Abstract: An adaptive Helmholtz resonator was designed and
adapted to hydraulics. The resonator was controlled by open- and
closed-loop controls so that 20 dB attenuation of the peak-to-peak
value of the pulsating pressure was maintained. The closed-loop
control was noted to be better, albeit it was slower because of its low
pressure and temperature variation, which caused variation in the
effective bulk modulus of the hydraulic system. Low-pressure
hydraulics contains air, which affects the stiffness of the hydraulics,
and temperature variation changes the viscosity of the oil. Thus, an
open-loop control loses its efficiency if a condition such as
temperature or the amount of air changes after calibration. The
instability of the low-pressure hydraulic system reduced the
operational frequency range of the Helmholtz resonator when
compared with the results of an analytical model.
Different dampers for hydraulics are presented. Then analytical
models of a hydraulic pipe and a hydraulic pipe with a Helmholtz
resonator are presented. The analytical models are based on the wave
equation of sound pressure. Finally, control methods and the results
of experiments are presented.
Abstract: In this paper, a new reverse converter for the moduli set {2n, 2n–1, 2n–1–1} is presented. We improved a previously introduced conversion algorithm for deriving an efficient hardware design for reverse converter. Hardware architecture of the proposed converter is based on carry-save adders and regular binary adders, without the requirement for modular adders. The presented design is faster than the latest introduced reverse converter for moduli set {2n, 2n–1, 2n–1–1}. Also, it has better performance than the reverse converters for the recently introduced moduli set {2n+1–1, 2n, 2n–1}
Abstract: Hepatocellular carcinoma, also called hepatoma, most
commonly appears in a patient with chronic viral hepatitis. In
patients with a higher suspicion of HCC, such as small or subtle
rising of serum enzymes levels, the best method of diagnosis
involves a CT scan of the abdomen, but only at high cost. The aim of
this study was to increase the ability of the physician to early detect
HCC, using a probabilistic neural network-based approach, in order
to save time and hospital resources.
Abstract: Web 2.0 (social networking, blogging and online
forums) can serve as a data source for social science research because
it contains vast amount of information from many different users.
The volume of that information has been growing at a very high rate
and becoming a network of heterogeneous data; this makes things
difficult to find and is therefore not almost useful. We have proposed
a novel theoretical model for gathering and processing data from
Web 2.0, which would reflect semantic content of web pages in
better way. This article deals with the analysis part of the model and
its usage for content analysis of blogs. The introductory part of the
article describes methodology for the gathering and processing data
from blogs. The next part of the article is focused on the evaluation
and content analysis of blogs, which write about specific trend.
Abstract: In this paper, we apply the FM methodology to the
cross-section of Romanian-listed common stocks and investigate the
explanatory power of market beta on the cross-section of commons
stock returns from Bucharest Stock Exchange. Various assumptions
are empirically tested, such us linearity, market efficiency, the “no
systematic effect of non-beta risk" hypothesis or the positive
expected risk-return trade-off hypothesis. We find that the Romanian
stock market shows the same properties as the other emerging
markets in terms of efficiency and significance of the linear riskreturn
models. Our analysis included weekly returns from January
2002 until May 2010 and the portfolio formation, estimation and
testing was performed in a rolling manner using 51 observations (one
year) for each stage of the analysis.
Abstract: This current research focused on development of degradable starch based packaging film with enhanced mechanical properties. A series of low density polyethylene (LDPE)/tapioca starch compounds with various tapioca starch contents were prepared by twin screw extrusion with the addition of maleic anhydride grafted polyethylene as compatibilizer. Palm cooking oil was used as processing aid to ease the blown film process, thus, degradable film can be processed via conventional blown film machine. Studies on their characteristics, mechanical properties and biodegradation were carried out by Fourier Transform Infrared (FTIR) spectroscopy and optical properties, tensile test and exposure to fungi environment respectively. The presence of high starch contents had an adverse effect on the tensile properties of LDPE/tapioca starch blends. However, the addition of compatibilizer to the blends improved the interfacial adhesion between the two materials, hence, improved the tensile properties of the films. High content of starch amount also was found to increase the rate of biodegradability of LDPE/tapioca starch films. It can be proved by exposure of the film to fungi environment. A growth of microbes colony can be seen on the surface of LDPE/tapioca starch film indicates that the granular starch present on the surface of the polymer film is attacked by microorganisms, until most of it is assimilated as a carbon source.
Abstract: Carbon nanotubes (CNTs) are attractive because of
their excellent chemical durability mechanical strength and electrical
properties. Therefore there is interest in CNTs for not only electrical
and mechanical application, but also biological and medical
application.
In this study, the dispersion power of surfactant-treated multiwalled
carbon nanotubes (MWCNTs) and their effect on the antibacterial
activity were examined. Surfactant was used sodium
dodecyl-benzenesulfonate (SDBS). UV-vis absorbance and
transmission electron microscopy(TEM) were used to characterize the
dispersion of MWCNTs in the aqueous phase, showing that the
surfactant molecules had been adsorbed onto the MWCNTs surface.
The surfactant-treated MWCNTs exhibited antimicrobial activities
to streptococcus mutans. The optical density growth curves and viable
cell number determined by the plating method suggested that the
antimicrobial activity of surfactant-treated MWCNTs was both
concentration and treatment time-dependent.
Abstract: Electrical resistivity is a fundamental parameter of metals or electrical conductors. Since resistivity is a function of temperature, in order to completely understand the behavior of metals, a temperature dependent theoretical model is needed. A model based on physics principles has recently been developed to obtain an equation that relates electrical resistivity to temperature. This equation is dependent upon a parameter associated with the electron travel time before being scattered, and a parameter that relates the energy of the atoms and their separation distance. Analysis of the energy parameter reveals that the equation is optimized if the proportionality term in the equation is not constant but varies over the temperature range. Additional analysis reveals that the theoretical equation can be used to determine the mean free path of conduction electrons, the number of defects in the atomic lattice, and the ‘equivalent’ charge associated with the metallic bonding of the atoms. All of this analysis provides validation for the theoretical model and provides insight into the behavior of metals where performance is affected by temperatures (e.g., integrated circuits and temperature sensors).
Abstract: To simulate heating systems in buildings, a research oriented computer code has been developed in Sharif University of Technology in Iran where the climate, existing heating equipment in buildings, consumer behavior and their interactions are considered for simulating energy consumption in conventional systems such as heaters, radiators and fan-coils. In order to validate the computer code, the available data of five buildings was used and the computed consumed energy was compared with the estimated energy extracted from monthly bills. The initial heating system was replaced by the alternative system and the effect of this change was observed on the energy consumption. As a result, the effect of changing heating equipment on energy consumption was investigated in different climates. Changing heater to radiator renders energy conservation up to 50% in all climates and changing radiator to fan-coil decreases energy consumption in climates with cold and dry winter.
Abstract: This paper presents the design and implementation of a fully integrated transimpedance amplifier (TIA) as the analog frontend receiver for Capacitive Micromachined Ultrasound Transducers (CMUTs) for ultrasound biomicroscope imaging application. The amplifier is designed to amplify the received signals from 17.5MHz to 52.5MHz with a center frequency of 35MHz. The TIA was fabricated in GF 0.18μm 1P6M 30V high voltage process. The measurement results show that the designed amplifier can reach a transimpedance gain of 61.08dBΩ and operating frequency from 17.5MHz to 100MHz with 1VP-P output voltage under 6V power supply.
Abstract: Sorghum flour was supplemented with 15 and 30%
chickpea flour. Sorghum flour and the supplement were fermented at
35 oC for 0, 8, 16, and 24 h. Changes in pH, titrable acidity, total
soluble solids, protein content, in vitro protein digestibility and
amino acid composition were investigated during fermentation and/or
after supplementation of sorghum flour with chickpea. The pH of the
fermenting material decreased sharply with a concomitant increase in
the titrable acidity. The total soluble solids remained unchanged with
progressive fermentation time. The protein content of sorghum
cultivar was found to be 9.27 and that of chickpea was 22.47%. The
protein content of sorghum cultivar after supplementation with15 and
30% chickpea was significantly (P ≤ 0.05) increased to 11.78 and
14.55%, respectively. The protein digestibility also increased after
fermentation from 13.35 to 30.59 and 40.56% for the supplements,
respectively. Further increment in protein content and digestibility
was observed when supplemented and unsupplemented samples were
fermented for different periods of time. Cooking of fermented
samples was found to increase the protein content slightly and
decreased digestibility for both supplements. Amino acid content of
fermented and fermented and cooked supplements was determined.
Supplementation was found to increase the lysine and therionine
content. Cooking following fermentation decreased lysine,
isoleucine, valine and sulfur containg amino acids.
Abstract: The Beijing road traffic system, as a typical huge
urban traffic system, provides a platform for analyzing the complex
characteristics and the evolving mechanisms of urban traffic systems.
Based on dynamic network theory, we construct the dynamic model
of the Beijing road traffic system in which the dynamical properties
are described completely. Furthermore, we come into the conclusion
that urban traffic systems can be viewed as static networks, stochastic
networks and complex networks at different system phases by
analyzing the structural randomness. As well as, we demonstrate the
evolving process of the Beijing road traffic network based on real
traffic data, validate the stochastic characteristics and the scale-free
property of the network at different phases
Abstract: The experiment was performed to evaluate the effect
of GA3, 2,4-D on fruit growth and fruit quality of wax apple. The
experiment consisted of Red A, Monulla, Atu, Red B cultivars. GA3
and 2,4-D were applied at the small bud and petal fall stage.
Physiological, biochemical characters of fruit were recoded. The
result showed application of GA3, 2,4-D greatly response in
increasing fruit set for all treatment as compared to control. Fruit
weight, fruit size were increased at 10 ppm 2,4-D in ‘Red A’, ‘Red
B’, however it was also enhancing at 10 ppm GA3 in ‘Monulla’,
‘Atu’. For ‘Monulla’, ‘Atu’ fruit crack reduced by 10 ppm 2,4-D
application, but ‘Red B’, ‘Red A’ gave least fruit crack at 10 and 30
ppm GA3, respectively. ‘Monulla’, ‘Atu’ and ‘Red B’ resulted in
response well to 10 ppm GA3 on improving TSS, whereas
application of 30 ppm GA3 greatly enhancing TSS in ‘Red A’. For
‘Atu’ titratable acidity markedly reduced by 10 ppm GA3
application, but spraying with 30 ppm GA3 greatly response in
reducing titratable acidity in ‘Red A’, ‘Red B’ and ‘Monulla’. It was
concluded that GA3, 2,4-D can be an effective tool to enhancing fruit
set, fruit growth as well as improving fruit quality of wax apple.
Abstract: Prolonged immobilization leads to significant
weakness and atrophy of the skeletal muscle and can also impair the
recovery of muscle strength following injury. Therefore, it is
important to minimize the period under immobilization and accelerate
the return to normal activity. This study examined the effects of heat
treatment and rest-inserted exercise on the muscle activity of the lower
limb during knee flexion/extension. Twelve healthy subjects were
assigned to 4 groups that included: (1) heat treatment + rest-inserted
exercise; (2) heat + continuous exercise; (3) no heat + rest-inserted
exercise; and (4) no heat + continuous exercise. Heat treatment was
applied for 15 mins prior to exercise. Continuous exercise groups
performed knee flexion/extension at 0.5 Hz for 300 cycles without rest
whereas rest-inserted exercise groups performed the same exercise but
with 2 mins rest inserted every 60 cycles of continuous exercise.
Changes in the rectus femoris and hamstring muscle activities were
assessed at 0, 1, and 2 weeks of treatment by measuring the
electromyography signals of isokinetic maximum voluntary
contraction. Significant increases in both the rectus femoris and
hamstring muscles were observed after 2 weeks of treatment only
when both heat treatment and rest-inserted exercise were performed.
These results suggest that combination of various treatment techniques,
such as heat treatment and rest-inserted exercise, may expedite the
recovery of muscle strength following immobilization.
Abstract: CFD simulations are carried out in arterial stenoses
with 48 % areal occlusion. Non-newtonian fluid model is selected for
the blood flow as the same problem has been solved before with
Newtonian fluid model. Studies on flow resistance with the presence
of surface irregularities are carried out. Investigations are also
performed on the pressure drop at various Reynolds numbers. The
present study revealed that the pressure drop across a stenosed artery
is practically unaffected by surface irregularities at low Reynolds
numbers, while flow features are observed and discussed at higher
Reynolds numbers.
Abstract: This study extends research on the relationship
between marketing strategy and market segmentation by
investigating on market segments in the cement industry.
Competitive strength and rivals distance from the factory were used
as business environment. A three segment (positive, neutral or
indifferent and zero zones) were identified as strategic segments. For
each segment a marketing strategy (aggressive, defensive and
decline) were developed. This study employed data from cement
industry to fulfill two objectives, the first is to give a framework to
the segmentation of cement industry and the second is developing
marketing strategy with varying competitive strength. Fifty six
questionnaires containing close-and open-ended questions were
collected and analyzed. Results supported the theory that segments
tend to be more aggressive than defensive when competitive strength
increases. It is concluded that high strength segments follow total
market coverage, concentric diversification and frontal attack to their
competitors. With decreased competitive strength, Business tends to
follow multi-market strategy, product modification/improvement and
flank attack to direct competitors for this kind of segments. Segments
with weak competitive strength followed focus strategy and decline
strategy.
Abstract: Efficient utilization of existing water is a pressing
need for Pakistan. Due to rising population, reduction in present
storage capacity and poor delivery efficiency of 30 to 40% from
canal. A study to evaluate an irrigation system in the cotton-wheat
zone of Pakistan, after the watercourse lining was conducted. The
study is made on the basis of cropping pattern and salinity to evaluate
the system. This study employed an index-based approach of using
Geographic information system with field data. The satellite images
of different years were use to examine the effective area. Several
combinations of the ratio of signals received in different spectral
bands were used for development of this index. Near Infrared and
Thermal IR spectral bands proved to be most effective as this
combination helped easy detection of salt affected area and cropping
pattern of the study area. Result showed that 9.97% area under
salinity in 1992, 9.17% in 2000 and it left 2.29% in year 2005.
Similarly in 1992, 45% area is under vegetation it improves to 56%
and 65% in 2000 and 2005 respectively. On the basis of these results
evaluation is done 30% performance is increase after the watercourse
improvement.
Abstract: Context awareness is a capability whereby mobile
computing devices can sense their physical environment and adapt
their behavior accordingly. The term context-awareness, in
ubiquitous computing, was introduced by Schilit in 1994 and has
become one of the most exciting concepts in early 21st-century
computing, fueled by recent developments in pervasive computing
(i.e. mobile and ubiquitous computing). These include computing
devices worn by users, embedded devices, smart appliances, sensors
surrounding users and a variety of wireless networking technologies.
Context-aware applications use context information to adapt
interfaces, tailor the set of application-relevant data, increase the
precision of information retrieval, discover services, make the user
interaction implicit, or build smart environments. For example: A
context aware mobile phone will know that the user is currently in a
meeting room, and reject any unimportant calls. One of the major
challenges in providing users with context-aware services lies in
continuously monitoring their contexts based on numerous sensors
connected to the context aware system through wireless
communication. A number of context aware frameworks based on
sensors have been proposed, but many of them have neglected the
fact that monitoring with sensors imposes heavy workloads on
ubiquitous devices with limited computing power and battery. In this
paper, we present CALEEF, a lightweight and energy efficient
context aware framework for resource limited ubiquitous devices.
Abstract: A thin coating of hexamethyldisiloxane and subsequent O2-plasma treatment was performed on mirror-polished titanium in order to regulate the wide range of wettability including 106 and almost 0 degrees of contact angles. The adsorption behavior of
fibronectin and albumin in both individual and competitive mode,
and initial attachment of fibroblasts and osteoblasts were investigated.
Individually, fibronectin adsorption showed a biphasic inclination, whereas albumin showed greater adsorption to hydrophobic surfaces.
In competitive mode, in solution containing both fibronectin and albumin, fibronectin showed greater adsorption on hydrophilic
surfaces, whereas Alb predominantly adsorbed on hydrophobic
surfaces. Initial attachment of both cells increased with increase in
surface wettability, in particular, on super-hydrophilic surface, which
correlated well with fibronectin adsorption in competitive mode.
These results suggest that a cold plasma-surface modification enabled
to regulate the surface wettability, and fibronectin adsorption may be
responsible for increasing cell adhesion on hydrophilic surfaces in a
body fluid
Abstract: Dielectric sheet perturbation to the dominant TE111
mode resonant frequency of a circular cavity is studied and presented
in this paper. The dielectric sheet, placed at the middle of the airfilled
cavity, introduces discontinuities and disturbs the configuration
of electromagnetic fields in the cavity. For fixed dimensions of cavity
and fixed thickness of the loading dielectric, the dominant resonant
frequency varies quite linearly with the permittivity of the dielectric.
This quasi-linear relationship is plotted using Maple software and
verified using 3D electromagnetic simulations. Two probes are used
in the simulation for wave excitation into and from the cavity. The
best length of probe is found to be 3 mm, giving the closest resonant
frequency to the one calculated using Maple. A total of fourteen
different dielectrics of permittivity ranging from 1 to 12.9 are tested
one by one in the simulation. The works show very close agreement
between the results from Maple and the simulation. A constant
difference of 0.04 GHz is found between the resonant frequencies
collected during simulation and the ones from Maple. The success of
this project may lead to the possibility of using the middle loaded
cavity at TE111 mode as a microwave non-destructive testing of solid
materials.