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May 2021
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The Impact of Water Management Practices on Paddy Productivity in the Dry Zone of Sri Lanka
Warnakulasooriya W.I.U. and Shantha A.A.
ABSTRACT: Water is becoming a scare resource in Sri Lanka as all other parts of the world due to increased use for irrigation, industry and domestic purposes. In Sri Lanka, rice account for 25 percent of total cultivable land, and more than two million are engaged in farming as their main occupation. Highly water intensive rice cultivation consumes more than 70 percent pf the total water allocated for food production in the country. The aim of this study is to examine percent practices of irrigation water management by famers and tank on paddy productivity and livelihood implication of rural farming community. The study based on Rajanganaya reservoir and the survey consisted of 120 farmers which had been randomly chosen from the project site. Data was collected to the survey through a structured questionnaire and the analysis was conducted using four multiple linear regression models. The results partied that, when farmer water management efficiency index increases by one unit, the paddy productivity increased by 30.13kg in wet season (Maha) and 27.90 kgs in dry season (Yala). However, at tank level water management efficiency index increased by one unit, the paddy productivity increased by 7.8kg in wet season (Maha) and 12.9 kg in dry (Yala) season respectively. At farmer level water management practices have been shown a significant influence on paddy productivity rather than tank level management practices. Therefore, policy makers should give more priority for plot level water management practices and need more awareness programme among famer organization in the dry zone of sri lanka.
[ FULL TEXT PDF 1-9 ] 10.22587/ajbas.2021.15.5.1
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Impacts of Novel Corona Pneumonia 2019-nCov (Covid-19) On North East Farmers of Botswana and Mitigation Strategies
Gagopale Bosekeng, Lambani Chabo Bosekeng and Moagisi Innocent Ithuteng
ABSTRACT: The whole world is in great shock due to The Novel Corona pneumonia 2019-nCOV (COVID-19) which was first reported in Wuhan, China in December 2019, and spontaneously spread to all continents. Due to its quick spread, it was declared a pandemic by World Health Organization in February 2020. The economic effects of COVID-19 were first manifested in governments, and non-government sectors then rippled outwards to business communities, demanding urgent actions for containment. The first option for containing this pandemic was movement restrictions, shutting down of non-essential services and extreme social distancing. It is expected that these measures will have adverse effects on food production activities and marketing. Therefore, the objective of this study was to assess the impacts of this pandemic on farmers and the mitigation strategies in the north east district of Botswana. A proportionate stratified random sampling was used in this study. A total of 148 farmers was sampled for the survey, of which 96 were from rain-fed and 52 from horticulture. A full structured questionnaire was used to collect data. Movement restrictions had a significant impact (p < 0.012) on farm operations such as controlling pests and harvesting on time. Rain-fed respondents (70.8%) and 84.6% of horticulture farmers were expected to get a travel permit to their fields, on which some days they would not get it due to daily restricted numbers. National lockdown resulted in 68.2% of the respondents pausing production and 78.6% losing their crops due to pest damage while some crops were too ripe to be sold. The restrictions on movement also affected distribution, market and prices of agricultural produce. The use of mobile phones, adhering to COVID-19 protocols and absorption of farmer’s produce by the government, helped some farmers in continued production and sales. The adverse impacts of COVID-19 on agricultural production can be minimized by waiving movement restriction on farmers.
[ FULL TEXT PDF 10-16 ] 10.22587/ajbas.2021.15.5.2
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Solving the Multi-objective Convex Programming Problems to Get the Best Compromise Solution
Dr. Alia Gebreel
ABSTRACT: A multi-objective convex programming problem has several convex objectives that need to be minimized or maximized over a convex set of constraints. When these objectives are conflicting with each other, the set of compromise solutions is obtained rather than one optimal solution. Accordingly, the best compromise solution is a very important topic for researchers because it considers the backbone of multi-objective optimization problems. This paper introduces two methods to get the best compromise efficient solution of multi-objective convex programming problems. The first suggested method develops Alia's method. For more flexibility, this first proposed method is combined with the distance based method. Through the search process of the best efficient solution, these two proposed methods produce the quality efficient set. Actually, their solution is valid for any number of objectives based on a new way that calculates the normal of objectives. Besides, some examples are presented to illustrate these methods, and the results are compared with other works. Interestingly, the results indicate effectiveness and robustness of the proposed methods in solving such problems. Also, it is concluded that more research is required on this topic.
[ FULL TEXT PDF 17-29 ] 10.22587/ajbas.2021.15.5.3
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Effect of the radius of curvature of embrasure in connector area on the fracture resistance of three-unit zirconia fixed partial dentures
Tarek R. Abdelrehim, Amr A. Mahrous
ABSTRACT: BACKGROUND: Most clinical studies indicate that fixed partial denture's (FPDs) have an approximately high failure rate, especially around the connector area between the retainers and pontics. The configuration of the prosthesis components can have a significant impact on the stress distribution as the contour changes. Increase the fracture resistance of three units of FPD by modifying the connector configuration in sections where the stress pattern occurs with extreme stress. OBJECTIVES: This study aimed to evaluate the effect of the curvature radius on the connector embrasure areas on the fracture resistance of three-unit all-ceramic FPDs. it was made from IPS e.max ZirCAD. Methods: A total of 20 all-ceramic three-unit FPDs were fabricated from IPS e.max ZirCAD. They were divided into four groups with different connector's designs. All FPDs were adhesively bonded to the abutment teeth using resin cement. RESULTS: The mean fracture loads were highest for Group A (0.60 mm r OE and r GE). The results showed that a significant difference among fracture loads of different types of connector design. CONCLUSIONS: It can be concluded that change of the radius of curvature of the connector area showed to be critical for the fracture resistance of all-ceramic fixed partial dentures. The fracture resistance can be improved by constructing larger radii of gingival and occlusal embrasure in the connector area.
[ FULL TEXT PDF 30-34 ] 10.22587/ajbas.2021.15.5.4
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