Wednesday, 2 August 2017
Engineering Journal : May issue 2017
Abstract— A hybrid photovoltaic solar dryer was designed, constructed and tested in the Department of Food Science and Technology, Modibbo Adama University of Technology Yola, Nigeria. The thin layer drying behaviour of tomato slices using a hybrid drying method compared to solar and open sun drying was investigated. The dryer consists of solar collector, photovoltaic solar panel, battery and drying chamber. The dryer was operated as both a solar-energy dryer and as a hybrid solar dryer. The drying performance of the dryer was evaluated with fresh tomato slice and compared with open sun drying under the same climatic conditions. The dryer recorded a raised temperature of 62℃ attainable in the drying chamber of hybrid dryer and 54oC attainable in the drying chamber of solar dryer. The moisture content of tomato slices was reduced from 94.22 % wet basis to 10 % in 6 hours for hybrid drying method while it took 9 hours to achieve the same moisture content reduction in the solar dryer. The average drying rate and the efficiency was computed as 0.0800kg/h and 71% for hybrid dryer and 0.0578kg/h and 65% for solar-energy dryer respectively. The quality of the tomato samples dried using the hybrid dryer was superior to those of solar and sun drying methods. From the result of this study it shows that a hybrid solar-energy dryer using photovoltaic (PV) solar panel suggested a promising process for adoption to preserve tomato which can prevent it from spoilage and post-harvest losses. The good quality and shelf stable dried tomato slices is indicative for a sustainable productivity that will create a sound avenue for economic growth in tomato producing regions of the world.
Keywords— design, hybrid dryer, photovoltaic solar panel, solar dryer and tomatoes.
Abstract— The research aim was to the study the intelligent soil moisture control system in agricultural green house based on Adriano Uno microcontroller automation control. This kind of intelligent soil moisture control system helps to control the moisture level of the field and supply the water if required. In this research embedding a control system into an automatic water pump controller depend upon the moisture of the soil. This system also ability to detect the level of methane gas in the green house. The intelligent soil moisture control system in agricultural green house designed in the research had wonderful effort of man-machine interface, it is very simple, cheep and convenient high degree of automation system. Not only that this system helps to prevent wastage of water. This system is a prototype, which makes this self-sufficient, watering itself from a reservoir. Solar energy is used in this system makes it more environment friendly.
Keywords— ATmega328p microcontroller, temperature sensor, methane sensor, soil moisture sensor , solar cell, DC Motor. L293D Motor Driver.
Abstract— Safety management is associated with the policies, objectives, procedures, methods, roles and functions that aim at controlling hazard and risk in socio-technical systems. Companies that have implemented effective OSH Management system have reported benefit from increase operational efficiency, reduction in insurance cost and improve in workers retention and satisfaction. Many accidents that occur at construction site are due inadequate adherence of workers to work procedures. The awareness and perception of workers toward safety, health and their working environment are important aspect to enhance the building construction to the better condition to the workers. Workers play an important role in accomplishment of the building construction. All these supporting evidence reflects on the needs to study building construction workers knowledge of safety management system. The study is a criteria – based study, in which 24 construction companies were selected for the study The respondent samples used in the study were drawn from the total population of permanent construction workers in the 24 construction companies selected. The total numbers of permanent construction workers in the 24 construction companies are 750 while 254 were selected for the study. The research questionnaires were administered on 254 permanent construction workers within the 24 construction companies in Abuja. The analysis of the questionnaires survey data was undertaken using the statistical package for social science (SPSS) version 20. A reliability test was conducted on the data in order to control error within the data. The Cronbach’s Alpha of the two variable data are .853 and .863 respectively and make the data reliable. Correlation analysis was conducted in order to determine the relationship between worker’s general knowledge and worker’s safety management knowledge and the result was found to be significant (P<0.005). This relationship was modelled using simple linear regression and from the model the result shows that improvement on the worker’s safety management system knowledge practice on sites will improves general knowledge among construction workers. Therefore, workers’ knowledge of safety management systems significantly influences the overall benefits of safety management system on the construction sites. As such there is need for potential improvement on the knowledge or awareness of the workers to safety management system as perceived from the analysis in order to bring about the expected high performance standard on construction sites.
Keywords— Safety Management, Knowledge, Workers, Construction Sites, Improvement.
Abstract— Concrete is the most widely used construction material worldwide. Strength of a concrete structure may have to be assessed without causing physical damage to it, due to various reasons like its monumental importance or the legal dispute on whether the strength of the concrete in the structure is satisfactory enough or not. In an attempt to meet the above demand, correlation and comparison between Destructive Test (DT) and Non Destructive Test (NDT) were carried out.
A total of 24 concrete cubes (150 mm x 150 mm x 150 mm) were cast with concrete mix ratio of 1:2:4. 12 cubes were tested destructively for compressive strength with compression machine and 12 cubes were also tested non-destructively with Schmidt Rebound Hammer. Compressive strength test results at curing ages (7, 14, 21 and 28days.) were collated and analysed.
The results obtained from the non-destructive testing method were correlated with the results obtained from destructive testing method. The coefficient of correlation between the two set of compressive strength was 0.988 which indicates a perfect relationship between compressive strength results from both methods.
Keywords— Compressive Strength, Non Destructive test, Destructive Compression test, Schmidt Rebound Hammer.
Abstract— This study examines the effect of revenue diversification across and within interest and non-interest income on bank stability and performance in Tunisian banks over the period 2001-2014. Using panel estimations and instrumental variables approach to handle the endogeneity problem of diversification variables. We find that revenue diversifications among and within interest and non-interest revenue generating operations boost bank profitability and stability. Our findings suggest also that the benefits from diversification are largest for banks with more shifts to nontraditional banking business lines (investment banking) while, absent for banks which follow cross-selling strategies of financial services.
Keywords— bank performance, bank stability, interest income, non-interest income, Tunisian Banks.
Abstract— The effect of nanoparticles on the performance of nanofluids during flow through pipes with dual twisted tape inserts. A detailed literature survey on the use of twisted tape inserts and computation thermal properties of nanofluids is presented. Expressions for nanofluid thermal properties computation are discussed. Properties for Al2O3 and TiO2 nanofluid with volume fraction of 0.1 are computed. CFD simulations to study the behaviour of fluid during heat transfer when flowing through pipes with dual twisted tape inserts. Results of these simulations are discussed in the paper.
Keywords— nanofluid, CFD, Twisted Tape Inserts, Al2O3 nanofluid, TiO2 nanofluid.
Abstract— This paper aims to design size and implement a Photo Voltaic system (PV system) for powering a living room. The required load to be powered by the PV system is completely determined. A comparison between using normal and power saving loads is carried out. The power saving loads is chosen to reduce the overall cost of the required system. The proposed PV system for powering the predetermined load is introduced. Each part of the system is designed and sized based on the load requirement. Finally, the practical implementation for the overall PV system for powering the required load is done. The implemented system works in an efficient way.
Keywords— Design, Sizing, Implementation, PV system.
Abstract— A comprehensive study of fluidized bed nitriding was performance on a carbon steel (grade AISI St 41) and low alloy steel (grade AISI 4140) at 550 0C in 20 % N2 and 80 % NH3 atmosphere at a flow rate gasses of 0.7 m3/hr. Various surface roughness were used to incorporate nitrogen into these steels. The nitride layer formed at AISI 4140 showed better surface roughness and surface hardness than AISI St 41. With low chromium alloy (grade AISI 4140), nitrogen diffusion is more uniform in the lower surface roughness after nitriding process. It has been found that the surface microhardness of the compound layer increases with decreasing surface roughness and chromium alloy contents. The layer nitride has a decrease surface roughness ranging from 50 % at 0,1 µm to about 17 % at 0,5 µm. On the contrary, the carbon steel without chromium alloy (grade AISI St 41) sample show an enhance surface roughness between 1.3 to 2.5 times after nitriding process, but on 0.5 µm surface roughness sample show a decrease surface roughness of about 10%. All sample show an enhanced surface microhardness after nitriding significantly. Chromium alloy is found to enhanced the nitriding efficiency. Without chromium in the steel, a lower surface roughness provides a supplementary amount of implanted nitrogen available for further diffusion, and the uniform of the surface passive oxide. So, with limited surface roughness, more uniform layers with higher amounts of nitrogen can be achieved by low chromium alloy. However, with limited solubility of nitrogen atom in α-Fe into iron nitride form, the nitrogen becomes supersaturated reaction and nitride layer is more brittle and porosity. It is can be ascribed to the nitrogen solubility in the nitride layer, which at AISI St 41 is higher due to the formation of porosity phase while at AISI 4140 a phase rich in nitrogen (ϒand ε phases) is formed.
Keywords— roughness, fluidized bed, nitride layers, microstructures, SEM.
Abstract— The influence of some chemical impregnating such as polyphosphate urea, ZnCl2, AlCl3, FeCl3, H2NaPO4, H3PO4 on the carbonization process of viscose fiber cloth at the temperature range from 30 to 700 0C was studied in detail. By the thermalgravimetric analysis, the obtained results have showed that the presence of these chemical impreganating agents caused lowering the activation energy and increasing the carbonization viscose mass left at 7000C. The polyphosphate urea was proven to be a good chemical agent for the carbonization process.
Keywords— Viscose fiber, TGA, carbonization process.
Abstract— The Sign language is very important for people who have hearing and speaking deficiency. It is the only mode of communication for such people to convey their messages. In this paper, a feature detection scheme is introduced called SURF, which stands for Speeded Up Robust Features. The real time images will be captured first and then stored in directory and on recently captured image and feature extraction will take place to identify which sign has been articulated by the user through SURF algorithm. A Text to Speech conversion is also included in this project. An experimental result shows that the proposed approach performs well with low time.
Keywords— speeded up robust feature, Convolutional neural network, Text to speech, Deep dynamic neural network.
Abstract— It is becoming interestingly apparent that innovations of the classical antibiotics are not effective, that induces need for novel drugs. Peptide antibiotics exhibit a group of secondary metabolites with hydrophobic and cyclic structures containing d-amino acidc like compounds with more resistant to proteolytic degradation. Bacterial peptides can possess bactericidal, fungicidal, metal chelating and immunomodulation activities. Several bacteriocins are active as food preservation, resulting in foods with more naturally preserved and rich in nutritional properties. Antimicrobial peptides used against infections are isolated mainly from mesophilic bacterial species. Novel antibacterial peptides from thermophilic species are more stable at higher temperatures and pH, and can be improved by variation of cultivation conditions. These cells can growth either autotrophically or heterotrophically. Under mixotrophic conditions can utilize pyruvate or hydrogen with thiosulfate. The present review provides a general overview on primary structure of selected antibiotic peptides and their potential for industrial purposes as well as environmental and biotechnological applications.
Keywords— antibacterial peptides, novel drugs, metabolites, hydrophobic structure, immunomodulation.
Abstract— Major challenge in field of wireless sensor networks (WSN) is to provide full coverage of a sensing field and connectivity of relaying nodes. Many applications—such as object tracking, healthcare, natural environment protection and battlefield intrusion detection —requires the full coverage at any time. Load balancing aims to optimize resource use, maximize throughput, minimize response time, and avoid overload of any single resource. In this paper we are over viewing techniques which are used in WSN for load balancing. The maximum cover tree (MCT) difficulty is to construct several connected cover trees and difficult in Nondeterministic Polynomial (NP)-Complete problem, Ant colony based scheduling Algorithm (ACB-SA) can used to solve the efficient coverage problem but it has time delay as drawback, And Temperature aware Algorithms that seek to save energy but the implementation is complex. In order to mitigate limitations above, Novel maximum connected load-balancing cover tree (MCLCT) algorithm is proposed and it is composed by two sub strategies: a coverage-optimizing recursive (COR) heuristic and a probabilistic load-balancing (PLB) method. This Algorithm provides the better coverage and connectivity among others which is presented as a result of this survey. Simulation results show the output in terms of energy efficiency and connectivity maintenance.
Keywords— wireless sensor networks, Coverage / connectivity preservation, scheduling, lifetime maximization.
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