Open Access Short Research Article

Tensile Properties of High-purity Ca Metal

Austin Shaw, Liang Tian, Alan Russell

Current Journal of Applied Science and Technology, Page 1-6
DOI: 10.9734/BJAST/2016/26293

Recent interest in using calcium (Ca) as a reinforcement metal in Al/Ca metal-metal composites prompted this study of the mechanical properties of high-purity Ca metal. Previously reported measurements of Ca’s mechanical properties were performed on Ca of relatively low purity (~95 at%). Ca used in this study was purified by sublimation to reduce O, N, and C concentrations, yielding 99.95% purity metal for fabrication of tensile test specimens. Yield strength, ultimate tensile strength, ductility, and strain rate sensitivity of high-purity Ca were measured at both 77K and 295K for annealed and cold-worked Ca. Annealed samples were found to be more strain-rate sensitive than as-swaged samples. Both as-annealed and as-swaged Ca samples were stronger and more ductile at 77K than at 295K, behavior that seems to be supported by molecular dynamics simulations of perfect Ca single crystals.

Open Access Original Research Article

The Numerical Study of Efforts from the 4r Symmetrical Spherical Quadrilateral Mechanism with Technical Deviations

Ion Bulac

Current Journal of Applied Science and Technology, Page 1-16
DOI: 10.9734/BJAST/2016/24669

The technological (geometrical) deviations determine in the intermediate couples of the cardan joint supplementary efforts due to restrained movement. The 4R spherical quadrilateral mechanism, where by R is notated the rotation kinematic pair, from which is obtained the cardan mechanism, is of third family, as consequence, multiple statically indeterminate and for calculating the reactions from the kinematic pairs it is applied the elastic linear calculation, using the relative displacements method noted in plukerian coordinates. The results of the numerical solving of this problem will be presented under the form of a diagrams and will be commented.

Open Access Original Research Article

The Interaction between Photon and Free Electron

Wei-Xing Xu

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2016/25738

Based on the quantum mechanics, we discussed the interaction between the photon and free electron. We found: 1.The interaction between the photon and free electron is handedness dependent; 2. Compared to the left handedness photon situation, the frequency of right handedness photon will shift to the more infrared side after its interaction with the free electron and 3.The contribution from the interaction between the magnetic moment of free electron and the magnetic vector of photon to the frequency shift is not handedness dependent.

Open Access Original Research Article

Fuelless Power Generating Set and Power Inverter System: Analysis of Load and Efficiency Appraisal

I. O. Adewumi, B. A. Adelekan

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/23160

There is need for engineers to search for alternative power source as it is important due to need for a cleaner source of power that is environmental friendly. Fuelless power generator as fuelless generation is a device that is understood to function without the need for internal combustion engine which usually request for fuel as a source of input while power inverter or an inverter is an electrical power converter that changes direct current (D.C) to alternating current (A.C). Both inverter and fuelless power generating set was designed and constructed at Federal College of Agriculture, Moor Plantation Ibadan, Nigeria by the author. This research will focus on comparison of the two devices in terms of there load performance. The performance evaluation of the machine revealed that when there is no load acting on the machine, the efficiency of the machine is said to be at 0%. It can be concluded that the machine had the highest efficiency of 97.40% at a load of 100W and the lowest efficiency of 71.70% at a load of 600W. It was also observed that there is a decrease in the output of the machine when there is a high increase in the load. The result of the performance evaluation of the fuel-less power generating set shows that the machine is said to have an average efficiency of 56.43% at load of 600W for continuous operation. The peak efficiency of the constructed fuel-less power generating set will be 89.1% at load of 100W. For comparison, the result obtained from Power inverter, has clearly confirmed that the highest efficiency recorded is at 96.27% which is more higher than that of the fuel-less power generating set which is at 89.1%, at a load of 100W respectively.

Open Access Original Research Article

Silver Nanoparticles as Inhibition Agents of Cooling Tower Microorganisms

Jenny Arratia-Quijada, Juan José Villa Diaz, Ma. Ofelia Rodríguez García, Israel Ceja Andrade, Gregorio Guadalupe Carbajal Arízaga

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/25686

Silver nanoparticles are widely studied and the antibacterial activity is well-known. Although several methods of synthesis have been described, this article reports the simplest procedure using low cost reagents and a low consumption of energy, where silver nitrate is reduced by nitrate ions in an aqueous solution from pH 10.60 to 11.02. A relatively controlled dispersion of sizes was achieved and particles presented sizes between 49 and 76 nm dependent on the pH.

Solutions of these particles were used to incubate a mixture of Pseudomona spp. ATCC and Pseudomona spp. recovered from a water well. All the particles were affective against inhibition of these bacteria after 3 hours of incubation. Specifically, 49 nm particles reached suitable efficiency after 120 minutes even if they were diluted 50 or 10%, whereas particles with 65 nm demonstrated  having an efficient inhibitory effect on Pseudomona spp. at 10 or 100% of concentration after 140 minutes of incubation. Results obtained with both sizes proved that the contact time (140 minutes) to reduce the colony forming units (CFU) per milliliter (x105) to values lower than 1 is an adequate time for applications in water treatments of cooling towers. Additionally, the procedure here followed with low cost and low energy, facilitates the design of advanced antimicrobial treatments for cooling towers at industrial levels.

Open Access Original Research Article

Validation of Process Performance through Reliability Measurement

Christopher Chukwutoo Ihueze, Ebisike Paschal Soroibe

Current Journal of Applied Science and Technology, Page 1-13
DOI: 10.9734/BJAST/2016/20813

This study employed excels graphic tools to model and evaluate the reliability of production system using Eleme Petrochemical in Nigeria as a case study. The mean time between failures (MTBF) is the reliability parameter used. The exponential distribution function model was used to evaluate the consistency of ten production components and five cooling tower fans in series arrangement as an individual component in a production system. The Eleme Petrochemical production probability distribution function has exponential reliability distribution model with a reliability of 0.9999 within five hundred hours of operation while the reliabilities of critical components ranges from 0.63 to 0.89 for five hundred hours of operation. For 1000 hours of operation the reliability of components ranges from 0.40 to 0.63. Most of the system components have reliability of 0.37 at their mean lives. The hazard rate has exponential distribution described as chance failure phase in reliability analysis. This report recommends scheduled maintenance of 500hours and provision of redundancy to ensure maintainability and serviceability.

Open Access Original Research Article

Effects of Used Engine Oil as an Admixture in Concrete Durability

S. Beddu, N. Shafiq, M. F. Nuruddin, N. L. M. Kamal, S. N. Sadon

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2016/20738

Excellent flowability is one of the important characteristics of concrete for easier handling and placing and it facilitates the removal of undesirable air voids by introducing superplasticizer (SP). But due to environmental issue related to the waste during SP production, alternatives being initiate to incorporate used engine oil (UEO) that has the same function as SP. It was reported that UEO resulted in improving some concrete properties therefore can lead to counter problems of higher SP cost and UEO disposal. The principal aim of this research mainly to identify the effectiveness of UEO in durability improvement of concrete. Investigation of porosity, chloride penetration and high elevated temperature exposure was conducted. From the result obtained, UEO decrease the concrete porosity and comparable with SP. The result of chloride penetration showed that incorporation of 0.5% of UEO did not cause any adverse effect as compared to the control mix, which meant that UEO could improve the concrete durability. Elevated temperature exposure test was conducted and the percentage strength loss of concrete with UEO was almost similar to the mix with SP. It can be stated that UEO performed very good in durability improvement and comparable with SP.

Open Access Original Research Article

Genetic Algorithm-based Cost Optimization Model for Power Economic Dispatch Problem

Samuel A. Oluwadare, Gabriel B. Iwasokun, Olatubosun Olabode, O. Olusi, Akintoba E. Akinwonmi

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2016/24347

In any power generation and distribution system, a continuous balance must be maintained between electrical generation and varying load demand, while the system frequency, voltage levels, and security must all be kept constant and the cost of generation maintained at minimal level. Numerous classical techniques such as Lagrange, linear programming, non-linear programming and quadratic programming-based methods have been proposed for attaining these objectives. The attendant weaknesses to these methods include economic dispatch problem-induced non-optimal power flow and cost increment. Classical approach-based solution to the economic dispatch problem suffered some limitations, which include restriction to the local minima while the cost functions show non-convex or piecewise discontinuity in the functional space. Furthermore, treatments of operational constraints are very difficult using the classical approach. This paper reports on the formulation of a Genetic Algorithm (GA)-based model as a solution to the problems of economic power dispatch. The model considered GA as numerical optimization algorithms based on the principle inspired from the genetic and evolution mechanisms observed in natural systems and population of living being. The implementation of the model produced an application whose performance evaluation on power demand and transmission loss of three power generating systems and three Nigerian Thermal Power Plants showed superior performances of the new model over some existing ones.

Open Access Original Research Article

Influence of Adhesive Application on the Bond Strength between Feldspathic Ceramic and Resin Cements

Ana Maria Spohr, Bruna Gomes Daudt, Eveline De Bona Johann, Maurício do Nascimento Gerhardt, Rafael Nascimento Lourenci

Current Journal of Applied Science and Technology, Page 1-6
DOI: 10.9734/BJAST/2016/25600

Aim: To evaluate the influence of an adhesive on the bond strength between feldspathic ceramic and two resin cements. In addition the interface between the resinous materials and the feldspathic ceramic was evaluated microscopically.

Methodology: Forty-eight feldspathic ceramic discs were imbedded in self-curing acrylic resin and randomly divided into four groups as follows (n=12 per group): G1 – hydrofluoric acid + silane + adhesive + RelyX ARC; G2 – hydrofluoric acid + silane + adhesive + RelyX U100; G3 – hydrofluoric acid + silane + RelyX ARC; G4 – hydrofluoric acid + silane + RelyX U100. Cones of composite resin were bonded to the ceramic surface using the resin cements and then light cured. After storage in distilled water at 37°C for 24 h, the specimens were subjected to tensile bond strength tests in a universal testing machine at a crosshead speed of 1 mm/minute. Analysis of Variance (ANOVA) and Tukey’s test (α=0.05) were used to statistically analyse the results.

Results: The bond strength means (MPa) followed by the same letter were not significantly different: G1 (28.34 MPa)a, G2 (28.05 MPa)a, G3 (21.92 MPa)b, G4 (18.19 MPa)b. Scanning Electron Microscopy images showed that the adhesive and the two resin cements infiltrated the surface irregularities created by the hydrofluoric acid.

Conclusion: Adhesive application on the ceramic that was etched with hydrofluoric acid and silanized increased the bond strength between the resin cements and the feldspathic ceramic.

Open Access Original Research Article

Conversion of CO2 to CH4 by a Pulsed Hydrogen Plasma Shower Method

Keisuke Arita, Satoru Iizuka

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2016/26169

Aims: To suppress the emission of CO2 to the environment and to save the consumption of fossil fuels, CO2 was converted to CH4 by a newly developed hydrogen shower method with a hydrogen pulse plasma.

Study Design: Research study.

Place and Duration of Study: This study was performed for 2013 - 2015 at Department of Electrical Engineering, Tohoku University, Sendai, Miyagi, Japan.

Methodology: The experiment was carried out in a small chamber which was divided into two parts by an orifice disc of 3-mm-thickness stainless plate with one 0.5-mm-diameter hole at the center. Hydrogen gas was supplied from the left part, where hydrogen radicals of H* and H2* were produced by a pulse discharge. Hydrogen radicals were supplied through the orifice from the left part to the right part as a hydrogen radical shower. Carbon dioxide was directly supplied to the right reaction part, where CO2 was able to collide with hydrogen radicals and as a result CH4 was produced. 

Results: Dependences of CO2 decomposition ratio α, methane selectivity β, and energy efficiency γ on hydrogen flow rate, electrode distance, discharge tube diameter, applied voltage, electrode diameter, and gas feeding type were investigated. Methane was produced from carbon dioxide by using a hydrogen radical shower method. Methane was only organic species produced from CO2. Only CO was detected as non-organic by-product. It was found that the decomposition ratio α, methane selectivity β, and energy efficiency γ were α = 32%, β = 37%, and γ = 1.6 L/kWh, respectively, under optimized condition at the flow rate ratio of CO2: H2 = 1:2, gap distance of d = 6 mm, and input power of Pin = 4.6 W (1.2 kV, 3.8 mA) with a use of 6-mm-diameter electrode.  

Conclusion: Energy efficiency in our case was fairly improved. Hydrogen radical shower method was very effective for the conversion of CO2 to CH4.