scholarly journals Effective Radii of Macromolecules in Dilute Polyvinyl Alcohol Solutions

2018 ◽  
Vol 63 (2) ◽  
pp. 144 ◽  
Author(s):  
O. V. Khorolskyi
Keyword(s):  
Experimental Data ◽  
Polyvinyl Alcohol ◽  
Dimethyl Sulfoxide ◽  
Temperature Interval ◽  
Shear Viscosity ◽  
Low Temperatures ◽  
Concentration Dependences ◽  
Concentration Interval ◽  
Temperature Dependences ◽  
Pva Solutions

The temperature and concentration dependences of the effective radii of polyvinyl alcohol (PVA) macromolecules have been studied on the basis of experimental data on the viscosity of dilute PVA solutions in dimethyl sulfoxide (DMSO) and water, as well as using the Malomuzh–Orlov theory of shear viscosity in polymer solutions. The temperature dependences of the effective radii of PVA macromolecules in DMSO are shown to be linear in the temperature interval 293÷353 K. At the same time, those dependences are more complicated for aqueous PVA solutions. Namely, the effective radii of macromolecules remain unchanged at relatively low temperatures and PVA concentrations, but they decrease nonlinearly at higher temperatures and concentrations. The concentration dependences of the effective radii of PVA macromolecules in both solvents are found to decrease nonlinearly in the concentration interval 0.3–3 wt.%.

scholarly journals Calculation of the Macromolecular Size of Bovine Serum Albumin from the Viscosity of Its Aqueous Solutions

2020 ◽  
Vol 65 (1) ◽  
pp. 41 ◽  
Author(s):  
O. V. Khorolskyi ◽  
Yu. D. Moskalenko
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Aqueous Solutions ◽  
Temperature Interval ◽  
Shear Viscosity ◽  
Bovine Serum ◽  
Viscosity Data ◽  
Self Diffusion ◽  
Concentration Interval ◽  
Calculation Results

On the basis of experimental data for the shear viscosity of aqueous bovine serum albumin (BSA) solutions and in the framework of the Malomuzh–Orlov cellular approach, the surface of effective radii of BSA macromolecules has been plotted for the constant pH = 5.2 in the concentration interval of 2.0–27.2 wt% and the temperature interval 278–318 K. A rapid nonlinear increase in the effective radii of BSA macromolecules is shown to take place up to BSA concentrations of about 5 wt% in the whole examined temperature interval. The maxima of the effective radii of BSA macromolecules are observed at a BSA concentration of 5 wt%, and their position is temperature-independent. In the concentration interval 5.0–27.2 wt%, the effective radii of BSA macromolecules decrease, and this reduction is linear at BSA concentrations higher than 10 wt%. A comparison of the calculation results with literature data on the self-diffusion coefficient of macromolecules in solutions testifies to the efficiency of the Malomuzh–Orlov formula for calculating the macromolecular radii of globular proteins on the basis of shear viscosity data for their aqueous solutions.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

Reorientational dynamics of highly asymmetric binary non-polymeric mixtures – a dielectric spectroscopy study

2021 ◽  
Vol 23 (12) ◽  
pp. 7200-7212 ◽  
Author(s):  
Thomas Körber ◽  
Felix Krohn ◽  
Christian Neuber ◽  
Hans-Werner Schmidt ◽  
Ernst A. Rössler
Keyword(s):  
Dielectric Spectroscopy ◽  
Spectroscopy Study ◽  
Concentration Dependences ◽  
Temperature Dependences ◽  
Reorientational Dynamics

Two separated relaxations α1 and α2 with different temperature dependences are identified in the mixtures. They are attributed to the dynamics associated with the high-Tg (α1) and the low-Tg component (α2) with distinct Tg concentration dependences.

scholarly journals Anomalous Temperature and Field Behaviors of Magnetization in Cubic Lattice Frustrated Ferromagnets

2015 ◽  
Vol 233-234 ◽  
pp. 3-7
Author(s):  
A.N. Ignatenko ◽  
Andrey A. Katanin ◽  
Valentin Yu. Irkhin
Keyword(s):  
Experimental Data ◽  
Monte Carlo Simulation ◽  
Low Temperatures ◽  
Strong Field ◽  
Wave Spectrum ◽  
Exchange Interactions ◽  
Thermal Fluctuations ◽  
Anomalous Temperature ◽  
Cubic Lattice ◽  
Spin Wave Spectrum

Thermodynamic properties of cubic Heisenberg ferromagnets with competing exchange interactions are considered near the frustration point where the coefficient D in the spin-wave spectrum Ek ~ Dk2vanishes. Within the Dyson-Maleev formalism it is found that at low temperatures thermal fluctuations stabilize ferromagnetism by increasing the value of D. For not too strong frustration this leads to an unusual "concave" shape of the temperature dependence of magnetization, which is in agreement with experimental data on the europium chalcogenides. Anomalous temperature behavior of magnetization is confirmed by Monte Carlo simulation. Strong field dependence of magnetization (paraprocess) at finite temperature is found near the frustration point.

Using Exponential Cubic Splines to Predict Low Temperature Behavior of Elastomeric Materials

1994 ◽  
Author(s):  
Terry E. Shoup ◽  
George R. Fegan
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Low Temperatures ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Considerable Difficulty ◽  
Spline Curves ◽  
Different Types ◽  
Elastomeric Materials ◽  
Energy Absorbing

Abstract Because of their desirable elastic and energy absorbing properties, elastomeric materials have been widely used as shock mounts and pressure seals. The high sensitivity of the elastic modulus of these materials to changes in temperature has been a source of considerable difficulty to the development of robust design methods based on analytical techniques. This paper presents a simple analytical method for predicting the elastic modulus for a group of five different types of elastomers when used at low temperatures. The method is based on the application of exponential cubic spline curves to smooth experimental data. The method is applied to experimental data from the literature to illustrate its usefulness.

EXPERIMENTAL RESEARCH ON COMPRESSION FOAM COOLING DURING ITS DELIVERY AT DIFFERENT AMBIENT TEMPERATURE MODES

2021 ◽  
Vol 4 ◽  
pp. 40-44
Author(s):  
Gumirov A. ◽  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Low Temperatures ◽  
Empirical Method ◽  
Research Application ◽  
Mass Consumption ◽  
Operating Modes ◽  
Research Findings ◽  
Conducting Research ◽  
The Impact

Purpose. The article describes methodology for conducting research on parameters of compression foam cooling during its delivery through hose-pump systems depending on the operating modes of the foam generating installation. The impact of mass consumption of compression foam on its cooling at low temperatures has been examined. The application of a mathematical model of air-foam mixture movement in hose-pump systems at different temperature modes has been substantiated. Methods. Empirical method-experiment has been used for research. Findings. A number of experiments have been carried out to confirm the developed model of compression foam moving in hose-pump systems at different temperature modes. A mobile installation for generating and delivering compression foam has been used as the object of the research. Inaccuracy in calculations obtained with the help of a mathematical model in comparison with the experimental data is 10% which makes a possible to claim that the model of compression foam moving in hose-pump systems at different temperature modes has been chosen properly. Research application field. According to the obtained data, it is possible to plan means and forces of fire units for extinguishing fires using compression foam at low temperatures. Conclusions. The developed mathematical model of compression foam movement during its delivery through hose-pump systems is confirmed by experimental data. The dependence of mass consumption impact on compression foam cooling when it is delivered through fire hoses at low temperatures has been obtained experimentally.

scholarly journals The system CaO-MgO-FeO-SiO2 and its bearing on the origin of ultrabasic and basic rocks

1960 ◽  
Vol 32 (249) ◽  
pp. 459-470 ◽  
Author(s):  
Peter J. Wyllie
Keyword(s):  
Experimental Data ◽  
Temperature Interval ◽  
Wide Temperature Range ◽  
Multicomponent System ◽  
Small Temperature ◽  
Experimental Procedure ◽  
Temperature Range ◽  
A Value ◽  
Basaltic Magmas ◽  
Basic Rocks

SummaryExperimental data in the system CaO-MgO-FeO-SiO2 suggest that there may be a plateau on the liquidus and solidus of the multicomponent system basalt-peridotite. If this is so, fusion of peridotite would produce only basaltie magmas over a wide temperature range; when the temperature reached a value such that the liquid crossed the threshold of the plateau, there would be a rapid increase in the amount of fusion for small temperature increases, with the formation of picritic magmas; basaltic magmas containing suspended forsteritic olivine crystals could dissolve them if the temperature rose slightly above that of the plateau threshold; a high proportion of a picritic magma would crystallize in a small temperature interval, with the precipitation of forsteritic olivine that was only slightly zoned. These possibilities are compared with current theories, and it is concluded that several petrological axioms may require critical re-examination. An experimental procedure is outlined to determine the shape of the liquidus and solidus in the basalt-peridotite system.

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