|
Thermal Characterization and Surface Morphology
of Natural Rubber (NR)/Nitrile Butadiene Rubber (NBR) Blend
-- A Kala
The objective of this paper is to evaluate the thermal properties such as stability, degradation and glass
transition temperature of Natural Rubber (NR) blended with Nitrile Butadiene Rubber (NBR) at 80:20
concentrations. Thermogravimetric Analysis (TGA) has been successfully exploited to study the thermal properties of the blend in
the temperature range of room temperature to 600 °C. The temperature increased in the steps of 20 °C/min, whereas
the heating rate is varied dynamically when the weight change occurs. In addition, the studies on the power loss per
minute were also carried out using Differential Scanning Calorimetry (DSC) under Argon (Ar) atmosphere with the Ar flow
being 80.0 mL/min. The heating rate is 10 °C/min. The DSC studies were carried out in the temperature range of – 125 °C to
+200 °C. Scanning Electron Microscopy (SEM) has been used to study the surface morphology of NR/NBR blend.
© 2009 IUP. All Rights Reserved.
Loop Quantum Gravity in Ashtekar
and Lagrange-Finsler Variables and Fedosov Quantization of General Relativity
Sergiu I Vacaru
We propose a unified approach to loop quantum gravity and Fedosov quantization of gravity following the geometry
of double space-time fibrations and their quantum deformations. There are considered pseudo-Rlemannian
manifolds enabled with (1) a nonholonomic 2 + 2 distribution defining a Nonlinear connection (N-connection) structure and
(2) Arnowitt-Deser-Misner 3 + 1 decomposition. The Ashtekar-Barbero variables are generalized and adapted to the
N-connection structure which allows us to write the general relativity theory equivalently in terms of Lagrange-Finsler
variables and related canonical almost symplectic forms and connections. The Fedosov results are redefined for gravitational
gauge like connections and there are analyzed conditions when the star product for deformation quantization is computed
in terms of geometric objects in loop quantum gravity. We speculate on equivalence of quantum gravity theories with 3
+ 1 and 2 + 2 splitting and quantum analogs of the Einstein equations.
© 2009 IUP. All Rights Reserved.
Scale Invariant Theory of Gravitation
in Non-Diagonal Bianchi Type II Space-Time
-- Bivudutta Mishra
In this paper, the problem of non-diagonal Bianchi type II space-time is investigated in Wesson's scale invariant theory
of gravitation with the matter field in the form of perfect fluid. The gauge function b depends on time coordinate only (Dirac gauge). It is found that the perfect fluid does not survive and Bianchi type II space-time turns out to be flat in this theory.
© 2009 IUP. All Rights Reserved.
Time is Derived from Motion
-- Amrit S Sorli
Today in physics, there are two fundamental approaches to time. The first and the most common approach says that
we use clocks to measure the time component of space-time, space and time being cofounded as the basis of physical
reality. However, this approach has no experimental support. There is no evidence whatsoever that clocks measure one aspect
of space-time, and in reality we cannot observe space-time at all. The second approach says time is cofounded with
motion through space. This approach is supported by experiment and observation. We employ clocks to accumulate local
internal motion, and then use the result to calibrate duration. This is then employed in the measurement of external motion
or material change, and the comparative rate of such change. Our evidence tells us that this rate of change varies
with gravity, being commonly known as gravitational time dilation. However, we can only measure space and motion, not
time, and thus we must assert that the true basis of fundamental reality is space and motion rather than space-time. This
means that space itself is in some respect timeless. Motion runs in timeless space.
© 2009 IUP. All Rights Reserved.
Binding Energy of Nucleus Using
Few-Body Interactions
M R Pahlavani , R Morad J and F Mojrian
A simple approach based on semiempirical mass formula and the Kelson-Garvey model by considering one, two and
three body interactions has been developed to construct an analytical formula for binding energy. Binding energies for
some nuclei are calculated via this method and compared with the available data. Also, an equation that expressed the
relation between binding energies of the neighboring nuclei was obtained.
© 2009 IUP. All Rights Reserved.
|
