Pub Date : 2011-12-01DOI: 10.17485/IJST/2011/V4I12/30299
O. E. Simolowo, O. Adeniji
This study is on the modification and improvement of an "Ogi" (ground corn slurry) sieving machine that was earlier designed based on suction principle. A vibration machine for the sieving of a major staple food and primary infant diet in many countries in Africa popularly known as "Ogi" has been fabricated in this work. Experimental performance tests were carried out using the modified machine and the results were compared with the conventional or manual sieving process. In Nigeria, and many African countries, the domestic and medium-scale processing of various food slurry such as those for corn, sorghum, soya beans and millet have been done manually over the years with little or no technological development. These manual processes are associated with obvious constraints such as excessive length of time, tedium and boredom coupled with inherent unhygienic conditions surrounding these processes. Results showed that the newly designed vibration sieving machine was more efficient than the manual process. It had an average filtration rate of 1.6 x10 -5 m 3 /s against 8.68x10 -6 m 3 /s for the manual method, thereby bringing about over 82% improvement over the manual sieving process. Hence, this work presents a remarkable contribution to the processing of various staple foods in Nigeria and Africa as a whole by applying the principles of vibration to the design of new sieving equipment.
{"title":"Prototype design and performance analysis of a sieving machine for improved food slurry processing in Nigeria.","authors":"O. E. Simolowo, O. Adeniji","doi":"10.17485/IJST/2011/V4I12/30299","DOIUrl":"https://doi.org/10.17485/IJST/2011/V4I12/30299","url":null,"abstract":"This study is on the modification and improvement of an \"Ogi\" (ground corn slurry) sieving machine that was earlier designed based on suction principle. A vibration machine for the sieving of a major staple food and primary infant diet in many countries in Africa popularly known as \"Ogi\" has been fabricated in this work. Experimental performance tests were carried out using the modified machine and the results were compared with the conventional or manual sieving process. In Nigeria, and many African countries, the domestic and medium-scale processing of various food slurry such as those for corn, sorghum, soya beans and millet have been done manually over the years with little or no technological development. These manual processes are associated with obvious constraints such as excessive length of time, tedium and boredom coupled with inherent unhygienic conditions surrounding these processes. Results showed that the newly designed vibration sieving machine was more efficient than the manual process. It had an average filtration rate of 1.6 x10 -5 m 3 /s against 8.68x10 -6 m 3 /s for the manual method, thereby bringing about over 82% improvement over the manual sieving process. Hence, this work presents a remarkable contribution to the processing of various staple foods in Nigeria and Africa as a whole by applying the principles of vibration to the design of new sieving equipment.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68192710","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 discusses the potentials of meeting the wood demand and achieving SFM in Sub-Saharan Africa (SSA) through the establishment of forest plantations. The paper reviews forest plantation ownership and distribution patterns in SSA and the factors –silvicultural, ecological, and economic that affect supply and demand for wood at both domestic and international markets. The risk associated with investing in forest plantations and their susceptibility to pest and disease attacks are highlighted. But with sound silvicultural practices these fears are allayed. Ecological sustainability is in most situations ensured, but there are risks associated with burning logging slash after harvesting. It is found that efficiency in plantation management and success in achieving sustainable wood supply depends to a large extent on whether the plantations are owned and managed by the public or the private sector. Many public sector managed plantations are poorly managed and not profit-oriented. They have other environmental and social services and benefits as objectives. Many benefits from such activities are not easily quantifiable in monetary terms and therefore cannot be used to determine the profitability of the plantations. Thus, in financial analysis, most public sector owned and managed plantations are unprofitable and not economically viable because these important benefits are excluded in the calculations. Private owned forest plantations are well managed and aim at profit maximization and therefore integrate plantations to wood processing plants to improve the form and value of wood and make the wood products more competitive in both domestic and export markets. As a way forward, a number of actions are listed to ensure long-term viability of forest plantations in SSA.
{"title":"Plantation Forestry in Sub Saharan Africa: Silvicultural, Ecological and Economic Aspects","authors":"S. Chamshama, F. Nwonwu, B. Lundgren, G. Kowero","doi":"10.4314/DAI.V21I3.48210","DOIUrl":"https://doi.org/10.4314/DAI.V21I3.48210","url":null,"abstract":"This paper discusses the potentials of meeting the wood demand and achieving SFM in Sub-Saharan Africa (SSA) through the establishment of forest plantations. The paper reviews forest plantation ownership and distribution patterns in SSA and the factors –silvicultural, ecological, and economic that affect supply and demand for wood at both domestic and international markets. The risk associated with investing in forest plantations and their susceptibility to pest and disease attacks are highlighted. But with sound silvicultural practices these fears are allayed. Ecological sustainability is in most situations ensured, but there are risks associated with burning logging slash after harvesting. It is found that efficiency in plantation management and success in achieving sustainable wood supply depends to a large extent on whether the plantations are owned and managed by the public or the private sector. Many public sector managed plantations are poorly managed and not profit-oriented. They have other environmental and social services and benefits as objectives. Many benefits from such activities are not easily quantifiable in monetary terms and therefore cannot be used to determine the profitability of the plantations. Thus, in financial analysis, most public sector owned and managed plantations are unprofitable and not economically viable because these important benefits are excluded in the calculations. Private owned forest plantations are well managed and aim at profit maximization and therefore integrate plantations to wood processing plants to improve the form and value of wood and make the wood products more competitive in both domestic and export markets. As a way forward, a number of actions are listed to ensure long-term viability of forest plantations in SSA.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508658","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48173
K. Kokou, Y. Nuto
In this study, plant species currently used for charcoal production were identified in major charcoal production centres or supply basins (SBs) in Togo. Impact of environmental policies on this activity were also assessed. Therefore, a sample of 310 charcoal producers in four SBs in different ecological areas throughout Togo, were selected. Law regulating charcoal production, currently appointed to protect the environment were also analysed. Results reveal that the average quantity of charcoal produced is 323,353 tons per year. Producers are women (52%) averaging 39 years of age. A category of seasonal producers are pupils who practice this activity during the holidays. Charcoal is made in temporary kilns at the soil surface. In each SB an average of 15 native plant species are used. Transporters influence traders and traders influence producers with regard to charcoal quality. However, demand comes from final consumer who prefers heavy charcoal. This study shows that environmental policies do not influence charcoal production in Togo due to the weakness of existing laws, no coordination between the institutions in charge of the environment and the overall failure of the energy policy.
{"title":"Assessment of Charcoal Production and Impact of Environmental Policies in Limited Forest Resources Countries: The case of Togo, West Africa","authors":"K. Kokou, Y. Nuto","doi":"10.4314/DAI.V21I1-2.48173","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48173","url":null,"abstract":"In this study, plant species currently used for charcoal production were identified in major charcoal production centres or supply basins (SBs) in Togo. Impact of environmental policies on this activity were also assessed. Therefore, a sample of 310 charcoal producers in four SBs in different ecological areas throughout Togo, were selected. Law regulating charcoal production, currently appointed to protect the environment were also analysed. Results reveal that the average quantity of charcoal produced is 323,353 tons per year. Producers are women (52%) averaging 39 years of age. A category of seasonal producers are pupils who practice this activity during the holidays. Charcoal is made in temporary kilns at the soil surface. In each SB an average of 15 native plant species are used. Transporters influence traders and traders influence producers with regard to charcoal quality. However, demand comes from final consumer who prefers heavy charcoal. This study shows that environmental policies do not influence charcoal production in Togo due to the weakness of existing laws, no coordination between the institutions in charge of the environment and the overall failure of the energy policy.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508706","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48177
Y. Yin, F. Shu-qiong
The currency crises were divided into the macro-economic vulnerability crisis, the declining competitiveness crisis; the self- fulfilling crisis; the led crisis by bank-crisis; the debt default crisis; the reversal crisis of capital flow; and the contagious crisis. Against the study on the financial stability and the early-warning systems having the lack of the predicting external crisis and monitoring internal risk, the analyzing framework of the financial macro-monitoring system based on the currency crises was proposed. A three-layer indicator set being made of the leading indicators was built as a core set, which regarded the six-type currency crises occurring in emerging market as the key, considered the impact of the bank system crisis for the monetary system. The macro-prudential indicators as a feature set would monitor internal risk. An interpretative illustration was progressed to the macro-monitoring indicators including the core set and the feature set.
{"title":"Analysis and Construction of the Macro-monitoring Indicators Based on the Currency Crisis","authors":"Y. Yin, F. Shu-qiong","doi":"10.4314/DAI.V21I1-2.48177","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48177","url":null,"abstract":"The currency crises were divided into the macro-economic vulnerability crisis, the declining competitiveness crisis; the self- fulfilling crisis; the led crisis by bank-crisis; the debt default crisis; the reversal crisis of capital flow; and the contagious crisis. Against the study on the financial stability and the early-warning systems having the lack of the predicting external crisis and monitoring internal risk, the analyzing framework of the financial macro-monitoring system based on the currency crises was proposed. A three-layer indicator set being made of the leading indicators was built as a core set, which regarded the six-type currency crises occurring in emerging market as the key, considered the impact of the bank system crisis for the monetary system. The macro-prudential indicators as a feature set would monitor internal risk. An interpretative illustration was progressed to the macro-monitoring indicators including the core set and the feature set.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508777","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48195
J. Agea, S. Nansereko, J. Obua, Daniel Waiswa, M. Buyinza, F. Yikii
This study assessed the attitudes of out-of-school youths towards tree planting activities in Masaka district, central Uganda. Data were collected using 104 semi-structured questionnaires. Logistic regression was used to show the influence of demographic and socio-economic characteristics of the respondents on their attitudes towards tree planting. Summative attitudes index varied from 320 for those who liked very much tree planting activities to 6 for those who disliked very much tree planting activities. Opinions on willingness to plant and tender trees also varied widely from summative index of 305 for those who would very much plant and manage the trees to 5 for those who would very much not plant and manage the trees. Sex, age, education, occupation, distance to the nearest trading centre and land ownership significantly contributed to variation in the attitudes. Factors such as lack of capital; land and tree tenure security; long payback period from planted trees; bad beliefs, taboos and superstitions about certain trees hindered out-of-school youths’ efforts. There is a need to develop clear policies and by-laws to guide and induce the out-of-school youths to plant trees as a livelihood opportunity.
{"title":"Attitudes of out-of-school youths towards tree planting activities in Central Uganda: a case study of Masaka District","authors":"J. Agea, S. Nansereko, J. Obua, Daniel Waiswa, M. Buyinza, F. Yikii","doi":"10.4314/DAI.V21I1-2.48195","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48195","url":null,"abstract":"This study assessed the attitudes of out-of-school youths towards tree planting activities in Masaka district, central Uganda. Data were collected using 104 semi-structured questionnaires. Logistic regression was used to show the influence of demographic and socio-economic characteristics of the respondents on their attitudes towards tree planting. Summative attitudes index varied from 320 for those who liked very much tree planting activities to 6 for those who disliked very much tree planting activities. Opinions on willingness to plant and tender trees also varied widely from summative index of 305 for those who would very much plant and manage the trees to 5 for those who would very much not plant and manage the trees. Sex, age, education, occupation, distance to the nearest trading centre and land ownership significantly contributed to variation in the attitudes. Factors such as lack of capital; land and tree tenure security; long payback period from planted trees; bad beliefs, taboos and superstitions about certain trees hindered out-of-school youths’ efforts. There is a need to develop clear policies and by-laws to guide and induce the out-of-school youths to plant trees as a livelihood opportunity.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508972","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48170
K. Lichun, L. Bin, Y. Jin
Computer imaging is a complex multi-discipline science with broad application and well developed theory. A brief knowledge of computer imaging is presented in this paper. An image feature is a descriptor of an image, which can avoid redundant data and reduce the effects of noise and variance. In computer imaging, feature selection is vital for researchers and processors. Feature extraction and image processing are based on the mathematical selection, computation and manipulation of image features with high efficiency, robustness and invariance. Common image features are expressed under definitions of feature measurements, which is stated in this paper. This paper mainly brings an overall presentation of different sorts of image features and classifies them into specified types. Based on different purposes of application, three main ways are put forward in this paper to categorize image features. The first one is based on the nature of the image. The features applied to a binary image are different from the ones applied to a gray-level image or a color image. The second classification separates visible features from invisible features. The last one classifies image features into global image features and local image features. A clear statement is given for each way of classification and each type of image feature. Every image feature has both merits and defects, hence when selecting features for further image application, a clear cognition of different features is required. Well applied image features and the algorithms related to them are highlighted in this paper with analysis and comparison.
{"title":"Classifications of image features: a survey","authors":"K. Lichun, L. Bin, Y. Jin","doi":"10.4314/DAI.V21I1-2.48170","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48170","url":null,"abstract":"Computer imaging is a complex multi-discipline science with broad application and well developed theory. A brief knowledge of computer imaging is presented in this paper. An image feature is a descriptor of an image, which can avoid redundant data and reduce the effects of noise and variance. In computer imaging, feature selection is vital for researchers and processors. Feature extraction and image processing are based on the mathematical selection, computation and manipulation of image features with high efficiency, robustness and invariance. Common image features are expressed under definitions of feature measurements, which is stated in this paper. This paper mainly brings an overall presentation of different sorts of image features and classifies them into specified types. Based on different purposes of application, three main ways are put forward in this paper to categorize image features. The first one is based on the nature of the image. The features applied to a binary image are different from the ones applied to a gray-level image or a color image. The second classification separates visible features from invisible features. The last one classifies image features into global image features and local image features. A clear statement is given for each way of classification and each type of image feature. Every image feature has both merits and defects, hence when selecting features for further image application, a clear cognition of different features is required. Well applied image features and the algorithms related to them are highlighted in this paper with analysis and comparison.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508643","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48181
N. F. Olele, J. Ekelemu
The physico-chemical parameters and periphyton composition of Onah Lake was monitored. The data obtained revealed that the concentration of all the nutrients were higher during the dry season than the rainy season. The observation connotes a discernible seasonal pattern in the concentration of the various nutrients in the lake. With the exception of transparency, total alkalinity and conductivity, that were significantly different (P parameters were not significantly different (p>0.05) in the stations. Transparency was significantly lower in the upstream station as opposed to the down stream station that recorded a higher value. The condition favoring the abundance of nutrients was discussed. The principal component analyzer generated a sequence of variates known as components in a correlation matrics. Three components were selected which account for 100% of variance in the physico-chemical parameter, viz: ionic conductivity factor contributed 26.07%, nutrient factor contributed 40.61% while dissolved oxygen factor contributed 33.32%. Three divisions, eight families and ten species of periphyton were encountered. The most abundant periphyton species recorded are Closterium spp. (26.37%) Cosmarium spp. (18.63%) and Ulothrix spp. (16.56%). The least encountered species was Anabaena spp. (2.88%). This was not implicated in any toxic bloom.
{"title":"Physical, chemical and periphyton/phytoplankton study of Onah Lake, Asaba, Nigeria","authors":"N. F. Olele, J. Ekelemu","doi":"10.4314/DAI.V21I1-2.48181","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48181","url":null,"abstract":"The physico-chemical parameters and periphyton composition of Onah Lake was monitored. The data obtained revealed that the concentration of all the nutrients were higher during the dry season than the rainy season. The observation connotes a discernible seasonal pattern in the concentration of the various nutrients in the lake. With the exception of transparency, total alkalinity and conductivity, that were significantly different (P parameters were not significantly different (p>0.05) in the stations. Transparency was significantly lower in the upstream station as opposed to the down stream station that recorded a higher value. The condition favoring the abundance of nutrients was discussed. The principal component analyzer generated a sequence of variates known as components in a correlation matrics. Three components were selected which account for 100% of variance in the physico-chemical parameter, viz: ionic conductivity factor contributed 26.07%, nutrient factor contributed 40.61% while dissolved oxygen factor contributed 33.32%. Three divisions, eight families and ten species of periphyton were encountered. The most abundant periphyton species recorded are Closterium spp. (26.37%) Cosmarium spp. (18.63%) and Ulothrix spp. (16.56%). The least encountered species was Anabaena spp. (2.88%). This was not implicated in any toxic bloom.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508854","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48187
Hs Nyandieka, J. Maina, C. Nyamwange
Aflatoxin contamination is a common occurrence in corn-based agricultural commodities such as grains and oilseed crops that are normally stored in warm moist places. Since aflatoxins are highly toxic and carcinogenic, this study was undertaken to determine the use of ammoniation procedures to destroy aflatoxin in contaminated maize samples. Strains of Aspergillus parasiticus were used to contaminate maize samples collected from market centers in Eldoret Municipality. They were then decontaminated by ammoniation procedure under normal temperature and pressure. High performance liquid chromatography was used for analysis of aflatoxin content in maize crop samples. The results revealed that ammoniation procedure can destroy over 90% of the aflatoxin in maize and may be considered economically viable especially where alternative foodstuffs are not available or affordable.
{"title":"Detoxification of aflatoxin in artificially contaminated maize crop by ammoniation procedures","authors":"Hs Nyandieka, J. Maina, C. Nyamwange","doi":"10.4314/DAI.V21I1-2.48187","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48187","url":null,"abstract":"Aflatoxin contamination is a common occurrence in corn-based agricultural commodities such as grains and oilseed crops that are normally stored in warm moist places. Since aflatoxins are highly toxic and carcinogenic, this study was undertaken to determine the use of ammoniation procedures to destroy aflatoxin in contaminated maize samples. Strains of Aspergillus parasiticus were used to contaminate maize samples collected from market centers in Eldoret Municipality. They were then decontaminated by ammoniation procedure under normal temperature and pressure. High performance liquid chromatography was used for analysis of aflatoxin content in maize crop samples. The results revealed that ammoniation procedure can destroy over 90% of the aflatoxin in maize and may be considered economically viable especially where alternative foodstuffs are not available or affordable.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508874","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48189
Bt Lebele-Alawa
Sustenance of rotor-blade design shape is fundamental to the gas-turbine compressor performance. Blade deterioration causes adverse pressure gradient which imposes unfavourable force on the boundary layer, resulting in aerodynamic losses. This paper investigates the relationship between rotor-blade deterioration and pressure losses in a gas-turbine plant. This was achieved by measuring certain performance characteristics of an operational gas-turbine. Corresponding theoretical predictions were obtained from computer simulations. Rotor-blade deterioration result in 1.2 percent drop in pressure ratio across the compressor, with a corresponding drop in isentropic efficiency from 0.83 to 0.72.
{"title":"On Rotor-Blade Deterioration and Pressure Losses in a Gas-Turbine Plant","authors":"Bt Lebele-Alawa","doi":"10.4314/DAI.V21I1-2.48189","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48189","url":null,"abstract":"Sustenance of rotor-blade design shape is fundamental to the gas-turbine compressor performance. Blade deterioration causes adverse pressure gradient which imposes unfavourable force on the boundary layer, resulting in aerodynamic losses. This paper investigates the relationship between rotor-blade deterioration and pressure losses in a gas-turbine plant. This was achieved by measuring certain performance characteristics of an operational gas-turbine. Corresponding theoretical predictions were obtained from computer simulations. Rotor-blade deterioration result in 1.2 percent drop in pressure ratio across the compressor, with a corresponding drop in isentropic efficiency from 0.83 to 0.72.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508919","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}
Pub Date : 2009-11-25DOI: 10.4314/DAI.V21I1-2.48175
M. Keraka, W. Serem
Kenya has borne the major brunt of HIV/AIDS for close to two decades. The problem being exacerbated among childbearing mothers as the probability of giving birth to HIV infected baby is heightened. Availability of safe and effective contraceptive and high quality reproductive health counseling can help a woman practice safer sex and determine her future childbearing on a more responsible and informed basis. Therefore, a study to determine how knowledge on contraceptives influenced fertility choices was conducted in Uasin Gishu district Rift valley province in Kenya from September 2005 to December 2005. Data was collected by systematic random sampling from 400 HIV infected mothers in their reproductive age. Interview schedules were administered to the respondents at three sites. Data was analyzed by descriptive statistics. Knowledge on contraceptive was almost universal among the respondents with 99.0% of the respondents being aware of at least one method that women could use to avoid pregnancy. Majority (41.6%) knew at least three methods of family planning followed by 30.4% who knew at least four methods while few respondents (3.5%) knew more than six methods of family planning. Desire for additional children was found to increase markedly with the number of methods that respondents were knowledgeable about; none of the respondents who were knowledgeable about one method desired to get any more additional children whereas 30.5% of those who knew at least three methods desired to get additional children. However, desire for additional births reduced drastically among those who knew more than four family planning methods with none of those who knew six methods desiring to get additional children. It is seen from the study that it is only with adequate knowledge regarding family planning that one is able to adopt better family planning practices. It is thus recommended that reproductive health counseling be improved among the HIV infected mother.
{"title":"Factors Influencing Fertility Choices Among HIV Infected Mothers in Uasin Gishu District, Kenya","authors":"M. Keraka, W. Serem","doi":"10.4314/DAI.V21I1-2.48175","DOIUrl":"https://doi.org/10.4314/DAI.V21I1-2.48175","url":null,"abstract":"Kenya has borne the major brunt of HIV/AIDS for close to two decades. The problem being exacerbated among childbearing mothers as the probability of giving birth to HIV infected baby is heightened. Availability of safe and effective contraceptive and high quality reproductive health counseling can help a woman practice safer sex and determine her future childbearing on a more responsible and informed basis. Therefore, a study to determine how knowledge on contraceptives influenced fertility choices was conducted in Uasin Gishu district Rift valley province in Kenya from September 2005 to December 2005. Data was collected by systematic random sampling from 400 HIV infected mothers in their reproductive age. Interview schedules were administered to the respondents at three sites. Data was analyzed by descriptive statistics. Knowledge on contraceptive was almost universal among the respondents with 99.0% of the respondents being aware of at least one method that women could use to avoid pregnancy. Majority (41.6%) knew at least three methods of family planning followed by 30.4% who knew at least four methods while few respondents (3.5%) knew more than six methods of family planning. Desire for additional children was found to increase markedly with the number of methods that respondents were knowledgeable about; none of the respondents who were knowledgeable about one method desired to get any more additional children whereas 30.5% of those who knew at least three methods desired to get additional children. However, desire for additional births reduced drastically among those who knew more than four family planning methods with none of those who knew six methods desiring to get additional children. It is seen from the study that it is only with adequate knowledge regarding family planning that one is able to adopt better family planning practices. It is thus recommended that reproductive health counseling be improved among the HIV infected mother.","PeriodicalId":50577,"journal":{"name":"Discovery and Innovation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70508764","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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