Vol. 08, Issue 2, July 2013
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Item littleStudy On The Shear Strength Of Foundry Sand Cores Using Clay And Cassava Starch As Binder(Daffodil International University, 2013-07) Akinlabi, Oyetunji; S.O, Seidu,; A. I, OpaluwaSand cores for casting intricate shapes were produced from Ojolofe silica sand using cassava starch and Iyoloko clay, Idah Kogi State Nigeria as binders. Various compositions (6 – 12% water 4 – 12% cassava starch and 5% Iyoloko clay) and Ojolofe silica sand were mixed to produce standard cores samples of two different types (green and baked). Cores samples were baked at different temperatures ranging from 90 and 200oC for 60 – 150 minutes. Determination of shear strengths was carried out on a large number of green and baked cores samples. Appropriate baking conditions and optimum core mixtures were established for cassava starch/clay bonded cores at 180oC and 2 hours respectively; and clay addition was found to increase both the green and baked strengths values. The optimum clay/starch core mixture with the best shear strength values was found to be core produced with 10% starch, 10% water and 5% clay. Their green and baked shear strength values were 31.1 KN/m2 and 498.1 KN/m2 respectively. These values were found to be adequate for production of strong sand cores using starch/clay as binders for non-ferrous and ferrous castings as collaborated by successfully casting of a T – joint pipe aluminum casting.Item Energy Consumption by Battery Operated Auto-rickshaws(Daffodil International University, 2013-07) Rana, Md. Sohel; Hossain, Fahim; Roy, Shuvangkor Shusmoy; Mitra, Suman KumarThe paper contains primary data based analysis on the energy consumption aspect of battery operated auto-rickshaws which is one of the crucial issues in the transportation system of a developing country like Bangladesh. Several aspects associated with the mode such as its energy consumption rate, effects of recharging of the mode on local town’s energy provision capacity, and the mode’s contribution in attenuation of transport related emissions are explored in the paper. The paper with scientific research outcomes would provide guidelines to the policy makers of a country regarding whether and how to incorporate the mode in the local town’s transportation system. Battery operated auto-rickshaw offers lower travel cost than rickshaw and greater travel comfort than other urban para-transits like auto tempo, nosimon and public transport like minibus, and therefore attracts urban passengers significantly from those modes. Around 88% of people living in a city where battery operated auto-rickshaws are available, use the mode now to meet their travel demand. Through attracting passengers from fuel operated vehicles, thus the mode replaces them at great extent. A considerable percentage of daily electricity demand of local towns is consumed by the mode which creates pressure on local electricity supply in turn. However, considering the duration and period of load shedding caused due to recharging the mode, energy consumption by the mode can be negotiated as the mode is liable only for 1.53 hours of load shedding a day which takes place at off-peak period (between 11:00 PM and 7:00 AM) at nightItem Effect Of Microencapsulating Of Denim Fabrics With Herbal Extract On The Handle And Care Properties(Daffodil International University, 2013-07) Sumithra, M.; Raaja, N.VasugiIn recent years, handle and Care properties has become a major requirement in textiles. .In the present study focuses on the micro-encapsulation to the 100 % cotton denim fabric using three herbal extracts of Ricinus communis, Senna auriculata and Euphorbia hirta to impart their antimicrobial efficiency by finishing the methanol extracts of these herbs on the denim fabric. The combinations of 1 part of Ricinus communis, 3 part of Senna auriculata and 2 part of Euphorbia hirta and conditions by ENISO20645 have been studied and the antimicrobial efficiency of these extracts (1:3:2) and the conditions of 20kgf/cm2 pressure and 20m/min rpm speed are followed by pad dry cure method for best results. To enhance the durability of the finished fabric, treated and washed samples are tested using such test methods- Drape Coefficient (%) (IS 8357/1977) ,Air Permeability Test (IS 11056: 1984) etc ,SEM and FTIR .The result indicated that the drapabilty and crease recovery of the sample was found increased after washes along with air permeability increase.The maximum was noticed in washed samples. Further the stiffness was found predominantly reduced after washing, and no change noticed in water repellency. In the SEM analyzed it was clear that the microcapsules were present in interstices of the fiber assembly of fabric even after 30 washes proving the adherence of the finishing in the samples and in the FTIR the stretching frequencies were found to exist even after 10, 20 and 30 washes.Item Effect of Variable Electric Conductivity on Radiative Heat Transfer Flow along a Vertical Plate of Micropolar Fluid with Variable Heat Flux and Uniform Source (or Sink) in a Porous Media(Daffodil International University, 2013-07) Uddin, M. J.A two-dimensional steady convective flow of a micropolar fluid past a vertical porous flat plate in the presence of radiation with variable heat flux has been analyzed numerically. The local similarity solutions for the flow, velocity profile, microrotation and heat transfer characteristics are illustrated graphically for various parameters entering into the problems. The effects of the pertinent parameters on the local skin friction coefficient, plate couple stress and the heat transfer are also calculated. Effect of variable electric conductivity and constant electric conductivity has been analyzed numerically for the skin friction coefficient and rate of heat transfer. The result shows that for Magnetic field parameter, Prandlt number, temperature dependent heat source (or sink) parameter and space dependent heat source (or sink) parameter, the variable electric conductivity is high pronounced than that of constant electric conductivity for micropolar fluid for both the case of skin friction coefficient and Nusselt number.Item Recent Climatic Trends in Bangladesh(Daffodil International University, 2013-07) Ishrat A, Keka; I, Matin; D.A., , BanuThis work is an attempt to study the characteristics of different climatic parameters and the recent climatic trends in Bangladesh by using the surface climatological data at 30 stations for the period of 34 years from 1971 to 2004. The Co-efficient of variation of annual rainfall varies from 14.3% at Satkhira to 30.8% at Chandpur. In analyzing the temperature over Bangladesh, a general increasing trend has been noticed. The annual maximum temperature shows positive trends of +0.023 oC/ year at Barisal. The annual minimum temperature shows positive trends at all stations except Hatiya. Drought analysis has been done throughout the country. The monthly drought analysis shows that the period from November to April is affected by drought. Bangladesh has experienced droughts of major magnitude in 1971, 1978, 1979, 1981, 1982, 1989, 1992, 1994 and 1995. Climatologically Bangladesh was divided in different zones by six different methods. According to Koppen classification, more than 50% of the total stations of the country falls under the ‘Tropical monsoon: Hot; seasonally excessive rainfall’ type of climate and the remaining 50% falls under ‘Tropical savanna: Hot; seasonally dry’ type and “Subtropical monsoon: Mild winter; dry winter, hot summer” type of climate.Item Effect of M: L ratio on dyeing of jute fabrics using REMAZOL RR & DRIMAREN HF(Daffodil International University, 2013-07) Iqbal, Md. Asib; Chowdhury, Nazmina; Moniruzzaman, Mohammad; Mohajan, Suman; Rashid, Mir Akmam NoorReactive dyes are widely used for dyeing and printing cellulosic materials and blends containing cellulosic portion. Remazol RR & Drimaren HF both are Reactive dyes widely used in Jute dyeing .From the comparison result, it is also seen that due to low M: L ratio strength and hydrolysis% of both dyes increase & decrease respectively. The result of strength & Hydrolysis% is different from Drimaren HF & Remazol RR. Here we showed that Drimaren HF combination is better than Remazol RR combination.Item Applications of Palm Oil and Palm Kernel Oils in different food products of Bangladesh(Daffodil International University, 2013-07) Hossain, Md. BellalAmong the commonly used vegetable oils and fats, palm oil is by far the most versatile. After refining, palm oil possesses all the characteristics required for many uses without hydrogenation. By fractionating palm oil, its uses are further increased. Hydrogenation and interesterification increase its uses even further, especially in making specialized and sophisticated edible products. Its versatility makes it a suitable raw material for many applications both in edible and non-edible products. The functionality of shortenings to be used in cakes, "butter cream" fillings, biscuits and pastry is dependent on several factors, such as a smooth consistency to facilitate mixing and a fine crystal structure in the solid fat phase. This contributes to smoothness, and is essential in cake making and creaming applications.Item The Physicochemical Effect of Leachates on Ground Water within Okpuno-Egbu Umudim Dumpsite Nnewi, Anambra State Nigeria(Daffodil International University, 2013-07) Momoh, Stephen O.; Mgbemena, Chinedum O.; Agbadua, Segun A.; Matthew, David O.Water samples were collected from six different borehole sites at radial distances of 50metres, 90metres, 100metres, 130 metres 150 metres and 220 metres respectively within the vicinity of Okpuno-Egbu, Umudim, Nnewi dumpsite in Anambra State, Nigeria and analyzed for physicochemical properties, microbiological and heavy metals levels. The parameters determined were the turbidity, conductivity, pH, total dissolved solids (TDS), Total Hardness, Iron, Nitrate, Phosphate, Sulphates, Magnesium, Chloride, Calcium and heavy metals such as Copper, Zinc and Lead, Cadmium using conventional equipment and standard laboratory procedures. These parameters were compared with control samples and the established international and national standards - World Health Organization (WHO),U.S Environmental Protection Agency(USEPA) and National Agency for Food and Drug Administration and Control(NAFDAC). The water samples from borehole sites within radial distances of 50 to 130 meters from the dumpsite geographical location was found to contain high concentrations of cadmium above approved standards. This study among other things revealed firstly, that the dumpsite leachates are a major source of the Cadmium pollution in this geographic location and secondly, the contaminant level of the water from the various sites are a function of the proximal distance to the dumpsite and the topography of the borehole site.Item Development of Martempered Ductile Iron by Step-Quenching Method in Warm Water(Daffodil International University, 2013-07) Akinlabi, Oyetunji; A. A, Barnabas; J.O.T, AdewaraThe evaluation of the suitability of warm water for interrupted quenching of ductile cast irons in the production of Martempered Ductile Iron (MDI) was carried out. Ductile cast irons used were normalized at a temperature of 850oC for 60 minutes. The normalized specimens were subsequently heat-treated in muffle furnace to a pre-determined temperature of 850oC for 30 minutes, then step-quenched in warm water maintained at temperature of 80oC for 40 seconds followed by tempering at different tempering temperatures (175oC-425oC) and times (30-180 minutes). Hardness test was used to evaluate the mechanical property while the metallographic examinations that produced different microstructures were used to evaluate the transformation behavior. The results showed that the developed MDI has a high average hardness value of 53Rc at the lowest transformation temperature, and 19.6Rc at the highest transformation temperature. Metallographic analysis showed that untempered martensite was obtained at holding temperature below 250oC, tempered martensite at 250oC to 325oC, tempered martensite at holding temperature of 350oC for short holding times, above which the specimen is over-tempered (depending on the holding time). This showed that warm water is a suitable quenchant for the production of MDI.Item Investigation of Foundry Properties of Oshogbo and Saki Silica Sand Deposits(Daffodil International University, 2013-07) Ayoola, W.A.; Oyetunji, A.; Adeosun, S. O.; Sekunowo, O. I.; Bodude, M. O.The quality of moulding sand used in foundry usually exerts significant influence on cast properties. It is therefore imperative that the moulding characteristics of a green sand deposit are established prior to its application. This work compares the foundry properties of moulding sand from River Osun and Saki with a view to determining their suitability for casting household utensils. In addition, it also investigated the effect of termite hill activities on moulding sand. Samples of the sands were obtained from different locations within the deposits in Oshogbo and Saki respectively. AFS sieve analysis was performed on the sand to obtain 600 µm grain sizes. These compositions were later mixed in different proportions and then subjected to green and dry compression strengths, shatter index, permeability and moisture content tests. The results obtained indicated that Oshogbo sand deposit has superior green and dry compression strengths values of 16.35 kN/m2 and 14.49 kN/m2 over that of Saki which exhibited 9.3 kN/m2 and 8.3 kN/m2 respectively. The highest permeability of 193 ml/min was demonstrated by Saki compared with 79 ml/min by Oshogbo deposits while the difference in their moisture contents is insignificant. The shatter index of 64 % and 72 % was obtained for Oshogbo and Saki sands respectively. These results demonstrated the possible utility of both sands for making of sand casting moulds. However, Oshogbo deposit is recommended for its higher fraction of the 600µm grain being the preferred size with demonstrable foundry sand desired properties.