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Rolling Element
Bearing Fault Detection via Vibration Signal Analysis -
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Pratesh Jayaswal, A K Wadhwani and K B Mulchandani
Rolling
Element Bearings (REB) are widely used machine components
in the vast majority of rotating machines. The condition monitoring
of bearings is very impotant for assessing the overall machine
performance. Vibration-based signal analysis methods have
been widely used for bearing fault diagnosis for several decades.
Various vibration signature analysis techniques have been
developed for single defect diagnosis of REB. There is a lot
of scope of investigation in multiple fault detection for
REB. In this present work, an investigation is made on the
time and frequency domain techniques for fault identification
of REB. Vibration signatures were collected from the housing
of bearing in four bearing conditions. The bearings condition
considered as a healthy bearing and bearing with outer race,
inner race and rolling element defects. The objective of this
work is to investigate the feasibility of Fast Fourier Transform
(FFT) and band pass analysis for fault identification of REB
with multiple faults. Experiments under three faulty and healthy
conditions have confirmed that the filtered signals under
three frequency bands can be valuable signatures for fault
identification and the Root Mean Square (RMS) values of filtered
signals can be further utilized as parameters of diagnostic
importance.
©
2008 The Icfai University Press. All Rights Reserved.
Structural
and Microstructural Evolution in BaTiO3 Ceramic
Nanoparticles - -
T K Mandal
The
structure and microstructure of BaTiO3 nanoparticles
synthesized by polymeric precursor method are correlated with
the mean crystallite size and tetragonality ratio, c/a. Williamson-Hall
integral breadth method is used for evaluation of microstructural
quantities like, mean crystallite size and microstrain, etc.
The structural evolution and the related change in properties
with respect to the used method in this paper and other reported
methods are tried to correlate with the tetragonality ratio,
c/a. The structure of the synthesized nanoparticles is characterized
with XRD, SEM, TEM and EDX analysis.
Microstructural parameters of BaTiO3 nanoparticles
are measured with the XRD line profile analysis.
©
2008 The Icfai University Press. All Rights Reserved.
Sensitivity
Analysis of a High Gain Helix Twt Using HFSS
- - Vikas
Kumar and Vishnu Srivastava
Dispersion
shaping is the most important concern in ensuring the stability
of a Traveling Wave Tube (TWT). Dispersion with respect to
variation in helix parameters: (a) pitch, (b) tape width,
(c) tape thickness and (d) relative permittivity of the dielectric
support rods have been studied. The helix structure for the
Ku Band helix TWT was simulated using the Ansoft High Frequency
Structure Simulator (HFSS) simulator and the dispersion graphs
were plotted. The sensitivity of the propagation constant
and interaction impedance with respect to change in the helix
parameters have been predicted.
©
2008 The Icfai University Press. All Rights Reserved.
Design
and Development of Slanted Slot Microstrip Antenna for Multi-Frequency
Operation and Circular Polarization
- -
S K Satnoor, R M Vani, R B Konda, S N Mulgi and P V Hunagund
In
this paper, an electromagnetically coupled two pair-slanted
slot microstrip antenna (SSMSA) is presented to achieve multi-frequency
operation with adequate impedance bandwidth and circular polarization
(CP). The design consists of two pairs of slanted slots etched
on the ground plane of the top surface of the substrate material
and are excited by back microstrip line-feed which is placed
at the bottom surface of the substrate material. This antenna
operates at four bands of frequencies within X-band and shows
the property of CP with minimum axial ratio. Such antennas
can find application in satellite and radar communication
systems.
©
2008 The Icfai University Press. All Rights Reserved.
Emission
and Performance Characteristics of a Single Cylinder Compression
Ignition Engine Operating on Esterified Rice Bran Vegetable
Oil and Diesel Fuel -
- K Thirupathi Reddy, P Ram Reddy and P V Ramana Murthy
The
alkyl monoesters of fatty acids derived from vegetable oils
or animal fats, known as biodiesel, is attracting considerable
interest as an alternative fuel for diesel engines. Biodiesel-fueled
engines produce less carbon monoxide, unburned hydrocarbons,
and particulate emissions than diesel-fueled engines. However,
biodiesel has different chemical and physical properties than
diesel fuel, including a larger bulk modulus and a higher
cetane number. Some of these properties can be affected by
oxidation of the fuel during storage. These changes can affect
the timing of the combustion process and potentially cause
increase in emissions of oxides of nitrogen. The objective
of the study is to evaluate the effect of injection and combustion
time on biodiesel combustion and exhaust emissions. Experimental
investigations have been carried out using biodiesel as an
alternative fuel in single cylinder, compression-ignition
engine under various operating conditions and injection timings
with respect to TDC. Various parameters such as brake power,
peak pressure rise, and emissions during combustion process
under various operating conditions with diesel, biodiesel
and biodiesel blends were measured and the results analyzed.
In conclusion, the conditions under which improvement in emissions
can be achieved have been reported.
©
2008 The Icfai University Press. All Rights Reserved.
Optimum
Modeling of MEMS Characteristics:An Analytical Solution Approach
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- M Z Shaikh, Shankarappa F Kodad and B C Jinaga
With
progressing monolithic integration of entire Microelectromechanical
systems (MEMS) on one chip fabricated by standard IC technology
we have to cope with the problem that the operation of embedded
transducer elements is considerably affected by touch-down
effect, cross-coupling and parasitic effects. Referring to
a NCMOS-integrated capacitive pressure sensor as an illustrative
example, we demonstrate that a touch-down effect analysis
on the device level is indispensable to understand the interplay
of various effects, which contribute to the sensor output.
On the basis of this analysis we are able to build a physically-based
macro model for the predictive simulation of the system performance.
©
2008 The Icfai University Press. All Rights Reserved.
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