ISSN 2756-3251
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 5 (4), pp. 001-007, April, 2014. © International Scholars Journals
Full Length Research Paper
Elemental analysis of atmospheric aerosols in Gaborone
T.S. Verma* and Shibu K. John
Department of Physics, University of Botswana, Pvt Bag 0022, Gaborone, Botswana
Accepted 22 September, 2013
Abstract
Aerosols are mixture of solid and liquid particles and have considerable variation in terms of their chemical composition and size. In this study the elemental composition of aerosol particles in the atmosphere of a city, Gaborone, was carried out. The elemental analysis was done by environmental scanning electron microscope (ESEM). The results clearly show that the composition of the particles observed was very complex. It also showed the presence of elements Al, Si, Fe, K, Ca, Mg, Zn, Na, Cu, Pb, Ti, Ni, Pt, Au and Cr. The most frequently occurred element was silicon and the least frequently occurred element was platinum. Our measurements also revealed that the elements which had an amount more than 90% were copper, lead, nickel and gold.
Key words: Atmospheric particles, elements, minerals.
Shibu K. John, T.S. Verma*
Page: 1 - 7
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 5 (3), pp. 001-010, March, 2014. © International Scholars Journals
Full Length Research Paper
Fatigue and rutting strain analysis of flexible pavements designed using CBR methods
Emmanuel O. Ekwulo1* and Dennis B. Eme2
1Civil Engineering Department, Rivers State University of Science and Technology P.M.B. 5080 Port Harcourt, Rivers State, Nigeria.
2Civil and Environmental Engineering Department, University of Port Harcourt. Port Harcourt, Rivers State, Nigeria.
Accepted 25 November, 2013
Abstract
The layered elastic analysis of pavements designed using three known CBR methods; the Asphalt Institute, the National Crushed Stone Association and the Nigerian CBR methods were carried out to evaluate their fatigue strain and rutting deformation characteristics. The elastic properties of the materials were determined. Structural thickness requirement of the pavements were carried out using their respective design charts for a traffic volume of 3000 vehicles/day and expected load repetition of 3.2 x 106. Stresses, strains and deflections due to 80 kN single axle load having a tyre pressure of 690.78 kPa were computed by analyzing the effect due to 20 kN single axle load spaced 30.5 mm centre to centre. Strain evaluation was carried out at the underside of the asphalt bound layer and at the top of the subgrade 15.25 mm (midway) between the 20 kN axle loads. The Heukelom and Klomp Model, and the Asphalt Institute Model were used to evaluate pavement response. Results showed that the horizontal tensile strains on the underside of the asphalt bound layer were 355.50, 355.34 and 371.91 µЄ for Asphalt Institute CBR, NCSA CBR and the Nigerian CBR methods respectively. Similarly, the vertical compressive strains at the top of the subgrade were found to be -924.033, -906.7 and -774.24 µЄ for Asphalt Institute CBR, NCSA CBR and the Nigerian CBR methods respectively. The resulting fatigue and rutting strains were compared with the permissible values using the Heukelom and Klomp Model, and it was found that the computed vertical compressive strains were more than permissible values. In terms of fatigue, the damage factors were found to be less than 1.0 while in terms of rutting, the damage factors were greater than 1.0 for both models. It was concluded that flexible pavements designed using the three known CBR methods are prone to failure due rutting deformation and recommended the use of mechanistic procedures in the design of flexible pavements in developing tropical countries. The study was carried out with the layered elastic analysis software EVERSTRESS.
Key words: Layered elastic analysis, fatigue, rutting, strains, design, flexible pavement, CBR.
Dennis B. Eme, Emmanuel O. Ekwulo*
Page: 1 - 10
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 4 (3), pp. 001-013, March, 2013. © International Scholars Journals
Full Length Research Paper
Farmers’ ethno-ecological knowledge of vegetable pests and pesticidal plant use in Malawi and Zambia
Stephen P. Nyirenda1, Gudeta W. Sileshi2*, Steven R. Belmain3, John F. Kamanula4, Brighton M. Mvumi5, Phosiso Sola6, Greenwell K. C. Nyirenda7 and Philip C. Stevenson3,8
1Department of Agricultural Research Services, Lunyangwa Agricultural Research Station, P.O. Box 59, Mzuzu, Malawi.
2World Agroforestry Centre (ICRAF), Southern Africa Programme, Chitedze Agricultural Research Station, P.O. Box 30798, Lilongwe, Malawi.
3Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, United Kingdom.
4Mzuzu University, P/Bag 201, Luwinga, Mzuzu 2, Malawi.
5Department of Soil science and Agricultural Engineering, University of Zimbabwe, P.O. Box MP167, Mount Pleasant, Harare, Zimbabwe.
6Southern Alliance for Indigenous Resources, Box BE 398, Belvedere, Harare, Zimbabwe.
7University of Malawi, Bunda College, P.O. Box 219, Lilongwe, Malawi.
8Royal Botanic Gardens, Kew, Surrey, TW9 3DS, United Kingdom.
Accepted 25 August, 2012
Abstract
While pests are a major constraint in vegetable production in many parts of Southern Africa, little is known about farmers’ knowledge and management practices. A survey was conducted among 168 and 91 vegetable farmers in Northern Malawi and Eastern Zambia, respectively, to evaluate their knowledge, attitudes and traditional management practices in tomato and crucifers (brassica). All respondents in Malawi and Zambia reported pest damage on tomato and crucifers, and 75% had used synthetic pesticides. The use of pesticidal plants, cultural practices and resistant varieties constituted a smaller portion of the pest control options in both crucifers and tomato. Over 70% of the respondents were aware of pesticidal plants, and more female (75%) than male (55%) respondents reported using them. While over 20 different plant species were mentioned by respondents, Tephrosia vogelii accounted for 61 and 53% of the pesticidal species known to respondents in Malawi and Zambia, respectively. Farmers with small landholdings were more inclined to use pesticidal plants than those with medium and large landholding highlighting the importance of this management alternative for poor farmers. Most respondents were willing to cultivate pesticidal plants, which indicate that farmers understand the potential value of these plants in pest management.
Key words: Azadirachta, brasicca, Tephrosia, Tithonia, tomato, Vernonia.
Gudeta W. Sileshi*, Phosiso Sola, John F. Kamanula, Greenwell K. C. Nyirenda and Philip C. Stevenson, Brighton M. Mvumi, Stephen P. Nyirenda, Steven R. Belmain
Page: 1 - 13
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 4 (3), pp. 001-006, March, 2013. © International Scholars Journals
Full Length Research Paper
Land tenure, investment and adoption of Sawah rice production technology in Nigeria and Ghana: A qualitative approach
Oladele O. I.1*, Kolawole A.2 and T. Wakatsuki3
1Department of Agricultural Economics and Extension, North –West University Mafikeng Campus, South Africa.
2C/O Hirose Project International Institute of Tropical Agriculture Ibadan, Nigeria.
3Faculty of Agriculture, Kinki University, Nara 332-7204, Japan.
Accepted 22 November, 2012
Abstract
This paper explores the linkages among land tenure, investment and adoption of Sawah rice production technology in Nigeria and Ghana. Focus group discussion was held with farmers adopting Sawah technology; in all the villages where Sawah rice technology had been introduced. The study found that in Nigeria, land tenure system was predominantly through inheritance, while those on hired land had an average period of about 3 years as the tenancy period, while in Ghana land tenure system was based on lease and sharecropping. Farmers reported that the use of secured renting is a coping strategy with the land tenure problem in order to ensure the sustainability of Sawah technology. The farmers were also of the opinion that, investment in Sawah technology is worthy and with higher returns on the long run. The study recommends that issues of land tenure rights must be properly ascertained by farmers, in order to enhance continuous adoption and sustained profit from Sawah technology.
Key words: Sawah technology, land tenure, investment, adoption, secured rent.
Kolawole A. and T. Wakatsuki, Oladele O. I.*
Page: 1 - 6
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 4 (2), pp. 001-011, February, 2013. © International Scholars Journals
Full Length Research Paper
Demand analysis for frozen food in Turkey: Case of Izmir
Zerrin Kenano lu Bekta1*, Bülent Miran1, Özlem Karahan Uysal1, Cihat Günden1 and Murat Cankurt2
1Department of Agricultural Economics, Faculty of Agriculture, Ege University, Bornova-Izmir, Turkey.
2Department of Agricultural Economics, Agriculture Adnan Menderes University, Faculty of Agriculture, Aydın, Turkey.
Accepted 21 September, 2012
Abstract
The aim of this study was to analyse the frozen food demand among consumers in Izmir, one of the three biggest provinces in Turkey. The study used a questionnaire survey of 271 randomly selected consumers; data was collected between December 2006 and February 2007. Heckman models were used for demand estimates. From demand estimates, price elasticity was found to be -0.53 for potatoes, -0.49 for peas, -0.28 for green beans, -0.80 for strawberries and -0.69 for cherries. The study calculated price premium that consumers would be willing to pay for consuming frozen food. It was found that consumers would pay an 82% price premium for frozen peas; 108% for frozen strawberries; and 130% for frozen cherries. It was found that consumers were not willing to pay a price premium for frozen potatoes or frozen green beans.
Key words: Frozen food, Heckman two stage estimation method, willingness to pay, Turkey.
Zerrin Kenano lu Bekta*, Özlem Karahan Uysal, Cihat Günden and Murat Cankurt, Bülent Miran
Page: 1 - 11
Research Article
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 3 (3), pp. 001-008, March, 2012. © International Scholars Journals
Full Length Research Paper
Delineation of management zones by classification of soil physico-chemical properties in the Northern Savanna of Nigeria
Salami, Biola Titilope1*, Okogun, Jacob Ade2 and Sanginga, Ntenranya3
1Department of Crop Production, Soil and Environmental Management, Bowen University, Iwo, Osun State, Nigeria.
2Department of Agronomy, University Of Ibadan, Ibadan, Nigeria.
3Tropical Soil Biology and Fertility Institute of Ciat (TSBF-CIAT) P. O. Box 30677, Nairobi Kenya.
Accepted 21 November, 2011
Abstract
This study was designed to identify properties that explained variability in soils of farmers’ fields in Kaya, within the northern Guinea savanna benchmark and group the soils on the basis of the identified properties. Ridge and furrow soil samples from farmers’ fields were analyzed for determination of physical and chemical properties. Principal component analysis of soil properties extracted and characterized factors that described the overall soil fertility variation; potential fertility, available phosphorus, organic matter, acidity and sand-silt. Component scores were computed and used for cluster analysis. Five soil cluster groups corresponding to potential management zones were identified. In Cluster A soils were sandy, low in phosphorus, organic matter and exchangeable bases. Cluster B was characterized by acidic and silty soils with low exchangeable bases, organic matter and phosphorus. Soils within Cluster C were acidic, sandy in texture, with low exchangeable bases, phosphorus and organic matter. In the single member Cluster D, the soil was rich in organic matter and phosphorus. Cluster E soils were high in exchangeable bases and organic matter but low in phosphorus. The identified soil clusters are delineated management zones and this determines their suitability or otherwise for specific agronomic management practices.
Key words: Cluster analysis, northern guinea savanna, principal component analysis.
Ntenranya , Salami , Biola Titilope*, Okogun , Jacob Ade and Sanginga
Page: 1 - 8