Abstract: We investigated a modified thermal evaporation
method in the growth process of ZnO nanowires. ZnO nanowires
were fabricated on p-type silicon substrates without using a metal
catalyst. A simple horizontal double-tube system along with
chemical vapor diffusion of the precursor was used to grow the ZnO
nanowires. The substrates were placed in different temperature
zones, and ZnO nanowires with different diameters were obtained for
the different substrate temperatures. In addition to the nanowires,
ZnO microdiscs with different diameters were obtained on another
substrate, which was placed at a lower temperature than the other
substrates. The optical properties and crystalline quality of the ZnO
nanowires and microdiscs were characterized by room temperature
photoluminescence (PL) and Raman spectrometers. The PL and
Raman studies demonstrated that the ZnO nanowires and microdiscs
grown using such set-up had good crystallinity with excellent optical
properties. Rectifying behavior of ZnO/Si heterostructures was
characterized by a simple DC circuit.
Abstract: Waterlogging reduces shoot and root growth and final
yield of wheat. Waterlogged sites have a combination of low slope,
high rainfall, heavy texture and low permeability. This study was
aimed the importance of waterlogging on root growth and wheat
yield. In order to study the effects of different waterlogging duration
(0, 10, 20 and 30 days) at growth stages (1-leaf stage, tillering stage
and stem elongation stage) on root growth of wheat cultivars
(Chamran, Vee/Nac and Yavaroos), one pot experiment was carried
out. The experiment was a factorial according to a RCBD with three
replications. Results showed that root dry weight and total root
length in the anthesis and grain ripening stages and biological and
grain yields were significantly different between cultivars, growth
stages and waterlogging durations. Vee/Nac was found superior with
respect to other cultivars. Susceptibility to waterlogging at different
growth stages for cultivars was 1-leaf stage > tillering stage > stem
elongation stage. Under waterlogging treatments, grain and
biological yields, were decreased 44.5 and 39.8%, respectively. Root
length and root dry weight were reduced 55.1 and 45.2%,
respectively, too. In this experiment, decrease at root growth because
of waterlogging reduced grain and biological yields. Based on the
results, even short period (10 days) of waterlogging had
unrecoverable effects on the root growth and grain yield of wheat.
Abstract: The present disposal routes of sewage sludge represent a critical environmental issue in Egypt. Recently, there has been an increasing concern about sewage sludge management due to the environmental risks, which resulted from the fast expansion of wastewater treatment plants without equal attention in dealing with the produced sludge. This paper discusses the current situation of sewage sludge management in Egypt presenting a brief overview of the existing wastewater treatment plants, sludge production and characteristics as well as options of beneficial use and potential demand of sewage sludge under Egyptian conditions. The characteristics of sewage sludge are discussed considering the results of own sampling and analysis as well as previous studies. Furthermore, alternative treatment scenarios for sewage sludge, which have been recently developed in Egypt, are discussed and perspectives for a sustainable agricultural use are outlined.
Abstract: Overhead conveyor systems are in use in many installations around the world, meeting the widest range of applications possible. Overhead conveyor systems are particularly preferred in automotive industry but also at post offices. Overhead conveyor systems must always be integrated with a logistical process by finding the best way for a cheaper material flow in order to guarantee precise and fast workflows. With their help, any transport can take place without wasting ground and space, without excessive company capacity, lost or damaged products, erroneous delivery, endless travels and without wasting time. Ultra-light overhead conveyor systems are rope-based conveying systems with individually driven vehicles. The vehicles can move automatically on the rope and this can be realized by energy and signals. Crossings are realized by switches. Ultra-light overhead conveyor systems provide optimal material flow, which produces profit and saves time. This article introduces two new ultra-light overhead conveyor designs in logistics and explains their components. According to the explanation of the components, scenarios are created by means of their technical characteristics. The scenarios are visualized with the help of CAD software. After that, assumptions are made for application area. According to these assumptions scenarios are visualized. These scenarios help logistics companies achieve lower development costs as well as quicker market maturity.
Abstract: In this paper presents the mathematical model of
hydrothermal processes in thermal power plant with different wind
direction scenarios in the water reservoir, which is solved by the
Navier - Stokes and temperature equations for an incompressible
fluid in a stratified medium. Numerical algorithm based on the
method of splitting by physical parameters. Three dimensional
Poisson equation is solved with Fourier method by combination of
tridiagonal matrix method (Thomas algorithm).
Abstract: The effect of chemical treatment in CdCl2 on the
compositional changes and defect structures of potentially useful ZnS
solar cell thin films prepared by vacuum deposition method was
studied using the complementary Rutherford backscattering (RBS)
and Thermoluminesence (TL) techniques. A series of electron and
hole traps are found in the various as deposited samples studied.
After treatment, perturbation on the intensity is noted; mobile defect
states and charge conversion and/or transfer between defect states are
found.
Abstract: This paper describes the authorization system
architecture for Pervasive Grid environment. It discusses the
characteristics of classical authorization system and requirements of
the authorization system in pervasive grid environment as well.
Based on our analysis of current systems and taking into account the
main requirements of such pervasive environment, we propose new
authorization system architecture as an extension of the existing grid
authorization mechanisms. This architecture not only supports user
attributes but also context attributes which act as a key concept for
context-awareness thought. The architecture allows authorization of
users dynamically when there are changes in the pervasive grid
environment. For this, we opt for hybrid authorization method that
integrates push and pull mechanisms to combine the existing grid
authorization attributes with dynamic context assertions. We will
investigate the proposed architecture using a real testing environment
that includes heterogeneous pervasive grid infrastructures mapped
over multiple virtual organizations. Various scenarios are described
in the last section of the article to strengthen the proposed mechanism
with different facilities for the authorization procedure.
Abstract: This paper describes the architectural design
considerations for building a new class of application, a Personal
Knowledge Integrator and a particular example a Knowledge Theatre.
It then supports this description by describing a scenario of a child
acquiring knowledge and how this process could be augmented by
the proposed architecture and design of a Knowledge Theatre. David
Merrill-s first “principles of instruction" are kept in focus to provide
a background to view the learning potential.
Abstract: Current technological advances pale in comparison to the changes in social behaviors and 'sense of place' that is being empowered since the Internet made it on the scene. Today-s students view the Internet as both a source of entertainment and an educational tool. The development of virtual environments is a conceptual framework that needs to be addressed by educators and it is important that they become familiar with who these virtual learners are and how they are motivated to learn. Massively multiplayer online role playing games (MMORPGs), if well designed, could become the vehicle of choice to deliver learning content. We suggest that these games, in order to accomplish these goals, must begin with well-established instructional design principles that are co-aligned with established principles of video game design. And have the opportunity to provide an instructional model of significant prescriptive power. The authors believe that game designers need to take advantage of the natural motivation player-learners have for playing games by developing them in such a way so as to promote, intrinsic motivation, content learning, transfer of knowledge, and naturalization.
Abstract: Populations of wild boar present in semi-arid of central Iran. We studied features influencing bed site selection by this species in semi-arid central steppe of Iran. Habitat features of the detected bed site were compared with randomly selected by quantifying number of habitat variables in semi- arid area in Iran. The results revealed that the most important influencing factors in bed site selection were vegetation cover, number of Artemisia sieberi, percentage cover and height of Acer cinerascens, percentage cover and height of Amygdalus scoparia. This is the first ecological study of the wild boar in a protected area of the semi desert biome of Iran. Sustainability of wild boar populations in this area dependent to shrubs of Amygdalus scoparia and Acer cinerascens for thermal and camouflage cover.
Abstract: The necessity of ever-increasing use of distributed
data in computer networks is obvious for all. One technique that is
performed on the distributed data for increasing of efficiency and
reliablity is data rplication. In this paper, after introducing this
technique and its advantages, we will examine some dynamic data
replication. We will examine their characteristies for some overus
scenario and the we will propose some suggestion for their
improvement.
Abstract: In this paper, a Bayesian Network (BN) based system
is presented for providing clinical decision support to healthcare
practitioners in rural or remote areas of India for young infants or
children up to the age of 5 years. The government is unable to
appoint child specialists in rural areas because of inadequate number
of available pediatricians. It leads to a high Infant Mortality Rate
(IMR). In such a scenario, Intelligent Pediatric System provides a
realistic solution. The prototype of an intelligent system has been
developed that involves a knowledge component called an Intelligent
Pediatric Assistant (IPA); and User Agents (UA) along with their
Graphical User Interfaces (GUI). The GUI of UA provides the
interface to the healthcare practitioner for submitting sign-symptoms
and displaying the expert opinion as suggested by IPA. Depending
upon the observations, the IPA decides the diagnosis and the
treatment plan. The UA and IPA form client-server architecture for
knowledge sharing.
Abstract: The Iranian bentonite was first characterized by
Scanning Electron Microscopy (SEM), Inductively Coupled Plasma
mass spectrometry (ICP-MS), X-ray fluorescence (XRF), X-ray
Diffraction (XRD) and BET. The bentonite was then treated
thermally between 150°C-250°C at 15min, 45min and 90min and
also was activated chemically with different concentration of
sulphuric acid (3N, 5N and 10N). Although the results of thermal
activated-bentonite didn-t show any considerable changes in specific
surface area and Cation Exchange Capacity (CEC), but the results of
chemical treated bentonite demonstrated that such properties have
been improved by acid activation process.
Abstract: Macrophomina phaseolina is a devastating soil-borne
fungal plant pathogen that causes charcoal rot disease in many
economically important crops worldwide. So far, no registered
fungicide is available against this plant pathogen. This study was
planned to examine the antifungal activity of an allelopathic grass
Cenchrus pennisetiformis (Hochst. & Steud.) Wipff. for the
management of M. phaseolina isolated from cowpea [Vigna
unguiculata (L.) Walp.] plants suffering from charcoal rot disease.
Different parts of the plants viz. inflorescence, shoot and root were
extracted in methanol. Laboratory bioassays were carried out using
different concentrations (0, 0.5, 1.0, …, 3.0 g mL-1) of methanolic
extracts of the test allelopathic grass species to assess the antifungal
activity against the pathogen. In general, extracts of all parts of the
grass exhibited antifungal activity. All the concentrations of
methanolic extracts of shoot and root significantly reduced fungal
biomass by 20–73% and 40–80%, respectively. Methanolic shoot
extract was fractionated using n-hexane, chloroform, ethyl acetate
and n-butanol. Different concentrations of these fractions (3.125,
6.25, …, 200 mg mL-1) were analyzed for their antifungal activity.
All the concentrations of n-hexane fraction significantly reduced
fungal biomass by 15–96% over corresponding control treatments.
Higher concentrations (12.5–200 mg mL-1) of chloroform, ethyl
acetate and n-butanol also reduced the fungal biomass significantly
by 29–100%, 46–100% and 24–100%, respectively.
Abstract: The morphology, mineralogical and chemical
composition of a low-grade nickel ore from Mpumalanga, South
Africa, were studied by scanning electron microscope (SEM), X-ray
diffraction (XRD) and X-ray fluorescence (XRF), respectively. The
ore was subjected to atmospheric agitation leaching using sulphuric
acid to investigate the effects of acid concentration, leaching
temperature, leaching time and particle size on extraction of nickel
and cobalt. Analyses results indicated the ore to be a saprolitic nickel
laterite belonging to the serpentine group of minerals. Sulphuric acid
was found to be able to extract nickel from the ore. Increased acid
concentration and temperature only produced low amounts of nickel
but improved cobalt extraction. As high as 77.44% Ni was achieved
when leaching a -106+75μm fraction with 4.0M acid concentration at
25oC. The kinetics of nickel leaching from the saprolitic ore were
studied and the activation energy was determined to be 18.16kJ/mol.
This indicated that nickel leaching reaction was diffusion controlled.
Abstract: Today, building automation is advancing from simple
monitoring and control tasks of lightning and heating towards more
and more complex applications that require a dynamic perception
and interpretation of different scenes occurring in a building. Current
approaches cannot handle these newly upcoming demands. In this
article, a bionically inspired approach for multimodal, dynamic scene
perception and interpretation is presented, which is based on neuroscientific
and neuro-psychological research findings about the perceptual
system of the human brain. This approach bases on data from diverse
sensory modalities being processed in a so-called neuro-symbolic
network. With its parallel structure and with its basic elements being
information processing and storing units at the same time, a very
efficient method for scene perception is provided overcoming the
problems and bottlenecks of classical dynamic scene interpretation
systems.
Abstract: This paper considers a scheduling problem in flexible
flow shops environment with the aim of minimizing two important
criteria including makespan and cumulative tardiness of jobs. Since
the proposed problem is known as an Np-hard problem in literature,
we have to develop a meta-heuristic to solve it. We considered
general structure of Genetic Algorithm (GA) and developed a new
version of that based on Data Envelopment Analysis (DEA). Two
objective functions assumed as two different inputs for each Decision
Making Unit (DMU). In this paper we focused on efficiency score of
DMUs and efficient frontier concept in DEA technique. After
introducing the method we defined two different scenarios with
considering two types of mutation operator. Also we provided an
experimental design with some computational results to show the
performance of algorithm. The results show that the algorithm
implements in a reasonable time.
Abstract: In this article, the design of a Supply Chain Network
(SCN) consisting of several suppliers, production plants, distribution
centers and retailers, is considered. Demands of retailers are
considered stochastic parameters, so we generate amounts of data via
simulation to extract a few demand scenarios. Then a mixed integer
two-stage programming model is developed to optimize
simultaneously two objectives: (1) minimization the fixed and
variable cost, (2) maximization the service level. A weighting method
is utilized to solve this two objective problem and a numerical
example is made to show the performance of the model.
Abstract: Mobile robots are used in a large field of scenarios,
like exploring contaminated areas, repairing oil rigs under water,
finding survivors in collapsed buildings, etc. Currently, there is no
unified intuitive user interface (UI) to control such complex mobile
robots. As a consequence, some scenarios are done without the
exploitation of experience and intuition of human teleoperators.
A novel framework has been developed to embed a flexible and
modular UI into a complete 3-D virtual reality simulation system.
This new approach wants to access maximum benefits of human
operators. Sensor information received from the robot is prepared for
an intuitive visualization. Virtual reality metaphors support the
operator in his decisions. These metaphors are integrated into a real
time stereo video stream. This approach is not restricted to any
specific type of mobile robot and allows for the operation of different
robot types with a consistent concept and user interface.
Abstract: Efficient luminescence is reported for the first time in Eu2+ activated double Chlorides A2BCl4 (A=Alkali metal, B=Alkaline earth element). A simple wet-chemical preparation is described. Emission intensities are comparable to that of the commercial phosphor. Excitation covers near UV region. These phosphors may be useful for applications like solid state lighting, scintillation detectors and X-ray storage using photo-stimulable phosphors.