Influence Of External Effects Research Articles

Crystal-packing analysis of translation initiation factor 2 reveals new details of its function

Eukaryotic and archaeal translation initiation factor 2 in complex with GTP delivers the initiator methionyl-tRNA to the small ribosomal subunit. Over the past 20 years, thanks to the efforts of various research groups, including ours, this factor from the archaeon Sulfolobus solfataricus and its individual subunits have been crystallized in ten different space groups. Analysis of the molecular packing in these crystals makes it possible to better understand the roles of functionally significant switches and other elements of the nucleotide-binding pocket during the function of the factor as well as the influence of external effects on its transition between active and inactive states.

Особенности межмолекулярного взаимодействия в нефтяных дисперсных системах

Oil, gas condensates, oil products present a complex colloidal-dispersed system which often demonstrates the abnormally changing properties when external conditions change. Mixing the petroleum products can be accompanied by a non-linear behavior accompanied by synergistic and antagonistic effects. Understanding of the oil and oil products as oil dispersed systems, the specific features of intermolecular interaction largely clarify their behavior, changes in properties, chemistry and mechanism of reactions occurring in them. Petroleum systems are polydisperse, in which the components can coexist in different aggregate states, and the size of the dispersed phase can vary over a wide range. They consist of diverse compounds that differ in properties, structure, shapes and sizes of molecules. Due to the variety of components that make up oil disperse systems the intermolecular interactions determine such a feature of the behavior of oil systems as the phenomenon of self-organization and structuring, which manifest themselves when external influences change and are sensitive to them. They are characterized by the absence of charge and a minimum of charge-polarization interactions of molecules, and intermolecular interactions are largely determined by the presence of paramagnetic molecules. The uncompensated spin of macromolecular compounds due to the steric obstacles, a homolytic dissociation, and the presence of microelement compounds ensure the paramagnetism of petroleum dispersed systems. This leads to developing the stable associative combinations and the formation of complex structural units capable of redistributing components and layers between phases under the influence of external effects. Comprehensive analysis and unanimity of views on the physical and chemical interactions of the components of oil systems leading to a change in their structure, open up fundamentally new opportunities for intensifying processes in the practice of production, transportation and processing of hydrocarbon raw materials and the use of petroleum products, and also allow predicting the behavior of oil systems in processes which they are participating.

Имитационные модели оценки опасности возникновения подземных аварий в угольных шахтах

The article is related to the safety issues of the coal mines considering not only the standard conditions of their operation, but also the influence of external effects, personnel errors during mining operations and operation of controls and automation. The relationship between the causes of accidents and sources of hazards is shown. The analysis of mine safety research methods was carried out, which allow to identify the most dangerous causes and conditions of the underground accidents to one degree or another. It is shown that at the mining sites, despite the extremely small, but non-zero probability, accidents still occur due to the probability densities of rare dangerous situations leading to severe consequences. The expediency of logical-probabilistic methods for modeling scenarios of possible accidents, which are interpreted by the cause-and-effect diagrams of the occurrence of a chain of incidents, is asserted. Based on the normalization of the frequencies of occurrence of emergency situations in coal mining, a rationale is given for the transition from the weights of various initiating conditions to their contributions to emergency situations. Simulation models of decision-making for operational substantive analysis of emergency situations were developed, including an assessment of the weights and contributions of mining and geological, mining and technical factors, and personnel errors to the risk of methane explosion occurrence, fires and gasification of workings in case of violations in the degassing systems. It is shown that the existing hazards must be able to measure, i.e. have numerical scales. These hazardrs can be assessed based on the construction of hazard trees. Using them, as well as assessments of emergency changes in the state of the technosphere of coal mines, which are based on the analysis of cause-and-effect relationships of hazard sources, simulation models of the hazard of underground accidents were formed and implemented. These models can be considered as functional models of any emergency situation, allowing to obtain analytical estimates of variations in emergency situations by their weights and contributions to the hazard of emergency situations.

Effect of permeability-reducing admixtures on concrete properties at different cement dosages

Concrete is the most common building material used worldwide. Significantly high strength values have been achieved owing to developing material technology. Besides compressive strength, durability properties should also be taken into consideration since concrete is exposed to several external effects throughout its service life. Durability properties are mainly associated with the voids in the internal structure and surface of concrete. Even if not exposed to any external effects, concrete contains several pores and micro-cracks. These pores and cracks enlarge with the influence of external effects, and new cracks are developed. Therefore, various methods are used to prevent the permeability of harmful liquids and gases into concrete structures. In this study, permeability-reducing admixtures (PRAs) and various cement dosages were used to produce concrete mixtures. The main purpose is to examine the interaction of these additives with the cement dosage. Workability, compressive strength, and depth of water penetration under pressure tests were conducted to observe the effect of PRA on these parameters. The admixture crystallized in the internal structure of the concrete and created a fuller volume. While the compressive strength increased as a result of the crystallized product, the depth of water penetration decreased. Slump tests revealed that the additive was compatible with all cement dosages, and it did not significantly affect the workability properties of the concrete. Expectedly, the compressive strength increased as the cement dosage increased, while the positive effect of the PRA additive gradually decreased. The PRA additive also contributed to the decrease in the depth of water penetration, but its impact decreased as the cement dosage increased. It was concluded based on present findings that PRA additive, which is the most effective at the lowest cement dosage, increased the compressive strength values by 9.44% at this dosage and decreased the depth of water penetration under pressure by 26.09%.

Thermal and gas dynamic investigations at Lastarria volcano, Northern Chile. The influence of precipitation and atmospheric pressure on the fumarole temperature and the gas velocity

Fumaroles are hydrothermal manifestations commonly associated with active volcanoes. The dynamics of fumaroles are affected by interactions with internal and external factors, however, hazardous access and corrosive gases have so far limited successful case studies. In this study we report and discuss the results of continuous thermal monitoring carried out on three high temperature (>250°C) fumaroles at the Lastarria volcano Chile, together with simultaneously measured meteorological parameters from December 2013 to March 2016. In addition, the dynamic pressure and the CO2 concentration were recorded in a fourth vent. The investigated sites are located in the largest and most dominant fumarole field which developed in a fracture system on the north-west flank of the volcanic edifice.We detect external factors controlling the fumarole temperature and the dynamic gas pressure, for a better understanding of changes in these parameters and, consequently, to improve the evaluation of volcanic and hydrothermal activity.Selected fumaroles showed a continuous decrease in temperature, or remained unbiased from this trend showing that the influence of external effects on outlet temperature is strongly site dependent. But generally, significant decreases in all vent temperatures can be observed in response to intensive precipitation. Diurnal variations occur only in the coolest fourth fumarole, where gas temperature, gas pressure and CO2 concentration are inversely correlated with atmospheric pressure. Small barometric pressure reductions account for an increase in mass flow subsequently resulting in a higher temperature and CO2 concentration.The temperatures and thermodynamic properties of the fumarolic gas and infiltrated precipitation water were used to calculate the amount of discharging gas from the investigated field with about 67×106m3 per day which is equivalent to 3545tons.

Influence of external effects on the electrical properties of high pressure perovskite-like phases CaCu3Ti4-xVxO12

Samples of high pressure perovskite-like phases CaCu3Ti4-xVxO12, x = 0.1, 0.2, 0.3, 0.4 and 0.5 were synthesized at high-pressure and high-temperature conditions in a toroid-type high-pressure chamber. Their electrical properties were studied by impedance spectroscopy in the frequency range from 1 Hz to 30 MHz at temperatures of 300 to 600 K and at pressures of 10 to 30 GPa.

The effect of the ambient temperature and refractive index on the spectral characteristics of long-period fiber gratings with a corrugated polymeric coating

This paper presents an experimental study of how external factors—the ambient temperature and refractive index—affect the transmission spectra in the resonance region of long-period fiber gratings with a corrugated polymeric coating. The influence of external effects on the spectral shift and amplitude of resonances is studied for the core and cladding modes of long-period gratings.

Theoretical and experimental investigation of the influence of external effects on the electronic structure of Ce-based heavy-fermion systems

The electronic structure of Ce systems with different degrees of hybridization of f electrons with outer-shell electrons and the effect of pressure on the change in the electronic structure has been investigated. A correlation between the parameters of X-ray photoelectron spectra and the magnitude of the heavy-fermion state is established. The total and partial densities of states of atoms were calculated using the TB LMTO ASA method. X-ray photoelectron study of the effect of an X-ray induced vacancy in the inner levels on the shape of the Ce3d spectra for Ce-based systems with different degrees of covalence has been performed. It is shown that there is a relationship between the magnitude of the heavy-fermion state and the intensity of the shakedown satellites in X-ray photoelectron spectra and that the magnitude of the heavy-fermion state decreases under pressure.

The influence of external effects on the structurization of lubricating materials

The methods of drop spreading over the solid body surface and rotational viscosimetry have been used to explore the processes of structurization of lubricating material. It is demonstrated how the surfactants and superdispersed oil particles (artificial structurization nuclei) influence the evolution of these processes.

Intersectoral external effects, multiplicities & indeterminacies

This contribution focuses on the scope for indeterminacies that originate from global capital stock externalities in a reference two-sector growth model. A set of sufficient conditions for local indeterminacies and oscillations is established and builds upon a new class of intersectoral dependency in competitive economies. The uniqueness of the steady state is also questioned and conditions for global indeterminacies are delimited. The underlying features of preferences and sectoral production technologies are assessed in this paper. It is shown that the principal attribute of a two-sector environment, i.e., a non-linear production possibility frontier, directly underlies indeterminacies. It is the influence of external effects on the relative price of the investment good that leads to these phenomena, a key role being detected in this perspective for external effects in the consumption good sector.

Investigation of the influence of external effects on the behavior of gold impurity in silicon

Properties of gold atoms in silicon and the change of their energy levels under uniform pressure are investigated. The investigations demonstrated that the band gap of silicon varies under the influence of pressure (P) and temperature (T) with a rate ∂E/∂P=−1.5×10−11 eV/Pa and ∂E/∂T=−3.2×10−6 eV/K.

Influence of external effects on the structure and molecular dynamics of oriented copolymers and blends on the basis of polypropylene and polyethylene

In polyethylene (PE)-polypropyle (PP) blends, the greatest changes in dynamic and structural parameters occur on the addition of 1–10% of PE to PP. In this case the orientation of PE chains in amorphous domains increases appreciably, the rigidity of the amorphous domains grows and the elasticity modulus is enhanced. Reversible stretching of oriented blends is accompanied by a growth of molecular mobility which is independent of the degree of orientational drawing and blend composition. Stability with respect to ozone changes slightly with blend composition, whereas stability towards UV irradiation drops sharply in blends of PP with small amounts of PE. The behaviour of copolymers on stretching changes sharply on addition of 5% PE units to PP. Reversible strain of oriented copolymers containing <5% ethylene units is accompanied by a growth of mobility, while this dependence changes to the opposite at higher ethylene contents. Sorption properties change similarly with changes in mobility. Stability towards ozone and UV action decreases in samples containing 5% ethylene units. Structural models are proposed for explaining the observed regularities.

The Influence of External Effects on the Proton Conductivity of an Hydrogen‐Bonded Chain

AbstractA theoretical study is made of stimulation of hydrogen‐bonded‐chain‐proton conductivity in a constant longitudinal electric field by light‐and‐ultrasonic effects. The suggested mechanism of light effect is caused by nonactivated phonon transitions of charge carriers from the base level of one knot through an internal excited state to the base state of the neighbouring knot. The suggested mechanism of ultrasonic effect is caused by amplitude increase of acoustic fluctuations of the hydrogen bonded‐chain structure, that modulate the distance between knots, i.e. by increase of the resonance integral overlap of the carrier wave functions.

A mathematical model of the problem of diagnosing a thermoelastic medium

The diagnosis problem is understood to mean the problem of determining material characteristics by means of information on the physical fields originating therein under the influence of external effects. The problem is from the class of inverse problems of mathematical physics /1/ and is solved using the model of generalized thermomechanics for weakly anisotropic media. As a result of the analysis of wave processes in such a medium, a method is developed for determining the thermoelastic characteristics by means of the temperature and displacement values on the half-space boundary. Examples of calculating specific characteristics are examined.