org/10.4314/mejs.v11i1.10
{"title":"Reduced Tillage and Intercropping as a Means to Increase Yield and Financial Return in the Drylands of Tigray, northern Ethiopia: A Case Study under Rainfed and Irrigation Conditions","authors":"Alemtsehay Tsegay, A. Kidane, G. Tesfay, Girmay Kahsay, B. Abrha, J. Aune","doi":"10.4314/MEJS.V10I2.4","DOIUrl":"https://doi.org/10.4314/MEJS.V10I2.4","url":null,"abstract":"Intensive tillage is a major sustainability concern in cereal dominated cropping systems in the drylands of Tigray, Ethiopia. Hence, on-farm trials were conducted to investigate the yield and economic advantage of reduced tillage and intercropping for two seasons. A factorial experiment in a complete randomized block design was carried out at Adigudom located in Hintalo-Wajirat district in South-Eastern Tigray in 2014 (rain-fed) and 2015 (irrigated). The experiment consisted of four tillage frequencies (zero, one, two and four) and three types of cropping systems (sole maize, sole soybean and maize-soybean intercropping) in three/four replications. Maize, variety “Melkassa 2”, and soybean, variety “Awassa 91” were used. Grain and biomass yields, and harvest index of both crops were analysed. Yield advantage of intercropping was evaluated using land equivalent ratio (LER) and partial budget analysis was used for the financial evaluation. The grain and biomass yields of both crops were significantly increased (p<0.05) as the tillage frequencies increased from zero to four in both seasons but the frequent tillage with sole cropping was not economically viable as the two times tillage with maize-soybean intercropping gave 126% greater net benefit compared to the four times tillage sole maize, which is practiced by farmers in the study area. The net benefit was strongly influenced by the main effects of tillage and intercropping in both seasons (p<0.001) and by their interaction in 2014 (p<0.05). Significantly higher LER (1.87-2.12) was recorded from maize-soybean intercropping over sole cropping in all the tillages and both seasons. Hence, two alternative options are suggested that farmers could apply in the drylands of Tigray: (i) keeping the sole cropping culture of maize production, and reducing number of tillages from 4 to 2 that would give 374%and 705% Marginal Rate of Return (MRR), respectively, under the rainfed and irrigated conditions compared to zero tillage sole maize; or (ii) intercropping maize with soybean and reducing tillage frequency from 4to 2 that would give 608% and 585% MRR in the respective growing seasons, compared to zero tillage maize-soybean intercropping. Taking these results into account, two times tillage combined with maize-soybean intercropping can be a good option in dryland areas of Tigray to achieve higher total intercrop yield at a low cost and larger LER. Moreover, reduced tillage can minimize soil degradation and benefit farmers with poor access to draft power or female-headed households constrained with labour for ploughing. Keywords : Tillage; Intercropping; Maize; Soybean; Tigray; Ethiopia. Please find erratum for this article here: https://dx.doi.org/10.4314/mejs.v11i1.10","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/MEJS.V10I2.4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42500560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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