Abstract
The clock paradox is
analyzed for the case when the onward and return trips cover the same
‘distance’ (as observed
by the traveling twin) but at unequal velocities. In this case the
stationary twin observes
the distances covered by her sister during the onward and return
trips to be different.
The analysis is presented using formulations of special relativity and
the
only requirement for
consistency is that all observations are made from any one chosen
inertial frame. The
analysis suggests that a defining feature of an inertial frame should be
based on the continued
maintenance of the distinctive synchronicity of the clocks co-moving
The Partial Molar Volumes of FeCl2 and FeCl3 in Ternary Solutions
H20-HCI-FeCIx from Density Measurements
Giovanni Di Loreto and Luca D’Ottone
Abstract
The partial molar volumes of iron (III) and iron (II) in water at
infinite dilution were extrapolated from high precision density
measurements giving a value of -33.89 [cm3 mole-1] for iron (III) and a
value of -2.45 [cm3 mole-1] for iron (II) in the conventional scale
where 0 H
+
V = 0[cm3mole-1].
Density measurements were carried on in ternary solutions of
FeClx-H2O-HCl to suppress potential hydrolysis and oxidation processes.
A brief comparison of this work with previously published data is
provided supporting our determination for the partial molar volume of
iron (III). The value for the partial molar volume of iron (II) should
still be object of study since poor agreement was found with the very
few fragmented literature data.
Full Article
Abstract
The sticking probability
of self-assembled 1-octadecanethiol on the surface of polycrystalline Au
was measured using cyclic voltammetry. A Langmuir-like adsorption
kinetics was observed for the 1-octadecanethiol adsorption on Au at high
micro-molar concentrations which became more
precursor-like at
7.0-10.0 x 10-4
mM concentrations. At 5.0 x 10-4 mM concentration, the adsorption
isotherm
revealed an additional feature which could be explained by the initial
adsorption of the solvent methanol or one of its by-products and
subsequent removal by the strong Au-S bond formation. It could be also
explained by the formation of a "lying down" phase of the
1-octadecanethiol on Au surface. This phenomenon was reproducibly
observed for the 1-octadecanethiol and results compare well with other
methods reported in the literature.
Full Article
New Method of
Synthesis of Stannic Phosphotungstate and its Characterization as Ion
Exchanger
Susheel K Mittal, Rabindra Nath
J. S.
Banait
Abstract
Stannic Phosphotungstate (SnPW) was synthesized by a novel
method by the reaction of Tin (II) salt with tungstate and
phosphoric acid in the presence of dilute sulphuric acid and
hydrogen peroxide. The product was characterized as weakly
acidic ion exchanger by pH titrations against alkali metal
hydroxides. Ion exchange capacity for alkali and alkaline
earth metal ions, distribution coefficients for a number of
bivalent metal ions, effect of heat on ion exchange capacity
were studied for the ion exchanger. The compound shows
excellent chemical stabilities towards acid, neutral and
organic solutions. Study of distribution coefficients for
various metal ions suggests that SnPW is selective for Pb2+,
Ba2+ and Ca2+ in the order,
respectively. Structural studies of the compound were
carried out using TGA, XRD, FTIR and XRF. Chemical
composition of the compound was determined by XRF and the
mole ratio was found to be Sn:P:W = 3:1:1.2
Full Article
Proton NMR Determination of Mg2+ and Ca2+ Concentrations Using
Tetrasodium EDTA Complexes
Steven Han, Errol V. Mathias, Yong Ba
Abstract
The
quantitative determination of metal ion concentration was previously
achieved using disodium EDTA and proton NMR spectroscopy. One drawback
using disodium EDTA arose from the determination of group II A metal
ions. It was not feasible to distinguish between the chemical shifts of
the free EDTA and complexed EDTA. It was found that by using a stronger
chelator, tetrasodium EDTA, the chemical shift separation of the free
EDTA and the Mg2+ and Ca2+ EDTA complexes in the proton NMR spectra was
readily achieved, which facilitates the determination of these metal
ions by proton NMR spectroscopy.
Full Article
Immobilized Metal Affinity Chromatography (IMAC) of Mushroom Tyrosinase
Andrew Powell, Norman Siu, Jennifer K. Inlow and William H. Flurkey
Abstract
Partially purified and crude commercial
mushroom (Agaricus bisporus) tyrosinase was
subjected to immobilized metal ion affinity
chromatography (IMAC) with Cu2+, Ni2+, Co2+, and Zn2+ metal ions bound
to iminodiacetic acid (IDA) agarose. Under high salt conditions (500 mM
NaCl) tyrosinase was retained on all immobilized metal IDA resins. In
contrast, under low salt conditions (10 mM NaCl) tyrosinase was adsorbed
only onto Cu2+ IDA agarose. Yields of recovered enzyme were high, and
some of these IMAC resins removed contaminating proteins. The enzyme was
also adsorbed onto Cu2+ DEAE columns under low salt conditions but not
under high salt conditions. Although Cu2+ IDA columns have previously
been used to purify polyphenol oxidases from a variety of plants
sources, this is the first report of the use of other metal ions
chelated to IDA to bind this enzyme, and it is the first report showing
the effects of salt
concentration on binding of this enzyme to
IMAC resins.
Full Article
Abstract
In this
paper a discussion arises about causality in Relativity leading to argue
inherent issues.
After
that, by presenting formal analogies between General Relativity and
continuum lagrangian
description, there follows a hypothetical approach for deriving the
equations of gravitational
radiation
based on the application of the two fundamental quadratic forms of
Space-Time (see
equ.
(3.6)). Moreover, a technique of resolution is touched. As last
expectation, the paper would
want to
bring substantial novelties in matter of genesis and especially of
gravitational waves
Abstract
The emerging quantum
physics - quantum computing conceptual bridge, mandates a \grand uni-cation"
of space-time-matter and quantum information: an \all quantized" quantum
digital world. The present article suggests an equivalence principle, to
include space-time and entropy beyond Einstein's matter-energy uni
cation E = mc2
with the \ xed" correlation with space-time from general
relativity
G = T. It requires tripling time, not more space dimensions as in
String Theory, while complexifying the
energy-momentum tensor to include entropy, and nally unify space and
time by a generalized Wick rotation: an \external supersymmetry" which
trades parallel and sequential quantum computing relative to a
space-time coordinate system. The Feynman Path Integral algebraic
formalism already has a place for this, when interpreting entropy as a
measure of symmetry.
Full Article
Abstract
According to generally
accepted cosmological model, the universe is in a state of inflationary
and accelerating expansion. Almost all visible galaxies appear not only
to be moving away from us, as observed by Hubble at the beginning of the
last century, but they are accelerating. This is described as an
accelerating expansion of the space-time continuum where galaxies are
left as some sort of gravitational islands immune to this universal
effect. There is overwhelming observational evidence, which appears to
support this concept. However, is it possible to explain an accelerating
expansion as a contraction of the universe? Could it be possible that
our universe is in a state of free fall with gravitational acceleration?
Galactic clusters appear to dominate the Northern Galactic hemisphere
and the results of regression analyses performed
in this study indicate
statistically significant positive correlation between the maximum Log10
galactic rotation velocities and the Galactic latitudes (r=0.06,
p=0.001). The difference between the means of maximum Log10 rotation
velocities for distant galaxies in the Northern vs. the Southern
Galactic hemisphere is also statistically significant (t=2.58,
p=0.0049). This indicates that the universe does not appear to be
perfectly homogenous and isotropic in all directions. Based on the
observed complex galactic structure distribution and considering
currently available galactic rotation velocity and cosmic microwave
background (CMB) data, it is not impossible for the universe to be
contracting. Although our universe could still be expanding, rotating,
or even contracting, we have no sufficient scientific evidence to accept
a particular model as valid at this time. Limitations and uncertainties
associated with our study of the universe should be duly acknowledged.
Full Article
Boundaries of thermal stability of a vibrationally nonequilibrium
flowing gas considering constant energy pumping power
Salahdeen M. Younis
Abstract
The boundaries of
the existence of a vibrationally nonequilibrium gas was theoretically
studied. The gas was flowing in a circular tube with fixed surface
temperature and the nonequilibrium state was maintained by pumping
energy into the gas vibrational modes by an external source of power I.
Results showed that the gas vibrational energy ε increases by increasing
I to a certain maximum value Im above which ε took a fixed maximum value
εm and the gas got heated. The variation of εm with Reynolds number, the
density and type of the gas, the length and diameter of the tube was
determined.
Full Article
Abstract
Ag/Au alloy and Ag/Au core-shell nanoparticles (NPs)
stabilized by Generation 4 PAMAM
(Polyamidoamine) dendrimer were synthesized in aqueous solution. The
alloy was prepared by the reduction of mixtures of metal ions using
NaBH4. The plasmon resonance absorption bands of the mixture NPs were
red shifted as χAu increased indicating alloy formation. The
concentration dependent average diameter was 2.92 ±0.57 nm at χAu =
0.50. The core-shell composites were prepared by reducing Au+3 with
ascorbic acid in solution containing silver NPs seeds. The
characteristic surface plasmon absorption of silver NPs at about 400 nm
in the seed solution was progressively weakened with the incremental
addition of 0.1 mM HAuCl4 in the presence of ascorbic acid and
ultimately vanished completely. The disappearance of Ag plasmon
absorption was accompanied by the growth, intensification and red
shifting of gold NPs absorption reaching a λmax of 576 nm at χAu = 0.75.
HRTEM dark field mode image shows that core-shell composite NPs with
average diameter of 14.5 ±2.7 nm are produced, when Ag seeds are allowed
to stand 30 minutes at room temperature before capped with Au. Reducing
the standing time to 5 minutes, the average particle diameters decreases
to 6.2 ± 1.5 nm.
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