Abstract: An experiment of vented gas explosions involving two
different cylinder vessel volumes (0.2 and 0.0065 m3) was reported,
with equivalence ratio (Φ) ranged from 0.3 to 1.6. Both vessels were
closed at the rear end and fitted at the other side with a circular
orifice plate that gives a constant vent coefficient (K =Av/V2/3) of
16.4. It was shown that end ignition gives higher overpressures than
central ignition, even though most of the published work on venting
uses central ignition. For propane and ethylene, it is found that rich
mixtures gave the highest overpressures and these mixtures are not
considered in current vent design guidance; which the guideline is
based on mixtures giving the maximum flame temperature. A strong
influence of the vessel volume at constant K was found for methane,
propane, ethylene and hydrogen-air explosions. It can be concluded
that self- acceleration of the flame, which is dependent on the
distance of a flame from the ignition and the ‘suction’ at the vent
opening are significant factors affecting the vent flow during
explosion development in vented gas explosion. This additional
volume influence on vented explosions is not taken into account in
the current vent design guidance.
Abstract: The aim of the present investigation was to compare
sex differences in thyroid gland structure of rabbits. Five adult male
and five adult female (3.1-3.5 kg body weight) New Zealand white
rabbits were used in the experiment. Results showed that at light
microscopic level, there was no sex difference in microscopic
appearance of the thyroid glands. At electron microscopic level,
however, the mitochondria and the microvilli of the follicular cells
are more numerous and the Golgi complex is also more extensive in
male rabbits in comparison to females. Results obtained from
micrometric measurements showed that the volume density of the
follicles is higher in males than in females, but the differences are not
statistically significant .The volume density of epithelium and the
height of follicular cells are significantly greater in males than in
females and reverse is true about the volume density of interstitium
(p
Abstract: Modern Society is strongly dependent on a reliable
power supply. The availability of cheap and reliable supply of
electrical energy is an indicator of societal welfare. Uninterrupted
reliable operation of a modern power system depends to a great
extent on reliable and satisfactory performance of insulators under
different environmental conditions. This paper reports result of
natural pollution tests that have been done at sites around city of
Aligarh (India). Flashover voltage per insulation distance (FOVUID)
of porcelain disc insulator for different pH values, ESDD has been
recorded for proper correlation between electrical and chemical
parameters. The pH of the contaminants has been suggested to be an
effective pollution severity indicator and may be used as a diagnostic
parameter for proper maintenance of porcelain insulators.
Abstract: Bionanotechnology deals with nanoscopic interactions between nanostructured materials and biological systems. Polymer nanocomposites with optimized biological activity have attracted great attention. Nanoclay is considered as reinforcing nanofiller in manufacturing of high performance nanocomposites. In current study, organomodified-nanoclay with negatively charged silicate layers was incorporated into biomedical grade silicone rubber. Nanoparticle loading has been tailored to enhance cell behavior. Addition of nanoparticles led to improved mechanical properties of substrate with enhanced strength and stiffness while no toxic effects was observed. Results indicated improved viability and proliferation of cells by addition of nanofillers. The improved mechanical properties of the matrix result in proper cell response through adjustment and arrangement of cytoskeletal fibers. Results can be applied in tissue engineering when enhanced substrates are required for improvement of cell behavior for in vivo applications.
Abstract: The localization of software products is essential for reaching the users of the international market. An important task for this is the translation of the user interface into local national languages. As graphical interfaces are usually optimized for the size of the texts in the original language, after the translation certain user controls (e.g. text labels and buttons in dialogs) may grow in such a manner that they slip above each other. This not only causes an unpleasant appearance but also makes the use of the program more difficult (or even impossible) which implies that the arrangement of the controls must be corrected subsequently. The correction should preserve the original structure of the interface (e.g. the relation of logically coherent controls), furthermore, it is important to keep the nicely proportioned design: the formation of large empty areas should be avoided. This paper describes an algorithm that automatically rearranges the controls of a graphical user interface based on the principles above. The algorithm has been implemented and integrated into a translation support system and reached results pleasant for the human eye in most test cases.
Abstract: This paper has as its main aim to analyse how
corporate web pages can become an essential tool in order to detect
strategic trends by firms or sectors, and even a primary source for
benchmarking. This technique has made it possible to identify the key
issues in the strategic management of the most excellent large Spanish
firms and also to describe trends in their long-range planning, a way of
working that can be generalised to any country or firm group. More
precisely, two objectives were sought. The first one consisted in showing
the way in which corporate websites make it possible to obtain direct
information about the strategic variables which can define firms. This
tool is dynamic (since web pages are constantly updated) as well as
direct and reliable, since the information comes from the firm itself, not
from comments of third parties (such as journalists, academicians,
consultants...). When this information is analysed for a group of firms,
one can observe their characteristics in terms of both managerial tasks
and business management. As for the second objective, the methodology
proposed served to describe the corporate profile of the large Spanish
enterprises included in the Ibex35 (the Ibex35 or Iberia Index is the
reference index in the Spanish Stock Exchange and gathers periodically
the 35 most outstanding Spanish firms). An attempt is therefore made to
define the long-range planning that would be characteristic of the largest
Spanish firms.
Abstract: Understanding driving behavior is a complicated
researching topic. To describe accurate speed, flow and density of a
multiclass users traffic flow, an adequate model is needed. In this
study, we propose the concept of standard passenger car equivalent
(SPCE) instead of passenger car equivalent (PCE) to estimate the
influence of heavy vehicles and slow cars. Traffic cellular automata
model is employed to calibrate and validate the results. According to
the simulated results, the SPCE transformations present good
accuracy.
Abstract: This work develops a novel intelligent “model of dynamic decision-making" usingcell assemblies network architecture in robot's movement. The “model of dynamic decision-making" simulates human decision-making, and follows commands to make the correct decisions. The cell assemblies approach consisting of fLIF neurons was used to implement tasks for finding targets and avoiding obstacles. Experimental results show that the cell assemblies approach of can be employed to efficiently complete finding targets and avoiding obstacles tasks and can simulate the human thinking and the mode of information transactions.
Abstract: The pyrolysis characteristics and kinetics of seven marine biomass, which are fixed Enteromorpha clathrata, floating Enteromorpha clathrata, Ulva lactuca L., Zosterae Marinae L., Thallus Laminariae, Asparagus schoberioides kunth and Undaria pinnatifida (Harv.), were studied with thermogravimetric analysis method. Simultaneously, cornstalk, which is a grass biomass, and sawdust, which is a lignocellulosic biomass, were references. The basic pyrolysis characteristics were studied by using TG- DTG-DTA curves. The results showed that there were three stages (dehydration, dramatic weight loss and slow weight loss) during the whole pyrolysis process of samples. The Tmax of marine biomass was significantly lower than two kinds of terrestrial biomass. Zosterae Marinae L. had a relatively high stability of pyrolysis, but floating Enteromorpha clathrata had lowest stability of pyrolysis and a good combustion characteristics. The corresponding activation energy E and frequency factor A were obtained by Coats-Redfern method. It was found that the pyrolysis reaction mechanism functions of three kinds of biomass are different.
Abstract: In order to derive important parameters concerning
mobile subscriber MS with ongoing calls in Low Earth Orbit Mobile
Satellite Systems LEO MSSs, a positioning system had to be
integrated into MSS in order to localize mobile subscribers MSs and
track them during the connection. Such integration is regarded as a
complex implementation. We propose in this paper a novel method
based on advantages of mobility model of Low Earth Orbit Mobile
Satellite System LEO MSS which allows the evaluation of instant of
subsequent handover of a MS even if its location is unknown. This
method is utilized to propose a Dynamic Channel Reservation DCRlike
scheme based on the DCR scheme previously proposed in
literature. Results presented show that DCR-like technique gives
different QoS performance than DCR. Indeed, an improve in
handover blocking probability and an increase in new call blocking
probability are observed for the DCR-like technique.
Abstract: Most of the collision warning systems currently
available in the automotive market are mainly designed to warn
against imminent rear-end and lane-changing collisions. No collision
warning system is commercially available to warn against imminent
turning collisions at intersections, especially for left-turn collisions
when a driver attempts to make a left-turn at either a signalized or
non-signalized intersection, conflicting with the path of other
approaching vehicles traveling on the opposite-direction traffic
stream. One of the major factors that lead to left-turn collisions is the
human error and misjudgment of the driver of the turning vehicle
when perceiving the speed and acceleration of other vehicles
traveling on the opposite-direction traffic stream; therefore, using a
properly-designed collision warning system will likely reduce, or
even eliminate, this type of collisions by reducing human error. This
paper introduces perceptual framework for a proposed collision
warning system that can detect imminent left-turn collisions at
intersections. The system utilizes a commercially-available detection
sensor (either a radar sensor or a laser detector) to detect approaching
vehicles traveling on the opposite-direction traffic stream and
calculate their speeds and acceleration rates to estimate the time-tocollision
and compare that time to the time required for the turning
vehicle to clear the intersection. When calculating the time required
for the turning vehicle to clear the intersection, consideration is given
to the perception-reaction time of the driver of the turning vehicle,
which is the time required by the driver to perceive the message
given by the warning system and react to it by engaging the throttle.
A regression model was developed to estimate perception-reaction
time based on age and gender of the driver of the host vehicle.
Desired acceleration rate selected by the driver of the turning vehicle,
when making the left-turn movement, is another human factor that is
considered by the system. Another regression model was developed
to estimate the acceleration rate selected by the driver of the turning
vehicle based on driver-s age and gender as well as on the location
and speed of the nearest approaching vehicle along with the
maximum acceleration rate provided by the mechanical
characteristics of the turning vehicle. By comparing time-to-collision
with the time required for the turning vehicle to clear the intersection,
the system displays a message to the driver of the turning vehicle
when departure is safe. An application example is provided to
illustrate the logic algorithm of the proposed system.
Abstract: By analyzing the sources of energy and power
loss in PWM (Pulse Width Modulation) controlled drivers of
water electrolysis cells, it is possible to reduce the power
dissipation and enhance the efficiency of such hydrogen
production units. A PWM controlled power driver is based on
a semiconductor switching element where its power
dissipation might be a remarkable fraction of the total power
demand of an electrolysis system. Power dissipation in a
semiconductor switching element is related to many different
parameters which could be fitted into two main categories:
switching losses and conduction losses. Conduction losses are
directly related to the built, structure and capabilities of a
switching device itself and indeed the conditions in which the
element is handling the switching application such as voltage,
current, temperature and of course the fabrication technology.
On the other hand, switching losses have some other
influencing variables other than the mentioned such as control
system, switching method and power electronics circuitry of
the PWM power driver. By analyzings the characteristics of
recently developed power switching transistors from different
families of Bipolar Junction Transistors (BJT), Metal Oxide
Semiconductor Field Effect Transistors (MOSFET) and
Insulated Gate Bipolar Transistors (IGBT), some
recommendations are made in this paper which are able to
lead to achieve higher hydrogen production efficiency by
utilizing PWM controlled water electrolysis cells.
Abstract: In intensity modulated radiation therapy (IMRT)
treatment planning, beam angles are usually preselected on the basis of
experience and intuition. Therefore, getting an appropriate beam
configuration needs a very long time. Based on the present situation,
the paper puts forward beam orientation optimization using ant colony
optimization (ACO). We use ant colony optimization to select the
beam configurations, after getting the beam configuration using
Conjugate Gradient (CG) algorithm to optimize the intensity profiles.
Combining with the information of the effect of pencil beam, we can
get the global optimal solution accelerating. In order to verify the
feasibility of the presented method, a simulated and clinical case was
tested, compared with dose-volume histogram and isodose line
between target area and organ at risk. The results showed that the
effect was improved after optimizing beam configurations. The
optimization approach could make treatment planning meet clinical
requirements more efficiently, so it had extensive application
perspective.
Abstract: The role of the pollen grain, with to the reproductive
process of higher plants, is to deliver the spermatic cells to the
embryo sac for egg fertilization. The aim of this project was study
the effect of electromagnetic fields on structure and pollen grains
development in Chenopodium album. Anthers of Chenopodium
album L. were collected at different stages of development from
control (without electromagnetic field) and plants grown at 10m from
the field sources. Structure and development of pollen grains were
studied and compared. The studying pollen structure by Light and
Scanning electron microscopy showed that electromagnetic fields
reduction of pollen grains number and male sterility, thus , in some
anthers, pollen grains were attached together and deformed compared
to control ones. The data presented suggest that prolonged exposures
of plants to magnetic field may cause different biological effects at
the cellular tissue and organ levels.
Abstract: It is shown that the relationship of tick-borne
encephalitis virus with the human body comes in two ways, the
development of acute infection with the outcome in convalescence
and long stay by the virus in the body, its persistence in the nervous
tissue with periodic reactivation and prolonged circulating
immunoglobulin M. In spite of the fact that tick-borne encephalitis
virus has a tropism for nerve tissue, involvement in the process of
blood cells is an integral component of the infection. Comprehensive
study of the relation of factors of innate and adaptive immunity in the
tick-borne encephalitis providing insight into the features of chronic
disease.
Abstract: Three reactor types were explored and successfully
used for pigment production by Monascus: shake flasks, and shaken
and stirred miniaturized reactors. Also, the use of dielectric
spectroscopy for the on-line measurement of biomass levels was
explored. Shake flasks gave good pigment yields, but scale up is
difficult, and they cannot be automated. Shaken bioreactors were less
successful with pigment production than stirred reactors.
Experiments with different impeller speeds in different volumes of
liquid in the reactor confirmed that this is most likely due oxygen
availability. The availability of oxygen appeared to affect biomass
levels less than pigment production; red pigment production in
particular needed very high oxygen levels. Dielectric spectroscopy
was effectively used to continuously measure biomass levels during
the submerged fungal fermentation in the shaken and stirred
miniaturized bioreactors, despite the presence of the solid substrate
particles. Also, the capacitance signal gave useful information about
the viability of the cells in the culture.
Abstract: The field of biomedical materials plays an imperative
requisite and a critical role in manufacturing a variety of biological
artificial replacements in a modern world. Recently, titanium (Ti)
materials are being used as biomaterials because of their superior
corrosion resistance and tremendous specific strength, free- allergic
problems and the greatest biocompatibility compared to other
competing biomaterials such as stainless steel, Co-Cr alloys,
ceramics, polymers, and composite materials. However, regardless of
these excellent performance properties, Implantable Ti materials have
poor shear strength and wear resistance which limited their
applications as biomaterials. Even though the wear properties of Ti
alloys has revealed some improvements, the crucial effectiveness of
biomedical Ti alloys as wear components requires a comprehensive
deep understanding of the wear reasons, mechanisms, and techniques
that can be used to improve wear behavior. This review examines
current information on the effect of thermal and thermomechanical
processing of implantable Ti materials on the long-term prosthetic
requirement which related with wear behavior. This paper focuses
mainly on the evolution, evaluation and development of effective
microstructural features that can improve wear properties of bio
grade Ti materials using thermal and thermomechanical treatments.
Abstract: Wood as a natural renewable material is vulnerable to
degradation by microorganisms and susceptible to change in
dimension by water. In order to effectively improve the durability of
wood, an active reagent, maleic anhydride (Man) was selected for
wood modification. Man was first dissolved into a solvent, and then
penetrated into wood porous structure under a vacuum/pressure
condition. After a final catalyst-thermal treatment, wood modification
was finished. The test results indicate that acetone is a good solvent for
transporting Man into wood matrix. SEM observation proved that
wood samples treated by Man kept a good cellular structure, indicating
a well penetration of Man into wood cell walls. FTIR analysis
suggested that Man reacted with hydroxyl groups on wood cell walls
by its ring-ether group, resulting in reduction of amount of hydroxyl
groups and resultant good dimensional stability as well as fine decay
resistance. Consequently, Man modifying wood to improve its
durability is an effective method.
Abstract: Recently, nanomaterials are developed in the form of nano-films, nano-crystals and nano-pores. Lanthanide phosphates as a material find extensive application as laser, ceramic, sensor, phosphor, and also in optoelectronics, medical and biological labels, solar cells and light sources. Among the different kinds of rare-earth orthophosphates, yttrium orthophosphate has been shown to be an efficient host lattice for rare earth activator ions, which have become a research focus because of their important role in the field of light display systems, lasers, and optoelectronic devices. It is in this context that the 4fn- « 4fn-1 5d transitions of rare earth in insulating materials, lying in the UV and VUV, are the aim of large number of studies .Though there has been a few reports on Eu3+, Nd3+, Pr3+,Er3+, Ce3+, Tm3+ doped YPO4. The 4fn- « 4fn-1 5d transitions of the rare earth dependent to the host-matrix, several matrices ions were used to study these transitions, in this work we are suggesting to study on a very specific class of inorganic material that are orthophosphate doped with rare earth ions. This study focused on the effect of Ce3+ concentration on the structural and optical properties of Ce3+ doped YPO4 yttrium orthophosphate with powder form prepared by the Sol Gel method.
Abstract: If organizations like Mellat Bank want to identify its
customer market completely to reach its specified goals, it can
segment the market to offer the product package to the right segment.
Our objective is to offer a segmentation model for Iran banking
market in Mellat bank view. The methodology of this project is
combined by “segmentation on the basis of four part-quality
variables" and “segmentation on the basis of different in means".
Required data are gathered from E-Systems and researcher personal
observation. Finally, the research offers the organization that at first
step form a four dimensional matrix with 756 segments using four
variables named value-based, behavioral, activity style, and activity
level, and at the second step calculate the means of profit for every
cell of matrix in two distinguished work level (levels α1:normal
condition and α2: high pressure condition) and compare the segments
by checking two conditions that are 1- homogeneity every segment
with its sub segment and 2- heterogeneity with other segments, and
so it can do the necessary segmentation process. After all, the last
offer (more explained by an operational example and feedback
algorithm) is to test and update the model because of dynamic
environment, technology, and banking system.