Abstract: Construction industry mainly focuses on the superstructure, infrastructure, and oil and gas industry. The development of infrastructure projects in developing countries attracted a lot of foreign construction contractors, consultants, suppliers and diversified workforce to interfere and to be evolved in such huge investment. Reducing worksite delays in such projects require knowledge and attention. Therefore, it is important to identify the influencing delay attributes affecting construction projects. The significant project factors affecting construction delays were investigated. Data collection was carried out through an online web survey system to capture significant factors. Significant factors were determined with importance index and relevant recommendations are made. The output of the data analysis would lead the industry experts better assess the impact of construction delays on construction projects.
Abstract: In this paper, a low voltage high performance current mirror is presented. Its most important specifications, which are improved in this work, are analyzed and formulated proving that it has such outstanding merits as: Very low input resistance of 26mΩ, very wide current dynamic range of 8 decades from 10pA to 1mA (160dB) together with an extremely low current copy error of less than 0.6ppm, and very low input and output voltages. Furthermore, the proposed current mirror bandwidth is 944MHz utilizing very low power consumption (267μW) and transistors count. HSPICE simulation results are performed using TSMC 0.18μm CMOS technology utilizing 1.8V single power supply, confirming the theoretically proved outstanding performance of the proposed current mirror. Monte Carlo simulation of its most important parameter is also examined showing its sufficiently resistance against technology process variations.
Abstract: Tribological properties that include nanoparticles are an alternative to improve the tribological behaviour of lubricating oil, which has been investigated by many researchers for the past few decades. Various nanostructures can be used as additives for tribological improvement. However, this also depends on the characteristics of the nanoparticles. In this study, tribological investigation was performed to examine the effect of CuO nanoparticles on the tribological behaviour of Syntium 800 SL 10W−30. Three parameters used in the analysis using the wear tester (piston ring) were load, revolutions per minute (rpm), and concentration. The specifications of the nanoparticles, such as size, concentration, hardness, and shape, can affect the tribological behaviour of the lubricant. The friction and wear experiment was conducted using a tribo-tester and the Response Surface Methodology method was used to analyse any improvement of the performance. Therefore, two concentrations of 40 nm nanoparticles were used to conduct the experiments, namely, 0.005 wt % and 0.01 wt % and compared with base oil 0 wt % (control). A water bath sonicator was used to disperse the nanoparticles in base oil, while a tribo-tester was used to measure the coefficient of friction and wear rate. In addition, the thermal properties of the nanolubricant were also measured. The results have shown that the thermal conductivity of the nanolubricant was increased when compared with the base oil. Therefore, the results indicated that CuO nanoparticles had improved the tribological behaviour as well as the thermal properties of the nanolubricant oil.
Abstract: This paper discusses the effect of using blast furnace iron slag as a part of fine aggregate on the mechanical performance of hot mix asphalt (HMA). The mechanical performance was evaluated based on various mechanical properties that include; Marshall/stiffness, indirect tensile strength and unconfined compressive strength. The effect of iron slag content on the mechanical properties of the mixtures was also investigated. Four HMA with various iron slag contents, namely; 0%, 5%, 10% and 15% by weight of total mixture were studied. Laboratory testing has revealed an enhancement in the compressive strength of HMA when iron slag was used. Within the tested range of iron slag content, a considerable increase in the compressive strength of the mixtures was observed with the increase of slag content. No significant improvement on Marshall/stiffness and indirect tensile strength of the mixtures was observed when slag was used. Even so, blast furnace iron slag can still be used in asphalt paving for environmental advantages.
Abstract: Squalene is a valuable component of the oil composed of 30 carbon atoms and is mainly used for cosmetic materials. The main concern of this article is to study the Squalene composition in the Lebanese olive oil and to compare it with foreign oil results. To our knowledge, extraction of Squalene from the Lebanese olive oil has not been conducted before. Three different techniques were studied and experiments were performed on three brands of olive oil, Al Wadi Al Akhdar, Virgo Bio and Boulos. The techniques performed are the Fractional Crystallization, the Soxhlet and the Esterification. By comparing the results, it is found that the Lebanese oil contains squalene and Soxhlet method is the most effective between the three methods extracting about 6.5E-04 grams of Squalene per grams of olive oil.
Abstract: The layout optimization of building blocks of unequal areas has applications in many disciplines including VLSI floorplanning, macrocell placement, unequal-area facilities layout optimization, and plant or machine layout design. A number of heuristics and some analytical and hybrid techniques have been published to solve this problem. This paper presents an efficient high-quality building-block layout design technique especially suited for solving large-size problems. The higher efficiency and improved quality of optimized solutions are made possible by introducing the concept of Promising Infant Clusters in a constructive placement procedure. The results presented in the paper demonstrate the improved performance of the presented technique for benchmark problems in comparison with published heuristic, analytic, and hybrid techniques.
Abstract: In order to predict and model wrinkling which is caused by out of plane deformation due to compressive loading in the plane of the material during composite prepregs forming, it is necessary to quantitatively understand the relative magnitude of the bending stiffness. This study aims to examine the bending properties of out-of-autoclave (OOA) thermosetting prepreg under vertical cantilever test condition. A direct method for characterizing the bending behavior of composite prepregs was developed. The results from direct measurement were compared with results derived from an image-processing procedure that analyses the captured image during the vertical bending test. A numerical simulation was performed using ABAQUS to confirm the bending stiffness value.
Abstract: Among other traditional and non-traditional
additives, polymers have shown an efficient performance in the field
and improved sustainability. Polyacrylamide (PAM) is one such
additive that has demonstrated many advantages including a
reduction in permeability, an increase in durability and the provision
of strength characteristics. However, information about its effect on
the improved geotechnical characteristics is very limited to the field
performance monitoring. Therefore, a laboratory investigation was
carried out to examine the basic and engineering behaviors of three
types of soils treated with a PAM additive. The results showed an
increase in dry density and unconfined compressive strength for all
the soils. The results further demonstrated an increase in unsoaked
CBR and a reduction in permeability for all stabilized samples.
Abstract: The paper presents an additive manufacturing process for the production of metal and composite parts. It is termed as composite metal foil manufacturing and is a combination of laminated object manufacturing and brazing techniques. The process has been described in detail and is being used to produce dissimilar aluminum to copper foil single lap joints. A three dimensional finite element model has been developed to study the thermo-mechanical characteristics of the dissimilar Al/Cu single lap joint. The effects of thermal stress and strain have been analyzed by carrying out transient thermal analysis on the heated plates used to join the two 0.1mm thin metal foils. Tensile test has been carried out on the foils before joining and after the single Al/Cu lap joints are made, they are subjected to tensile lap-shear test to analyze the effect of heat on the foils. The analyses are designed to assess the mechanical integrity of the foils after the brazing process and understand whether or not the heat treatment has an effect on the fracture modes of the produced specimens.
Abstract: In this paper, a prototype PEM fuel cell vehicle
integrated with a 1 kW air-blowing proton exchange membrane fuel
cell (PEMFC) stack as a main power sources has been developed for
a lightweight cruising vehicle. The test vehicle is equipped with a
PEM fuel cell system that provides electric power to a brushed DC
motor. This vehicle was designed to compete with industrial
lightweight vehicle with the target of consuming least amount of
energy and high performance. Individual variations in driving style
have a significant impact on vehicle energy efficiency and it is well
established from the literature. The primary aim of this study was to
assesses the power and fuel consumption of a hydrogen fuel cell
vehicle operating at three difference driving technique (i.e. 25 km/h
constant speed, 22-28 km/h speed range, 20-30 km/h speed range).
The goal is to develop the best driving strategy to maximize
performance and minimize fuel consumption for the vehicle system.
The relationship between power demand and hydrogen consumption
has also been discussed. All the techniques can be evaluated and
compared on broadly similar terms. Automatic intelligent controller
for driving prototype fuel cell vehicle on different obstacle while
maintaining all systems at maximum efficiency was used. The result
showed that 25 km/h constant speed was identified for optimal
driving with less fuel consumption.
Abstract: Hydrogen produced by means of polymer electrolyte
membrane electrolyzer (PEME) is one of the most promising
methods due to clean and renewable energy source. In the process,
some energy loss due to mass transfer through a PEM is caused by
diffusion, electro-osmotic drag, and the pressure difference between
the cathode channel and anode channel. In PEME, water molecules
and ionic particles transferred between the electrodes from anode to
cathode, Extensive mixing of the hydrogen and oxygen at anode
channel due to gases cross-over must be avoided. In recent times the
consciousness of safety issue in high pressure PEME where the
oxygen mix with hydrogen at anode channel could create, explosive
conditions have generated a lot of concern. In this paper, the steady
state and simulation analysis of gases crossover in PEME on the
temperature and pressure effect are presented. The simulations have
been analysis in MATLAB based on the well-known Fick’s Law of
molecular diffusion. The simulation results indicated that as
temperature increases, there is a significant decrease in operating
voltage.
Abstract: Economic development and growth are significantly
linked to the consistent and sustainable sector of small and medium
enterprises (SMEs). Banks are the frontrunners in financing and
advising SMEs. The main objective of the study is to assess the
tendency of SMEs to use the Islamic bank. Model was developed
using quantitative method with a hypothetical-deductive testing
approach. Model (N = 364) used primary data on the tendency of
SMEs to use Islamic banks gathered from questionnaire. It is found
by Mann-Whitney test that the tendency to use Islamic bank varies
between those firms which consider formal financing with the ones
relying on informal financing with the latter tends more to use
Islamic bank. This study can serve academic researchers, policy
makers, and developing countries as a model of SMEs’ desirability to
Islamic banking.
Abstract: The aim of this study is to identify the suitability of
Virtual Learning Environment (VLE) in welding simulator
application towards Computer-Based Training (CBT) in developing
skills upon new students at the Advanced Technology Training
Center (ADTEC) Batu Pahat, Johor, Malaysia and GIATMARA,
Batu Pahat, Johor, Malaysia. The significance of the study is to create
a computer-based skills development approach in welding technology
among new students in ADTEC and GIATMARA as well as to
cultivate the elements of general skills among them. This study is
also important in elevating the number of individual knowledge
workers (K-workers) working in manufacturing industry in order to
achieve a national vision which is to be an industrial nation in the
year of 2020. The design of the study is a survey type of research
which using questionnaires as the instruments and some 136 students
from ADTEC and GIATMARA were interviewed. Descriptive
analysis is used to identify the frequency and mean values. The
findings of the study show that the welding technology has developed
skills in the students because of the application of VLE simulated at a
high level and the respondents agreed that the skills could be
embedded through the application of the VLE simulator. In summary,
the VLE simulator is suitable in welding skills development training
in terms of exposing new students with the relevant characteristics of
welding skills and at the same time spurring the students’ interest
towards learning more about the skills.
Abstract: Review of studies carried out on the use of bagasse
ash for the improvement of deficient soils in Nigeria, with emphasis
on lateritic and black cotton soils is presented. Although, the bagasse
ash is mostly used as additive to the conventional soil stabilizers
(cement and lime), the studies generally showed improvement in the
geotechnical properties of the soils, either modified or stabilized with
the ash. This showed the potentials of using this agricultural waste
(bagasse ash) in the improvement of geotechnical properties of
deficient soils, thus suggesting that using this material at large scale
level in geotechnical engineering practice could help in the provision
of stable and durable structures, reduce cost of soil improvement and
also reduces environmental nuisance caused by the unused waste in
Nigeria.
Abstract: For a rigid body sliding on a rough surface, a range of
uncertainty or non-uniqueness of solution could be found, which is
termed: Painlevé paradox. Painlevé paradox is the reason of a wide
range of bouncing motion, observed during sliding of robotic
manipulators on rough surfaces. In this research work, the existence
of the paradox zone during the sliding motion of a two-link (P-R)
robotic manipulator with a unilateral constraint is investigated.
Parametric study is performed to investigate the effect of friction,
link-length ratio, total height and link-mass ratio on the paradox zone.
Abstract: This work is on decision tree-based classification for
the disbursement of scholarship. Tree-based data mining
classification technique is used in other to determine the generic rule
to be used to disburse the scholarship. The system based on the
defined rules from the tree is able to determine the class (status) to
which an applicant shall belong whether Granted or Not Granted. The
applicants that fall to the class of granted denote a successful
acquirement of scholarship while those in not granted class are
unsuccessful in the scheme. An algorithm that can be used to classify
the applicants based on the rules from tree-based classification was
also developed. The tree-based classification is adopted because of its
efficiency, effectiveness, and easy to comprehend features. The
system was tested with the data of National Information Technology
Development Agency (NITDA) Abuja, a Parastatal of Federal
Ministry of Communication Technology that is mandated to develop
and regulate information technology in Nigeria. The system was
found working according to the specification. It is therefore
recommended for all scholarship disbursement organizations.
Abstract: Human beings have the ability to make logical
decisions. Although human decision - making is often optimal, it is
insufficient when huge amount of data is to be classified. Medical
dataset is a vital ingredient used in predicting patient’s health
condition. In other to have the best prediction, there calls for most
suitable machine learning algorithms. This work compared the
performance of Artificial Neural Network (ANN) and Decision Tree
Algorithms (DTA) as regards to some performance metrics using
diabetes data. WEKA software was used for the implementation of
the algorithms. Multilayer Perceptron (MLP) and Radial Basis
Function (RBF) were the two algorithms used for ANN, while
RegTree and LADTree algorithms were the DTA models used. From
the results obtained, DTA performed better than ANN. The Root
Mean Squared Error (RMSE) of MLP is 0.3913 that of RBF is
0.3625, that of RepTree is 0.3174 and that of LADTree is 0.3206
respectively.
Abstract: Artificial neural networks have gained a lot of interest
as empirical models for their powerful representational capacity,
multi input and output mapping characteristics. In fact, most feedforward
networks with nonlinear nodal functions have been proved to
be universal approximates. In this paper, we propose a new
supervised method for color image classification based on selforganizing
feature maps (SOFM). This algorithm is based on
competitive learning. The method partitions the input space using
self-organizing feature maps to introduce the concept of local
neighborhoods. Our image classification system entered into RGB
image. Experiments with simulated data showed that separability of
classes increased when increasing training time. In additional, the
result shows proposed algorithms are effective for color image
classification.
Abstract: The modeling lung respiratory system that has complex anatomy and biophysics presents several challenges including tissue-driven flow patterns and wall motion. Also, the pulmonary lung system because of that they stretch and recoil with each breath, has not static walls and structures. The direct relationship between air flow and tissue motion in the lung structures naturally prefers an FSI simulation technique. Therefore, in order to toward the realistic simulation of pulmonary breathing mechanics the development of a coupled FSI computational model is an important step. A simple but physiologically relevant three-dimensional deep long geometry is designed and fluid-structure interaction (FSI) coupling technique is utilized for simulating the deformation of the lung parenchyma tissue that produces airflow fields. The real understanding of respiratory tissue system as a complex phenomenon have been investigated with respect to respiratory patterns, fluid dynamics and tissue viscoelasticity and tidal breathing period.
Abstract: Academicians at the Arab Open University have
always voiced their concern about the efficacy of the blended
learning process. Based on 75% independent study and 25% face-toface
tutorial, it poses the challenge of the predisposition to
adjustment. Being used to the psychology of traditional educational
systems, AOU students cannot be easily weaned from being spoonfed.
Hence they lack the motivation to plunge into self-study. For
better involvement of AOU students into the learning practices, it is
imperative to diagnose the factors that impede or increase their
motivation. This is conducted through an empirical study grounded
upon observations and tested hypothesis and aimed at monitoring and
optimizing the students’ learning outcome. Recommendations of the
research will follow the findings.