 |
 |
[4] viXra:2006.0239 [pdf] submitted on 2020-06-26 08:11:40
Authors: Sosale Chandrasekhar
Comments: Pages.
It is argued that the conventional view of the Gibbs free energy apparently contravenes the first law of thermodynamics because of the temperature dependence of the entropy term therein. Thus, the yield of the Gibbs free energy in a system undergoing change is not constant, hence implying that energy is being created or destroyed in the process. The ambiguity can be traced to the entropy concept of the original Carnot theorem, which is manifestly dubious and illusory, as argued previously. Unrelatedly, the nuclear fusion controversy is explored in terms of chemical potential changes, arguing that fusion would be viable—if at all—in a closed equilibrium reactor: in the absence of this constraint, fusion runs afoul of mass-energy equivalence. (This also has devastating implications for the stability of the material universe.) It is also most intriguing that nuclear fusion was initially proposed as the origin of solar energy, and appears to have predated the theory of nuclear structure.
Category: Chemistry
[3] viXra:2006.0238 [pdf] submitted on 2020-06-26 08:13:09
Authors: Sosale Chandrasekhar
Comments: 6 Pages.
It is argued that the key concepts of quantum theory—Planck’s quantum proposal, de Broglie’s wave–particle dualism and Schrödinger’s wave function idea—are neither incontestable nor integrated seamlessly into the fabric of quantum theory. In fact, it is doubtful whether classical wave treatments can serve as the basis for analysing (purported) matter waves at all. Also, an element of circular reasoning apparently surrounds the wave function concept, as the Hamiltonian-based Schrödinger equation is constrained to lead to the discrete solutions that represent quantization. These ambiguities appear particularly damning against the backdrop of the dubious Rayleigh–Jeans–Planck analysis of black body radiation, and the discredited evidence for the wave theory of radiation (based on purported diffraction phenomena). These considerations raise intriguing questions about the role of mathematical modelling in the study of natural phenomena (not to mention certain pedagogical quandaries). Thus, quantum theory—cloaked though it is in forbidding mathematical rigor—must submit to a dispassionate analysis of its extent and compass, particularly in view of its ostensible subversion of common-sense notions of reality.
Category: Chemistry
[2] viXra:2006.0154 [pdf] submitted on 2020-06-17 10:59:00
Authors: Sosale Chandrasekhar
Comments: 3 Pages.
The titled concept has not been broached so far, and arises from the fact that bond angle strain increases as the square of the concerned angle (torsional strain also behaving similarly). Macrocyclic systems can thus accumulate less overall strain than smaller systems, whether in the ground state or transition state. Although strain delocalisation is generally overridden by forbidding entropic barriers in macrocyclization reactions, strain delocalisation may well be important in enzyme catalysis. This is because entropic effects are largely minimised within the organized interior of an enzyme molecule, so that preferred reaction trajectories are more easily achieved. (Strain delocalisation would also play a role in duplex formation in nucleic acids.)
Category: Chemistry
[1] viXra:2006.0051 [pdf] submitted on 2020-06-06 12:08:25
Authors: R. Köferstein
Comments: Pages. The paper was published in: Journal of Alloys and Compounds 590 (2014) 324–330. DOI: 10.1016/j.jallcom.2013.12.120
The preparation of phase-pure nano-sized BiFeO3 by a combustion-like method using starch as complexing agent is described herein. Phase evolution and development of the crystallite size during the synthesis were monitored depending on the heat treatment and the composition of the (BiFe)-gels. Phase-pure BiFeO3 was obtained at a low heating rate and calcination temperatures between 500 and 600 °C. Above 600 °C the BiFeO3 gradually decomposed to Bi25FeO40 and Bi2Fe4O9. The investigations showed that the appearance of
secondary phases depends on the heating rate, calcination temperature, and the fuel to
oxidizer ratio in the (BiFe)-gel. The use of HNO3 instead of acetic acid in the preparation of the (BiFe)-gel promotes the formation of secondary phases. To study the phase stability the
phase-pure BiFeO3 powder (1c) obtained after calcining at 550 °C (dcryst = 37 nm) was
sintered to ceramic bodies up to 800 °C. During sintering the BiFeO3 phase decomposed to
Bi25FeO40 and Bi2Fe4O9 gradually. The activation energy for the decomposition process
during sintering was calculated to 337±19 kJ/mol using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) model. Magnetic measurements on phase-pure BiFeO3 powders show maximal magnetization of about 0.7 emu/g at 90 kOe and coercivities between 5−7 kOe at 300 K. Investigations at 10 K reveal a loop shift (exchange-bias) up to 2.9 kOe in the negative direction. The optical band gaps of the phase-pure BiFeO3 powders were determined as
2.28(4) eV.
Category: Chemistry
| Third-Party Links: |
|