Abstract: This paper uses quasi-steady molecular statics model
and diamond tool to carry out simulation temperature rise of nanoscale
orthogonal cutting single-crystal silicon. It further qualitatively
analyzes temperature field of silicon workpiece without considering
heat transfer and considering heat transfer. This paper supposes that
the temperature rise of workpiece is mainly caused by two heat sources:
plastic deformation heat and friction heat. Then, this paper develops a
theoretical model about production of the plastic deformation heat and
friction heat during nanoscale orthogonal cutting. After the increased
temperature produced by these two heat sources are added up, the
acquired total temperature rise at each atom of the workpiece is
substituted in heat transfer finite difference equation to carry out heat
transfer and calculates the temperature field in each step and makes
related analysis.
Abstract: In this work, grinding or microcutting tools in the form of pellets were manufactured using a bounded alumina abrasive grains. The bound used is a vitreous material containing quartz feldspars, kaolinite and a quantity of hematite. The pellets were used in glass grinding process to replace the free abrasive grains lapping process. The study of the elaborated pellets were done to define their effectiveness in the grinding process and to optimize the influence of the pellets elaboration parameters. The obtained results show the existence of an optimal combination of the pellets elaboration parameters for each glass grinding phase (coarse to fine grinding). The final roughness (rms) reached by the elaborated pellets on a BK7 glass surface was about 0.392 μm.
Abstract: An unsupervised classification algorithm is derived
by modeling observed data as a mixture of several mutually
exclusive classes that are each described by linear combinations of
independent non-Gaussian densities. The algorithm estimates the
data density in each class by using parametric nonlinear functions
that fit to the non-Gaussian structure of the data. This improves
classification accuracy compared with standard Gaussian mixture
models. When applied to textures, the algorithm can learn basis
functions for images that capture the statistically significant structure
intrinsic in the images. We apply this technique to the problem of
unsupervised texture classification and segmentation.
Abstract: The steady incompressible flow has been solved in cylindrical coordinates in both vapour region and wick structure. The governing equations in vapour region are continuity, Navier-Stokes and energy equations. These equations have been solved using SIMPLE algorithm. For study of parameters variation on heat pipe operation, a benchmark has been chosen and the effect of changing one parameter has been analyzed when the others have been fixed.
Abstract: The automatic discrimination of seismic signals is an important practical goal for the earth-science observatories due to the large amount of information that they receive continuously. An essential discrimination task is to allocate the incoming signal to a group associated with the kind of physical phenomena producing it. In this paper, we present new techniques for seismic signals classification: local, regional and global discrimination. These techniques were tested on seismic signals from the data base of the National Geophysical Institute of the Centre National pour la Recherche Scientifique et Technique (Morocco) by using the Moroccan software for seismic signals analysis.
Abstract: The purpose of Grid computing is to utilize
computational power of idle resources which are distributed in
different areas. Given the grid dynamism and its decentralize
resources, there is a need for an efficient scheduler for scheduling
applications. Since task scheduling includes in the NP-hard problems
various researches have focused on invented algorithms especially
the genetic ones. But since genetic is an inherent algorithm which
searches the problem space globally and does not have the efficiency
required for local searching, therefore, its combination with local
searching algorithms can compensate for this shortcomings. The aim
of this paper is to combine the genetic algorithm and GELS (GAGELS)
as a method to solve scheduling problem by which
simultaneously pay attention to two factors of time and number of
missed tasks. Results show that the proposed algorithm can decrease
makespan while minimizing the number of missed tasks compared
with the traditional methods.
Abstract: Pollution emission levels of aircraft engines are a
nowadays high concern. Any technological advance that could reduce
emission levels is always welcome. In what concerns aircraft engines,
a possible solution for this problem could be the use of regenerators
and intercoolers. These components might reduce the specific fuel
consumption, increase efficiency and specific thrust and consequently
reduce the pollution levels of the engine. This is not a novel solution.
These heat exchangers are already is use in stationary engines. For
aircraft engines, the extra weight of the needed hardware could
overcome the fuel saved. This work compares a conventional engine
with configurations that use intercoolers and regenerators.
Abstract: Tumour suppressors are key participants in the
prevention of cancer. Regulation of their expression through
miRNAs is important for comprehensive translation inhibition of
tumour suppressors and elucidation of carcinogenesis mechanisms.
We studies the possibility of 1521 miRNAs to bind with 873 mRNAs
of human tumour suppressors using RNAHybrid 2.1 and ERNAhybrid
programmes. Only 978 miRNAs were found to be
translational regulators of 812 mRNAs, and 61 mRNAs did not have
any miRNA binding sites. Additionally, 45.9% of all miRNA binding
sites were located in coding sequences (CDSs), 33.8% were located
in 3' untranslated region (UTR), and 20.3% were located in the
5'UTR. MiRNAs binding with more than 50 target mRNAs and
mRNAs binding with several miRNAs were selected. Hsa-miR-5096
had 15 perfectly complementary binding sites with mRNAs of 14
tumour suppressors. These newly indentified miRNA binding sites
can be used in the development of medicines (anti-sense therapies)
for cancer treatment.
Abstract: Since large power transformers are the most
expensive and strategically important components of any power
generator and transmission system, their reliability is crucially
important for the energy system operation. Also, Circuit breakers are
very important elements in the power transmission line so monitoring
the events gives a knowledgebase to determine time to the next
maintenance. This paper deals with the introduction of the
comparative method of the state estimation of transformers and
Circuit breakers using continuous monitoring of voltage, current.
This paper gives details a new method based on wavelet to apparatus
insulation monitoring. In this paper to insulation monitoring of
transformer, a new method based on wavelet transformation and
neutral point analysis is proposed. Using the EMTP tools, fault in
transformer winding and the detailed transformer winding model
were simulated. The current of neutral point of winding was analyzed
by wavelet transformation. It is shown that the neutral current of the
transformer winding has useful information about fault in insulation
of the transformer.
Abstract: Intradiscal and intervertebral pressure transducers
were developed. They were used to map the pressures in the nucleus
and within the annulus of the human spinal segments. Their stressrelaxation
were recorded over a period of time for nucleus
pressure, applied load, and peripherial strain against time. The
results show that for normal discs, pressures in the nucleus are
viscoelastic in nature with the applied compressive load.
Mechanical strains which develop around the periphery of the
vertebral body are also viscoelastic with the applied compressive
load. Applied compressive load against time also shows viscoelastic
behavior. However, annulus does not respond viscoelastically with
the applied load. It showed a linear response to compressive loading.
Abstract: A novel concept to balance and tradeoff between
make-to-stock and make-to-order has been hybrid MTS/MTO production context. One of the most important decisions involved in
the hybrid MTS/MTO environment is determining whether a product
is manufactured to stock, to order, or hybrid MTS/MTO strategy. In this paper, a model based on analytic network process is developed to tackle the addressed decision. Since the regarded decision deals with
the uncertainty and ambiguity of data as well as experts- and
managers- linguistic judgments, the proposed model is equipped with
fuzzy sets theory. An important attribute of the model is its generality due to diverse decision factors which are elicited from the
literature and developed by the authors. Finally, the model is validated by applying to a real case study to reveal how the proposed
model can actually be implemented.
Abstract: Location-based services (LBS) exploit the known
location of a user to provide services dependent on their geographic
context and personalized needs [1].
The development and arrival of broadband mobile data networks
supported with mobile terminals equipped with new location
technologies like GPS have finally created opportunities for
implementation of LBS applications. But, from the other side,
collecting location information data in general raises privacy
concerns.
This paper presents results from two surveys of LBS acceptance in
Croatia. The first survey was administered on 181 students, and the
second extended survey involved pattern of 180 Croatian citizens.
We developed questionnaire which consists of descriptions of 15
different applications with scale which measures perceptions and
attitudes of users towards these applications.
We report the results to identify potential commercial applications
for LBS in B2C segment. Our findings suggest that some types of
applications like emergency&safety services and navigation have
significantly higher rate of acceptance than other types.
Abstract: The biological activity of A. pullulans isolates against
species of the genus Fusarium, bacteria of the genus Azotobacter and
pseudomonads colonizing wheat kernels was evaluated. A field
experiment was carried out in 2009-2011, in north-eastern Poland.
Winter wheat (cv. Bogatka) plants were sprayed with a cell
suspension of A. pullulans at a density of 106 - 108 per cm3 water at
the stem elongation stage and the heading stage. Untreated plants
served as control. The abundance of epiphytic yeasts, bacteria of the
genus Azotobacter, pseudomonads and Fusarium pathogens on wheat
grain was estimated at harvest and after six months’ storage. The
average size of yeast communities was significantly greater on wheat
kernels treated with a cell suspension of A. pullulans, compared with
control samples. In 2010-2011, biological control reduced the
abundance of some species of the genus Fusarium.
Abstract: Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation by heavy rain.
In this Paper we have studied the heavy rain effects on the aerodynamic efficiency of cambered NACA 64-210 and symmetric
NACA 0012 airfoils. Our results show significant increase in drag and decrease in lift. We used preprocessing software gridgen for creation of geometry and mesh, used fluent as solver and techplot as postprocessor. Discrete phase modeling called DPM is used to model the rain particles using two phase flow approach. The rain particles are assumed to be inert.
Both airfoils showed significant decrease in lift and increase in drag in simulated rain environment. The most significant difference between these two airfoils was the NACA 64-210 more sensitivity than NACA 0012 to liquid water content (LWC). We believe that the results showed in this paper will be useful for the designer of the commercial aircrafts and UAVs, and will be helpful for training of the pilots to control the airplanes in heavy rain.
Abstract: The Kowsar dam supply water for different usages
such as drinking, industrial, agricultural and aquaculture farms
usages and located next to the city of Dehdashat in Kohgiluye and
Boyerahmad province in southern Iran. There are some towns and
villages on the Kowsar dam watersheds, which Dehdasht and Choram
are the most important and populated cities in this area. The study
was undertaken to assess the status of water quality in the urban areas
of the Kowsar dam. A total of 28 water samples were collected from
6 stations on surface water and 1 station from groundwater on the
watershed of the Kowsar dam. All the samples were analyzed for Ni
concentration using standard procedures. The results were compared
with other national and international standards. Among the analyzed
samples, as the maximum value of Nickel (0.01 mg/L) was observed
on the station 2 at the autumn 2010, all the samples analyzed were
within the maximum admissible limits by the United States
Environmental Protection Agency, EU, WHO and the Iranian. In
general results of the present study have shown that a Ni mean value
of station No. 2 with 0.006 mg/L is higher than the other stations. Ni
level of all samples and stations have had normal values and this is an
indication of pollution potential and hazards because of human
activity and waste water of towns in the areas, which can effect on
human health implications in future. This research, therefore,
recommends the government and other responsible authorities to take
suitable improving measures in the Kowsar dam watersheds.
Abstract: Methanol-to-olefins (MTO) coupled with
transformation of coal or natural gas to methanol gives an interesting
and promising way to produce ethylene and propylene. To investigate
solid concentration in gas-solid fluidized bed for methanol-to-olefins
process catalyzed by SAPO-34, a cold model experiment system is
established in this paper. The system comprises a gas distributor in a
300mm internal diameter and 5000mm height acrylic column, the
fiber optic probe system and series of cyclones. The experiments are
carried out at ambient conditions and under different superficial gas
velocity ranging from 0.3930m/s to 0.7860m/s and different initial bed
height ranging from 600mm to 1200mm. The effects of radial
distance, axial distance, superficial gas velocity, initial bed height on
solid concentration in the bed are discussed. The effects of distributor
shape and porosity on solid concentration are also discussed. The
time-averaged solid concentration profiles under different conditions
are obtained.
Abstract: In aerospace applications, interactions of airflow with
aircraft structures can result in undesirable structural deformations.
This structural deformation in turn, can be predicted if the natural
modes of the structure are known. This can be achieved through
conventional modal testing that requires a known excitation force in
order to extract these dynamic properties. This technique can be
experimentally complex because of the need for artificial excitation
and it is also does not represent actual operational condition. The
current work presents part of research work that address the practical
implementation of operational modal analysis (OMA) applied to a
cantilevered hybrid composite plate employing single contactless
sensing system via laser vibrometer. OMA technique extracts the
modal parameters based only on the measurements of the dynamic
response. The OMA results were verified with impact hammer modal
testing and good agreement was obtained.
Abstract: Ants are fascinating creatures that demonstrate the
ability to find food and bring it back to their nest. Their ability as a
colony, to find paths to food sources has inspired the development of
algorithms known as Ant Colony Systems (ACS). The principle of
cooperation forms the backbone of such algorithms, commonly used
to find solutions to problems such as the Traveling Salesman
Problem (TSP). Ants communicate to each other through chemical
substances called pheromones. Modeling individual ants- ability to
manipulate this substance can help an ACS find the best solution.
This paper introduces a Dynamic Ant Colony System with threelevel
updates (DACS3) that enhance an existing ACS. Experiments
were conducted to observe single ant behavior in a colony of
Malaysian House Red Ants. Such behavior was incorporated into the
DACS3 algorithm. We benchmark the performance of DACS3 versus
DACS on TSP instances ranging from 14 to 100 cities. The result
shows that the DACS3 algorithm can achieve shorter distance in
most cases and also performs considerably faster than DACS.
Abstract: Low temperature (LT) is one of the most abiotic
stresses causing loss of yield in wheat (T. aestivum). Four major
genes in wheat (Triticum aestivum L.) with the dominant alleles
designated Vrn–A1,Vrn–B1,Vrn–D1 and Vrn4, are known to have
large effects on the vernalization response, but the effects on cold
hardiness are ambiguous. Poor cold tolerance has restricted winter
wheat production in regions of high winter stress [9]. It was known
that nearly all wheat chromosomes [5] or at least 10 chromosomes of
21 chromosome pairs are important in winter hardiness [15]. The
objective of present study was to clarify the role of each chromosome
in cold tolerance. With this purpose we used 20 isogenic lines of
wheat. In each one of these isogenic lines only a chromosome from
‘Bezostaya’ variety (a winter habit cultivar) was substituted to
‘Capple desprez’ variety. The plant materials were planted in
controlled conditions with 20º C and 16 h day length in moderately
cold areas of Iran at Karaj Agricultural Research Station in 2006-07
and the acclimation period was completed for about 4 weeks in a
cold room with 4º C. The cold hardiness of these isogenic lines was
measured by LT50 (the temperature in which 50% of the plants are
killed by freezing stress).The experimental design was completely
randomized block design (RCBD)with three replicates. The results
showed that chromosome 5A had a major effect on freezing
tolerance, and then chromosomes 1A and 4A had less effect on this
trait. Further studies are essential to understanding the importance of
each chromosome in controlling cold hardiness in wheat.
Abstract: This research aimed to study correlation between
work satisfaction and organization core value of officers in
Waterworks Authority, Bangkean Branch. Sample group of the study
was 112 officers who worked in the Waterworks Authority,
Bangkean Branch. Questionnaires were employed as a research tools,
while, Percentage, Mean, Standard Deviation, T-test, One-way
ANOVA, and Pearson Product Moment Correlation were claimed as
statistics used in this study. Researcher found that overall and
individual aspects of work satisfaction namely, work characteristic,
work progress, and colleagues significantly correlated with
organization core value in aspect of perception in choice of work at
0.5, 0.01, and 0.01 respectively. Also, such aspects were compatible
with income at .05 which indicated the low level of correlation, mid
low correlation respectively at the same direction, same direction,
opposite direction, and same direction, correspondingly.