A Method of Comparison and Critical Analysis of the Physical Properties of Homologs and Isomers. The Molecular Volume of Alkanes*

1936 ◽  
Vol 58 (1) ◽  
pp. 153-157 ◽  
Author(s):  
George Calingaert ◽  
John W. Hladky
Keyword(s):  
Physical Properties ◽  
Critical Analysis ◽  
Molecular Volume

scholarly journals The ash heap of crystallography: restoring forgotten basic knowledge

2015 ◽  
Vol 48 (4) ◽  
pp. 1290-1298 ◽  
Author(s):  
Massimo Nespolo
Keyword(s):  
Physical Properties ◽  
Critical Analysis ◽  
Unit Cell ◽  
Basic Knowledge ◽  
Crystal Forms ◽  
Structural Symmetry

A critical analysis of some basic notions often overlooked in crystallographic education is presented to correct some common oversights occurring both in the literature and in textbooks. The crystal forms (face forms), defined in terms of their geometric eigensymmetry, are 47 in number, not 48 as often found in the literature. The split of the dihedron into dome and sphenoid calls for the consideration of the physical properties of the faces building a form; in that case, however, the same criterion should be used for all forms. By taking the handedness of the faces as representative of the physical properties of the faces, the occurrence of 130 crystallographic face forms (97 affine face forms and 33 enantiomorphic pairs) is demonstrated. Next, the correct use of non-coprime Miller indices when a centred unit cell is adopted is shown, and the inconsistent multiplication of Miller indices in the Bravais–Friedel–Donnay–Harker law is pointed out. A geometric derivation of the reflection conditions is reviewed. Finally, the inconsistent presentation of metric restrictions imposed by the structural symmetry is pointed out and corrected.

Natural Materials for Thermal Insulation and Passive Cooling Application

2015 ◽  
Vol 666 ◽  
pp. 1-16 ◽  
Author(s):  
Anna Laura Pisello ◽  
Federica Rosso
Keyword(s):  
Physical Properties ◽  
Thermal Insulation ◽  
Critical Analysis ◽  
Numerical Data ◽  
Energy Performance ◽  
International Standards ◽  
Passive Cooling ◽  
Natural Materials ◽  
Outdoor Spaces ◽  
Indoor And Outdoor

In this chapter a critical analysis about natural materials to enhance energy performance and thermal comfort in indoor and outdoor spaces is dealt with. In particular, thermal insulation and passive cooling application in buildings are analyzed. The physical properties permitting to achieve these benefits are presented, as well as the method and the international standards to measure them. Benefits deriving from these materials’ employment as insulation layers or buildings envelope in general of, or in the case of urban paving, are described and then the single materials are illustrated.Experimental and numerical data, as reported in the bibliography, support the dissertation with examples from the most recent research contributions.

Two interpenetrating monoclinic superlattices of a self-assembling rodcoil copolymer thin film

1994 ◽  
Vol 52 ◽  
pp. 442-443
Author(s):  
L. S. Li ◽  
S. I. Stupp
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Physical Properties ◽  
Microphase Separation ◽  
Film Plane ◽  
Molecular Volume ◽  
Cross Linking ◽  
Self Assembling ◽  
Lamellar Morphology ◽  
Flexible Coil

In earlier work, we showed that the rodcoil copolymer (I), containing a rigid board-like mesogenic block connected to a flexible coil-like diblock of approximately 7 isoprene and 7 styrene units, undergoes a microphase separation in thin films cast from solution. The thin films exhibit a lamellar morphology with a mesogenic core sublayer, a polyisoprene (PI) sublayer and a polystyrene (PS) sublayer alternating along the normal to the layers. If the ratio of the molecular volume of the coil-like chain block to that of the mesogenic block could be increased to a certain value a different morphology of thin films would be expected. After cross-linking among the PI blocks, a molecular object with mesogenic core axes oriented perpendicular to the film plane could be formed which would significantly affect physical properties of thin films. In an attempt to obtain a different micTodomain morphology in thin films a similar rod-coil copolymer with approximately 15 isoprene and 15 styrene units in the coil-like chain block (II) was synthesized in our laboratory.

scholarly journals On the molecular heat and volume of the rare earths and their sulphates

1881 ◽  
Vol 31 (206-211) ◽  
pp. 46-51
Keyword(s):  
Rare Earth ◽  
Physical Properties ◽  
Rare Earths ◽  
Royal Academy ◽  
Rare Earth Metals ◽  
Molecular Volume ◽  
Academy Of Sciences ◽  
The Rare Earth

At the request of the Royal Academy of Sciences at Stockholm, we some years ago undertook an extended research into the physical properties of the rare earth-metals and their compounds. Having performed the laborious task of separating and purifying their oxides, we are now able to publish our first series of determinations concerning their principal properties, which chemically are of the greatest im­portance, viz., molecular heat and molecular volume.

scholarly journals Evolution of Cometary Debris: Physical Aspects

1989 ◽  
Vol 116 (1) ◽  
pp. 593-606 ◽  
Author(s):  
Anton Hajduk
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Observational Data ◽  
Critical Analysis ◽  
Dust Particles ◽  
Mass Distributions ◽  
Cometary Dust ◽  
Nongravitational Forces

AbstractCometary dust particles, larger grains, and fragments as products of the disintegration processes are subjected to gravitational and nongravitational forces, causing their dynamical and physical evolution. Critical analysis of some fairly large differences in the observational data obtained for the mass productions, dust/gas ratios, cut-off masses, particle size/mass distributions, erosion factors, bulk densities, and other physical properties of particles leads to a more complex view of the cometary matter than is assumed in some of the current models. This view allows reasonable limits for the dynamical and physical interrelations between the debris and its parent bodies to be obtained.

The Photometric Properties of the Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  
Physical Properties ◽  
Ap Stars

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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