Abstract: In this paper, we have developed an explicit analytical
drain current model comprising surface channel potential and
threshold voltage in order to explain the advantages of the proposed
Gate Stack Double Diffusion (GSDD) MOSFET design over the
conventional MOSFET with the same geometric specifications that
allow us to use the benefits of the incorporation of the high-k layer
between the oxide layer and gate metal aspect on the immunity of the
proposed design against the self-heating effects. In order to show the
efficiency of our proposed structure, we propose the simulation of the
power chopper circuit. The use of the proposed structure to design a
power chopper circuit has showed that the (GSDD) MOSFET can
improve the working of the circuit in terms of power dissipation and
self-heating effect immunity. The results so obtained are in close
proximity with the 2D simulated results thus confirming the validity
of the proposed model.
Abstract: The purpose of this paper is to conceptualize a futureoriented
human work environment and organizational activity in
deep mines that entails a vision of good and safe workplace. Futureoriented
technological challenges and mental images required for
modern work organization design were appraised. It is argued that an
intelligent-deep-mine covering the entire value chain, including
environmental issues and with work organization that supports good
working and social conditions towards increased human productivity
could be designed. With such intelligent system and work
organization in place, the mining industry could be seen as a place
where cooperation, skills development and gender equality are key
components. By this perspective, both the youth and women might
view mining activity as an attractive job and the work environment
as a safe, and this could go a long way in breaking the unequal
gender balance that exists in most mines today.
Abstract: This study presents a hybrid neural network and Gravitational Search Algorithm (HNGSA) method to solve well known Wessinger's equation. To aim this purpose, gravitational search algorithm (GSA) technique is applied to train a multi-layer perceptron neural network, which is used as approximation solution of the Wessinger's equation. A trial solution of the differential equation is written as sum of two parts. The first part satisfies the initial/ boundary conditions and does not contain any adjustable parameters and the second part which is constructed so as not to affect the initial/boundary conditions. The second part involves adjustable parameters (the weights and biases) for a multi-layer perceptron neural network. In order to demonstrate the presented method, the obtained results of the proposed method are compared with some known numerical methods. The given results show that presented method can introduce a closer form to the analytic solution than other numerical methods. Present method can be easily extended to solve a wide range of problems.
Abstract: The concept of flexible manufacturing is highly
appealing in gaining a competitive edge in the market by quickly
adapting to the changing customer needs. Scheduling jobs on flexible
manufacturing systems (FMSs) is a challenging task of managing the
available flexibility on the shop floor to react to the dynamics of the
environment in real-time. In this paper, an agent-oriented scheduling
framework that can be integrated with a real or a simulated FMS is
proposed. This framework works in stochastic environments with a
dynamic model of job arrival. It supports a hierarchical cooperative
scheduling that builds on the available flexibility of the shop floor.
Testing the framework on a model of a real FMS showed the
capability of the proposed approach to overcome the drawbacks of
the conventional approaches and maintain a near optimal solution
despite the dynamics of the operational environment.
Abstract: Many non-conventional adsorbent have been studied
as economic alternative to commercial activated carbon and mostly
agricultural waste have been introduced such as rubber leaf powder
and hazelnut shell. Microwave Incinerated Rice Husk Ash
(MIRHA), produced from the rice husk is one of the low-cost
materials that were used as adsorbent of heavy metal. The aim of
this research was to study the feasibility of using MIRHA500 and
MIRHA800 as adsorbent for the removal of Cu(II) metal ions from
aqueous solutions by the batch studies. The adsorption of Cu(II) into
MIRHA500 and MIRH800 favors Fruendlich isotherm and imply
pseudo – kinetic second order which applied chemisorptions
Abstract: In this paper, using a model transformation approach a system of linear delay differential equations (DDEs) with multiple delays is converted to a non-delayed initial value problem. The variational iteration method (VIM) is then applied to obtain the approximate analytical solutions. Numerical results are given for several examples involving scalar and second order systems. Comparisons with the classical fourth-order Runge-Kutta method (RK4) verify that this method is very effective and convenient.
Abstract: An organic bulk heterojunction (BHJ) was fabricated using a blended film containing Copper (II) tetrakis(4-acumylphenoxy) phthalocyanine (Tc-CuPc) along with [6,6]-Phenyl C61 butyric acid methyl ester (PCBM). Weight ratio between Tc-CuPc and PCBM was 1:1. The electrical properties of Tc-CuPc: PCBM BHJ were examined. Rectifying nature of the BHJ was displayed by current-voltage (I-V) curves, recorded in dark and at various temperatures. At low voltages, conduction was ohmic succeeded by space-charge limiting current (SCLC) conduction at higher voltages in which exponential trap distribution was dominant. Series resistance, shunt resistance, ideality factor, effective barrier height and mobility at room temperature were found to be 526 4, 482 k4, 3.7, 0.17 eV and 2×10-7 cm2V-1s-1 respectively. Temperature effect towards different BHJ parameters was observed under dark condition.
Abstract: Teaching and learning about sustainability is a pedagogical endeavour with various innate difficulties and increased demands. Higher education has a dual role to play in addressing this challenge: to identify and explore innovative approaches and tools for addressing the complex and value-laden nature of sustainability in more meaningful ways, and to help teachers to integrate these approaches into their practice through appropriate professional development programs. The study reported here was designed and carried out within the context of a Masters course in Environmental Education. Eight teachers were collaboratively engaged in reconstructing a digital game microworld which was deliberately designed by the researchers to be questioned and evoke critical discussion on the idea of ‘sustainable city’. The study was based on the design-based research method. The findings indicate that the teachers’ involvement in processes of co-constructing the microworld initiated discussion and reflection upon the concepts of sustainability and sustainable lifestyles.
Abstract: Climate change is one of the greatest environmental,
economic, and social challenges of our time. Urban transportation has
had a major negative impact on our environment—most of our air
pollution comes from transport.
This paper explores ways to move toward a more sustainable
transport system by focusing on creating a more efficient and livable
city and improving the environmental efficiency of transport activity.
The analytical study covers some international examples of applying
sustainable transportation and uses them to suggest a frame work to
develop the transportation system in Egypt to be sustainable and more
intelligent.
Abstract: Alkali treated oil palm empty fruit bunch (EFB) fibres
(TEFBF) and untreated EFBF fibers (UEFBF) were incorporated in
polypropylene (PP) with and without malic anhydride grafted PP
(MAPP) and magnesium hydroxide as flame retardant (FR) to
produce TEFBF-PP and UEFBF-PP composites by the melt casting
method. The composites were characterized by mechanical and
burning tests along with a scanning electron microscope and Fourier
transform infrared spectroscopy. The significant improvement in
flexural modulus (133%) and flame retardant property (60%) of
TEFBF-PP composite with MAPP and FR is observed. The improved
mechanical property is discussed by the development of encapsulated
textures.
Abstract: The fact that traditional food safety system in the
absence of food safety culture is inadequate has recently become a
cause of concern for food safety professionals and other stakeholders.
Focusing on implementation of traditional food safety system i.e
HACCP prerequisite program and HACCP without the presence of
food safety culture in the food industry has led to the processing,
marketing and distribution of contaminated foods. The results of this
are regular out breaks of food borne illnesses and recalls of foods
from retail outlets with serious consequences to the consumers and
manufacturers alike. This article will consider the importance of food
safety culture, the cases of outbreaks and recalls that occurred when
companies did not make food safety culture a priority. Most
importantly, the food safety cultures of some food industries in South
Africa were assessed from responses to questionnaires from food
safety/food industry professionals in Durban South Africa. The
article was concluded by recommending that both food
industry employees and employers alike take food safety culture
seriously.
Abstract: The area of knowledge management has been in the
highlight for enterprises over the past three decades. Many
enterprises would like to have knowledge management and work hard
to achieve it, however they are often confused about which direction
to take to be successful and this point is especially true for Small and
Medium Enterprises (SMEs) in developing countries. Many large
companies have realized that knowledge is one of the richest
resources which an organization possesses and knowledge
management is a part of the foundation for a sustainable competitive
advantage. Much work has been done in the area of knowledge
management, but most of it has served large enterprises. This
research provides a Model of knowledge management strategy for
SMEs. It is based on analysis, insights and recommendations and it is
presented so that SMEs in developing countries can easily understand
and implement this model.
Abstract: Air bubbles have been detected in human circulation
of end-stage renal disease patients who are treated by hemodialysis.
The consequence of air embolism, air bubbles, is under recognized
and usually overlooked in daily practice. This paper shows results of
a capacitor based detection method that capable of detecting the
presence of air bubbles in the blood stream in different frequencies.
The method is based on a parallel plates capacitor made of platinum
with an area of 1.5 cm2 and a distance between the two plates is 1cm.
The dielectric material used in this capacitor is Dextran70 solution
which mimics blood rheology. Simulations were carried out using
RC circuit at two frequencies 30Hz and 3 kHz and results compared
with experiments and theory. It is observed that by injecting air
bubbles of different diameters into the device, there were significant
changes in the capacitance of the capacitor. Furthermore, it is
observed that the output voltage from the circuit increased with
increasing air bubble diameter. These results demonstrate the
feasibility of this approach in improving air bubble detection in
Hemodialysis.
Abstract: This paper presents the communication network for
machine vision system to implement to control systems and logistics
applications in industrial environment. The real-time distributed over
the network is very important for communication among vision node,
image processing and control as well as the distributed I/O node. A
robust implementation both with respect to camera packaging and
data transmission has been accounted. This network consists of a
gigabit Ethernet network and a switch with integrated fire-wall is
used to distribute the data and provide connection to the imaging
control station and IEC-61131 conform signal integration comprising
the Modbus TCP protocol. The real-time and delay time properties
each part on the network were considered and worked out in this
paper.
Abstract: The direct discharge of palm oil mill effluent (POME) wastewater causes serious environmental pollution due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Traditional ways for POME treatment have both economical and environmental disadvantages. In this study, a membrane anaerobic system (MAS) was used as an alternative, cost effective method for treating POME. Six steady states were attained as a part of a kinetic study that considered concentration ranges of 8,220 to 15,400 mg/l for mixed liquor suspended solids (MLSS) and 6,329 to 13,244 mg/l for mixed liquor volatile suspended solids (MLVSS). Kinetic equations from Monod, Contois and Chen & Hashimoto were employed to describe the kinetics of POME treatment at organic loading rates ranging from 2 to 13 kg COD/m3/d. throughout the experiment, the removal efficiency of COD was from 94.8 to 96.5% with hydraulic retention time, HRT from 400.6 to 5.7 days. The growth yield coefficient, Y was found to be 0.62gVSS/g COD the specific microorganism decay rate was 0.21 d-1 and the methane gas yield production rate was between 0.25 l/g COD/d and 0.58 l/g COD/d. Steady state influent COD concentrations increased from 18,302 mg/l in the first steady state to 43,500 mg/l in the sixth steady state. The minimum solids retention time, which was obtained from the three kinetic models ranged from 5 to 12.3 days. The k values were in the range of 0.35 – 0.519 g COD/ g VSS • d and values were between 0.26 and 0.379 d-1. The solids retention time (SRT) decreased from 800 days to 11.6 days. The complete treatment reduced the COD content to 2279 mg/l equivalent to a reduction of 94.8% reduction from the original.
Abstract: A research project dealing with the phytoremediation
of a soil polluted by some heavy metals is currently running. The
case study is represented by a mining area in Hamedan province in
the central west part of Iran. The potential of phytoextraction and
phytostabilization of plants was evaluated considering the
concentration of heavy metals in the plant tissues and also the
bioconcentration factor (BCF) and the translocation factor (TF). Also
the several established criteria were applied to define
hyperaccumulator plants in the studied area. Results showed that
none of the collected plant species were suitable for phytoextraction
of Cu, Zn, Fe and Mn, but among the plants, Euphorbia macroclada
was the most efficient in phytostabilization of Cu and Fe, while,
Ziziphora clinopodioides, Cousinia sp. and Chenopodium botrys
were the most suitable for phytostabilization of Zn and Chondrila
juncea and Stipa barbata had the potential for phytostabilization of
Mn. Using the most common criterion, Euphorbia macroclada and
Verbascum speciosum were Fe hyperaccumulator plants. Present
study showed that native plant species growing on contaminated sites
may have the potential for phytoremediation.
Abstract: Let D = 1 be a positive non-square integer and let δ = √D or 1+√D 2 be a real quadratic irrational with trace t =δ + δ and norm n = δδ. Let γ = P+δ Q be a quadratic irrational for positive integers P and Q. Given a quadratic irrational γ, there exist a quadratic ideal Iγ = [Q, δ + P] and an indefinite quadratic form Fγ(x, y) = Q(x−γy)(x−γy) of discriminant Δ = t
2−4n. In the first section, we give some preliminaries form binary quadratic forms, quadratic irrationals and quadratic ideals. In the second section, we obtain some results on γ, Iγ and Fγ for some specific values of Q and P.
Abstract: The effect of SnO2 surface modification by Ag nanoclusters, synthesized by SILD method, on the operating characteristics of thin film gas sensors was studied and models for the promotional role of Ag additives were discussed. It was found that mentioned above approach can be used for improvement both the sensitivity and the rate of response of the SnO2-based gas sensors to CO and H2. At the same time, the presence of the Ag clusters on the surface of SnO2 depressed the sensor response to ozone.
Abstract: A method of dynamic mesh based airfoil optimization is proposed according to the drawbacks of surrogate model based airfoil optimization. Programs are designed to achieve the dynamic mesh. Boundary condition is add by integrating commercial software Pointwise, meanwhile the CFD calculation is carried out by commercial software Fluent. The data exchange and communication between the software and programs referred above have been accomplished, and the whole optimization process is performed in iSIGHT platform. A simplified airfoil optimization study case is brought out to show that aerodynamic performances of airfoil have been significantly improved, even save massive repeat operations and increase the robustness and credibility of the optimization result. The case above proclaims that dynamic mesh based airfoil optimization is an effective and high efficient method.
Abstract: The rapid growth of e-Commerce services is
significantly observed in the past decade. However, the method to
verify the authenticated users still widely depends on numeric
approaches. A new search on other verification methods suitable for
online e-Commerce is an interesting issue. In this paper, a new online
signature-verification method using angular transformation is
presented. Delay shifts existing in online signatures are estimated by
the estimation method relying on angle representation. In the
proposed signature-verification algorithm, all components of input
signature are extracted by considering the discontinuous break points
on the stream of angular values. Then the estimated delay shift is
captured by comparing with the selected reference signature and the
error matching can be computed as a main feature used for verifying
process. The threshold offsets are calculated by two types of error
characteristics of the signature verification problem, False Rejection
Rate (FRR) and False Acceptance Rate (FAR). The level of these two
error rates depends on the decision threshold chosen whose value is
such as to realize the Equal Error Rate (EER; FAR = FRR). The
experimental results show that through the simple programming,
employed on Internet for demonstrating e-Commerce services, the
proposed method can provide 95.39% correct verifications and 7%
better than DP matching based signature-verification method. In
addition, the signature verification with extracting components
provides more reliable results than using a whole decision making.