Determination of Settling Efficiency of Solid Finely Dispersed Particles Within Devices with Rectangular Separators

2019 ◽  
pp. 79-84
Author(s):  
I. N. Madyshev ◽  
O. S. Dmitrieva ◽  
A. V. Dmitriev
Keyword(s):  
Dispersed Particles

The Evolution of Morphology in NR/HDPE Blends. Part I. Microscopy for Unvulcanized Blends

1998 ◽  
Vol 71 (5) ◽  
pp. 966-974 ◽  
Author(s):  
Pasaree Laokijcharoen ◽  
A. Y. Coran
Keyword(s):  
Phase Morphology ◽  
Specimen Preparation ◽  
Sampling Device ◽  
Preparation Methods ◽  
Platinum Alloy ◽  
Dispersed Particles ◽  
Cold Pressed ◽  
Internal Mixer ◽  
Kinetics Of

Abstract Phase morphology is an important factor in the determination of properties of polymer blends. In this work, methods for determining phase morphology of unvulcanized natural rubber (NR)/high-density polyethylene (HDPE) blends were investigated. Small, quick-quenched samples were taken from the internal mixer for examination under scanning electron microscopy (SEM). There was almost no interruption of the mixing because the sampling device was designed for preventing the coalescence of dispersed particles. Three specimen-preparation methods for SEM were considered: (i) OsO4 vapor staining, followed by carbon coating; (ii) toluene etching of NR phase at room temperature, followed by coating of the surface with a platinum alloy; (iii) crosslinking of NR phase by S2Cl2 vapor and then etching of HDPE phase by using boiling xylene. Method (i), OsO4 staining of cryogenic microtomed samples, was selected for the work on the kinetics of dispersion during the mixing process. Vast differences in phase morphology were observed among the types of samples: quick quenched, cold pressed, and compression molded. We considered the quick-quenched samples to have the phase morphology, which was the most similar to that of the blend during its mixing.

scholarly journals INTERPHASE OF BUILDING COMPOSITIONS

2021 ◽  
Author(s):  
А.М. Айзенштадт ◽  
Ю.В. Соколова ◽  
Т.А. Дроздюк ◽  
М.А. Авдушева
Keyword(s):  
Kinetic Model ◽  
Building Materials ◽  
Materials Science ◽  
Colloidal Chemistry ◽  
Dispersed Particles ◽  
Quantitative Characteristics ◽  
Methodological Approaches ◽  
Methodological Principles ◽  
Transformation Processes

Целью данной работы является демонстрация нескольких методологических подходов к решению задач управления процессами трансформационных превращений вещества на границе раздела фаз макроповерхности и в дисперсных системах, которые можно, на наш взгляд, использовать в качестве критериев количественной характеристики одного из основополагающих законов научного направления «Геоника» - закона «Сродства структур». Предложенные подходы базируются на фундаментальных положениях физической и коллоидной химии, кристаллоэнергетики. В качестве данных критериев, позволяющих управлять структурообразованием на межфазной границе, предложены энергетическая интерпретация кинетической модели топохимического взаимодействия компонентов и значение аналоговой постоянной Гамакера. Разработаны методологические принципы экспериментального определения этих характеристик. Проведена апробация предложенных подходов на примере различных тонкодисперсных композиций: глиоксаль-кора, базальт-кора, базальт-полиминеральный кварцево-полевошпатовый песок и базальт-сапонит. Кроме того, коллоидно-химический подход к созданию суспензий на основе тонкодисперсных частиц горных пород, обладающих специфическими свойствами, позволяет синтезировать агрегативно устойчивые суспензии магнитных жидкостей. Приводятся примеры их использования в строительном материаловедении. This work aims to demonstrate several methodological approaches to solving problems of controlling the transformation processes of matter at the interface of the macro-surface and in dispersed systems, which, in our opinion, can be used as criteria for the quantitative characteristics of one of the fundamental laws of the scientific direction "Geonics" - the "Affinity of structures" law. The proposed approaches are based on the fundamental principles of physical and colloidal chemistry, crystal energy. The energy interpretation of the kinetic model of the topochemical interaction of thecomponents and the analog Hamaker constant value are proposed as these criteria make it possible to control the structure formation at the interface. We have developed the methodological principles for the experimental determination of these characteristics. We have tested the proposed approaches on various finely dispersed compositions: glyoxal-bark, basalt-bark, basalt-polymineral quartz-feldspar sand, and basalt-saponite. Besides, the colloidal-chemical approach to the creation of suspensions based on finely dispersed particles of rocks with specific properties makes it possible to synthesize aggregately stable suspensions of magnetic fluids. Examples of their use in building materials science are given.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

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