Accumulation Of Internal Energy Research Articles

PyFragMS-A Web Tool for the Investigation of the Collision-Induced Fragmentation Pathways.

Dissociation induced by the accumulation of internal energy via collisions of ions with neutral molecules is one of the most important fragmentation techniques in mass spectrometry (MS), and the identification of small singly charged molecules is based mainly on the consideration of the fragmentation spectrum. Many research studies have been dedicated to the creation of databases of experimentally measured tandem mass spectrometry (MS/MS) spectra (such as MzCloud, Metlin, etc.) and developing software for predicting MS/MS fragments in silico from the molecular structure (such as MetFrag, CFM-ID, CSI:FingerID, etc.). However, the fragmentation mechanisms and pathways are still not fully understood. One of the limiting obstacles is that protomers (positive ions protonated at different sites) produce different fragmentation spectra, and these spectra overlap in the case of the presence of different protomers. Here, we are proposing to use a combination of two powerful approaches: computing fragmentation trees that carry information of all consecutive fragmentations and consideration of the MS/MS data of isotopically labeled compounds. We have created PyFragMS—a web tool consisting of a database of annotated MS/MS spectra of isotopically labeled molecules (after H/D and/or 16O/18O exchange) and a collection of instruments for computing fragmentation trees for an arbitrary molecule. Using PyFragMS, we investigated how the site of protonation influences the fragmentation pathway for small molecules. Also, PyFragMS offers capabilities for performing database search when MS/MS data of the isotopically labeled compounds are taken into account.

The Study of the Influence of Ultrasonic Vibrations on Structural Changes of Steel

The paper describes a cause of the geometric accuracy degradation of slender metallic products during their operation, which consists in the relaxation of residual stresses accumulated while product manufacturing. The most promising technology among the existing technologies of residual stress relaxation is based on the use of vibromechanical vibrations. This technology has high performance and low energy consumption. The reason for the relaxation of residual stresses under the action of vibromechanical vibrations is the gradual accumulation of internal energy, which leads to plastic dislocation shifts upon reaching a critical level. The dislocation motion under the action of vibromechanical vibrations continues until the dislocations take a more compact layout that corresponds to the equilibrium energy state. For technological implementation of the process there was developed a method of ultrasonic stabilization of elastic plates, which serve as sensing elements in differential-pressure transducers. The experimental studies of ultrasonic stabilization are carried out. According to the results of the studies, there have been conducted tests of the microstructure of the control samples. It is established that the samples of steel 20CH13 subject to ultrasonic treatment have a more uniform structure than the samples after the factory technology of long "aging". This confirms the assumption about the structural-energy processes occurring during vibromechanical relaxation of residual stresses. The technology of ultrasonic stabilization can be recommended as a replacement to the "aging" technology on the basis of the obtained results.

Thermodynamic Analysis of the Contributions from Dislocational Substructures to Deformation Processes in Single Crystals of Nickel

A thermodynamic analysis of deformation mechanisms is performed, based on an experimental study of dislocational substructures that form as a result of the deformation of single crystals of nickel at room temperature. It is shown that in single crystals of pure nickel, strain produces a mainly thermal effect. The most important factors responsible for the accumulation of internal energy are elastic and dislocational components.

Some general relations of the development of complex molecular objects at early stages of biosphere formation as a consequence of the physical properties of condensed medium

We analyzed the character of molecular transformations under conditions of condensed media, in which intermolecular interactions always occur. It was shown that, instead of discrete transfer of external energy into the molecule, the energy characteristics of the condensed medium (appearance of zones) could result in gradual accumulation of internal energy in reaction centers owing to sequential thermal collisions with particles of the medium initiating the chemical reaction. This does not require high temperatures. The established physical properties related to the energy characteristics of condensed media could play an important role in molecular transformations and, consequently, formation of complex molecular objects at early stages of biosphere formation.

Multi-Agents Computational Experiment on Twice-Linked Model of Unconventional Emergencies Evolution Mechanism

Based on the cellular automaton principle and multi-agents theory of complex systems, the generation and the evolutionary mechanism of unconventional emergencies have been studied and the twice-linked model of he evolutionary mechanism of unconventional emergencies has been established with calculating experiments being carried out in this study. The conclusion is reached that the internal causes of unconventional incident is the accumulation of internal energy. Evolution process of twice-linked systems is a process that the constantly-accumulated energy in the promoted system is first suddenly released, and then the internal energy in the linkage system is stimulated and also released in a large-scale. These two outbreaks are almost at the same time, and the eruption of the linkage system can be more than twice as powerful as that of promoted system. The linkage effect of unconventional emergencies could be totally prevented only when no transfer possibility or 100% ceasing ability in linkage system or no network space density occur.

On the nature of abnormalities in the structural mechanical behavior of glassy polymers

Literature data on abnormalities in the mechanical behavior (stress relaxation in the initial section of the stress-strain (compression) diagram, stress growth under isothermal heating, a low-temperature contribution to the temperature-induced strain recovery of deformed polymer glasses, a soft compliant phase upon the tensile drawing of a glassy polymer revealed by dynamic mechanical tests) and in the thermophysical behavior (accumulation of internal energy at early stages of deformation and an exothermic DSC peak below the glass transition temperature) of the deformed glassy polymers are considered. The above abnormalities can be explained taking into account two fundamental features of amorphous polymers, first, the inhomogeneous character of inelastic deformation in glassy polymers, which leads to the development of discrete regions of plastically deformed material in the initial polymer (shear bands and/or crazes), and, second, a marked decrease in T g of highly dispersed oriented material filling both shear bands and crazes.

Accumulation of Internal Energy in Multiply Connected Bodies

Description is given to methods for determination of the internal energy in isotropic and anisotropic plates and shells weakened by various openings and in rods with cavities. It is found out what share the number of openings or cavities, their shapes, and the distance between them have in the accumulation of the internal energy. Various types of static and dynamic loading are considered.

Grinding Effects on the Synthesis and Sintering of Cordierite

Grinding effects on the synthesis and sintering of cordierite were investigated. The grinding of a precursor gel derived from colloidal processing promoted the homogeneous distribution of elements in the gel, resulting in improved reactivity for the formation of cordiertie. Grinding the calcined powder enhanced the homogeneity of the resulting powder and caused the accumulation of internal energy as crystal strain; consequently, the densities of the sintered bodies increased and the optimum temperature range for sintering widened.

Solution of contact problems for an inhomogeneous half-space when pressed by a circular-cylinder stamp

One of the reasons for fatigue failure is the absorption of cyclic-deformation energy by a solid [2], i.e., failure preceded by the gradual accumulation of internal energy. Wear on solids by frictional contact, as is known [3], can also be characterized by a fatigue mechanism of surface failure. This means that one of the stages preceding the development of effective methods of combating the premature wearing out of joints should be a study of the distribution of the applied mechanical energy in the near-surface layers of the solids which are in contact. The nature of the distribution of the applied energy also affects the physicochemical processes accompanying friction and wear, for example the conversion of mechanical energy to thermal energy, electrical energy, etc.