Abstract: The present work involves measurements to examine
the effects of initial conditions on aerodynamic and acoustic
characteristics of a Jet at M=0.8 by changing the orientation of sharp
edged orifice plate. A thick plate with chamfered orifice presented divergent and convergent openings when it was flipped over. The centerline velocity was found to decay more rapidly for divergent
orifice and that was consistent with the enhanced mass entrainment
suggesting quicker spread of the jet compared with that from the convergent orifice. The mixing layer region elucidated this effect of
initial conditions at an early stage – the growth was found to be comparatively more pronounced for the divergent orifice resulting in
reduced potential core size. The acoustic measurements, carried out in the near field noise region outside the jet within potential core
length, showed the jet from the divergent orifice to be less noisy. The frequency spectra of the noise signal exhibited that in the initial
region of comparatively thin mixing layer for the convergent orifice,
the peak registered a higher SPL and a higher frequency as well. The noise spectra and the mixing layer development suggested a direct correlation between the coherent structures developing in the initial
region of the jet and the noise captured in the surrounding near field.
Abstract: Brushless DC motor with high torque density and slim
topology for easy loading for robot system is proposed and
manufactured. Electromagnetic design is executed by equivalent
magnetic circuit model and numerical analysis. Manufactured motor is
tested and verified characteristics comparing with conventional BLDC
motor.
Abstract: The objective of this study was to determine the
effects of garlic oil (Allium sativa), turmeric powder (Curcuma longa
Linn) and Monensin on Total apparent digestibility of nutrients in
Baloochi lambs. The experiment was designed as a 4 x 4 Latin square
using 4 ruminally baloochi lambs with 4 treatments in four 28-d
periods. Treatments were control (no additive), garlic oil (0. 4 g/d),
monensin (0. 2 g/d) and turmeric powder (20 g/d). Total apparent
digestibility's (% of intake) of organic matter (OM), dry matter (DM),
crud protein (CP), ether extract(EE), non fiber carbohydrate (NFC),
acid detergent fiber (ADF) and neutral detergent fiber (NDF) in the
total tract were not influenced by addition of either additives.
Abstract: In this paper a study on the vibration of thin
cylindrical shells with ring supports and made of functionally
graded materials (FGMs) composed of stainless steel and
nickel is presented. Material properties vary along the
thickness direction of the shell according to volume fraction
power law. The cylindrical shells have ring supports which are
arbitrarily placed along the shell and impose zero lateral
deflections. The study is carried out based on third order shear
deformation shell theory (T.S.D.T). The analysis is carried out
using Hamilton-s principle. The governing equations of motion of
FGM cylindrical shells are derived based on shear deformation
theory. Results are presented on the frequency characteristics,
influence of ring support position and the influence of boundary
conditions. The present analysis is validated by comparing results
with those available in the literature.
Abstract: The national economy development affects the vehicle
ownership which ultimately increases fuel consumption. The rise of
the vehicle ownership is dominated by the increasing number of
motorcycles. This research aims to analyze and identify the
characteristics of fuel consumption, the city transportation system,
and to analyze the relationship and the effect of the city
transportation system on the fuel consumption. A multivariable
analysis is used in this study. The data analysis techniques include: a
Multivariate Multivariable Analysis by using the R software. More
than 84% of fuel on Java is consumed in metropolitan and large
cities. The city transportation system variables that strongly effect the
fuel consumption are population, public vehicles, private vehicles and
private bus. This method can be developed to control the fuel
consumption by considering the urban transport system and city
tipology. The effect can reducing subsidy on the fuel consumption,
increasing state economic.
Abstract: In this paper the influence of heterogeneous traffic on
the temporal variation of ambient PM10, PM2.5 and PM1
concentrations at a busy arterial route (Sardar Patel Road) in the
Chennai city has been analyzed. The hourly PM concentration, traffic
counts and average speed of the vehicles have been monitored at the
study site for one week (19th-25th January 2009). Results indicated
that the concentrations of coarse (PM10) and fine PM (PM2.5 and
PM1) concentrations at SP road are having similar trend during peak
and non-peak hours, irrespective of the days. The PM concentrations
showed daily two peaks corresponding to morning (8 to 10 am) and
evening (7 to 9 pm) peak hour traffic flow. The PM10 concentration is
dominated by fine particles (53% of PM2.5 and 45% of PM1). The
high PM2.5/PM10 ratio indicates that the majority of PM10 particles
originate from re-suspension of road dust. The analysis of traffic flow
at the study site showed that 2W, 3W and 4W are having similar
diurnal trend as PM concentrations. This confirms that the 2W, 3W
and 4W are the main emission source contributing to ambient PM
concentration at SP road. The speed measurement at SP road showed
that the average speed of 2W, 3W, 4W, LCV and HCV are 38, 40,
38, 40 and 38 km/hr and 43, 41, 42, 40 and 41 km/hr respectively for
the weekdays and weekdays.
Abstract: In recent years fuel cell vehicles are rapidly appearing
all over the globe. In less than 10 years, fuel cell vehicles have gone
from mere research novelties to operating prototypes and demonstration
models. At the same time, government and industry in development
countries have teamed up to invest billions of dollars in partnerships
intended to commercialize fuel cell vehicles within the early
years of the 21st century.
The purpose of this study is evaluation of model and performance
of fuel cell hybrid electric vehicle in different drive cycles. A fuel
cell system model developed in this work is a semi-experimental
model that allows users to use the theory and experimental relationships
in a fuel cell system. The model can be used as part of a complex
fuel cell vehicle model in advanced vehicle simulator (ADVISOR).
This work reveals that the fuel consumption and energy efficiency
vary in different drive cycles. Arising acceleration and speed in a
drive cycle leads to Fuel consumption increase. In addition, energy
losses in drive cycle relates to fuel cell system power request. Parasitic
power in different parts of fuel cell system will increase when
power request increases. Finally, most of energy losses in drive cycle
occur in fuel cell system because of producing a lot of energy by fuel
cell stack.
Abstract: Ascorbic acid (AA), commonly known as vitamin C, is essential for normal functioning of the body and maintenance of metabolic integrity. Among its various roles are as an antioxidant, a cofactor in collagen formation and other reactions, as well as reducing physical stress and maintenance of the immune system. Recent collaborative research between the Australian Defence Science and Technology Organisation (DSTO) in Scottsdale, Tasmania and RMIT University has sought to overcome the problems arising from the inherent instability of ascorbic acid during processing and storage of foods. The recent work has demonstrated the potential of microencapsulation by spray drying as a means to enhance retention. The purpose of this current study has been focused upon the influence of spray drying conditions on the properties of encapsulated ascorbic acid. The process was carried out according to a central composite design. Independent variables were: inlet temperature (80-120° C) and feed flow rate (7-14 mL/minute). Process yield, ascorbic acid loss, moisture content, water activity and particle size distribution were analysed as responses. The results have demonstrated the potential of microencapsulation by spray drying as a means to enhance retention. Vitamin retention, moisture content, water activity and process yield were influenced positively by inlet air temperature and negatively by feed flow rate.
Abstract: The conventional assessment of human semen is a
highly subjective assessment, with considerable intra- and interlaboratory
variability. Computer-Assisted Sperm Analysis (CASA)
systems provide a rapid and automated assessment of the sperm
characteristics, together with improved standardization and quality
control. However, the outcome of CASA systems is sensitive to the
method of experimentation. While conventional CASA systems use
digital microscopes with phase-contrast accessories, producing
higher contrast images, we have used raw semen samples (no
staining materials) and a regular light microscope, with a digital
camera directly attached to its eyepiece, to insure cost benefits and
simple assembling of the system. However, since the accurate finding
of sperms in the semen image is the first step in the examination and
analysis of the semen, any error in this step can affect the outcome of
the analysis. This article introduces and explains an algorithm for
finding sperms in low contrast images: First, an image enhancement
algorithm is applied to remove extra particles from the image. Then,
the foreground particles (including sperms and round cells) are
segmented form the background. Finally, based on certain features
and criteria, sperms are separated from other cells.
Abstract: Electron back-scattered diffraction was used to follow the evolution of microstructure from the base metal to the stir zone (SZ) in a duplex stainless steel subjected to friction stir welding. In the stir zone (SZ), a continuous dynamic recrystallization (CDRX) was evidenced for ferrite, while it was suggested that a static recrystallization together with CDRX may occur for austenite. It was found that ferrite and austenite grains in the SZ take a typical shear texture of bcc and fcc materials respectively.
Abstract: Debates on residential satisfaction topic have been
vigorously discussed in family house setting. Nonetheless, less or
lack of attention was given to survey on student residential
satisfaction in the campus house setting. This study, however, tried to
fill in the gap by focusing more on the relationship between students-
socio-economic backgrounds and student residential satisfaction with
their on-campus student housing facilities. Two-stage cluster
sampling method was employed to classify the respondents. Then,
self-administered questionnaires were distributed face-to-face to the
students. In general, it was confirmed that the students- socioeconomic
backgrounds have significantly influence the students-
satisfaction with their on-campus student housing facilities. The main
influential factors were revealed as the economic status, sense of
sharing, and the ethnicity of roommates. Likewise, this study could
also provide some useful feedback for the universities administration
in order to improve their student housing facilities.
Abstract: This paper presents a simple three phase power flow
method for solution of three-phase unbalanced radial distribution
system (RDN) with voltage dependent loads. It solves a simple
algebraic recursive expression of voltage magnitude, and all the data
are stored in vector form. The algorithm uses basic principles of
circuit theory and can be easily understood. Mutual coupling between
the phases has been included in the mathematical model. The
proposed algorithm has been tested with several unbalanced radial
distribution networks and the results are presented in the article. 8-
bus and IEEE 13 bus unbalanced radial distribution system results
are in agreements with the literature and show that the proposed
model is valid and reliable.
Abstract: Fault detection determines faultexistence and detecting
time. This paper discusses two layered fault detection methods to
enhance the reliability and safety. Two layered fault detection methods
consist of fault detection methods of component level controllers and
system level controllers. Component level controllers detect faults by
using limit checking, model-based detection, and data-driven
detection and system level controllers execute detection by stability
analysis which can detect unknown changes. System level controllers
compare detection results via stability with fault signals from lower
level controllers. This paper addresses fault detection methods via
stability and suggests fault detection criteria in nonlinear systems. The
fault detection method applies tothe hybrid control unit of a military
hybrid electric vehicleso that the hybrid control unit can detect faults
of the traction motor.
Abstract: The paper deals with the development of portable aerosol concentrator and its application for the determination of nitrites and nitrates. The device enables the continuous trapping of pollutants in the air. An extensive literature search has been elaborated which aims at the development of samplers and the possibilities of their application in the continuous determination of volatile organic compounds. The practical part of the paper is focused on the development of the portable aerosol concentrator. The device using the Aerosol Enrichment Unit has been experimentally verified and subsequently realized. It operates on the principle of equilibrium accumulation of pollutants from the gaseous phase using absorption liquid polydisperse aerosol. The device has been applied for monitoring nitrites and nitrates in the air. The chemiluminescence detector was used for detection; the achieved detection limit for nitrites was 28 ng/m3 and for nitrates 78 ng/m3.
Abstract: Microscopic emission and fuel consumption models
have been widely recognized as an effective method to quantify real
traffic emission and energy consumption when they are applied with
microscopic traffic simulation models. This paper presents a
framework for developing the Microscopic Emission (HC, CO, NOx,
and CO2) and Fuel consumption (MEF) models for light-duty
vehicles. The variable of composite acceleration is introduced into
the MEF model with the purpose of capturing the effects of historical
accelerations interacting with current speed on emission and fuel
consumption. The MEF model is calibrated by multivariate
least-squares method for two types of light-duty vehicle using
on-board data collected in Beijing, China by a Portable Emission
Measurement System (PEMS). The instantaneous validation results
shows the MEF model performs better with lower Mean Absolute
Percentage Error (MAPE) compared to other two models. Moreover,
the aggregate validation results tells the MEF model produces
reasonable estimations compared to actual measurements with
prediction errors within 12%, 10%, 19%, and 9% for HC, CO, NOx
emissions and fuel consumption, respectively.
Abstract: The porous silicon (PS), formed from the anodization
of a p+ type substrate silicon, consists of a network organized in a
pseudo-column as structure of multiple side ramifications. Structural
micro-topology can be interpreted as the fraction of the interconnected
solid phase contributing to thermal transport. The
reduction of dimensions of silicon of each nanocristallite during the
oxidation induced a reduction in thermal conductivity. Integration of
thermal sensors in the Microsystems silicon requires an effective
insulation of the sensor element. Indeed, the low thermal conductivity
of PS consists in a very promising way in the fabrication of integrated
thermal Microsystems.In this work we are interesting in the
measurements of thermal conductivity (on the surface and in depth)
of PS by the micro-Raman spectroscopy. The thermal conductivity is
studied according to the parameters of anodization (initial doping and
current density. We also, determine porosity of samples by
spectroellipsometry.
Abstract: Let Xi be a Lacunary System, we established large
deviations inequality for Lacunary System. Furthermore, we gained
Marcinkiewicz Larger Number Law with dependent random variables
sequences.
Abstract: A novel behavioral detection framework is proposed
to detect zero day buffer overflow vulnerabilities (based on network
behavioral signatures) using zero-day exploits, instead of the
signature-based or anomaly-based detection solutions currently
available for IDPS techniques. At first we present the detection
model that uses shadow honeypot. Our system is used for the online
processing of network attacks and generating a behavior detection
profile. The detection profile represents the dataset of 112 types of
metrics describing the exact behavior of malware in the network. In
this paper we present the examples of generating behavioral
signatures for two attacks – a buffer overflow exploit on FTP server
and well known Conficker worm. We demonstrated the visualization
of important aspects by showing the differences between valid
behavior and the attacks. Based on these metrics we can detect
attacks with a very high probability of success, the process of
detection is however very expensive.
Abstract: In this paper, an automatic system of diagnosis was
developed to detect and locate in real time the defects of the wound
rotor asynchronous machine associated to electronic converter. For
this purpose, we have treated the signals of the measured parameters
(current and speed) to use them firstly, as indicating variables of the
machine defects under study and, secondly, as inputs to the Artificial
Neuron Network (ANN) for their classification in order to detect the
defect type in progress. Once a defect is detected, the interpretation
system of information will give the type of the defect and its place of
appearance.
Abstract: Defect prevention is the most vital but habitually
neglected facet of software quality assurance in any project. If
functional at all stages of software development, it can condense the
time, overheads and wherewithal entailed to engineer a high quality
product. The key challenge of an IT industry is to engineer a
software product with minimum post deployment defects.
This effort is an analysis based on data obtained for five selected
projects from leading software companies of varying software
production competence. The main aim of this paper is to provide
information on various methods and practices supporting defect
detection and prevention leading to thriving software generation. The
defect prevention technique unearths 99% of defects. Inspection is
found to be an essential technique in generating ideal software
generation in factories through enhanced methodologies of abetted
and unaided inspection schedules. On an average 13 % to 15% of
inspection and 25% - 30% of testing out of whole project effort time
is required for 99% - 99.75% of defect elimination.
A comparison of the end results for the five selected projects
between the companies is also brought about throwing light on the
possibility of a particular company to position itself with an
appropriate complementary ratio of inspection testing.