The Ratio of Specific Heats γ as a Fundamental Physical Property of Liquids

1956 ◽  
Vol 452 (2-3) ◽  
pp. 178-184 ◽  
Author(s):  
S. Parthasarathy
Keyword(s):  
Physical Property ◽  
Specific Heats ◽  
Fundamental Physical Property ◽  
Fundamental Physical

High Thermal Conductivity Materials

MRS Bulletin ◽  
2001 ◽  
Vol 26 (6) ◽  
pp. 440-444 ◽  
Author(s):  
Koji Watari ◽  
Subhash L. Shinde
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Physical Property ◽  
University Student ◽  
High Thermal Conductivity ◽  
Theoretical Support ◽  
Initial Work ◽  
Fundamental Physical Property ◽  
Good Conductor ◽  
Fundamental Physical

Every university student becomes familiar with the concept of thermal conductivity, a fundamental physical property of materials, through his or her textbooks. Initial work on high thermal conductivity was carried out in 1911 by Eucken, who discovered that diamond was a reasonably good conductor for heat at room temperature. Theoretical support for this discovery was established by Debye in 1914.

scholarly journals Physical parameters of selected Gaia mass asteroids

2020 ◽  
Vol 638 ◽  
pp. A11
Author(s):  
E. Podlewska-Gaca ◽  
A. Marciniak ◽  
V. Alí-Lagoa ◽  
P. Bartczak ◽  
T. G. Müller ◽  
...  
Keyword(s):  
Thermal Inertia ◽  
Physical Property ◽  
Physical Parameters ◽  
Good Precision ◽  
Main Belt ◽  
Shape Models ◽  
Solar System Bodies ◽  
Fundamental Physical Property ◽  
Thermophysical Modeling ◽  
The Masses

Context. Thanks to the Gaia mission, it will be possible to determine the masses of approximately hundreds of large main belt asteroids with very good precision. We currently have diameter estimates for all of them that can be used to compute their volume and hence their density. However, some of those diameters are still based on simple thermal models, which can occasionally lead to volume uncertainties as high as 20–30%. Aims. The aim of this paper is to determine the 3D shape models and compute the volumes for 13 main belt asteroids that were selected from those targets for which Gaia will provide the mass with an accuracy of better than 10%. Methods. We used the genetic Shaping Asteroids with Genetic Evolution (SAGE) algorithm to fit disk-integrated, dense photometric lightcurves and obtain detailed asteroid shape models. These models were scaled by fitting them to available stellar occultation and/or thermal infrared observations. Results. We determine the spin and shape models for 13 main belt asteroids using the SAGE algorithm. Occultation fitting enables us to confirm main shape features and the spin state, while thermophysical modeling leads to more precise diameters as well as estimates of thermal inertia values. Conclusions. We calculated the volume of our sample of main-belt asteroids for which the Gaia satellite will provide precise mass determinations. From our volumes, it will then be possible to more accurately compute the bulk density, which is a fundamental physical property needed to understand the formation and evolution processes of small Solar System bodies.

scholarly journals On the Fundamental Physical Constants: II. Field Coupling Geometry

2017 ◽  
Vol 9 (5) ◽  
pp. 62
Author(s):  
Ogaba Philip Obande
Keyword(s):  
Internal Structure ◽  
Periodic Group ◽  
Fundamental Constant ◽  
Physical Property ◽  
Fundamental Physical Constants ◽  
Physical Constants ◽  
Field Coupling ◽  
Fundamental Physical

We show that the chemical periodic group is geometric and that the fundamental constant FC is an intrinsic physical property of the atom, it is geometric, an invariant 3-D slice of spacetime that constitutes internal structure of the atom.

scholarly journals An advanced shape-fitting algorithm applied to quadrupedal mammals: improving volumetric mass estimates

2015 ◽  
Vol 2 (8) ◽  
pp. 150302 ◽  
Author(s):  
Charlotte A. Brassey ◽  
James D. Gardiner
Keyword(s):  
Body Mass ◽  
Three Dimensional ◽  
Physical Property ◽  
Skeletal Structure ◽  
Shape Fitting ◽  
Alpha Shapes ◽  
Fundamental Physical Property ◽  
Three Dimensional Models ◽  
The Individual ◽  
Ground Sloth

Body mass is a fundamental physical property of an individual and has enormous bearing upon ecology and physiology. Generating reliable estimates for body mass is therefore a necessary step in many palaeontological studies. Whilst early reconstructions of mass in extinct species relied upon isolated skeletal elements, volumetric techniques are increasingly applied to fossils when skeletal completeness allows. We apply a new ‘alpha shapes’ ( α -shapes) algorithm to volumetric mass estimation in quadrupedal mammals. α -shapes are defined by: (i) the underlying skeletal structure to which they are fitted; and (ii) the value α , determining the refinement of fit. For a given skeleton, a range of α -shapes may be fitted around the individual, spanning from very coarse to very fine. We fit α -shapes to three-dimensional models of extant mammals and calculate volumes, which are regressed against mass to generate predictive equations. Our optimal model is characterized by a high correlation coefficient and mean square error ( r 2 =0.975, m.s.e.=0.025). When applied to the woolly mammoth ( Mammuthus primigenius ) and giant ground sloth ( Megatherium americanum ), we reconstruct masses of 3635 and 3706 kg, respectively. We consider α -shapes an improvement upon previous techniques as resulting volumes are less sensitive to uncertainties in skeletal reconstructions, and do not require manual separation of body segments from skeletons.

Relationship of mechanical properties of crushed stone source rocks to their technological-mechanical performance

2020 ◽  
Author(s):  
Richard Prikryl
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Physical Property ◽  
Evaluation Process ◽  
Source Rocks ◽  
Crushed Stone ◽  
Strength Data ◽  
Fundamental Physical Property ◽  
Relationship Of ◽  
Selection Of

<p>Decision on suitability of rocks for production of crushed stone and their use in specific constructional activities relies on series of empirically-designed tests which partly simulate certain degradation forces acting during the service of aggregates. Tests for integrity of crushed stone particles subjected to mechanical forces employ several approaches simulating abrasion, attrition, and/or crushing; these can thus be generally designated as technological-mechanical performance (TMP) tests. Design of these tests has nothing to do with testing of mechanical properties viewed as fundamental physical property. However, numerous authors attempted to correlate certain mechanical properties (specifically uniaxial compressive strength data) with TMP of crushed stone source rocks. Unfortunately, relatively low correlation has been generally achieved.</p><p>In the recent study, this approach is re-examined by using not only ultimate strength data, but also knowledge on deformational process and on its energetic parameters. The results of laboratory experiments show, that some of the obtained data exhibit much tighter correlation; however, one has be very careful in selection of proper parameters. Thorough understanding of damage mechanisms of crushed stone particles (i.e. mechanisms of their wear and breakage during service life) makes critical part of this evaluation process.</p>

scholarly journals Contributions to the theory of the specific heat of crystals II—On the vibrational spectrum of cubical lattices and its application to the specific heat of crystals

1935 ◽  
Vol 148 (864) ◽  
pp. 384-406 ◽  
Keyword(s):  
Vibrational Spectrum ◽  
Specific Heat ◽  
Mass Difference ◽  
Three Dimensional ◽  
Physical Property ◽  
Small Mass ◽  
Dimensional Case ◽  
Linear Lattice ◽  
Debye Theory ◽  
Specific Heats

1—An investigation of the features of the vibrational spectrum of a cubical crystal has been made by means of a geometrical method described below; the two-dimensional case has been treated in detail, the three-dimensional case in outline. The main result has been the discovery of a number of maxima of the density of the vibrations. The significance of the results is discussed especially in relation to the Debye Theory of specific heats. 2—One-Dimensional Theory The density of the vibrations for a linear lattice containing two types of particles has been worked out in Part I. The density curves are shown in fig. 1, the mass difference causing the appearance of two additional maxima; it is as well to emphasize here that it is really the number of vibrations in the immediate neighbourhood of the maximum—what one might term the "weight" of the maximum—which is important, rather than the fact that the density becomes infinite. For instance, one obtains the first two maxima for very small mass differences, where one can hardly expect a perceptible difference in any physical property as compared with the case of equal masses.

Threshold Voltage Instabilities of Present SiC-Power MOSFETs under Positive Bias Temperature Stress

2016 ◽  
Vol 858 ◽  
pp. 481-484 ◽  
Author(s):  
Gerald Rescher ◽  
Gregor Pobegen ◽  
Tibor Grasser
Keyword(s):  
Temperature Stress ◽  
Threshold Voltage ◽  
Physical Property ◽  
Oxide Thickness ◽  
Positive Bias ◽  
Threshold Voltage Shift ◽  
Power Mosfets ◽  
Fundamental Physical Property ◽  
Bias Temperature Stress ◽  
Silicon Based

We study the threshold voltage (Vth) instability of commercially available silicon carbide (SiC) power MOSFETs or prototypes from four different manufacturers under positive bias temperature stress (PBTS). A positive bias near the Vth causes a threshold voltage shift of 0.7 mV per decade in time per nanometer oxide thickness in the temperature range between-50 °C and 150 °C. Recovery at +5 V after a 100 s +25 V gate-pulse causes a recovery between-1.5 mV/dec/nm and-1.0 mV/dec/nm at room temperature and is decreasing with temperature. All devices show similar stress, recovery and temperature dependent behavior indicating that the observed Vth instabilities are likely a fundamental physical property of the SiC-SiO2 system caused by electron trapping in near interface traps. It is important to note that the trapping is not causing permanent damage to the interface like H-bond-breakage in silicon based devices and is nearly fully reversible via a negative gate bias.

scholarly journals Macromolecular crowding limits growth under pressure

2021 ◽  
Author(s):  
Baptiste Alric ◽  
Cécile Formosa-Dague ◽  
Etienne Dague ◽  
Liam J Holt ◽  
Morgan Delarue
Keyword(s):  
Cell Growth ◽  
Macromolecular Crowding ◽  
Physical Property ◽  
Signaling Cascades ◽  
Yeast Saccharomyces Cerevisiae ◽  
Molecular Sensors ◽  
Confined Spaces ◽  
Microbial Infections ◽  
Domains Of Life ◽  
Fundamental Physical

Cells that grow in confined spaces eventually build up mechanical compressive stress. This growth-induced pressure (GIP) decreases cell growth. GIP is important in a multitude of contexts from cancer, to microbial infections, to biofouling, yet our understanding of its origin and molecular consequences remains limited. Here, we combine microfluidic confinement of the yeast Saccharomyces cerevisiae, with rheological measurements using genetically encoded multimeric nanoparticles (GEMs) to reveal that growth-induced pressure is accompanied with an increase in a key cellular physical property: macromolecular crowding. We develop a fully calibrated model that predicts how increased macromolecular crowding hinders protein expression and thus diminishes cell growth. This model is sufficient to explain the coupling of growth rate to pressure without the need for specific molecular sensors or signaling cascades. As molecular crowding is similar across all domains of life, this could be a deeply conserved mechanism of biomechanical feedback that allows environmental sensing originating from the fundamental physical properties of cells.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

A photoelectron microscope study of surfaces

1989 ◽  
Vol 47 ◽  
pp. 10-11
Author(s):  
W. Engel ◽  
M. Kordesch ◽  
A. M. Bradshaw ◽  
E. Zeitler
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Field Strength ◽  
Uv Light ◽  
Physical Property ◽  
Photon Flux ◽  
Mercury Lamp ◽  
Object Surface ◽  
The Sixties ◽  
Physical Features

Photoelectron microscopy is as old as electron microscopy itself. Electrons liberated from the object surface by photons are utilized to form an image that is a map of the object's emissivity. This physical property is a function of many parameters, some depending on the physical features of the objects and others on the conditions of the instrument rendering the image.The electron-optical situation is tricky, since the lateral resolution increases with the electric field strength at the object's surface. This, in turn, leads to small distances between the electrodes, restricting the photon flux that should be high for the sake of resolution.The electron-optical development came to fruition in the sixties. Figure 1a shows a typical photoelectron image of a polycrystalline tantalum sample irradiated by the UV light of a high-pressure mercury lamp.

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