Archives-December 

Friction-stir welding has received a huge interest in the last few years. The many advantages of this promising process have led researchers to present different theoretical and experimental explanation of the process. The way to quantitatively and qualitatively control the different parameters of the friction-stir welding process has not been paved. In this study, a refined energy based model that estimates the energy generated due to friction and plastic deformation is presented. The effect of the plastic deformation at low energy levels is significant and hence a scale factor is introduced to control its effect. The predicted heat energy and the obtained maximum temperature using the present model are compared to the theoretical and experimental results available in the literature and a good agreement is obtained. 

In the changing market scenario, the study of the supply chain model in a fuzzy environment is gaining phenomenal importance around the globe. In such a scenario, it is the need of the hour that a real supply chain is operated in an uncertain environment and the omission of any effects of uncertainty leads to inferior supply chain designs. This work presents a fuzzy possibilistic linear programming approach to make strategic resource – planning decisions in multi-product and multi-time period two-echelon supply chains. In this model, demand rate, holding cost, transportation cost, packing charge and toll fees are considered as triangular fuzzy numbers. The objective of the proposed model is to provide an optimal inventory level for the warehouses and distribution centers and also, minimizing the total cost related to transportation, inventory carrying, packing and toll fees of the entire supply chain for a finite planning horizon. An industrial case demonstrates the feasibility of applying the proposed model to real world problem in a two-echelon supply chain under uncertain environment. In addition to that, if the efficiency of the transportation will be increased by using the light weight eco-friendly plastic pail rather than the traditional one, then the reduction of the total cost in the supply chain is also analyzed.

The levels of fatty acids, phospholipids and sterols were determined in the testes of bulls, bucks (goats) and African giant pouch rats found in Nigeria. Results showed testes weights variations were (gram wet weight): 48.6-48.5 (bulls); 23.4-23.5 (bucks); 5.72-6.04 (African giant pouch rats). Crude fat range was 2.65-3.00 g/100 g dry weight; SFA varied from 27.0-48.0 % of total fatty acids; total unsaturated fatty acids varied from 52.0-73.0 %; PUFA range was 13.2-15.3 %; PUFA/SFA range was 0.274-0.565; MUFA/SFA range was 0.810-2.13; AA/DGLA range was 18.8-74.5; LA/ALA range was 2.81-19.1 whereas n-6/n-3 range was 4.38-10.4 and EPSI (PUFA/MUFA) range was 0.265-0.370. In the phospholipids, lecithin (phosphatidylcholine) was highest in all the samples with values of 236-307 mg/100 g or 44.7-45.7 %. Among the sterols only cholesterol was of any significant level with values of 260-378 mg/100 g or 99.992-99.994 %. Chi-square (X2) analysis showed that SFA, AA/DGLA and LA/ALA were significantly different among the samples. In phospholipids, the following parameters were signicantly different among the samples: Cephalin, Lecithin, Ptd-L-Ser (PS) whereas all phospholipid parameters were significantly different among themselves in the bulls, bucks and the African giant pouch rats. Cholesterol was also significantly different among the samples.

The research is about problem related to the heat stress among inside pipe welders at heavy industrial yard. Heat stress occurrence will causes several problems that affected the workers capability, health, perception and judgment in which it will reduces the efficiencies of work. The objectives of the research studies is to show the time region that worker might suffer from heat stress, compared the heat stress before and after safety procedure been executed, showed the correlation between several factors that contributes to the heat stress among workers and proposed a better work practice to the industry management. Methodology used in these research is done by heat environment monitor (QuesTemp34) which to measure the WBGT index. Analysis done by using QSPII to compare actual WBGT index with recommended WBGT index from ISO 7243 and SPSS software to evaluate the questionnaire. Expected result from the research is to identify the duration time of heat stress highly to occur and to compare the reduction of heat stress level between two conditions which is with and without blower.

An efficient, rapid and large scale propagation of the elite exotic, zero calorie, medicinal plant, Stevia rebaudiana Bert. through in vitro axillary bud multiplication was obtained on Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of BAP, Kn and Ascorbic acid. However, the high frequency of morphogenetic response from axillary meristem was optimized on MS medium supplemented with 5.5µm BAP along with 50 mg/l Ascorbic acid. On average 90-91 shoots were induced per-explant of the initial material. Non-rooted shoots were sub-cultured to ½ MS medium containing IBA (0.2-1.0µm) for rooting. However, shoots readily formed roots (100%) when sub-cultured to ½ MS basal medium containing IBA 0.5 µm. The rooted micro-shoots were carefully transferred to soil rite TC mix: garden soil: compost (1:1:1 v/v/v) and subsequently shifted to the field with a survival rate of 70±7%.

Mean temperature and precipitation are sensitive indicators of climate change. The present study examines the effect of climate change on temperature and precipitation regimes of Jhelum river basin using the predictor data of the global climate models (GCMs) and the local historical weather data. Multiple linear regression technique was used to carry out the downscaling of the GCM predictors. At the end of the 21st century the mean annual temperature of the Jhelum river basin is predicted to increase by 2.37°C, whereas the average annual precipitation is predicted to decrease substantially by 38.56%.

The large Peak to Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) system has undesirable effects on the system such as increase in the complexity of A/D convertor and reduction in the efficiency of power amplifier. In this paper, modified expression of Zadoff Chu sequence, generation of Zadoff Chu sequence using hardware efficient CORDIC algorithm and develop Zadoff Chu matrix transformation (ZCT) precoding based OFDM system to minimize PAPR in OFDM system. Zadoff Chu sequences are class of complex exponential polyphase sequences which has constant amplitude and these sequences posses’ good correlation properties. In ZCT pre coding based OFDM system, ZCT is applied to the constellation symbols before the Inverse Fast Fourier Transform (IFFT). The proposed system is simulated with VHDL and hardware efficient CORDIC algorithm is used for the generation of Zadoff Chu sequence. The achieved simulation results confirm that the proposed methods are capable of reducing the PAPR significantly by 3 dB for N=64 subcarrier and 16-QAM modulation at clip rate of 10-2.

Today, the consumption of Ready Mix Concrete (RMC) is rapidly increasing in India owing to the rapid growth in Infrastructural and Real Estate sectors. Supplying concrete with desired quality consistently has become a great challenge for the RMC suppliers. Hence, the evaluation as well as monitoring the quality of RMC production is critical. this paper is an attempt to a apply the Six Sigma DMAIC approach to a RMC Plant in Chakhan, Pune. The sigma level of the existing plant has been evaluated. Also the production is Statistically analyzed using various tools such as X bar chart and R charts and the process capability index has also been reported.

Wood properties of plantation grown (Mangifera indica L.) were evaluated in this study to determine the utilization potentials of this species in Nigeria. Five standing trees of Mangifera indica, were sampled at the butt, 50% merchantable length ML and 75% ML, and were radially partitioned into corewood, middlewood and outerwood, on the basis of distance from pith. Result obtained was analyzed using ANOVA at 5% level. MOR, MOE and MCS// decreased generally from base to top for all the sampled and variation in MOE was inconsistent. All properties studied increased from corewood to outerwood. The mean modulus of rupture (MOR) was 25.88N/mm2 which ranged 18.73 to 31.88 N/mm2 radially and the axial values ranged from 23.30 to 25.29 from 32.89 N/mm2.The mean modulus of elasticity (MOE) was 4628.20 N/mm2 and ranged from 7135.20 to 3665.60 N/mm2 radially and axially ranged from 4077.90 to 7334.20 N/mm. The mean maximum compressive test (MCS//) parallel to the grain was 13.00 N/mm2, it ranged from 11.50 to 18.0 N/mm2 radially while axially ranged from 11.30 to 14.60N/mm2. In particular, it was observed that Mangifera indica compared favourably with some economic tree species such as Chrysophyllum albidum, Hevea brasiliensis, Antaris africana and Hildergedia barteri but lower than those of economic tree species such as Milicia excelsa, khaya species, e.t.c. Woods of Mangifera indica varied significantly along and across the bole, and should be treated as such in their conversion and utilization. The wood is good in the production of low-to-medium items such as cabinet, chair frames and plywood production.

This work examined the influence of school farm on the learning of Agricultural Science in senior secondary schools in Ikwuano Local Government Area of Abia State. The study utilized a descriptive survey research design with random sampling techniques. Six public senior secondary schools were randomly selected from the twelve schools in Ikwuano and then one hundred and twenty (120) agricultural science students were randomly selected from the six schools sampled. (20 agricultural science students from each school sampled). Two research questions and one null hypothesis guided the study. Instrument for data collection was a 10-item structured questions. The method for data analysis were descriptive statistics (mean, pool mean and standard deviation) for answering the two research questions. z-test was used to analyze the formulated null hypothesis. The findings of the study are that school farm has a positive influence on the learning of Agricultural science in senior secondary schools in Ikwuano Local Government Area of Abia State. Based on these findings, it was recommended among others that government and even the school management should always ensure the establishment of a functional school farm in schools and both the agricultural science teachers and the students on their own should always ensure proper management and utilization of the school farm. More so, prices and awards should always be given to the best agricultural science students yearly in order to encourage and motivate others.