Periodicals of Engineering and Natural Sciences (PEN - International University of Sarajevo)
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Research about characteristics of designs from industrial designers and product designers
Full text linkDifference between industrial designer and product designer is not precisely defined. There is a lot of discussions and misunderstandings about these two professions. What is the job of industrial designer and what is the job of product designer? This question if often asked from people, which want to hire someone to design a new product for them. Through this research, same real-life design contest is given to group of students from Faculty of Mechanical Engineering, Department of Mechanical Design, at Industrial design course and to group of students from Academy of Fine Arts, Department of Product Design as product design project. Goal of the contest was to design an upholstered chair for indoor use with a modern and refined style. Goal of this research was to find some unique characteristic of designs from industrial designers and product designers. Resulted designs were evaluated analysing the fulfilment of the requirements criteria defined by contest and analysing additional criteria, which is important for new product design. Analysing the resulted designs some important conclusions are made. Most important conclusion is that industrial designer can be product designer but product designer cannot be industrial designer. For product design, engineering knowledge is not necessary, but for industrial design, it is most important
Investigating factors affecting feasibility study of construction projects in Iraq
Full text linkThe views at the construction field emboss that construction parties are looking for a higher benefit during implementing aspects of any project. The feasibility study is one of the serious and significant matters in construction sectors as well as in other engineering fields as it has a high impact on investment decision-making. To gain rigorous decisions from decision-makers or contractual parties (client, consultant, and contractor), there is a need for valuable feasibility studies in any construction project. This paper aims to study the influence of some identified factors on feasibility studies as well as the extents of priorities of various feasibility studies. In this paper, the critical factors that have an impact on sequences of initial feasibility studies during the lifecycle of a construction project were identified as well as the associated studies (legal, environment, marketing, technical, managerial, schedule, financial and economic). In this study, 12 factors were identified, analyzed, and thoroughly discussed to have recommendations of their impact on initial feasibility in construction projects in Iraq via a questionnaire survey and a series of expert interviews conducted in Iraq. The Analytical Hierarchy Process (AHP) as a multi-criteria decision support system was adopted to examine the weight of each factor. In addition, an analysis by the Relative Importance Index (RII) was carried out to rank eight types of feasibility studies in terms of their perceived importance. The results of AHP indicated that the local shortage of database about the feasibility study was the most critical factor. Indeed, RII\u27s result showed that all kinds of feasibility for construction projects in Iraq are not adopted by the client. In fact, the economic feasibility study was the most popular than others
A predictive model for liver disease progression based on logistic regression algorithm
Full text linkLiver disease counts to be one of the most prevalent diseases in the worldwide. Therefore, this paper is aim to address the problem of predicting liver disease progression. As the existing predictive models focus on predicting the label of disease; the probability of developing the disease is still obscure. This paper, therefore, has proposed a model to predict the probability occurrence of liver diseases. The proposed predictive model used logistic regression abilities to predict the probability of liver disease occurrence. ILPD dataset was used to analyze the performance of the model. The predictive model has shown outstanding performance with a prediction accuracy rate of 72.4%, the sensitivity of 90.3%, the specificity of 78.3 %, Type I Error of 9.7 %, Type II Error of 21.7 %, and ROC of 0.758%. The model has furthermore confirmed the feasibility of the laboratory tests such as as (Age; Direct Bilirubin (DB), Alamine_Aminotransferase (SGPT), Total_Protiens (TP), Albumin (ALB)) to predict the disease progression. The predictive model will be helpful to patients and doctors to realize the progression of the disease and make a suitable timely intervention
Integrated software package for simulation simulator - Grapher - 2D and 3D surfer representation verification and validation
Full text linkSimulation is one of the most important tools of engineering science. In this research an integrated engineering software package was designed to simulate oil reservoirs as an efficient tool which simplify the simulation process and provides the most requirements during the data entry, simulation of the reservoir, and till to reporting and documentation stage. The proposed package is capable to conduct analyzes and drawings in two or three dimensions with animated three dimensional virtual view which is most important feature. This integrated software package named Tiger 2000 can be used for any reservoir, whatever the geometric shape it represents. The 2000 Tiger can handle all operations that may occur in the reservoir such as production or injection as well as the water invasion of the reservoir. A number of engineering and software technologies have been used to accomplish this package, including Open GL, Visual Basic, FORTRAN Power Station, and Visual C. The integrated software package Tiger 2000 consists of five sub-packages: Simulator, Grapher, 2D and 3D Surfer for surface representation, 3D representation, representation of reservoir, aquifer and well sites as well as “Reservoir Show” which is an animated view of the simulated zones. The proposed software package in the current study is directly draw and represent the processed data and output results which is simplify the error detection, simulation and decision making for current and future reservoir processing and developments. This software package is the first of its kind designed in Iraq and the Arab world, where as all the calculations of oil and reservoir studies using ready-software purchased from foreign countries and costs up to millions of dollars. Although this is the first version of Tiger 2000, it is a big and very promising step towards Middle Eastern scientific software that serves scientific and engineering applications. Tiger 2000 can also be used even in simulating groundwater reservoirs and thus provides another service in the extraction and management of groundwater, especially as the abundance of water has become a top concern at all levels
Ballistic impact performance of laminated composite structures
Full text linkRecently published research indicates that laminated composites have limited applications in advanced structural systems due to their low impact performance. The aim of this study is to give general information about the most commonly used materials and ballistic test methods to the new researchers who want to work on ballistic related subjects. In addition, to summarize the topics related to simulation methods such as FEM and numerical methods which are used most in ballistics. Finally, it is to enlighten them by giving suggestions to the researchers who will work on ballistics in the future.This review paper is focused on the impact resistance and penetration behavior of composites reinforced with fibers as well as their suitability for modern structural applications. The historical development of composite laminates is first reviewed in detail, and notable researchers and their contributions are then reviewed. Also included are reviews on published experimental, numerical, and analytical work on the low velocity impact of composite laminates. Relevant results will be discussed and the recommendations that need to be resolved in the future will be addressed
Experimental and modeling stress concentration factor (SCF) of a tension poly lactic acid (PLA) plate with two circular holes
Full text linkThe design of high performance aircraft structures frequently includes various shape and size discontinuities for various purposes. The zones near to these notches become critical regions under various working loading. The stress concentration factor (SCF) and tensile strength degradation of poly lactic acid (PLA) plates are addressed in the current study through a combination of experimental and numerical studies using finite element (FE) modeling techniques. The present work performs stress concentration factor (SCF) of rectangular plates with two symmetrical circular holes under uniaxial tension load of two various types (PLA, PLA/15%carbon), which were determined in the current work experimentally and numerically using finite element method with help of Ansys software. The results of experimental test showed decay in tensile modulus and tensile strength is less than that of using plates without holes by (10%, 22.1%) for (PLA, PLA/15%carbon) respectively, and the apparent stress concentration factor is (3.33, 3.61) respectively. And showed decay in tensile strength is less than that of using plates without holes by (28.35%, 27.77%) for (PLA, PLA/15%carbon) respectively, due to the concentration of stresses around the holes. A finite element analysis is carried out and the outcomes have been estimated with experimental results for checking the efficient use of this article. The numerical results show the Von Mises stress distribution and stress concentration factor is (2.16, 2.35) for (PLA, PLA/15%carbon) respectively
Spatial study of causes and effects of the sandstorms using meteorological data and GIS: The case of Nasiriyah city, Iraq
Full text linkThe reoccurrence of sandstorms in Nasiriyah city (Southern Iraq) throughout the Summer season is a very important phenomenon and distinctive case that comes from the nearby regions. These storms restrict the financial activities of the city with expanded municipal effort as well as other well-being and environmental problems, and then bring a huge risk to the local residents. This paper uses Geographic Information System (GIS) and Remote Sensing Imagery to dimensionally discover the reasons causing sandstorms, understand the changes within certain periods of time, and then measure the sand-plume coverage during storms. This work has also made an attempt to get the correlation between meteorological records and spatial outputs to predict the direction and coverage range of the predicted future sandstorms which could help to take protective and preventive measures for the sake of the human being. The periods between 1972 and 2018 have been adopted to study the phenomena by using the information archive of the Nasiriyah Meteorological Center together with NASA\u27s open-source climate data and Landsat satellite imagery
Ceramic Wastes Usage as Alternative Aggregate in Mortar and Concrete
Full text linkIn the ceramic industry, huge amounts of wastes are generated during manufacturing and transportation processes. In order to decrease the need for landfill areas and increase environmentally harmful effects of such wastes, this industry is under pressure to finding effective ways for recycling its wastes and by-products. In addition, the construction industry requires new sources of aggregates due to running out of conventional virgin aggregates, saving energy, and protecting the environment. Therefore, recently, ceramic wastes are often used as coarse and/or fine aggregate both in mortar and concrete. In the present study, effects of using ceramic wastes as coarse and/or fine aggregate on the engineering properties of mortar and concrete are evaluated. These engineering properties are listed and compared according to their mechanical and durability properties. Reviewing of previous studies related with this subject in literature and discussion all results of the studies are conducted as the methodology of this study. Consequently, it was found out that the use of waste ceramic in the conventional concrete or mortar mix as fine/coarse aggregate is suitable as it can improve mechanical and durability properties of the concrete/mortar
Determination of Air Permeability Property of Air-Laid Nonwoven Fabrics Using Regression Analyses
Full text linkAir-laid nonwoven fabrics are generally used for hygienic care products such as diaper, adult nappy and sanitary napkins. Air permeability is one of the foremost properties that affect the usage performance of these hygienic care products. In this study, 10 different air-laid nonwoven fabric samples are produced. The porosity ratios of these samples are determined by digital image processing methods. Air permeability of the samples is tested by digital air permeability test device. Then regression analyses were applied to the experimental results using SPSS 21.0 package program. Finally regression equation was obtained for prediction of air permeability by using porosity, thickness and fabric weight
The importance of interlayers in diffusion welding - A review
Full text linkDuring the last few years diffusion welding has become significant attention regarding its suitable applications incomparison to traditional welding techniques. Bonding of dissimilar materials has always been a challenging taskdue to poor control on grain size and sensitive mechanical properties that could have been made by joining withtraditional welding techniques. Moreover, joining dissimilar materials such as Aluminum/steel, metal/glass,Aluminum/copper had been achieved with the usage of diffusion welding. This work presents a review of literatureregarding the importance of diffusion welding and influence of interlayers in diffusion welding. Additionally, thispaper provides different examples and applications of diffusion welding. Main advantages of this technique are,clean and undamaged exterior parts of weld, power savings, stable and strong bond, time efficiency