Abstract: Photonic Crystal Fibers (PCFs) can be used in optical
communications as transmission lines. For this reason, the PCFs with
low confinement loss, low chromatic dispersion, and low nonlinear
effects are highly suitable transmission media. In this paper, we
introduce a new design of index-guiding nanostructured photonic
crystal fiber (IG-NPCF) with ultra-low chromatic dispersion, low
nonlinearity effects, and low confinement loss. Relatively low
dispersion is achieved in the wavelength range of 1200 to 1600nm
using the proposed design. According to the new structure of
nanostructured PCF presented in this study, the chromatic dispersion
slope is -30(ps/km.nm) and the confinement loss reaches below 10-7
dB/km. While in the wavelength range mentioned above at the same
time an effective area of more than 50.2μm2 is obtained.
Abstract: Fingerprint based identification system; one of a well
known biometric system in the area of pattern recognition and has
always been under study through its important role in forensic
science that could help government criminal justice community. In
this paper, we proposed an identification framework of individuals by
means of fingerprint. Different from the most conventional
fingerprint identification frameworks the extracted Geometrical
element features (GEFs) will go through a Discretization process.
The intention of Discretization in this study is to attain individual
unique features that could reflect the individual varianceness in order
to discriminate one person from another. Previously, Discretization
has been shown a particularly efficient identification on English
handwriting with accuracy of 99.9% and on discrimination of twins-
handwriting with accuracy of 98%. Due to its high discriminative
power, this method is adopted into this framework as an independent
based method to seek for the accuracy of fingerprint identification.
Finally the experimental result shows that the accuracy rate of
identification of the proposed system using Discretization is 100%
for FVC2000, 93% for FVC2002 and 89.7% for FVC2004 which is
much better than the conventional or the existing fingerprint
identification system (72% for FVC2000, 26% for FVC2002 and
32.8% for FVC2004). The result indicates that Discretization
approach manages to boost up the classification effectively, and
therefore prove to be suitable for other biometric features besides
handwriting and fingerprint.
Abstract: A two dimensional numerical simulation has been
performed for incompressible and compressible fluid flow through
microchannels in slip flow regime. The Navier-Stokes equations have
been solved in conjunction with Maxwell slip conditions for
modeling flow field associated with slip flow regime. The wall
roughness is simulated with triangular microelements distributed on
wall surfaces to study the effects of roughness on fluid flow. Various
Mach and Knudsen numbers are used to investigate the effects of
rarefaction as well as compressibility. It is found that rarefaction has
more significant effect on flow field in microchannels with higher
relative roughness. It is also found that compressibility has more
significant effects on Poiseuille number when relative roughness
increases. In addition, similar to incompressible models the increase
in average fRe is more significant at low Knudsen number flows but
the increase of Poiseuille number duo to relative roughness is sharper
for compressible models. The numerical results have also validated
with some available theoretical and experimental relations and good
agreements have been seen.
Abstract: The purpose of this research was to demonstrate
prevalence of post-exposure preventive measures (PEP) after needlestick
injuries and its relationship with locus of control beliefs in a
sample of medical students. In this cross-sectional study, 300 medical
students with history of having experienced needle stick injuries
(NSI) for at least once filled in a questionnaire to determine if they
perceived themselves to be responsible and effective in preventing
blood born infections after NSI. About 38% of students did not seek
any professional consult or PEP after NSI due to lack of enough time
or access, anxiety about tests results, belief in uselessness of followup
and not being able to change destiny. These 114 students were not
different from others regarding their scores on NSI specific scale of
locus of health control. Thus, the potentiality of NSI locus of control
beliefs in predicting PEP was not seen in this study.
Abstract: A numerical simulation of micro Poiseuille flow has
performed for rarefied and compressible flow at slip flow regimes.
The wall roughness is simulated in two cases with triangular
microelements and random micro peaks distributed on wall surfaces
to study the effects of roughness shape and distribution on flow field.
Two values of Mach and Knudsen numbers have used to investigate
the effects of rarefaction as well as compressibility. The numerical
results have also checked with available theoretical and experimental
relations and good agreements has achieved. High influence of
roughness shape can be seen for both compressible and
incompressible rarefied flows. In addition it is found that rarefaction
has more significant effect on flow field in microchannels with
higher relative roughness. It is also found that compressibility has
more significant effects on Poiseuille number when relative
roughness increases.