Open Access Case Study

Study of Flexure Behavior of Beams Reinforced with Different Hybrid Percent of Glass and Carbon Bars

Mostafa A. Osman, Hala M. Ismail, Hoda A. Atya

Current Journal of Applied Science and Technology, Page 1-12
DOI: 10.9734/BJAST/2016/27643

An experimental program has been conducted in order to investigate the flexural behavior of concrete beams reinforced with hybrid glass and carbon bars. A test series of fifteen simple beams containing different types of reinforcement (steel, glass and hybrid carbon & glass) bars had been conducted in this investigation. The parameters included in the experimental program are the reinforcement ratio, the carbon fiber volume fraction (CFVF) in the bar and the strength of concrete. The effect of hybrid bars reinforcement on the flexural response, cracking load, crack propagation, deflection, ultimate capacity, strain in the reinforcement bar at middle of the span and failure characteristics for the beams, is examined. Based on the experimental results, It was founded that the beams reinforced with hybrid bars behave linearly up to cracking load with high initial stiffness and linearly after cracking with great reduction in stiffness, As the carbon fiber volume faction increase the deflection of the beam at ultimate load decrease, Beams reinforced with hybrid bars 40% C and 50% C with medium strength concrete give higher ultimate load than that of the beam reinforced with steel at the same strength of concrete, but  generally with less number of cracks.

Open Access Policy Article

Solar Energy in Ireland – A Position Paper

Lisandra Meneses

Current Journal of Applied Science and Technology, Page 1-16
DOI: 10.9734/BJAST/2016/30972

Solar energy has the potential to become a significant energy source in the Republic of Ireland. This paper presents arguments against and for solar energy with focus on planning, community benefits, environmental impacts and intermittency.

Ireland’s 2020 greenhouse gas (GHG) emissions reduction target is a 20% reduction in non-emission trading scheme (ETS) emissions compared to 2005 levels. However the deployment of solar energy will require citizens’ engagement and the government needs to play greater role in the transition to a low carbon future.

The paper presents a position regarding solar energy development in the Republic of Ireland, supported with several study cases.

Open Access Original Research Article

Heat Transfer Enhancement in Corrugated Plate Heat Exchanger

Maddali V. S. Murali Krishna, M. Basava Omkar Swamy, G. H. Manjunath, N. Venkateswara Rao, Battula Sreedhara Rao, P. V. Krishna Murthy

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2016/28438

Background of the Problem: Heat exchanger is a device in which heat transfer occurs from hot fluid to cold fluid and vice versa; It is used for many applications particularly for process industries. Plate type heat exchanger gives better solution in terms of heat transfer, when compared with different types of heat exchangers. Design pressure is less than 20 bar, while design temperature is less than 180°C for a plate heat exchanger. Little reports were available on heat transfer analysis of corrugated plate heat exchanger with variation of viscosity of fluid and corrugation angle.

Aim: Investigations were carried out to determine heat transfer rate of corrugated plate heat exchanger with varied corrugation angles of 30°, 40° and 50° with varied test fluids of water, 10% glycerin, 20% glycerin and 30% glycerin. 

Methodology: A single corrugation pattern on three plates arranged in parallel with varied chevron angles with spacing between the plates was 5 mm. Cold water/10% glycerol solution/20% glycerol solution/ and 30% glycerol solution were used as cold fluids, with the flow being counter flow. Hot water at 70°C at constant flow rate was used for heating the test fuels.

Design Variables: Test fluids of different viscosities and corrugation angles.

Brief Results: It was observed that heat transfer coefficient was higher for a given Reynolds number for 50° corrugation angle compared to other corrugation angles of 30° and 40°. By using Regression analysis, a new correlation was developed for corrugated plate heat exchanger for the prediction of Nusselt number, which was a function of Reynolds number, Prandtl number and corrugation angle. Nusselt number predicted by correlation was correlated with experimental result, which was deviated by 8% only from actual experimental result. Also the correlation was compared with that of other researchers in order to validate the data.

Open Access Original Research Article

Open Access Original Research Article

Hygrochromic Materials Generated by Multilayer of Elytron of the Necrobia rufipes

Issaka Ouedraogo, Mamoudou Traore, Alioune Ouedraogo, Belkacem Zeghmati

Current Journal of Applied Science and Technology, Page 1-6
DOI: 10.9734/BJAST/2016/30923

This paper focuses on to the study of the origins of Blue spectrum reflections of the elytron of Necrobia rufipes, of large family of Cleridae. We combine experimental and numerical method, to explain the structure responsible of the elytron blue color. The experimental results have shown a main peak at 450 nm for dry structure and 548 nm for the impregnated structure, under specular angle incidence 15°. This band reflecting correspond blue and green color. The numerical reproduction of the reflectance spectrum gives 447 nm and 506 nm. These results confirm that the multilayer is responsible for the blue color. We notice that the angle of incidence increases, the main reflection peak moves to smaller waves length. The impregnated structure shows a very interesting property that change color depending on the relative humidity rate. This property can be used in the food industry to control the temperature.

Open Access Original Research Article

Spatial and Seasonal Variation of Selected Water Quality Parameters in Chania River Catchment, Kenya

P. K. Kimani, G. T. Thiong’o, J. K. Mwangi

Current Journal of Applied Science and Technology, Page 1-16
DOI: 10.9734/BJAST/2016/30209

River systems in Kenya have been under threat from anthropogenic based pollution for a long time. River Chania which originates from the Aberdare Ranges and flows through highly productive agricultural land towards Thika town is one of these rivers. It is the only source of water for Thika town and parts of Machakos County. Non-point pollution from agricultural lands and point pollution resulting from settlement have led to water quality degradation in the river. The aim of this study was to investigate water quality in River Chania, assess types of pollution from the catchment and propose mitigation measures. Water sampling and analysis was done in accordance with the standard methods of the American water works association and statistical packages used for statistical analysis. Sampling was done in both wet and dry seasons and on seven different locations along a selected stretch of the river. Physical parameters were determined onsite using portable meters while anions; SO42-, NO3--N, NO2--N, PO43- and Cl- were determined using spectrophotometric methods. Metals analyzed were; Na, K, Ca, Mg, Mn, Fe, Zn, Cu, Pb and Cd using Atomic absorption spectrophotometer. Turbidity was the highest recorded parameter during the wet season with a mean of 169.4 NTU and its strong correlation with 75% of the parameters (Pearson’s r>0.5) meant that farming in the upper catchment had an effect on nitrate and phosphate among others leaching into the river during the wet season. In summary, 45% of the parameters showed significant seasonal variation (p<0.5) with mean concentration of 50% of the parameters being higher during the dry season. Turbidity, nitrate, nitrite, manganese, iron and lead exceeded WHO guidelines indicating poor water quality in the catchment. As domestic and industrial waste water contribute to point pollution downstream, unsustainable farming practices give rise to significant nonpoint pollution upstream of the river. The study recommends strict enforcement of environmental laws to curb point pollution and an incentive based approach to reduce non-point pollution with public enlightenment on how to control anthropogenic activities.

Open Access Original Research Article

Impact of Stochastic Load and Hybrid Distributed Generation Penetration Level on Transient Stability of Power Systems

P. K. Olulope, K. A. Folly

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2016/28163

The deployment and integration of hybrid power system into the distribution network is increasing because of the potential to provide higher quality and more reliable power to consumer than a system based on a single source. The combination of two or more energy sources and its integration into the distribution network coupled with the varying load introduce different dynamics into the system than the system with single source. The impact of stochastic load and increasing penetration of hybrid distributed generation on transient stability is presented in this paper. To investigate this impact, a detail modelling of grid connected hybrid wind/solar PV and small hydropower system with a single machine infinite system is carried out. The configuration of the proposed grid connected hybrid distributed generation (HDG) consists of a doubly-fed induction generator (DFIG), a solar PV and a small hydropower system (SHP) connected together. The wind turbine is integrated through PWM converter into the existing grid while the solar PV consists of DC sources integrated through PWM inverter and the hydro power is directly connected using a synchronous generator. The simulations were performed in DIgSILENT power factory software.

Open Access Original Research Article

Nexus between Leadership Styles and Performance of Small and Medium Manufacturing Firms in Kenya

Peter Kihara, Henry Bwisa, John Kihoro

Current Journal of Applied Science and Technology, Page 1-13
DOI: 10.9734/BJAST/2016/29341

This paper focuses on the nexus between leadership styles and performance of small and medium manufacturing firms (SME’s) in Kenya. The leadership styles examined include the transformational, transactional and passive/avoidant behaviour. This study is underpinned in the Dynamic Capabilities View of the firm and sought to examine whether leadership styles influences the performance of manufacturing SME’s. A triangulation of both quantitative and qualitative designs was used. Primary data was collected using a self-administered questionnaire from a sample of 115 firms obtained from a population of 165 manufacturing SMEs. Hypotheses were tested using bivariate correlations and regression analysis. The results indicated that leadership styles positively and significantly influences manufacturing SME’s performance (r =.259**P = .005). Secondly, most of the CEO’s in these firms practices transactional leadership style (composite mean score, 3.54), followed by transformational leadership (composite mean score, 3.42) and lastly passive/avoidant leadership (composite mean score, 3.12).Thirdly, this study found that transformational leadership style is the best in these firms (r =.297**P =.001; β1=.208, P=.013). The influence of transactional leadership style (r = .180, P =.054) and passive/avoidant leadership behaviour (r = .169, P = .071) was found to be insignificant.

Open Access Original Research Article

Useful Formulas for One-dimensional Differential Transform

Eman Anower Elmabrouk, Fawzi Abdelwahid

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2016/29916

In this work, we introduced new useful formulas for one-dimensional differential transform and applied the differential transform method to selected linear ordinary differential equations. This study showed that this method is powerful and efficient in finding series solutions for linear differential equations and capable of reducing the size of calculations comparing with other methods.

Open Access Original Research Article

Strength Properties of Concrete Produced With Iron Filings as Sand Replacement

Festus Adeyemi Olutoge, Michael Attah Onugba, Amana Ocholi

Current Journal of Applied Science and Technology, Page 1-6
DOI: 10.9734/BJAST/2016/29938

An experimental study was carried out to investigate the strength properties of concrete produced with iron filings as partial replacement for sand. Concrete specimens (cubes, cylinders and prisms) were cast and tested for compressive, split-tensile and flexural strengths at 0% (control mix), 10%, 20% and 30% replacement of sand by weight with iron filings after curing in water for 28 days. The results obtained showed that the compressive strength of concrete increased for the 10% and 20% replacement levels of sand with iron filings by 3.5% and 13.5% respectively while there was a decrease of 8% for the 30% replacement level. The split-tensile strength of concrete for the 10% and 20% replacement levels increased by 12.7% and 1% respectively and decreased marginally by 1.7% for the 30% replacement level when compared to the control mix. The flexural strength of concrete increased by 11.1% and 4.8% for the 10% and 20% replacement levels respectively while it decreased marginally by 1.6% for the 30% replacement level as compared to the control mix. An optimum of 10% and 20% replacement by weight of sand (fine aggregates) with iron filings in concrete mix is recommended for concrete production depending on the desirable property required in the concrete.