Abstract: In this article, biomechanical aspects of hen-s eggshell as a natural ceramic structure are studied. The images, taken by a scanning electron microscope (SEM), are used to investigate the microscopic aspects of the egg. It is observed that eggshell has a three-layered microstructure with different morphological and structural characteristics. Studies on the eggshell membrane (ESM) as a prosperous tissue suggest that it is placed to prevent the penetration of microorganisms into the egg. Finally, numerical models of the egg are presented to study the stress distribution and its deformation under different loading conditions. The effects of two different types of loading (hydrostatic and point loadings) on two different shell models (with constant and variable thicknesses) are investigated in detail.
Abstract: In this study three commercial semiconductor devices
were characterized in the laboratory for computed tomography
dosimetry: one photodiode and two phototransistors. It was evaluated
four responses to the irradiation: dose linearity, energy dependence,
angular dependence and loss of sensitivity after X ray exposure. The
results showed that the three devices have proportional response with
the air kerma; the energy dependence displayed for each device
suggests that some calibration factors would be applied for each one;
the angular dependence showed a similar pattern among the three
electronic components. In respect to the fourth parameter analyzed,
one phototransistor has the highest sensitivity however it also showed
the greatest loss of sensitivity with the accumulated dose. The
photodiode was the device with the smaller sensitivity to radiation,
on the other hand, the loss of sensitivity after irradiation is negligible.
Since high accuracy is a desired feature for a dosimeter, the
photodiode can be the most suitable of the three devices for
dosimetry in tomography. The phototransistors can also be used for
CT dosimetry, however it would be necessary a correction factor due
to loss of sensitivity with accumulated dose.
Abstract: Nowadays due to globalization of economy and
competition environment, innovation and technology plays key role
at creation of wealth and economic growth of countries. In fact
prompt growth of practical and technologic knowledge may results in
social benefits for countries when changes into effective innovation.
Considering the importance of innovation for the development of
countries, this study addresses the radical technological innovation
introduced by nanopapers at different stages of producing paper
including stock preparation, using authorized additives, fillers and
pigments, using retention, calender, stages of producing conductive
paper, porous nanopaper and Layer by layer self-assembly. Research
results show that in coming years the jungle related products will lose
considerable portion of their market share, unless embracing radical
innovation. Although incremental innovations can make this industry
still competitive in mid-term, but to have economic growth and
competitive advantage in long term, radical innovations are
necessary. Radical innovations can lead to new products and
materials which their applications in packaging industry can produce
value added. However application of nanotechnology in this industry
can be costly, it can be done in cooperation with other industries to
make the maximum use of nanotechnology possible. Therefore this
technology can be used in all the production process resulting in the
mass production of simple and flexible papers with low cost and
special properties such as facility at shape, form, easy transportation,
light weight, recovery and recycle marketing abilities, and sealing.
Improving the resistance of the packaging materials without reducing
the performance of packaging materials enhances the quality and the
value added of packaging. Improving the cellulose at nano scale can
have considerable electron optical and magnetic effects leading to
improvement in packaging and value added. Comparing to the
specifications of thermoplastic products and ordinary papers,
nanopapers show much better performance in terms of effective
mechanical indexes such as the modulus of elasticity, tensile strength,
and strain-stress. In densities lower than 640 kgm -3, due to the
network structure of nanofibers and the balanced and randomized
distribution of NFC in flat space, these specifications will even
improve more. For nanopapers, strains are 1,4Gpa, 84Mpa and 17%,
13,3 Gpa, 214Mpa and 10% respectively. In layer by layer self
assembly method (LbL) the tensile strength of nanopaper with Tio3
particles and Sio2 and halloysite clay nanotube are 30,4 ±7.6Nm/g
and 13,6 ±0.8Nm/g and 14±0.3,3Nm/g respectively that fall within
acceptable range of similar samples with virgin fiber. The usage of
improved brightness and porosity index in nanopapers can create
more competitive advantages at packaging industry.
Abstract: In electronegative-electropositive gas mixtures plasma, at a total pressure varying in the range of ten to hundred Torr, the appearance of a quasi-mochromatization effect of the emitted radiation was reported. This radiation could be the result of the generating mechanisms at molecular level, which is the case of the excimer radiation but also at atomic level. Thus, in the last case, in (Ne+1%Ar/Xe+H2) gas mixtures plasma in a dielectric barrier discharge, this effect, called M-effect, consists in the reduction of the discharge emission spectrum practice at one single, strong spectral line with λ = 585.3 nm. The present paper is concerned with the characteristics comparative investigation of the principal reaction mechanisms involved in the quasi-monochromatization effect existence in the case of the excimer radiation, respectively of the Meffect. Also, the paper points out the role of the metastable electronegative atoms in the appearance of the monochromatization – effect at atomic level.
Abstract: Having done in this study, air-conditioning
automation for patisserie shopwindow was designed. In the cooling
sector it is quite important to cooling up the air temperature in the
shopwindow within short time interval. Otherwise the patisseries
inside of the shopwindow will be spoilt in a few days. Additionally
the humidity is other important parameter for the patisseries kept in
shopwindow. It must be raised up to desired level in a quite short
time. Traditional patisserie shopwindows only allow controlling
temperature manually. There is no humidity control and humidity is
supplied by fans that are directed to the water at the bottom of the
shopwindows. In this study, humidity and temperature sensors
(SHT11), PIC, AC motor controller, DC motor controller, ultrasonic
nebulizer and other electronic circuit members were used to simulate
air conditioning automation for patisserie shopwindow in proteus
software package. The simulation results showed that temperature
and humidity values are adjusted in desired time duration by openloop
control technique. Outer and inner temperature and humidity
values were used for control mechanism.
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: 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: This paper explores the issues that influence online retailing in Saudi Arabia. Retailers in Saudi Arabia have been reserved in their adoption of electronically delivered aspects of their business. Despite the fact that Saudi Arabia has the largest and fastest growth of ICT marketplaces in the Arab region, e-commerce activities are not progressing at the same speed. Only very few Saudi companies, mostly medium and large companies from the manufacturing sector, are involved in e-commerce implementation. Based on qualitative data collected by conducting interviews with 16 retailers and 16 potential customers in Saudi Arabia, several factors influencing online retailing diffusion in Saudi Arabia are identified. However, government support comes the highest and most influencing factor for online retailing growth as identified by both parties; retailers and potential customers in Saudi Arabia.
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: Titanium alloys like Ti-6Al-2Sn-4Zr-6Mo (Ti-
6246) are widely used in aerospace applications. Component
manufacturing, however, is difficult and expensive as their
machinability is extremely poor. A thorough understanding of the
chip formation process is needed to improve related metal cutting
operations.In the current study, orthogonal cutting experiments have
been performed and theresulting chips were analyzed by optical
microscopy and scanning electron microscopy.Chips from aTi-
6246ingot were produced at different cutting speeds and cutting
depths. During the experiments, depending of the cutting conditions,
continuous or segmented chips were formed. Narrow, highly
deformed and grain oriented zones, the so-called shear zone,
separated individual segments. Different material properties have
been measured in the shear zones and the segments.
Abstract: This paper presents a remote on-line diagnostic system
for vehicles via the use of On-Board Diagnostic (OBD), GPS, and 3G
techniques. The main parts of the proposed system are on-board
computer, vehicle monitor server, and vehicle status browser. First,
the on-board computer can obtain the location of deriver and vehicle
status from GPS receiver and OBD interface, respectively. Then
on-board computer will connect with the vehicle monitor server
through 3G network to transmit the real time vehicle system status.
Finally, vehicle status browser could show the remote vehicle status
including vehicle speed, engine rpm, battery voltage, engine coolant
temperature, and diagnostic trouble codes. According to the
experimental results, the proposed system can help fleet managers and
car knockers to understand the remote vehicle status. Therefore this
system can decrease the time of fleet management and vehicle repair
due to the fleet managers and car knockers who find the diagnostic
trouble messages in time.
Abstract: This paper analyzed the perception of e-commerce
application services by construction material traders in Malaysia.
Five attributes were tested: usability, reputation, trust, privacy and
familiarity. Study methodology consists of survey questionnaire and
statistical analysis that includes reliability analysis, factor analysis,
ANOVA and regression analysis. The respondents were construction
material traders, including hardware stores in Klang Valley, Kuala
Lumpur.
Findings support that usability and familiarity with e-commerce
services in Malaysia have insignificant influence on the acceptance of
e-commerce application. However, reputation, trust and privacy
attributes have significant influence on the choice of e-commerce
acceptance by construction material traders. E-commerce
applications studied included customer database, e-selling, emarketing,
e-payment, e-buying and online advertising. Assumptions
are made that traders have basic knowledge and exposure to ICT
services. i.e. internet service and computers. Study concludes that
reputation, privacy and trust are the three website attributes that
influence the acceptance of e-commerce by construction material
traders.
Abstract: In this work we investigated the behavior of methane
hydrates dispersed in crude oils from different fields at temperatures
below 0°C. In case of crude oil emulsion the size of water droplets is
in the range of 50e100"m. The size of hydrate particles formed from
droplets is the same. The self-preservation is not expected in this
field. However, the self-preservation of hydrates with the size of
particles 24±18"m (electron microscopy data) in suspensions is
observed. Similar results were obtained for four different kinds of
crude oil and model system such as asphaltenes, resins and wax in ndecane.
This result can allow developing effective methods to prevent
the formation and elimination of gas-hydrate plugs in pipelines under
low temperature conditions (e. g. in Eastern Siberia). There is a
prospective to use experiment results for working out the technology
of associated petroleum gas recovery.
Abstract: A proposed small-signal model parameters for a pseudomorphic high electron mobility transistor (PHEMT) is presented. Both extrinsic and intrinsic circuit elements of a smallsignal model are determined using genetic algorithm (GA) as a stochastic global search and optimization tool. The parameters extraction of the small-signal model is performed on 200-μm gate width AlGaAs/InGaAs PHEMT. The equivalent circuit elements for a proposed 18 elements model are determined directly from the measured S- parameters. The GA is used to extract the parameters of the proposed small-signal model from 0.5 up to 18 GHz.
Abstract: Noble metal participation in nanostructured
semiconductor catalysts has drawn much interest because of their
improved properties. Recently, it has been discussed by many
researchers that Ag participation in TiO2, CuO, ZnO semiconductors
showed improved photocatalytic and optical properties. In this
research, Ag/ZnO nanocomposite particles were prepared by
Ultrasonic Spray Pyrolysis(USP) Method. 0.1M silver and zinc
nitrate aqueous solutions were used as precursor solutions. The
Ag:Zn atomic ratio of the solution was selected 1:1. Experiments
were taken place under constant air flow of 400 mL/min at 800°C
furnace temperature. Particles were characterized by X-Ray
Diffraction (XRD), Scanning Electron Microscope (SEM) and
Energy Dispersive Spectroscopy (EDS). The crystallite sizes of Ag
and ZnO in composite particles are 24.6 nm, 19.7 nm respectively.
Although, spherical nanocomposite particles are in a range of 300-
800 nm, these particles are formed by the aggregation of primary
particles which are in a range of 20-60 nm.
Abstract: The gustatory system allows animals to distinguish
varieties of food and affects greatly the consumption of food, hence
the health and growth of animals. In the current study, we
investigated the histogenesis of vallate papillae (VLP) in the rabbit
tongue using light and scanning electron microscopy. Samples were
obtained from rabbit embryos at the embryonic days 16-30 (E16-30),
and from newborns until maturity; 6 months. At E16, the first
primordia of vallate papillae were observed as small pits on the
surface epithelium of the tongue-s root. At E18, the caudal part was
prominent with loose mesenchymal tissue core; meanwhile the rostral
part of the papilla was remained as a thick mass of epithelial cells. At
E20-24, the side epithelium formed the primitive annular groove. At
E26, the primitive taste buds appeared only at the papillary surface
and reached their maturity by E28. The annular groove started to
appear at E26 became more defined at E28. The definitive vallate
papillae with substantial number of apparently mature taste buds
were observed by the end of the second week. We conclude that the
vallate papillae develop early and mature during the early postnatal
life.
Abstract: Buoyancy driven heat transfer of nanofluids in a
cylindrical enclosure used as a control unit in the subsea hydrocarbon
injection wells is investigated in this study. The governing equations
obtained with the Boussinesq approximation are solved using Comsol
Multiphysics finite element analysis and simulation software. The
base fluid is water and CuO is used as nanoparticles. Solution is
obtained for nanoparticle solid volume fraction of 8% and for
Rayleigh number in the range of 105-107. The results show that
nanoparticle usage in the cylindrical electronic control unit has a
significant effect on the flow and heat transfer.
Abstract: The main goal of this seminal paper is to introduce the
application of Wireless Sensor Networks (WSN) in long distance
infrastructure monitoring (in particular in pipeline infrastructure
monitoring) – one of the on-going research projects by the Wireless
Communication Research Group at the department of Electronic and
Computer Engineering, Nnamdi Azikiwe University, Awka. The
current sensor network architectures for monitoring long distance
pipeline infrastructures are previewed. These are wired sensor
networks, RF wireless sensor networks, integrated wired and wireless
sensor networks. The reliability of these architectures is discussed.
Three reliability factors are used to compare the architectures in
terms of network connectivity, continuity of power supply for the
network, and the maintainability of the network. The constraints and
challenges of wireless sensor networks for monitoring and protecting
long distance pipeline infrastructure are discussed.
Abstract: Simulation accuracy by recent dynamic vehicle
simulation multidimensional expression significantly has progressed
and acceptable results not only for passive vehicles but also for
active vehicles normally equipped with advanced electronic
components is also provided. Recently, one of the subjects that has it
been considered, is increasing the safety car in design. Therefore,
many efforts have been done to increase vehicle stability especially
in the turn. One of the most important efforts is adjusting the camber
angle in the car suspension system. Optimum control camber angle in
addition to the vehicle stability is effective in the wheel adhesion on
road, reducing rubber abrasion and acceleration and braking. Since
the increase or decrease in the camber angle impacts on the stability
of vehicles, in this paper, a car suspension system mechanism is
introduced that could be adjust camber angle and the mechanism is
application and also inexpensive. In order to reach this purpose, in
this paper, a passive double wishbone suspension system with
variable camber angle is introduced and then variable camber
mechanism designed and analyzed for study the designed system
performance, this mechanism is modeled in Visual Nastran software
and kinematic analysis is revealed.
Abstract: In the past, there were more researches of recommendation system in applied electronic commerce. However, because all circles promote information technology integrative instruction actively, the quantity of instruction resources website is more and more increasing on the Internet. But there are less website including recommendation service, especially for teachers. This study established an instruction resource recommendation website that analyzed teaching style of teachers, then provided appropriate instruction resources for teachers immediately. We used the questionnaire survey to realize teacher-s suggestions and satisfactions with the instruction resource contents and recommendation results. The study shows: (1)The website used “Transactional Ability Inventory" that realized teacher-s style and provided appropriate instruction resources for teachers in a short time, it reduced the step of data filter. (2)According to the content satisfaction of questionnaire survey, four styles teachers were almost satisfied with the contents of the instruction resources that the website recommended, thus, the conception of developing instruction resources with different teaching style is accepted. (3) According to the recommendation satisfaction of questionnaire survey, four styles teachers were almost satisfied with the recommendation service of the website, thus, the recommendation strategy that provide different results for teachers in different teaching styles is accepted.