5,943 research outputs found
The Law of Conservation of Energy in Chemical Reactions
Earlier it has been supposed that the law of conservation of energy in
chemical reactions has the following form: DU=DQ-PDV+SUM(muiDN) In the present
paper it has been proved by means of the theory of ordinary differential
equations that in the biggest part of the chemical reactions it must have the
following form: DU=DQ+PDV+SUM(muiDN) The result obtained allows to explain a
paradox in chemical thermodynamics: the heat of chemical processes measured by
calorimetry and by the Vant-Hoff equation differs very much from each other.
The result is confirmed by many experiments.Comment: e-mail me [email protected], 10 page
The Heats of Dilution. Calorimetry and Van't-Hoff
Earlier it has been found that there is a big difference between heats of
dilution measured by calorimetry and by the Van't-Hoff equation. In the present
paper a reason for that is proposed. Experimental data for dilution of benzene
and n-hexane in water were used.Comment: e-mail me [email protected], 6 page
Dependence of the Energy of Molecules on Interatomic Distance at Large Distances
Earlier it has been supposed that energy of molecules depends on interatomic
distance according to the curve 1, Fig. 1. However, dissociation of molecules
(for example, Te2=2Te) often is a chemical reaction. According to chemical
kinetics, chemical reactions overcome a potential barrier. This barrier is
absent at the curve 1. It is a very strong argument against the curve 1. It is
shown that the molecule energy dependence on interatomic distance can behave at
large distances not so but like the curve 2, Fig. 1. Earlier it has been
supposed that quantum chemical methods give a wrong result at big distances if
the wave function does not turn to zero. In this paper, it is been shown that
it must not turn to zero. The wave function can be a piecewise function.Comment: e-mail me [email protected], 6 pages; accepted at 32nd EGAS
Conference, Vilnius, 200
The 1st Law of Thermodynamics in Chemical Reactions
In the previous papers of the author it has been shown that the 1st law of
thermodynamics in chemical reactions is the following one: dU=dQ+PdV+SUM In the
present paper this theory was developed and it has been shown that the 1st law
of thermodynamics in chemical reactions has the following form: dC=-dU+dA and
-dU=dQ where dC is the change in the chemical energy, dU is the change in the
internal energy. Internal energy is the energy of thermal motion of molecules.Comment: e-mail me [email protected], 6 page
Thermodynamics of Substances with Negative Thermal Expansion Coefficient
The 1st law of thermodynamics for heat exchange is dQ=dU+PdV. According to K.
Martinas etc., J. Non-Equil. Thermod. 23 (4), 351-375 (1988), for substances
with negative thermal expansion coefficient, P in this law is negative. In the
present paper it has been shown that P for such substances is positive but the
sign before P must be minus not plus: dQ=dU-PdV.Comment: There was a misprint in Eq. (11), e-mail me [email protected], 7
page
Smooth 3-dimensional canonical thresholds
If is an algebraic variety with at worst canonical singularities and
is a \Q-Cartier hypersurface in , the canonical threshold of the pair
is the supremum of such that the pair is canonical.
We show that the set of all possible canonical thresholds of the pairs ,
where is a germ of smooth 3-dimensional variety, satisfies the ascending
chain condition. We also deduce a formula for the canonical threshold of
(\C^3,S), where S is a Brieskorn singularity.Comment: Dedicated to the memory of my advisor Vasilii Alekseevich Iskovskikh.
14 pages; v3: minor correction
Non-rational divisors over non-Gorenstein terminal singularities
Let be a germ of a 3-dimensional terminal singularity of index . If has type cAx/4, cD/3-3, cD/2-2, or cE/2, then assume that the
standard equation of in is non-degenerate with
respect to its Newton diagram. Let be a resolution. We show
that there are not more than 2 non-rational divisors , , on
such that and discrepancy . When such divisors
exist, we describe them as exceptional divisors of certain blowups of and
study their birational type.Comment: 17 pages, LaTeX2
Combinatorial structure of exceptional sets in resolutions of singularities
The dual complex can be associated to any resolution of singularities whose
exceptional set is a divisor with simple normal crossings. It generalizes to
higher dimensions the notion of the dual graph of a resolution of surface
singularity. The homotopy type of the dual complex does not depend on the
choice of a resolution and thus can be considered as an invariant of
singularity. In this preprint we show that the dual complex is homotopy trivial
for resolutions of 3-dimensional terminal singularities and for resolutions of
Brieskorn singularities. We also review our earlier results on resolutions of
rational and hypersurface singularities.Comment: 18 pages; to appear as a preprint of the Max-Planck-Institut, Bon
Full perturbation solution for the flow in a rotated torus
We present a perturbation solution for a pressure-driven fluid flow in a
rotating toroidal channel. The analysis shows the difference between the
solutions of full and simplified equations studied earlier. The result is found
to be reliable for {\it low} Reynolds number () as was the case for a
previously studied solution for high . The convergence conditions are
defined for the whole range of governing parameters. The viscous flow exhibits
some interesting features in flow pattern and hydrodynamic characteristics.Comment: 4 pages, 6 figure
Observability of B_(d)s-> mu mu decay with the CMS detector
We have updated our previous study on the possibility to observe the rare
B0_s -> 2mu decay with detailed simulation of the TDR version of the CMS
detector. The full simulation and reconstruction procedure has been done both
for the signal and background. We improved our previous results on expected
sensitivity using more sophisticated algorithms for the track and vertex
reconstruction and tighter selection criteria
- β¦