Abstract: Male factor infertility due to endocrine disturbances
such as abnormalities in prolactin levels are encountered in a
significant proportion. This case control study was carried out to
determine the effects of prolactin on the male reproductive tract,
using 200 male white rats. The rats were maintained as the control
group (G1), hypoprolactinaemic group (G2), 3 hyperprolactinaemic
groups induced using oral largactil (G3), low dose fluphenazine (G4)
and high dose fluphenazine (G5). After 100 days, rats were subjected
to serum prolactin (PRL) level measurements and for basic seminal
fluid analysis (BSA). The difference between serum PRL
concentrations of rats in G2, G3, G4 and G5 as compared to the
control group were highly significant by Student’s t-test (p
Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.
Abstract: A blood pressure monitor or sphygmomanometer can
be either manual or automatic, employing respectively either the
auscultatory method or the oscillometric method.
The manual version of the sphygmomanometer involves an
inflatable cuff with a stethoscope adopted to detect the sounds
generated by the arterial walls to measure blood pressure in an artery.
An automatic sphygmomanometer can be effectively used to
monitor blood pressure through a pressure sensor, which detects
vibrations provoked by oscillations of the arterial walls.
The pressure sensor implemented in this device improves the
accuracy of the measurements taken.
Abstract: This paper presents the variation of the dynamic
characteristics of a spindle with the change of bearing preload. The
correlations between the variation of bearing preload and fundamental
modal parameters were first examined by conducting vibration tests on
physical spindle units. Experimental measurements show that the
dynamic compliance and damping ratio associated with the
dominating modes were affected to vary with variation of the bearing
preload. When the bearing preload was slightly deviated from a
standard value, the modal frequency and damping ability also vary to
different extent, which further enable the spindle to perform with
different compliance. For the spindle used in this study, a standard
preload value set on bearings would enable the spindle to behave a
higher stiffness as compared with others with a preload variation. This
characteristic can be served as a reference to examine the variation of
bearing preload of spindle in assemblage or operation.
Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.
Abstract: This paper presents development of the light-weight manipulator with series elastic actuation for medical telediagnostics (USG examination). General structure of realized impedance control algorithm was shown. It was described how to perform force measurements based mainly on elasticity of manipulator links.
Abstract: In the present study we evaluated the nutritional status of 214 institutionalized elderly residents of both genders, aged 65 years and older of 11 care homes located in the district of Viseu (center of Portugal). The evaluation was based on anthropometric measurements and the Mini Nutritional Assessment (MNA) score.
The mean age of the subjects was 82.3 ± 6.1 years-old. Most of the elderly residents were female (72.0%). The majority had 4 years of formal education (51.9%) and was widowed (74.3%) or married (14.0%).
Men presented a mean age of 81.2±8.5 years-old, weight 69.3±14.5 kg and BMI 25.33±6.5 kg/m2. In women, the mean age was 84.5±8.2 years-old, weight 61.2±14.7 kg and BMI 27.43±5.6 kg/m2.
The evaluation of the nutritional status using the MNA score showed that 24.0% of the residents show a risk of undernutrition and 76.0% of them were well nourished.
There was a high prevalence of obese (24.8%) and overweight residents (33.2%) according to the BMI. 7.5% were considered underweight.
We also found that according to their waist circumference measurements 88.3% of the residents were at risk for cardiovascular disease (CVD) and 64.0% of them presented very high risk for CVD (WC≥88 cm for women and WC ≥102 cm for men).
The present study revealed the coexistence of a dual form of malnutrition (undernourished and overweight) among the institutionalized Portuguese concomitantly with an excess of abdominal adiposity. The high prevalence of residents at high risk for CVD should not be overlooked.
Given the vulnerability of the group of institutionalized elderly, our study highlights the importance of the classification of nutritional status based on both instruments: the BMI and the MNA.
Abstract: This paper deals with advanced state estimation algorithms for estimation of biomass concentration and specific growth rate in a typical fed-batch biotechnological process. This biotechnological process was represented by a nonlinear mass-balance based process model. Extended Kalman Filter (EKF) and Particle Filter (PF) was used to estimate the unmeasured state variables from oxygen uptake rate (OUR) and base consumption (BC) measurements. To obtain more general results, a simplified process model was involved in EKF and PF estimation algorithms. This model doesn’t require any special growth kinetic equations and could be applied for state estimation in various bioprocesses. The focus of this investigation was concentrated on the comparison of the estimation quality of the EKF and PF estimators by applying different measurement noises. The simulation results show that Particle Filter algorithm requires significantly more computation time for state estimation but gives lower estimation errors both for biomass concentration and specific growth rate. Also the tuning procedure for Particle Filter is simpler than for EKF. Consequently, Particle Filter should be preferred in real applications, especially for monitoring of industrial bioprocesses where the simplified implementation procedures are always desirable.
Abstract: Vertical slotted walls can be used as permeable
breakwaters to provide economical and environmental protection
from undesirable waves and currents inside the port. The permeable
breakwaters are partially protection and have been suggested to
overcome the environmental disadvantages of fully protection
breakwaters. For regular waves a semi-analytical model is based on
an eigenfunction expansion method and utilizes a boundary condition
at the surface of each wall are developed to detect the energy
dissipation through the slots. Extensive laboratory tests are carried
out to validate the semi-analytic models. The structure of the physical
model contains two walls and it consists of impermeable upper and
lower part, where the draft is based a decimal multiple of the total
depth. The middle part is permeable with a porosity of 50%. The
second barrier is located at a distant of 0.5, 1, 1.5 and 2 times of the
water depth from the first one. A comparison of the theoretical results
with previous studies and experimental measurements of the present
study show a good agreement and that, the semi-analytical model is
able to adequately reproduce most the important features of the
experiment.
Abstract: This paper conducts a comparison study using KES-FB and PhabrOmeter to measure 58 selected warp knitted fabric hand properties. Fabric samples were selected and measured by both KES-FB and PhabrOmeter. Results show differences between these two measurement methods. Smoothness and stiffness values obtained by KES-FB were found significant correlated (p value = 0.003 and 0.022) to the PhabrOmeter results while softness values between two measurement methods did not show significant correlation (p value = 0.828). Disagreements among these two measurement methods imply limitations on different mechanism principles when facing warp knitted fabrics. Subjective measurement methods and further studies are suggested in order to ascertain deeper investigation on the mechanisms of fabric hand perceptions.
Abstract: Tsunami early detection and warning systems have proved to be of ultimate importance, especially after the destructive tsunami that hit Japan in March 2012. Such systems are crucial to inform the authorities of any risk of a tsunami and of the degree of its danger in order to make the right decision and notify the public of the actions they need to take to save their lives. The purpose of this research is to enhance existing tsunami detection and warning systems. We first propose an automated and miniaturized model of an early tsunami detection and warning system. The model for the operation of a tsunami warning system is simulated using the data acquisition toolbox of Matlab and measurements acquired from specified internet pages due to the lack of the required real-life sensors, both seismic and hydrologic, and building a graphical user interface for the system. In the second phase of this work, we implement various satellite image filtering schemes to enhance the acquired synthetic aperture radar images of the tsunami affected region that are masked by speckle noise. This enables us to conduct a post-tsunami damage extent study and calculate the percentage damage. We conclude by proposing improvements to the existing telecommunication infrastructure of existing warning tsunami systems using a migration to IP-based networks and fiber optics links.
Abstract: This study applies the inverse method and three- dimensional CFD commercial software in conjunction with the experimental temperature data to investigate the heat transfer and fluid flow characteristics of the plate-fin heat sink in a closed rectangular enclosure for various values of fin height. The inverse method with the finite difference method and the experimental temperature data is applied to determine the heat transfer coefficient. The k-ε turbulence model is used to obtain the heat transfer and fluid flow characteristics within the fins. To validate the accuracy of the results obtained, the comparison of the average heat transfer coefficient is made. The calculated temperature at selected measurement locations on the plate-fin is also compared with experimental data.
Abstract: This investigation develops a revisable method for estimating the estimate value of equivalent 10 Hz voltage flicker (DV10) of a DC Electric Arc Furnace (EAF). This study also discusses three 161kV DC EAFs by field measurement, with those results indicating that the estimated DV10 value is significantly smaller than the survey value. The key point is that the conventional means of estimating DV10 is inappropriate. There is a main cause as the assumed Qmax is too small.
Although DC EAF is regularly operated in a constant MVA mode, the reactive power variation in the Main Transformer (MT) is more significant than that in the Furnace Transformer (FT). A substantial difference exists between estimated maximum reactive power fluctuation (DQmax) and the survey value from actual DC EAF operations. However, this study proposes a revisable method that can obtain a more accurate DV10 estimate than the conventional method.
Abstract: Wireless communications have been expanded very fast in recent decades. This technology relies on an extensive network of base stations and antennas, using radio frequency signals to transmit information. Devices that use wireless communication, while offering various services, basically act as sources of non-ionizing electromagnetic fields (EMF). Such devices are permanently present in human vicinity and almost constantly radiate, causing EMF pollution of the environment. This fact has initiated development of modern systems for observation of the EMF pollution, as well as for risk assessment. This paper presents the Serbian electromagnetic field monitoring network – SEMONT, designed for automated, remote and continuous broadband monitoring of EMF in the environment. Measurement results of the SEMONT monitoring at one of the test locations, within the main campus of the University of Novi Sad, are presented and discussed, along with corresponding exposure assessment of the general population, regarding the Serbian legislation.
Abstract: Non-linear FEM calculations are indispensable when important technical information like operating performance of a rubber component is desired. Rubber bumpers built into air-spring structures may undergo large deformations under load, which in itself shows non-linear behavior. The changing contact range between the parts and the incompressibility of the rubber increases this non-linear behavior further. The material characterization of an elastomeric component is also a demanding engineering task. In this paper a comprehensive investigation is introduced including laboratory measurements, mesh density analysis and complex finite element simulations to obtain the load-displacement curve of the chosen rubber bumper. Contact and friction effects are also taken into consideration. The aim of this research is to elaborate a FEM model which is accurate and competitive for a future shape optimization task.
Abstract: Various biomass based resources, which can be used
as an extender, or a complete substitute of diesel fuel may have very
significant role in the development of agriculture, industrial and
transport sectors in the energy crisis. Use of Karanja oil methyl ester
biodiesel in a CI DI engine was found highly compatible with engine
performance along with lower exhaust emission as compared to
diesel fuel but with slightly higher NOx emission and low wear
characteristics. The combustion related properties of vegetable oils
are somewhat similar to diesel oil. Neat vegetable oils or their blends
with diesel, however, pose various long-term problems in
compression ignition engines. These undesirable features of
vegetable oils are because of their inherent properties like high
viscosity, low volatility, and polyunsaturated character. Pongamia
methyl ester (PME) was prepared by transesterification process using
methanol for long term engine operations. The physical and
combustion-related properties of the fuels thus developed were found
to be closer to that of the diesel. A neat biodiesel (PME) was selected
as a fuel for the tribological study of biofuels.
Two similar new engines were completely disassembled and
subjected to dimensioning of various vital moving parts and then
subjected to long-term endurance tests on neat biodiesel and diesel
respectively. After completion of the test, both the engines were
again disassembled for physical inspection and wear measurement of
various vital parts. The lubricating oil samples drawn from both
engines were subjected to atomic absorption spectroscopy (AAS) for
measurement of various wear metal traces present. The additional
lubricating property of biodiesel fuel due to higher viscosity as
compared to diesel fuel resulted in lower wear of moving parts and
thus improved the engine durability with a bio-diesel fuel. Results
reported from AAS tests confirmed substantially lower wear and thus
improved life for biodiesel operated engines.
Abstract: Lately, with the increasing number of location-based applications, demand for highly accurate and reliable indoor localization became urgent. This is a challenging problem, due to the measurement variance which is the consequence of various factors like obstacles, equipment properties and environmental changes in complex nature of indoor environments. In this paper we propose low-cost custom-setup infrastructure solution and localization algorithm based on the Weighted Centroid Localization (WCL) method. Localization accuracy is increased by several enhancements: calibration of RSSI values gained from wireless nodes, repetitive measurements of RSSI to exclude deviating values from the position estimation, and by considering orientation of the device according to the wireless nodes. We conducted several experiments to evaluate the proposed algorithm. High accuracy of ~1m was achieved.
Abstract: This paper presents an intensive measurement studying of the network performance analysis when IEEE 802.11g Wireless Local Area Networks (WLAN) coexisting with IEEE 802.15.4 Wireless Personal Area Network (WPAN). The measurement results show that the coexistence between both networks could increase the Frame Error Rate (FER) of the IEEE 802.15.4 networks up to 60% and it could decrease the throughputs of the IEEE 802.11g networks up to 55%.
Abstract: This research studies the electroplating of zinc coating
in the zinc chloride bath mixed with supercritical CO2. The sodium
fluoride (NaF) was used as the bath additive to change the structure
and property of the coating, and therefore the roughness and corrosion
resistance of the zinc coating was investigated. The surface
characterization was performed using optical microscope (OM), X-ray
diffractometer (XRD), and α-step profilometer. Moreover, the
potentiodynamic polarization measurement in 3% NaCl solution was
employed in the corrosion resistance evaluation. Because of the
emulsification of the electrolyte mixed in Sc-CO2, the electroplated
zinc produced the coating with smoother surface, smaller grain, better
throwing power and higher corrosion resistance. The main role played
by the NaF was to reduce the coating’s roughness and grain size. In
other words, the CO2 mixed with the electrolyte under the supercritical
condition performed the similar function as brighter and leveler in zinc
electroplating to enhance the throwing power and corrosion resistance
of the coating.
Abstract: Using the technology acceptance model (TAM), this
study examined the external variables of technological complexity
(TC) to acquire a better understanding of the factors that influence the
acceptance of computer application courses by learners at Active
Aging Universities. After the learners in this study had completed a
27-hour Facebook course, 44 learners responded to a modified TAM
survey. Data were collected to examine the path relationships among
the variables that influence the acceptance of Facebook-mediated
community learning. The partial least squares (PLS) method was used
to test the measurement and the structural model. The study results
demonstrated that attitudes toward Facebook use directly influence
behavioral intentions (BI) with respect to Facebook use, evincing a
high prediction rate of 58.3%. In addition to the perceived usefulness
(PU) and perceived ease of use (PEOU) measures that are proposed in
the TAM, other external variables, such as TC, also indirectly
influence BI. These four variables can explain 88% of the variance in
BI and demonstrate a high level of predictive ability. Finally,
limitations of this investigation and implications for further research
are discussed.