Previous months:
2008 - 0808(1)
2010 - 1003(2) - 1008(1) - 1011(1)
2012 - 1204(1) - 1208(1) - 1209(1) - 1210(1) - 1212(3)
2013 - 1301(5) - 1302(2) - 1303(14) - 1304(4) - 1305(1)
Any replacements are listed further down
[38] viXra:1305.0139 [pdf] submitted on 2013-05-23 07:04:36
Authors: Sierra Rayne
Comments: 1 Page.
In their study, Wang et al. [Environ. Chem. 2011, 8, 389] use the COSMOtherm software program in an attempt to shed some insights into the physicochemical properties of various poly- and perfluorinated compounds. During the conformation dependent pKa investigations on n-perfluorooctanoic acid (PFOA), the authors appear to make a critical error in their analyses. Wang et al. appear to have allowed a transition from an acid form geometry to a very different anionic form geometry, which is not a correct way of calculating free energy changes during acid dissociation. This error explains why these authors obtained widely ranging conformation dependent pKa values (0.9 to 2.9) for PFOA dissociation. As has been previously shown [Rayne and Forest, J. Mol. Struc. THEOCHEM 2010, 949, 60], there are negligible conformation dependent effects on the pKa value of PFOA.
Category: Chemistry
[37] viXra:1304.0123 [pdf] submitted on 2013-04-22 22:24:14
Authors: Sierra Rayne
Comments: 2 Pages.
In their manuscript, Gramatica et al. [Mol. Inf. 2012, 31, 817-835] claim to conduct quantitative structure-activity relationship (QSAR) modeling on a suite of triazoles, benzotriazoles, and additional azo-aromatic compounds. However, a number of the compounds examined by these authors do not appear to be triazoles, benzotriazoles, or other azo-aromatic compounds. In some cases, the authors also appear to publish incorrect molecular structures which may affect the structural descriptors employed for QSAR development.
Category: Chemistry
[36] viXra:1304.0015 [pdf] submitted on 2013-04-03 21:56:39
Authors: Sierra Rayne
Comments: Pages.
In their article, Bronner and Goss [Environ. Sci. Technol., 2011, 45, 1307-1312] investigate the pH dependence of organic chemical sorption to soil organic matter. The authors report a log Koc value for benzoyl chloride in aqueous solution, despite this compound having a known hydrolysis half-life of only 16 seconds in water. This timeframe is far too short to allow the measurement of any equilibrium based partitioning coefficients. Consequently, one suspects that the log Koc value reported for benzoyl chloride is likely that of its hydrolysis product: benzoic acid. The authors also may have chosen two experimental conditions (pH 4.5 and 7.2) between which the ionization state of the carboxylic acids in the organic matter may have changed very little, and could instead have remained in effectively the same net ionization state between the two experimental pH endpoints. Thus, there does not appear to be sufficient evidence in this work to support the general claim therein that "protonation/deprotonation of carboxylic groups in humic matter has no significant influence on sorption ... even for polar organic molecules."
Category: Chemistry
[35] viXra:1304.0014 [pdf] submitted on 2013-04-03 22:15:51
Authors: Sierra Rayne
Comments: Pages.
In their article, Sacan et al. [J. Chem. Inf. Comput. Sci. 2004, 44, 985-992] construct a quantitative structure-property relationship model to predict the bioconcentration factors of purportedly nonionic organic compounds. A number of the compounds examined by these authors are not nonionic as claimed, but instead have associated pKa values that would render the molecules significantly, and - in some cases - effectively entirely, ionized under conditions relevant for bioconcentration in freshwater and/or marine aquatic systems.
Category: Chemistry
[34] viXra:1304.0007 [pdf] submitted on 2013-04-01 16:57:34
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Gotz et al. [Environ. Sci. Technol., 2008, 42, 3690-3696] use three different multimedia contaminant fate models to analyze the impact of implementing a two-particle-size polyparameter linear free energy relationship approach on metrics of persistence and long-range transport, and on calculated concentrations of semivolatile organic chemicals in the Arctic. One of the twelve compounds investigated is 2,4-D (2,4-dichlorophenoxyacetic acid), which is effectively entirely dissociated in aqueous systems. The authors do not appear to have considered the ionization of 2,4-D during their multimedia modeling exercises, particularly the effects of ionization on octanol-water and air-water partitioning behavior. Consequently, all modeling results presented for 2,4-D appear to be in significant error and should not be employed for risk assessment purposes.
Category: Chemistry
[33] viXra:1303.0200 [pdf] submitted on 2013-03-26 11:45:33
Authors: Sierra Rayne
Comments: 2 Pages.
In their article, Arnot and Mackay [Environ. Sci. Technol., 2008, 42, 4648-4654] use 200 chemicals from the Canadian Domestic Substances List (DSL) to illustrate a model that integrates persistence, bioaccumulation, toxicity, and quantity information for a specific substance to assess chemical exposure, hazard, and risk. The authors claim that the DSL chemicals used in their study are not expected to appreciably ionize at environmental pH. In contrast, a number of the compounds in this study have ionizable functional groups with environmentally relevant pKa values, meaning the corresponding partitioning properties are highly pH dependent, thereby rendering the modeling approach applied by these authors subject to a fatal conceptual and practical flaw. In addition, several compounds in the authors' dataset are expected to hydrolyze rapidly in aquatic systems, resulting in negligible environmental persistence.
Category: Chemistry
[32] viXra:1303.0199 [pdf] submitted on 2013-03-26 12:51:25
Authors: Andrew Nassif
Comments: 3 Pages. This report is part of a series I am doing on science which will later be published into a book. This is part 1.
Henry Louis Le Chatelier was one of the most influential chemists of all time. This paper will guide you to his greatest discovery in the world of physics and chemistry.
Category: Chemistry
[31] viXra:1303.0175 [pdf] submitted on 2013-03-23 21:55:23
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Qin et al. [Mol Divers (2010) 14:67-80] construct a quantitative structure-property relationship model to predict the bioconcentration factors of purportedly nonpolar organic compounds. A number of the compounds examined by these authors are not nonpolar as claimed, but instead have associated pKa values that would render the molecules significantly, and - in some cases - effectively entirely, ionized under conditions relevant for bioconcentration in freshwater and/or marine aquatic systems.
Category: Chemistry
[30] viXra:1303.0162 [pdf] submitted on 2013-03-21 22:19:09
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Endo and Goss [Chem. Res. Toxicol. 2011, 24, 2293-2301] claim to measure the bovine serum albumin water partition coefficients for 83 structurally diverse neutral organic chemicals and correlate the resulting values against corresponding octanol-water partition coefficients and polyparameter linear free energy relationship models based on descriptors for the neutral forms of each compound. However, several compounds in the authors' dataset would be significantly ionized under the experimental conditions being modeled against, and such ionization must be accounted for in any serum albumin binding modeling efforts.
Category: Chemistry
[29] viXra:1303.0150 [pdf] submitted on 2013-03-20 14:07:39
Authors: Sierra Rayne
Comments: 3 Pages.
In their article, Charif et al. [J. Mol. Struct. THEOCHEM 818 (2007) 1] used the B3LYP/6-311++G(d,p) density functional level of theory to estimate gas phase standard state (298.15 K, 1 atm) free energies of acid dissociation (ΔacidG°(g)) for 21 carbon acids. These authors then examined correlations between their B3LYP/6-311++G(d,p) ΔacidG°(g) values and corresponding experimental aqueous pKa measurements. Large errors are evident between experimental values and the B3LYP/6-311++G(d,p) calculated ΔacidG°(g) for propanedioic acid, diethyl ester, dimedone, isopropylidene malonate, barbituric acid, and toluene from this study. The findings call into question the generality of the correlation between ΔacidG°(g) and aqueous experimental pKa values for carbon acids proposed by Charif et al., and also highlight the need for additional studies to investigate what other carbon acid moieties may be outliers. In the present case, either the experimental aqueous pKa of toluene in the literature is incorrect, or the quantitative structure-property relationship proposed in Charif et al. is subject to large outliers that greatly diminish its broad applicability.
Category: Chemistry
[28] viXra:1303.0148 [pdf] submitted on 2013-03-20 10:08:12
Authors: Sierra Rayne
Comments: Pages.
In their article, Montero-Campillo et al. [J. Phys. Chem. A, 114 (2010) 10148-10155] use the B3LYP density functional with the 6-311+G(d,p) basis set to calculate the relative thermodynamic stabilities of the 89 linear and branched perfluorooctane sulfonic acid (PFOS) isomers in their molecular acid and dissociated anionic forms for the gas phase and aqueous and n-octanol solvent phases. A substantial body of work over the past decade has clearly demonstrated the inability of the B3LYP functional (and the majority of other widely employed density functionals) to accurately represent the relative thermodynamic stabilities of linear and branched alkanes (including perhydro, poly- and perhalogenated, and other functionalized derivatives). It has been specifically demonstrated using a range of theoretical methods (semiempirical, Hartree-Fock [HF], various density functionals, and second order Moller-Plesset perturbation theory) that the B3LYP branching error for perhydroalkane isomerizations also applies to perfluoroalkanes, and particularly to classes of compounds such as the 89 PFOS isomers, as well as the perfluoroalkanoic acids and perfluoralkyl sulfonyl/acyl fluorides in their acid and (where applicable) anionic forms. Consequently, the relative thermodynamic stabilities of the molecular acid and anionic PFOS isomers at the B3LYP/6-311+G(d,p) level of theory put forward by Montero-Campillo et al. are in substantial error, and the authors and readers are referred elsewhere to more accurate calculations.
Category: Chemistry
[27] viXra:1303.0142 [pdf] submitted on 2013-03-19 11:08:41
Authors: Sierra Rayne
Comments: Pages.
In their work, Hu et al. [Environ. Sci. Technol., 2011, 45, 3635-3642] investigate the oxidation of three antibiotics (ciprofloxacin, lincomycin, and trimethoprim) by potassium permanganate in buffered solutions at pH 7. The authors propose detailed mechanistic pathways for the oxidation of these substrates, but apparently do not consider the acid/base behavior of the compounds under consideration, resulting in erroneous mechanistic interpretations throughout the manuscript.
Category: Chemistry
[26] viXra:1303.0141 [pdf] submitted on 2013-03-19 11:46:07
Authors: Sierra Rayne
Comments: 1 Page.
In his article, Gharagheizi [Ind. Eng. Chem. Res. 2012, 51, 2797-2803] claims to develop a novel three-parameter equation for the calculation/prediction of the diffusion coefficient of nonelectrolyte organic compounds in water at infinite dilution. In contrast, many of the compounds investigated in this work are electrolytes in pure water at infinite dilution. Consequently, the molecular modeling efforts on the non-ionized molecular speciation of each compound were - in many cases - conducted on species that would not be dominantly present under the experimental conditions the modeling efforts are being developed against.
Category: Chemistry
[25] viXra:1303.0103 [pdf] submitted on 2013-03-14 09:47:34
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Wong and Wania [J. Environ. Monit., 2011, 13, 1569-1578] claim to estimate the partitioning properties (air-water partition coefficients and soil organic carbon-water partition coefficients) of twenty neutral organic chemicals using poly-parameter linear free energy relationships. Five of the 20 compounds in this study have ionizable functional groups with environmentally relevant pKa values, meaning the corresponding partitioning properties are highly pH dependent, thereby rendering the modeling approach applied by these authors subject to a fatal conceptual and practical flaw.
Category: Chemistry
[24] viXra:1303.0093 [pdf] submitted on 2013-03-12 22:54:13
Authors: Sierra Rayne
Comments: 1 Page.
In their article, DeBruyn and Gobas [2007. Environ Toxicol Chem 26:1803-1808] claim to "present a compilation and meta-analysis of published data to estimate the relative sorptive capacities of animal proteins and lipids for neutral organic chemicals." However, the dataset of these authors contains compounds that would be effectively entirely ionized at physiological pH values, rendering the assumption of neutrality and any subsequent analyses based thereupon incorrect.
Category: Chemistry
[23] viXra:1303.0073 [pdf] submitted on 2013-03-09 20:47:12
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Bhhatarai and Gramatica [Water Res. 45, 2011, 1463-1471] employ a quantitative structure-property relationship approach to model the physico-chemical properties of compounds they refer to as benzotriazoles, and to subsequently screen these compounds for environmental partitioning behavior. A substantial number of these compounds are not benzotriazoles and do not have similar properties as benzotriazoles. Consequently, it appears that the approach, assumptions, and results in this work must be viewed as potentially fundamentally flawed.
Category: Chemistry
[22] viXra:1303.0071 [pdf] submitted on 2013-03-09 22:03:28
Authors: Sierra Rayne
Comments: 1 Page.
In their study, Bhhatarai et al. [Mol. Inf. 2010, 29, 511-522] develop quantitative structure-activity relationships (QSARs) for the inhibition of HIV protease by 158 so-called 4-OH cycloalkyl-pyranones. A number of compounds termed 4-OH cycloalkyl-pyranones in this work do not appear to be cycloalkyl-pyranones.
Category: Chemistry
[21] viXra:1303.0070 [pdf] submitted on 2013-03-09 14:53:05
Authors: Sierra Rayne
Comments: 1 Page.
In their article, Yemis and Mazza [Yemis and Mazza, 2011, Bioresour. Technol. 102, 7371-7378] study the effects of different Bronsted acids, temperatures, times, substrate concentrations, and pH on the acid-catalyzed conversion of xylose, xylan and straw into furfural by microwave-assisted reaction. The authors appear to incorrectly classify phosphoric acid as a mineral acid, and claim to achieve pH values in solutions of acetic and formic acid below the apparent theoretical limits.
Category: Chemistry
[20] viXra:1303.0044 [pdf] submitted on 2013-03-07 09:55:14
Authors: Ana L. Teixeira, João P. Leal, Andre O Falcao
Comments: 26 Pages.
Stereoisomers have the same molecular formula and the same atom connectivity and their existence can be related to the presence of different three-dimensional arrangements. Stereoisomerism is of great importance in many different fields since the molecular properties and biological effects of the stereoisomers are often significantly different. Most drugs for example, are often composed of a single stereoisomer of a compound, and while one of them may have therapeutic effects on the body, another may be toxic. A challenging task is the automatic detection of stereoisomers using line input specifications such as SMILES or InChI since it requires information about group theory (to distinguish stereoisomers using mathematical information about its symmetry), topology and geometry of the molecule. There are several software packages that include modules to handle stereochemistry, especially the ones to name a chemical structure and/or view, edit and generate chemical structure diagrams. However, there is a lack of software capable of automatically analyzing a molecule represented as a graph and generate a classification of the type of isomerism present in a given atom or bond. Considering the importance of stereoisomerism when comparing chemical structures, this report describes a computer program for analyzing and processing steric information contained in a chemical structure represented as a molecular graph and providing as output a binary classification of the isomer type based on the recommended conventions. Due to the complexity of the underlying issue, specification of stereochemical information is currently limited to explicit stereochemistry and to the two most common types of stereochemistry caused by asymmetry around carbon atoms: chiral atom and double bond.
A Webtool to automatically identify and classify stereochemistry is available at http://nams.lasige.di.fc.ul.pt/tools.php
Category: Chemistry
[19] viXra:1302.0069 [pdf] submitted on 2013-02-11 22:15:01
Authors: Vadim V Nazarenko
Comments: 99 Pages.
DENSITY FUNCTIONAL THEORY (DFT) INVESTIGATION OF RSNNSR SYSTEMS
The structural variations and stabilities of RSNNSR systems were studied using the hybrid density functional theory (B3LYP) at various basis set levels. Computational methodology was based on the locally dense basis set approach (LDBS) that assigns various levels of the basis sets accordingly to the previously calibrated results that could be correlated to the experimental data.
The present study investigated the effect of the substituents (R) on the structure and the stabilities of RSNNSR systems. There were totally ten systems studied where R: H, CH3, CF3, tert-Butyl, C6H6, p-NO2C6H6 , p-CH3OC6H6.
The calculations revealed that the stability of the S-N bond is enhanced if there is a combination of the electron-releasing effect and the electron-withdrawing one that creates a push-pull effect (captodative effect) in the system. An increase of a positive charge on one of the sulfur atoms and a negative charge on the adjacent nitrogen atom increases delocalization of one the S’s lone pairs that creates a conjugation with the neighboring N atom and the β carbons through 2pπ-3pπ interactions.
The push-pull effect also influenced structural characteristics of the systems. One of the most notable ones is the variation of the NSCC dihedral angle in some of our systems from 89° to 21°
Category: Chemistry
[18] viXra:1302.0021 [pdf] submitted on 2013-02-04 11:10:19
Authors: Ana L. Teixeira, Rui C. Santos, João P. Leal, José A. Martinho Simões, Andre O. Falcao
Comments: 26 Pages.
Standard enthalpies of formation are used for assessing the efficiency and safety of
chemical processes in the chemical industry. However, the number of compounds for
which the enthalpies of formation are available is many orders of magnitude smaller
than the number of known compounds. Thermochemical data prediction methods are
therefore clearly needed. Several commercial and free chemical databases are
currently available, the NIST WebBook being the most used free source.
To overcome this problem a cheminformatics system was designed and built with two
main objectives in mind: collecting and retrieving critically evaluated thermochemical
values, and estimating new data. In its present version, by using cheminformatics
techniques, ThermInfo allows the retrieval of the value of a thermochemical property,
such as a gas-phase standard enthalpy of formation, by inputting, for example, the
molecular structure or the name of a compound. The same inputs can also be used to
estimate data (presently restricted to non-polycyclic hydrocarbons) by using the
Extended Laidler Bond Additivity (ELBA) method. The information system is
publicly available at http://www.therminfo.com or http://therminfo.lasige.di.fc.ul.pt.
ThermInfo’s strength lies in the data quality, availability (free access), search
capabilities, and, in particular, prediction ability, based on a user-friendly interface that
accepts inputs in several formats.
Category: Chemistry
[17] viXra:1301.0179 [pdf] submitted on 2013-01-29 12:08:33
Authors: Andrew Nassif
Comments: 3 Pages.
Chemistry requires lots of conceptual thinking as well as analytical actions. Chemistry is a science of measurement. Like physics, it also requires much mathematical sequences in it. Chemistry is the bridge of science, because it is a sub-subject of every major field of science including physics and geology. Boyle describes chemistry as the subject of major bodies. Chang describes chemistry as the study of matter and the changes it undergoes. Chang's definition, is the most commonly used today. Chemistry was thought to be created by the greeks (atomism), however, it was created hundreds of years before as a way ancient Egyptians used herbs to create a remedy, or used the science of proper mechanics to build the pyramids using a special chemical combination as the glue that held bricks together. Cleopatra herself was an alchemist.
Category: Chemistry
[16] viXra:1301.0177 [pdf] submitted on 2013-01-28 14:28:07
Authors: Sierra Rayne, Kaya Forest
Comments: 22 Pages.
Gas to aqueous phase standard state (1 atm to 1 mol/L; 298.15 K) free energies of solvation (ΔGosolv) were calculated for a range of neutral and ionic inorganic and organic compounds using various levels and combinations of Hartree-Fock and density functional theory (DFT) and composite methods (CBS-Q//B3, G4MP2, and G4) with the IEFPCM-UFF, CPCM, and SMD solvation models in Gaussian 09 (G09). For a subset of highly polar and generally polyfunctional neutral organic compounds previously identified as problematic for prior solvation models, we find significantly reduced ΔGosolv errors using the revised solvent models in G09. The use of composite methods for these compounds also substantially reduces their apparent ΔGosolv errors. In contrast, no general level of theory effects between the B3LYP/6-31+G** and G4 methods were observed on a suite of simpler neutral, anionic, and cationic molecules commonly used to benchmark solvation models. Further investigations on mono- and polyhalogenated short chain alkanes and alkenes and other possibly difficult functional groups also revealed significant ΔGosolv error reductions by increasing the level of theory from DFT to G4. Future solvent model benchmarking efforts should include high level composite method calculations to allow better discrimination of potential error sources between the levels of theory and the solvation models.
Category: Chemistry
[15] viXra:1301.0149 [pdf] submitted on 2013-01-24 13:15:06
Authors: Andrew Nassif
Comments: 5 Pages.
Chemistry is a branch of physical science that has to do with the study of the composition of matter and the study of everything composed of matter as well as based on the basis of atomism, fluid dynamics, and particle physics, as well as the action of measurements applied as a stoichiometry and a method in using chemistry. Chemistry in basically the central science, though it may be a branch of physical science, it is very distinct from physics. The world chemistry itself comes from the word alchemy which is derived from لكيمياء which is then derived from the greek word χημεία, this means he study of material, which is then translated to being the study of everything composed of matter. Ancient Egyptians themselves used synthetic chemistry as a study of herbs as well as using this branch of chemistry to help them plant crops in the fertile crust. Democritus's theory of atomism became the foundation of chemistry and elementary physics itself. Eventually Atomism brought forth ideas of models of the atoms around us and many generations later, the Quantum Mechanical Model was born. This is how the fundamental of chemistry came to be.
Category: Chemistry
[14] viXra:1301.0069 [pdf] submitted on 2013-01-12 12:39:20
Authors: Sierra Rayne, Kaya Forest
Comments: 2 Pages.
The partitioning behavior of disparlure ((7R,8S)-7,8-epoxy-2-methyloctadecane) - a sex pheromone of the gypsy moth, Lymantria dispar - between aqueous solutions and the organic solvents chloroform and n-heptane has been re-evaluated. Prior estimates from the literature of the aqueous-organic solvent partitioning coefficients (log P) for disparlure in these two solvent systems appear to have been underestimated by about 5-6 orders of magnitude. In the current work, we provide corrected log P(chloroform/water) and log P(heptane/water) values for disparlure of 9.87 and 9.15, respectively.
Category: Chemistry
[13] viXra:1301.0039 [pdf] submitted on 2013-01-07 12:08:49
Authors: Andrew Nassif
Comments: 4 Pages.
Element must be heated to produce emitted light, this is due to its chemical reaction caused by
absorbed energy, which is required in order to emit light. This is why elements acquire being
heated in order to emit light. Sometimes absorbed energy can cause electromagnetic radiation,
also these spectrums are different waves of lights due to the different energy levels of a chemical
reaction.
Category: Chemistry
[12] viXra:1212.0152 [pdf] submitted on 2012-12-26 20:21:48
Authors: Chun-Xuan Jiang
Comments: 5 Pages.
using mathematical method we prove that there are only 92 stable elements in nature and obtain the correct valence electron configurations of the elements.In Mendeleev periodic table the elements(1-18,29-36 and 46)have correct valence electron configurations and the elements(19-28,37-45 and 47-92)have wrong valence electron configurations.
Category: Chemistry
[11] viXra:1212.0097 [pdf] submitted on 2012-12-16 14:44:57
Authors: Sierra Rayne
Comments: 5 Pages.
In an earlier study (Kelly et al., PNAS, 2009, 106, 22346-22351), spatial patterns for the concentrations of particulate matter, particulate polycyclic aromatic compounds (PAC), and dissolved PAC in the snowpack around the Syncrude and Suncor upgrader facilities near the oil sands development at Fort McMurray, Alberta, Canada were determined. A reassessment of the datasets employed in this work yields significantly different deposition rates (by up to an order of magnitude) than reported, as well as reveals substantial sensitivity in deposition rate estimates depending on a range of equally valid regression types chosen. A high degree of uncertainty remains with regard to the quantities of particulate matter and PAC being deposited in the Athabasca River watershed from oil sands related activities.
Category: Chemistry
[10] viXra:1212.0031 [pdf] submitted on 2012-12-04 14:23:18
Authors: Filippo Busolo
Comments: 9 Pages.
Three new C60–end-capped molecular wires for molecular electronics were prepared, characterized and studied by cyclic voltammetry.
Category: Chemistry
[9] viXra:1210.0102 [pdf] submitted on 2012-10-19 02:55:41
Authors: Sosale Chandrasekhar
Comments: 18 Pages.
Macromolecular aggregation and mechanical strength characterize polymer behavior, but apparently remain enigmatic: small molecules prefer to be solvated but macromolecules prefer to aggregate. This is a consequence of the enormous loss of solvent entropy attending macromolecular solvation. The additivity of weak (e.g., van der Waals) forces in a macromolecule cannot explain aggregation, as the accompanying entropy loss would also be additive. However, even this would be overshadowed by the loss of solvent entropy in the case of its solvation. A thermodynamic basis for the aggregation, however, needs a reassessment of the van der Waals equation of state, a reinterpretation of the coefficient ‘a’ suggesting that the van der Waals force may be stronger (~15 kcal mol--1) than believed. Its manifestation is normally thwarted by the dominance of entropic effects in the weak interactions. The phenomenal mechanical properties of polymers are explicable by the above reassessment of current ideas.
Category: Chemistry
[8] viXra:1209.0055 [pdf] submitted on 2012-09-18 12:02:35
Authors: Mohit Kumar
Comments: 2 Pages.
Petrol, diesel and kerosene are important hydrocarbons which are widely used in different form in our life. The manufacture of hydrocarbons, such as petroleum, form paraffin is familiar commercial process. However, this process is very costly, involves elaborate method and is time consumable. Consequently, this process does not seem to be economically viable.
Category: Chemistry
[7] viXra:1208.0026 [pdf] submitted on 2012-10-01 12:44:19
Authors: Ray Hefferlin
Comments: 9 Pages. May appear in Int. J. Mol. Model, Vol 4, #1
Combined least-squares and neural-network forecasts for internuclear separations of main-group diatomic molecules, most with from 9 to 12 atomic valence electrons, are presented. We require that the standard-deviation bounds of the forecasts overlap each other; this requirement is met by 65 molecules, of which 46 seem not to have been studied previously. The composite errors average 0.1036Å on either side of the composite predictions. There is agreement with 33 of 41 independent test data (80.5%), and those not in agreement fall outside the composite error limits by an average of 1.83%.
Category: Chemistry
[6] viXra:1204.0075 [pdf] submitted on 2012-04-18 06:01:16
Authors: Sosale Chandrasekhar
Comments: 15 Pages.
The key assumption of activated complex theory (ACT), that the AC is in thermodynamic equilibrium with the reactants, needs to be reconsidered. This is because the formation of the AC is slower than its collapse to product. However, this can be remedied by assuming that the AC is formed in a rapid pre-equilibrium as a thermally activated species, which collapses to products in a slow step involving the diffusion of another AC molecule (or solvent in the case of a unimolecular reaction). This implies a violation of the principle of microscopic reversibility (PMR), as also the relation between standard free energy change and equilibrium constant (ΔGo = -RTlnK). However, it may be argued that not only do these not apply to processes performed irreversibly, but also that irreversibility requires the breakdown of the PMR. Accordingly, catalysts may alter equilibrium constants, and enzymes may regulate biochemical processes in hitherto unsuspected ways.
Category: Chemistry
[5] viXra:1011.0060 [pdf] submitted on 24 Nov 2010
Authors: Omar Yépez
Comments: 12 pages
The hypertorus electron model is applied to the chemical bond. As a consequence,
the bond topology can be determined. A linear correlation is found between the
normalized bond area and the bond energy. The normalization number is a whole number.
This number is interpreted as the Lewis's electron pair. A new electron distribution
in the molecule follows. This discovery prompts to review the chemical bond, as it is
understood in chemistry and physics.
Category: Chemistry
[4] viXra:1008.0016 [pdf] submitted on 7 Aug 2010
Authors: Chun-Xuan Jiang
Comments: 7 Pages.
It has been proved that the 5g = 18 is unstable, the heaviest element that occurs
naturally is uranium with an atomic number of 92 and the island of stability does not
exist using the modified Pauli principle. This is the Book proof.
Category: Chemistry
[3] viXra:1003.0099 [pdf] submitted on 6 Mar 2010
Authors: W. B. Vasantha Kandasamy, Florentin Smarandache
Comments: 126 pages
Industrial Biotechnology is an interdisciplinary topic to which
tools of modern biotechnology are applied for finding proper
proportion of raw mix of chemicals, determination of set points,
finding the flow rates etc., This study is significant as it results
in better economy, quality product and control of pollution. The
authors in this book have given only methods of industrial
biotechnology mainly to help researchers, students and chemical
engineers. Since biotechnology concerns practical and diverse
applications including production of new drugs, clearing up
pollution etc. we have in this book given methods to control
pollution in chemical industries as it has become a great health
threat in India. In some cases, the damage due to environmental
pollution outweighs the benefits of the product.
Category: Chemistry
[2] viXra:1003.0090 [pdf] submitted on 8 Mar 2010
Authors: Florentin Smarandache, V. Christianto
Comments: 9 pages
In this paper, we describe a very simple experiment with distilled water which
could exhibit anomalous potential electrical energy with very minimum preparation
energy. While this observed excess energy here is less impressive than [1][2]
and the material used is also far less exotic than common LENR-CANR experiments,
from the viewpoint of minimum preparation requirement - and therefore
less barrier for rapid implementation--, it seems that further experiments could be
recommended in order to verify and also to explore various implications of this
new proposition.
Category: Chemistry
[1] viXra:0808.0005 [pdf] submitted on 17 Aug 2008
Authors: Talbot Chubb
Comments: 4 pages
On May 22, a special announcement/presentation was
held at Osaka University by Prof. Yoshiaki Arata in the
presence of colleagues, guests, and press. The announcement
of new results took place in Arata Hall, a campus building
named for Prof. Arata, and a demonstration took place in the
Arata-Zhang laboratory room in a nearby research building.
A research paper describing recent results was made available
in Japanese and English versions.
Category: Chemistry
[2] viXra:1212.0152 [pdf] replaced on 2012-12-29 03:57:17
Authors: Chun-Xuan Jiang
Comments: 8 Pages.
Using the stable number theory we prove there are only 92 stable elements in nature and obtain the correct valence electron configurations of the elementsd. In Mendeleev periodic table the elements(1-18,29-36 and 46) have correct valence electron configurations and the elements(19-28,37-45 and 46-92) have wrong valence electron configurations.The elements have no periods.Appendix is wrong Mendeleev periodic table of electron configurations of the elements
Category: Chemistry
[1] viXra:1212.0152 [pdf] replaced on 2012-12-27 18:20:29
Authors: Chun-Xuan Jiang
Comments: 5 Pages.
using stable number theory[3] we prove there are only 92 stable elements n nature and obtain the correct valence electron configurations of the elements.In Mendeleev periodic table the elements(1-18,29-36 and 46)have correct valence electron configurations and the elements(19-28,37-45 and 47-92) have wrong valence electron configurations. The elements have no periods.
Category: Chemistry