Open Access Short Research Article

Design and Analysis of Carbon Fiber Reinforced Composite Shell Structure Using Classical Laminate Plate Theory

P. V. Gopal Krishna, Podila Meghana, A. Sai Kumar, K. Kishore

Current Journal of Applied Science and Technology, Page 1-12
DOI: 10.9734/BJAST/2017/31981

The main focus of this project is to understand the nature of these laminated composites when subjected to specific damage cases like loads. In order to understand the progression of the failure modes in a laminated composite, models were designed and analyzed using ANSYS 14.5. In this work composite cylinder is designed which can withstand an external pressure of 5 bar. Stress analysis of the structure is done using classical laminate theory theoretically and the result obtained is validated using finite element analysis procedure using ANSYS and the error is very less.

The behavior of the composite cylinder is checked by exploring the stresses and strains. The present work includes determination of optimum design parameters like fiber orientation. Finally, utilizing the finite element modeling of a cylindrical shell specimen, a relative comparison is made between the results of the finite element and the analytical method. The results thus obtained were found to be in good agreement in terms of damage size. To check the health of the composite cylindrical shell, failure criteria’s like Tsai-wu and Maximum stress criteria were also calculated in this paper.

Open Access Original Research Article

Evaluation of SDSM Performance in Simulating Rainfall and Temperature over Nigeria

Olaniran J. Matthew, Olawale E. Abiye

Current Journal of Applied Science and Technology, Page 1-15
DOI: 10.9734/BJAST/2017/32536

In this study, the performances of the Statistical Down-Scaling Model (SDSM) to simulate rainfall and temperature for the period 1995-2010 over Nigeria were evaluated. Twenty-year (1975-1994) station observations of rainfall and temperatures from 12 different locations scattered over the country were used as predictands in the SDSM model calibration. Large-scale atmospheric predictor variables were downscaled over each location and used in the SDSM to simulate daily rainfall and temperatures for the validation period. Model results were validated against four observation datasets (NMET, CRU, UDEL and GPCC) and biases in the simulations were derived. Results demonstrated that SDSM generally performed adequately well in reproducing the daily temperature and rainfall across the country. The biases in daily rainfall and temperature ranged between ± 1.0 mm/day and ± 0.79°C/day respectively. There were also good and significant agreements between the model simulations and the monthly observations of temperature (0.56≤ r ≤ 0.90) and rainfall (0.32 ≤ r ≤ 0.67) at p ≤ 0.01. The performances of the models varied across the stations and seasons with overall better simulations for temperature than rainfall.

 

Open Access Original Research Article

Nutritional Composition of Oyster Mushroom (Pleurotus ostreatus) Grown on Softwood (Daniella oliveri) Sawdust and Hardwood (Anogeissus leiocarpus) Sawdust

G. F. Ogundele, S. W. Salawu, I. A. Abdulraheem, O. P. Bamidele

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2017/28160

This study was conducted to examine the effect of two different substrates (sawdust) obtained from hardwood (Anogeissus leiocapus) and softwood (Daniellia oliveri) on nutritional composition and yield of oyster mushroom (Pleurotus ostreatus). The proximate composition, mineral content and various growth parameters were analysed on the harvested mushroom from the two substrates. The proximate composition result showed that oyster mushroom harvested from the hardwood sawdust (Anogeissus leiocapus) have the highest protein content (26.67%), ash (9.83%) and crude fibre (11.05%). The mushroom harvested from the hardwood sawdust (Anogeissus leiocapus) also had the highest mineral content with potassium having the highest (22.81 mg / 100 g). The growth assessment of the mushroom harvested from the two substrates showed that softwood sawdust (Daniellia oliveri) has a better yield than hardwood sawdust. In conclusion, hardwood sawdust (Anogeissus leiocapus) produced oyster mushroom with better nutritional quality than softwood sawdust (Daniellia oliveri).

Open Access Original Research Article

Forest Conservation: Knowledge, Attitudes and Practices of Preparatory School Students

Kidanemariam Paulos

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2017/32224

The main purpose of this study is to assess students’ environmental knowledge, attitude, and practice about forest conservation. Descriptive research method was used for the study. The participants of the study were 85 students from the preparatory school who were in the last year of their study. Results show that students in general, have a fair to a good level of environmental knowledge. However, this held knowledge did not escort them to environmentally responsible behavior. In addition, the findings of the study indicate that there was a positive correlation between knowledge and attitude and a weak relationship between students’ level of knowledge and environmental good practices. Similarly, very weak correlation was found between attitude and practice. Analyses of gender effect reveal that female students’ environmental participatory behavior was higher than their male counterparts. Results further pointed out that students living in rural area scored significantly higher than their urban counterparts on environmentally responsible action. Nonetheless, sizeable similar studies of this kind have been carried out in different parts of the world, this study is likely to contribute to the knowledge predestined on Ethiopian context that striving to rehabilitate degraded environment. The mismatch between environmental knowledge and environmentally favorable behavior calls for among others use of methodologies in classroom that help students to see their behavior more critically.

Open Access Original Research Article

Development of a Manually Operated Multi-purpose Roasting Machine

Olayinka Oladele Awopetu, Adegboye Foluso Aderibigbe

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2017/31679

Aim: The aim of this research is to design and fabricate multi-purpose roasting machine.

Study Design: Development of a manually operated multi-purpose roasting machine was achieved with the aid of conceptual sketch, design analysis and creo parametric software.

Place and Duration of Study: Department of Mechanical Engineering, Federal University of Technology, Akure, Ondo State, Nigeria, between July 2014 and October 2016.

Methodology: Design of the developed multi-purpose roasting machine was done using creo parametric software. Some factors were considered before fabrication of the developed machine such as selection of materials, operating parameters, manufacturing processes and functional requirements.

Results: The multi-purpose roasting machine was developed and tested on food items (maize and plantain).

Conclusion: The multi-purpose roasting machine was developed based on the design. The machine developed is a simple technology which can be easily operated by a single person of an average height of 1.4 m. The developed machine is a capable of roasting food items (maize, yams and plantain) depending on the choice of the operator and season of harvest. The bill of engineering measurements and evaluation (BEME) of the developed machine is 231.26 dollars.

 

Open Access Original Research Article

Geochemical Characteristic and Petrogenesis of Malumfashi Schist around Tandama Area, North-Western Nigeria

Idzi O. Alaku, Ogunbajo I. Moshood, Ako T. Agbor, Alabi A. Amos

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2017/30116

Malumfashi schists which occur in association with migmatite-gneisses and biotite granite, occupy about 60% of Tandama area, north-western Nigeria. These rocks were studied with a view to evaluate their compositional characteristics and their evolution.

The lithology revealed from systematic mapping and petrographic examinations shows that the schist is mica schist, which is part of the Malumfashi Schist Belt of Nigeria. The mica schist consists of greater than 50% micaceous minerals and less than 50% quartz and feldspar. It is light grey to silver grey in colour, well foliated and mostly weathered to rusty brown or reddish brown. Mineralogical determinations from optical studies show a high proportion of biotite and minor amounts of plagioclase and quartz. Chemical analysis of the samples obtained by Inductively Coupled Plasma Mass Spectrometry (ICPMS) instrumentation method, involving major and trace elements reveals the nature of the mica schist. The A-CN-K diagram reveals a shale protolith which suffered moderate to high chemical weathering, prior to being metamorphosed. Obtained Rb/Sr ratio (>0.4%) and SiO2/Al2O3 values support the shale protolith hypothesis for the schist, diagnostic geochemical features like the Na2O/Al2O3 values, trace element ratios such as Th/U and REE patterns suggest that the protolith are predominantly derived from felsic igneous sources. Tectonically, SiO2/Al2O3 versus K2O/Na2O plot revealed the protolith to have evolved within passive margin environment.

 

Open Access Original Research Article

Geochemical Characterization and Protolith of the Migmatite-Gneisses of Tandama Area, Katsina State, NW Nigeria

Idzi O. Alaku, Ogunbajo I. Moshood, Ako T. Agbor, Alabi A. Amos

Current Journal of Applied Science and Technology, Page 1-18
DOI: 10.9734/BJAST/2017/30117

Migmatite-gneisses, which include migmatite, granite gneiss, and augen gneiss, underlie more than 70% of Tandama area, in North-western Nigeria. They are associated with schists, and are intruded by granites and pegmatites. These rocks are thought to have undergone a reworking during the Pan-African Orogeny. The aim of this research is to present results of geochemical investigation of Migmatite-gneiss Complex in the study area with a view to determine their geochemical characteristics and petrogenesis. Whole rock geochemical analyses have been used to evaluate the characteristics, petrogenesis and mode of emplacement of the protoliths. Geochemically, these rocks show granitic affinities. They are metaluminous to weakly peraluminous I-type, with S-type characteristic, magnesian to ferroan and alkali calcic and calcic. The protoliths could have been derived from the partial melting of tonalitic to granodioritic crustal rocks at low pressure, thus, producing metaluminous to slightly peraluminous high-silica, ferroan, alkali-calcic to calc-alkali melts, which is why it has some S-type character. These varying features are an indication that the protoliths are derived from mainly crustal melt mingled with mantle-derived component. The varying REEs and trace elements pattern displayed by the rocks is typical signature of arc rocks or continental crustal materials: the LREEs and LILE enrichment along with Rb, K, Pb, and negative Nb, Ta, Ti are evident of this signature. The incompatible trace elements show similarity to those of continental crustal rocks as indicated by the ratios in Th/U (2.21 – 12.4), Th/Yb (2.60 – 90.95), Ta/Yb (0.03 - 1.43), Ce/Pb (mainly 0.30 – 29.23) and high Ba/Nb (8.56 – 2402), the values of Sr/Y are generally<100, which is an indication of subduction-related rocks,the trend in Sr/Y ratio relative to Y contents in the rocks reflects essentially two types of felsic protolith namely crustal melts and slab melts. Similarly, the magnesian characteristic indicates close affinity to relatively hydrous, oxidizing melts, which is broadly typical of settings related to subduction. The high-K nature is characteristics of crustal rocks derived from remelting and differentiation of arc-accretionary complex crust. The rare earth element (REE) distribution shows that the migmatite-gneisses are enriched in the lighter rare earth elements (LREE) Sm, Pr, Nd, La and Ce, in that order of increasing abundance, with average values of 4.81 ppm, 7.90 ppm, 27.50 ppm, 38.44 ppm, 68.22ppm, respectively; and relatively depleted in the heavy rare earth elements (HREE) Lu, Tm, Tb, Ho, Yb and Er, with average values ranging 0.28 ppm, 0.30 ppm, 0.58 ppm, 0.65ppm, 1.91 ppm and 1.88 ppm respectively, and they exhibit negative EU anomaly, indicating that the rocks are highly fractionated. REE-chondrite normalized spider plot and plots in the chemical discrimination diagrams including the Y versus Nb plot, show that the protoliths were derived from partial melting and differentiation of granitic magma of hybrid origin which were emplaced in volcanic arc (VAG) to Syn-collision granite (Syn-COLG) tectonic setting. Variations thus, suggest igneous precursors for the migmatite-gneisses of this area, were derived from differing sources and depths.