Abstract: Solidification cracking and hydrogen cracking are some defects generated in the fusion welding of ultrahigh carbon steels. However, friction stir welding (FSW) of such steels, being a solid-state technique, has been demonstrated to alleviate such problems encountered in traditional welding. FSW include different process parameters that must be carefully defined prior processing. These parameters included but not restricted to: tool feed, tool RPM, tool geometry, tool tilt angle. These parameters form a key factor behind avoiding warm holes and voids behind the tool and in achieving a defect-free weld. More importantly, these parameters directly affect the microstructure of the weld and hence the final mechanical properties of weld. For that, 3D finite element (FE) thermo-mechanical model was developed using DEFORM 3D to simulate FSW of carbon steel. At points of interest in the joint, tracking is done for history of critical state variables such as temperature, stresses, and strain rates. Typical results found include the ability to simulate different weld zones. Simulations predictions were successfully compared to experimental FSW tests. It is believed that such a numerical model can be used to optimize FSW processing parameters to favor desirable defect free weld with better mechanical properties.
Abstract: MBMS is a unidirectional point-to-multipoint bearer
service in which data are transmitted from a single source entity to
multiple recipients. For a mobile to support the MBMS, MBMS client
functions as well as MBMS radio protocols should be designed and
implemented. In this paper, we analyze the MBMS client functions
and describe the implementation of them in our mobile test-bed. User
operations and signaling flows between protocol entities to control the
MBMS functions are designed in detail. Service announcement
utilizing the file download MBMS service and four MBMS user
services are demonstrated in the test-bed to verify the MBMS client
functions.
Abstract: In a recent major industry-supported research and development study, a novel framework was developed and applied for assessment of reliability and quality performance levels in reallife power systems with practical large-scale sizes. The new assessment methodology is based on three metaphors (dimensions) representing the relationship between available generation capacities and required demand levels. The paper shares the results of the successfully completed stud and describes the implementation of the new methodology on practical zones in the Saudi electricity system.
Abstract: In this study, the thermal and mechanical properties of
basalt fibre reinforced concrete were investigated. The volume
fractions of basalt fibre of (0.1, 0.2, 0.3, and 0.5% by total mix
volume) were used. Properties such as heat transfer, compressive and
splitting tensile strengths were examined. Results indicated that the
strength increases with increase the fibre content till 0.3% then there
is a slight reduction when 0.5% fibre used. Lower amount of heat
conducted through the thickness of concrete specimens than the
conventional concrete was also recorded.
Abstract: In this work, we present a comparison between two
techniques of image compression. In the first case, the image is
divided in blocks which are collected according to zig-zag scan. In
the second one, we apply the Fast Cosine Transform to the image,
and then the transformed image is divided in blocks which are
collected according to zig-zag scan too. Later, in both cases, the
Karhunen-Loève transform is applied to mentioned blocks. On the
other hand, we present three new metrics based on eigenvalues for a
better comparative evaluation of the techniques. Simulations show
that the combined version is the best, with minor Mean Absolute
Error (MAE) and Mean Squared Error (MSE), higher Peak Signal to
Noise Ratio (PSNR) and better image quality. Finally, new technique
was far superior to JPEG and JPEG2000.
Abstract: Delayed wound healing in diabetes is primarily
associated with hyperglycemia, over-expression of inflammatory
marker, oxidative stress and delayed collagen synthesis. This
unmanaged wound is producing high economic burden on the
society. Thus research is required to develop new and effective
treatment strategies to deal with this emerging issue. Our present
study incorporates the evaluation of wound healing effects of 50%
ethanol extract of Ocimum sanctum (OSE) in streptozotocin
(45mg/kg)-induced diabetic rats with concurrent wound ulcer. The
animals showing diabetes (Blood glucose level >140 and
Abstract: Over the past few years, companies in developing
countries have implemented enterprise resource planning (ERP)
systems. Regardless of the various benefits of the ERP system, its
adoption and implementation have not been without problems. Many
companies have assigned considerable organizational resources to
their ERP projects, but have encountered unexpected challenges.
Neglecting a number of important factors in ERP projects might lead
to failure instead of success. User satisfaction is among those factors
that has a major influence on ERP implementation success. So, this
paper intends to investigate the key factors that create ERP users-
satisfaction and to discover whether ERP users- satisfaction varies
among different users- profiles. The study was conducted using a
survey questionnaire which was distributed to ERP users in Iranian
organizations. A total of 384 responses were collected and analyzed.
The findings indicated that younger ERP users tend to be more
satisfied with ERP systems. Furthermore, ERP users with more
experiences in IT and also more educated users have more
satisfaction with ERP softwares. However, the study found no
satisfaction differences between men and women users.
Abstract: This paper deals with a novel technique for the
fabrication of Spiral grooves in a dynamic thrust bearing. The main
scheme proposed in this paper is to fabricate the microgrooves using
desktop forming system. This process has advantages compared to the
conventional electro-chemical machining in the viewpoint of a higher
productivity. For this reason, a new testing apparatus is designed and
built for press forming microgrooves on a surface of the thrust bearing.
The material used in this study is sintered Cu-Fe alloy. The effects of
the forming load on the performance of micro press forming are
experimentally investigated. From the experimental results, formed
depths are closed to the target ones with increasing the forming load.
Abstract: Highly ordered TiO2 nanotube (TNT) arrays were
fabricated onto a pre-treated titanium foil by anodic oxidation with a
voltage of 20V in phosphoric acid/sodium fluoride electrolyte. A pretreatment
of titanium foil involved washing with acetone,
isopropanol, ethanol and deionized water. Carbon doped TiO2
nanotubes (C-TNT) was fabricated 'in-situ' with the same method in
the presence of polyvinyl alcohol and urea as carbon sources. The
affects of polyvinyl alcohol concentration and oxidation time on the
composition, morphology and structure of the C-TN were studied by
FE-SEM, EDX and XRD techniques. FESEM images of the
nanotubes showed uniform arrays of C-TNTs. The density and
microstructures of the nanotubes were greatly affected by the content
of PVA. The introduction of the polyvinyl alcohol into the electrolyte
increases the amount of C content inside TiO2 nanotube arrays
uniformly. The influence of carbon content on the photo-current of
C-TNT was investigated and the I-V profiles of the nanotubes were
established. The preliminary results indicated that the 'in-situ'
doping technique produced a superior quality nanotubes compared to
post doping techniques.
Abstract: The affect of the attendance percentage, the overall
GPA and the number of credit hours the student is enrolled in at
specific semester on the grade attained in specific course has been
studied. This study has been performed on three courses offered in
industrial engineering department at the Hashemite University in
Jordan. Study has revealed that the grade attained by a student is
strongly affected by the attendance percentage and his overall GPA
with a value of R2 of 52.5%. Another model that has been
investigated is the relation between the semester GPA and the
attendance percentage, the number of credit hours enrolled in at
specific semester, and the overall GPA. This model gave us a strong
relationship between the semester GPA and attendance percentage
and the overall GPA with a value of R2 of 76.2%.
Abstract: The Platform Screen Doors improve Indoor Air Quality
(IAQ) in the subway station; however, and the air quality is degraded
in the subway tunnel. CO2 concentration and indoor particulate matter
value are high in the tunnel. The IAQ level in subway tunnel degrades
by increasing the train movements. Air-curtain installation reduces
dusts, particles and moving toxic smokes and permits traffic by
generating virtual wall. The ventilation systems of the subway tunnel
need improvements to have better air-quality. Numerical analyses
might be effective tools analyze the flowfield inside the air-curtain
installed subway tunnel. The ANSYS CFX software is used for steady
computations of the airflow inside the tunnel. The single-track subway
tunnel has the natural shaft, the mechanical shaft, and the PSDs
installed stations. The height and width of the tunnel are 6.0 m and 4.0
m respectively. The tunnel is 400 m long and the air-curtain is installed
at the top of the tunnel. The thickness and the width of the air-curtain
are 0.08 m and 4 m respectively. The velocity of the air-curtain
changes between 20 - 30 m/s. Three cases are analyzed depending on
the installing location of the air-curtain. The discharged-air through
the natural shafts increases as the velocity of the air-curtain increases
when the air-curtain is installed between the mechanical and the
natural shafts. The pollutant-air is exhausted by the mechanical and the
natural shafts and remained air is pushed toward tunnel end. The
discharged-air through the natural shaft is low when the air-curtain
installed before the natural shaft. The mass flow rate decreases in the
tunnel after the mechanical shaft as the air-curtain velocity increases.
The computational results of the air-curtain installed tunnel become
basis for the optimum design study. The air-curtain installing location
is chosen between the mechanical and the natural shafts. The velocity
of the air-curtain is fixed as 25 m/s. The thickness and the blowing
angles of the air-curtain are the design variables for the optimum
design study. The object function of the design optimization is
maximizing the discharged air through the natural shaft.
Abstract: This study was conducted in order to determine the physical properties and stability of mayonnaise-like emulsions as affected by modified yam starches. Native yam starch was modified via pre-gelatinization and cross-linking phosphorylation procedures. The emulsions (50% oil dispersed phase) were prepared with 0.3% native potato, native yam, pre-gelatinized yam and cross-linking phosphorylation yam starches. The droplet size of surface weighted mean diameter was found to be significantly (p < 0.05) lower in the sample with cross-linking phosphorylation yam starch as compared to other samples. Moreover, the viscosity of the sample with pregelatinized yam starch was observed to be higher than that of other samples. The phase separation stability was low in the freshly prepared and stored (45 days, 5°C) emulsions containing native yam starch. This study thus generally suggested that modified yam starches were more suitable (i.e. better physical properties and stability) to be used as stabilizers in a similar system i.e. light mayonnaises, rather than a native yam starch.
Abstract: The paper presents a novel idea to control computer
mouse cursor movement with human eyes. In this paper, a working
of the product has been described as to how it helps the special
people share their knowledge with the world. Number of traditional
techniques such as Head and Eye Movement Tracking Systems etc.
exist for cursor control by making use of image processing in which
light is the primary source. Electro-oculography (EOG) is a new
technology to sense eye signals with which the mouse cursor can be
controlled. The signals captured using sensors, are first amplified,
then noise is removed and then digitized, before being transferred to
PC for software interfacing.
Abstract: Family structure that is culturally constructed in every
society is the basic unit of social structure. Purpose of the study was
to compare family structure, including marriage, residence, family
size, type, role sharing, authority, and communication patterns
between Muslim and Santal communities in rural Bangladesh. For
this we assumed that family structure with the elements was
significantly different between the two communities in rural
Bangladesh. In so doing, 288 active couples (145 for Muslim and 143
for Santal) selected by cluster random sampling were intensively
interviewed with a semi-structured questionnaire method. The results
of Pearson Chi-Squire Test reveal that there were significant
differences in the family structure followed by the two communities
in the study area. Further cross-cultural study should be done on why
family structure varies between the communities in Bangladesh.
Abstract: Saturated hydraulic conductivity of Soil is an
important property in processes involving water and solute flow in
soils. Saturated hydraulic conductivity of soil is difficult to measure
and can be highly variable, requiring a large number of replicate
samples. In this study, 60 sets of soil samples were collected at
Saqhez region of Kurdistan province-IRAN. The statistics such as
Correlation Coefficient (R), Root Mean Square Error (RMSE), Mean
Bias Error (MBE) and Mean Absolute Error (MAE) were used to
evaluation the multiple linear regression models varied with number
of dataset. In this study the multiple linear regression models were
evaluated when only percentage of sand, silt, and clay content (SSC)
were used as inputs, and when SSC and bulk density, Bd, (SSC+Bd)
were used as inputs. The R, RMSE, MBE and MAE values of the 50
dataset for method (SSC), were calculated 0.925, 15.29, -1.03 and
12.51 and for method (SSC+Bd), were calculated 0.927, 15.28,-1.11
and 12.92, respectively, for relationship obtained from multiple
linear regressions on data. Also the R, RMSE, MBE and MAE values
of the 10 dataset for method (SSC), were calculated 0.725, 19.62, -
9.87 and 18.91 and for method (SSC+Bd), were calculated 0.618,
24.69, -17.37 and 22.16, respectively, which shows when number of
dataset increase, precision of estimated saturated hydraulic
conductivity, increases.
Abstract: MicroRNAs (miRNAs) are small, non-coding and
regulatory RNAs about 20 to 24 nucleotides long. Their conserved
nature among the various organisms makes them a good source of
new miRNAs discovery by comparative genomics approach. The
study resulted in 21 miRNAs of 20 pre-miRNAs belonging to 16
families (miR156, 157, 158, 164, 165, 168, 169, 172, 319, 390, 393,
394, 395, 400, 472 and 861) in evergreen spruce tree (Picea). The
miRNA families; miR 157, 158, 164, 165, 168, 169, 319, 390, 393,
394, 400, 472 and 861 are reported for the first time in the Picea. All
20 miRNA precursors form stable minimum free energy stem-loop
structure as their orthologues form in Arabidopsis and the mature
miRNA reside in the stem portion of the stem loop structure. Sixteen
(16) miRNAs are from Picea glauca and five (5) belong to Picea
sitchensis. Their targets consist of transcription factors, growth
related, stressed related and hypothetical proteins.
Abstract: As wireless sensor networks are energy constraint networks
so energy efficiency of sensor nodes is the main design issue.
Clustering of nodes is an energy efficient approach. It prolongs the
lifetime of wireless sensor networks by avoiding long distance communication.
Clustering algorithms operate in rounds. Performance of
clustering algorithm depends upon the round time. A large round
time consumes more energy of cluster heads while a small round
time causes frequent re-clustering. So existing clustering algorithms
apply a trade off to round time and calculate it from the initial
parameters of networks. But it is not appropriate to use initial
parameters based round time value throughout the network lifetime
because wireless sensor networks are dynamic in nature (nodes can be
added to the network or some nodes go out of energy). In this paper
a variable round time approach is proposed that calculates round
time depending upon the number of active nodes remaining in the
field. The proposed approach makes the clustering algorithm adaptive
to network dynamics. For simulation the approach is implemented
with LEACH in NS-2 and the results show that there is 6% increase
in network lifetime, 7% increase in 50% node death time and 5%
improvement over the data units gathered at the base station.
Abstract: The objective of this research is to study principal
component analysis for classification of 67 soil samples collected from
different agricultural areas in the western part of Thailand. Six soil
properties were measured on the soil samples and are used as original
variables. Principal component analysis is applied to reduce the
number of original variables. A model based on the first two
principal components accounts for 72.24% of total variance. Score
plots of first two principal components were used to map with
agricultural areas divided into horticulture, field crops and wetland.
The results showed some relationships between soil properties and
agricultural areas. PCA was shown to be a useful tool for agricultural
areas classification based on soil properties.
Abstract: The objective of this work is to study the influence of the properties of the substrate on the retrofit (thin repair) of damaged concrete elements, with the SCC. Fluidity, principal characteristic of the SCC, would enable it to cover and adhere to the concrete to be repaired. Two aspects of repair are considered, the bond (Adhesion) and the tensile strength and the cracking. The investigation is experimental; It was conducted over test specimens made up of ordinary concrete prepared and hardened in advance (the material to be repaired) over which a self compacting concrete layer is cast. Three alternatives of SC concrete and one ordinary concrete (comparison) were tested. It appears that the self-compacting concrete constitutes a good material for repairing. It follows perfectly the surfaces- forms to be repaired and allows a perfect bond. Fracture tests made on specimens of self-compacting concrete show a brittle behaviour. However when a small percentage of fibres is added, the resistance to cracking is very much improve.
Abstract: Deep cold rolling (DCR) and low plasticity burnishing (LPB) process are cold working processes, which easily produce a smooth and work-hardened surface by plastic deformation of surface irregularities. The present study focuses on the surface roughness and surface hardness aspects of AISI 4140 work material, using fractional factorial design of experiments. The assessment of the surface integrity aspects on work material was done, in order to identify the predominant factors amongst the selected parameters. They were then categorized in order of significance followed by setting the levels of the factors for minimizing surface roughness and/or maximizing surface hardness. In the present work, the influence of main process parameters (force, feed rate, number of tool passes/overruns, initial roughness of the work piece, ball material, ball diameter and lubricant used) on the surface roughness and the hardness of AISI 4140 steel were studied for both LPB and DCR process and the results are compared. It was observed that by using LPB process surface hardness has been improved by 167% and in DCR process surface hardness has been improved by 442%. It was also found that the force, ball diameter, number of tool passes and initial roughness of the workpiece are the most pronounced parameters, which has a significant effect on the work piece-s surface during deep cold rolling and low plasticity burnishing process.