ARPN Journal of Engineering and Applied Sciences                         ISSN 1819-6608
   
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ARPN Journal of Engineering and Applied Sciences              February 2014 | Vol. 9  No. 2
   
Title:

Nonlinear finite element analysis of shallow reinforced concrete beams using solid65 element

Author (s):

M. A. Musmar, M. I. Rjoub and M. A. Abdel Hadi

Abstract:

Shallow reinforced concrete beams are widely used in building design and construction of waffle and ribbed slabs in Jordan and in many other countries. Previous researches included experimental based testing that has been widely used as a means to study the response of reinforced concrete flexural elements. In this regard the use of finite element analysis is gaining popularity as it is cost effective. Thus this work aims to study the behavior of shallow reinforced concrete beams when subjected to transverse loading, in terms of the resulting distribution of stresses, cracks and load deflection relationship, using finite element analysis utilzing ANSYS software. Solid65 eight noded isoparametric elements are used to model the concrete. The behavior of concrete material in compression is elasto-plastic work hardening model which is terminated at the onset of crushing. Link180 element models the reinforcement; the material model for the discrete steel reinforcement is linear elastic prior to initial yield surface, beyond that it is perfectly plastic.

 
 
 
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Title:

Estimating traffic operations at multi-lane roundabouts: a case study

Author (s):

Orazio Giuffrè, Anna Granà, Tullio Giuffrè and Roberta Marino

Abstract:

This paper addresses traffic modeling issues at urban multi-lane roundabouts where, despite circulating vehicles have priority, negotiation of the right-of-way can occur between antagonist traffic flows, as a result of minor drivers’ failing to obey the nominal operating rule (stop or yield control). Existing models for the estimation of operational performances have the shortcoming of not representing the interdependencies between entering and circulating vehicles at multi-lane roundabouts. An analytical capacity model derived from field observations was developed for this kind of intersections in a previous study. The complexity of the model lies in the difficulty of observing the behavioral parameters which are needed to implement the model. A procedure to get unknown behavioral parameters from traffic surveys is here proposed. This concerns saturation headways, often eluding direct observations due to rare occurrences of traffic conditions in which they can be observed. The unknown parameters were estimated through a regression model using onfield data collected at a multi-lane roundabout. The presence of data correlation within a cluster of observations required the estimation of the regression parameters through a generalized estimating equation model. Results gave insight into the analysis of operations at multi-lane roundabouts, containing evidence to support assumptions made for the estimation of unobservable parameters.

 
 
 
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Title:

Solving the dynamic models of reactive packed distillation process using difference formula approaches

Author (s): Abdulwahab GIWA
Abstract:

One of the complex processes encountered in process industries is reactive distillation because it involves the integration of both reaction and separation in a single unit. The process becomes more complex if the column used is a packed type because, in that case, its dynamic models are combinations of both ordinary and partial differential equations. Obtaining the appropriate method that can reliably give the solutions of these complex dynamic models is one of the challenges facing Process Engineers. It has been discovered that difference formula approaches can be applied to convert the partial differential models of the process to ordinary differential model types so that the overall resulting ordinary differential dynamic models of the process can be solved with the aid of ode command of MATLAB. Therefore, this work has been carried out to demonstrate how backward, forward and central difference formula approaches involving two data points are applied in solving the dynamic models developed for the reactive packed distillation column used for the production of ethyl acetate. The results obtained from the solutions of the dynamic models using the three different difference formula approaches were compared to the measured ones to determine the reliability of each of the approaches in solving the dynamic models of the reactive packed distillation process and backward difference formula approach was discovered to be the best because the liquid ethyl acetate mole fraction and the top segment temperature it gave were found to compare very well with the measured values.

 
 
 
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Title:

Offline handwritten devnagari digit recognition

Author (s): Rajiv Kumar and Kiran Kumar Ravulakollu
Abstract:

This paper presents a study on the performance of transformed domain features in Devnagari digit recognition. In this research the recognition performance is measured from features obtained in direct pixel value, Fourier Transform, Discrete Cosine Transform, Gaussian Pyramid, Laplacian Pyramid, Wavelet Transform and Curvelet Transform using classification schemes: Feed Forward, Function Fitting, Pattern Recognition, Cascade Neural Networks and K-nearest Neighbor (K-NN). The Gaussian Pyramid based feature with KNN classifier yielded the best accuracy of 96.93 % on the test set. The recognition accuracy was increased to 98.02% by using a majority voting classification scheme at expense of 0.26 % rejection rate. The majority voting classifiers are based on features: Gaussian pyramid, Laplacian pyramid, wavelet pyramid and direct pixel value using KNN classifiers.

 
 
 
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Title:

Sign language recognition: state of the art

Author (s): Ashok K Sahoo and Gouri Sankar Mishra

Abstract:

Sign language is used by deaf and hard hearing people to exchange information between their own community and with other people. Computer recognition of sign language deals from sign gesture acquisition and continues till text/speech generation. Sign gestures can be classified as static and dynamic. However static gesture recognition is simpler than dynamic gesture recognition but both recognition systems are important to the human community. The sign language recognition steps are described in this survey. The data acquisition, data preprocessing and transformation, feature extraction, classification and results obtained are examined. Some future directions for research in this area also suggested.

 
 
 
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Title:

Novel giant magnetoresistance model using multiple barrier potential

Author (s): Christian Fredy Naa, Suprijadi, Sparisoma Viridi and Mitra Djamal

Abstract:

This paper proposes a new model for Giant Magnetoresistance (GMR) and calculates its typical graph qualitatively. The model’s foundation is the microscopic mechanism in GMR, where the GMR effect can be explained by intrinsic and extrinsic potential. The potentials are spin-dependent. The potentials determine the transmission probability then it will give conductance value. Here, the multiple barrier potential model is proposed as the new GMR model. The transmission probability is determined using transfer matrix method. It was found that this model is fit qualitatively with the typical GMR graph.

 
 
 
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Title:

Modeling the stability of freestanding CNT probe/sensor in the vicinity of graphene layers considering casimir dispersion force

Author (s):

Rouhollah Shokuhifard, Mojtaba Ojakeh, Ameneh Langari and Maryam K. Hafshejani

Abstract:

Carbon nanotube (CNT) is one the most important nano-elements in fabrication of probes, sensors and other ultra-small devices that have a wide usage in engineering and medicine. In this paper, the deflection and instability of a freestanding CNT probe/sensor in the vicinity of the graphene layers are investigated. A nano-scale continuum model in conjunction with Euler beam theory is employed to obtain nonlinear constitutive equation of freestanding CNT by considering the effect of Casimir dispersion force. A numerical finite difference method is employed to solve the nonlinear governing equation.

 
 
 
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Title:

Simulation of air residence time distributions of spray droplets in a counter-current spray dryer

Author (s):

Eyitayo A. Afolabi and K.R Onifade

Abstract:

This research focused on the development of a fundamental model that can be used to predict the air residence time distribution of spray droplets in a counter-current spray dryer. The proposed model consists of two parallel sections. Firstly, two continuous stirred tanks and a plug-flow in between and secondly, a plug-flow and a stirred tank. A FORTRAN 77 program using Runge Kutta-Mersion subroutine was used to simulate the three first order differential and two linear model equations. The simulated results showed that at high water and airflow rates, more droplets enter into the mixing zones and large amount of moisture content evaporated at a short time interval. There was good agreement between the experimental data and simulated results airflow patterns which make it suitable for industrial application and the standard deviations obtained are within the acceptable limit.

 
 
 
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Title:

A reverse and enhanced AODV routing protocol for manets

Author (s):

M. Sanabani, R. Alsaqour and S. Kurkushi

Abstract:

Mobile Ad Hoc Network (MANET) is an autonomous collection of mobile users that communicate over relatively bandwidth constrained wireless links. Since the nodes are mobile, the network topology may change rapidly and unpredictably over time. The network is decentralized, where all network activity including discovering the topology and delivering packets must be executed by the nodes they, i.e., routing functionality will be incorporated into mobile nodes. An Ad-hoc On-demand Distance Vector routing (AODV) is a representative among the most widely studied on-demand ad hoc routing protocols. Previous protocols have shown some shortcomings on performance of AODV. AODV and most of the on demand ad hoc routing protocols use single RREP along the reverse path. Rapid change of topology causes that the RREP could not arrive to the source node, i.e., after a source node sends several RREQ packets; the node obtains a reply packet, especially on high speed mobility. This increases both in communication delay and power consumption as well as decrease in packet delivery ratio. To avoid these problems, we proposed a Reverse AODV (RAODV). RAODV tries multiple route replies which reduces the path fail correction packets and obtains better performance than other protocols. But RAODV has the most control packet overhead. Therefore, in this paper, we propose an Enhanced (EN-RAODV) that is improving the RAODV. The performance is evaluated through NS-2 simulator. Simulation results show that the proposed EN-RAODV improves the performance of network comparing with RAODV and AODV in most selected performance metrics such as packet delivery ratio, end to end delay, throughput, routing packet sent and routing overhead.

 
 
 
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Title: The association between client qualities and design team attributes of green building projects
Author (s): Mohamed S. Abd. Elforgani, Abdahadi Alnawawi and Ismail Ben Rahmat

Abstract:

The construction industry has become more complex due to changes in technology and the greater emphasis placed on satisfying green requirements. The design phase is the most important phase in determining the green performance of building projects. The performance of the design team is crucial. The selection of a design team should be based on a set of criteria. Therefore, a competent design teams is required to have a good understanding of environmental issues. Design teams require a range of competences such as skills of environmental assessments, initiatives and environmental background as the basis for design decisions. In addition, success of building projects greatly depends on the client’s performance. The performance of clients is crucial since decisions made will influence the overall project performance. The quality of clients’ representatives has potential influence on design team performance. In designing green buildings client’s attributes are critical factors to high performance of building projects. The propose of this study to identify the significant associations between variables of design team attributes and client qualities. To achieve mentioned aim a questionnaire survey was conducted to collect dada required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used for Rasch modeling to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. The results indicate that the influence of Clients’ Qualities on Design Team Attributes is extensive. Coordination ability has major influence on overall design team attributes. The higher the Client Knowledge on Green buildings the higher is the Design Team Attributes expected.

 
 
 
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Title:

A new creativity tool to assist food processing equipment design

Author (s):

M.T. Barbier, F. Giroux, Y. Coulibaly and C. Marouzé

Abstract:

A knowledge-based tool was implemented in order to assist in the design of food processing equipment. It was developed and suggested for the use of professionals who are seeking creative solutions for processing principles in a given context and under specific constraints, especially in the context of weak knowledge of food engineering and material properties, poor economic conditions, and impossibility of efficient use of existing design methodologies. This is usually the case in many developing countries where equipment supply is mostly limited to copies and adaptations of a few models despite the big size of small scale food processing sector, which results in the use of unsuitable equipment, lack of efficiency, and bad quality. This new tool uses knowledge-based methodology starting with the identification of the most useful function (MUF) to be achieved in order to identify the main product property change, hence leading to the implementation of the targeted product. MUFs are linked to scientific effects that can achieve them in order to suggest designers a wide range of potential solutions. To facilitate and orient access to useful knowledge for a given problem of food processing principles, this tool is designed using a database program and links to related and existing web-based sites. Selection of optimal equipment types is finally carried out by combining users’ manufacturing skills and specifications in terms of cost, maintenance and current use scheme.

 
 
 
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Title:

Energy analysis of a CHP fuel cell system to meet energy loads of a residential building

Author (s):

M. Pourmahmoud, G. R. Ashari, M. Ojakeh and M. K. Hafshejani

Abstract:

This study deals with the energy analysis of a polymer electrolyte membrane (PEM) fuel cell power system including burner, steam reformer, heat exchanger and water heater. This system has been considered to meet the electrical, heating, cooling and domestic hot water loads of a residential building located in Ahvaz. Natural gas is fuel of the system and system works in CHP mode. The energy requirements of residential building and the number of fuel cell stacks to meet them have been estimated. The method involved energy analysis and entropy generation through the months of the year. Results show that all the energy needs of the building can be met with 12 fuel cell stacks at a nominal capacity of 8.5 kW. Energy analysis of the CHP system shows that the increase in the ambient air temperature from 1oC to 40oC, will have an increase of entropy generation by 5.73%.Maximum entropy generates for 15 hour in 15th of June and 15th of July is estimated to amount at 12624 (kW/K). Entropy generation of this system through out a year is estimated to amount to 1004.54 GJ/k.year.

 
 
 
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