Focalization of Heat Waves in an Inhomogeneous System

2019 ◽  
Vol 44 (3) ◽  
pp. 303-313
Author(s):  
Antonio Sellitto ◽  
Ada Amendola ◽  
David Jou

Abstract Curved interfaces between material media with different characteristic speed for heat waves may be the basis for thermal lenses, concentrating the energy carried by parallel thermal rays on a focal point. This may be of practical use for the amplification of thermal signals and for the development of sensitive thermal sensors. When dissipative attenuation effects are taken into account, it turns out that these lenses could be of special interest in miniaturized probes, or in micro/nanosystems, and the optimization of the thermal lens for signal amplification may be calculated.

2021 ◽  
Vol 4 (1) ◽  
pp. 262-286
Author(s):  
Lev S. Perepiolkin

The focal point of the book under review is Europe as well as its interaction on the level of supply of resources with other regions of the world, primarily with the East. The author expands the usual notion of the “East”. He extends its boundaries to the regions, which supplied Europe with resources, starting with the actual East and extending it to the European North and even America. The author identifies a change in the main types of resources supply, from the wood and other commodities followed by luxury goods and energy carriers. The author shows a special interest in the influence of resource exchange on social processes in Europe and the East, as well as the formation of European academic economic thought. He also pays special attention to environmental problems related to the resource economy.


1997 ◽  
Vol 7 (1) ◽  
pp. 4-7
Author(s):  
Major Augustus Clement
Keyword(s):  

2020 ◽  
Vol 43 ◽  
Author(s):  
John Corbit ◽  
Chris Moore

Abstract The integration of first-, second-, and third-personal information within joint intentional collaboration provides the foundation for broad-based second-personal morality. We offer two additions to this framework: a description of the developmental process through which second-personal competence emerges from early triadic interactions, and empirical evidence that collaboration with a concrete goal may provide an essential focal point for this integrative process.


Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.


Author(s):  
R. W. Carpenter ◽  
I.Y.T. Chan ◽  
J. M. Cowley

Wide-angle convergent beam shadow images(CBSI) exhibit several characteristic distortions resulting from spherical aberration. The most prominent is a circle of infinite magnification resulting from rays having equal values of a forming a cross-over on the optic axis at some distance before reaching the paraxial focal point. This distortion is called the tangential circle of infinite magnification; it can be used to align and stigmate a STEM and to determine Cs for the probe forming lens. A second distortion, the radial circle of infinite magnification, results from a cross-over on the lens caustic surface of rays with differing values of ∝a, also before the paraxial focal point of the lens.


Author(s):  
Gertrude F. Rempfer

I became involved in electron optics in early 1945, when my husband Robert and I were hired by the Farrand Optical Company. My husband had a mathematics Ph.D.; my degree was in physics. My main responsibilities were connected with the development of an electrostatic electron microscope. Fortunately, my thesis research on thermionic and field emission, in the late 1930s under the direction of Professor Joseph E. Henderson at the University of Washington, provided a foundation for dealing with electron beams, high vacuum, and high voltage.At the Farrand Company my co-workers and I used an electron-optical bench to carry out an extensive series of tests on three-electrode electrostatic lenses, as a function of geometrical and voltage parameters. Our studies enabled us to select optimum designs for the lenses in the electron microscope. We early on discovered that, in general, electron lenses are not “thin” lenses, and that aberrations of focal point and aberrations of focal length are not the same. I found electron optics to be an intriguing blend of theory and experiment. A laboratory version of the electron microscope was built and tested, and a report was given at the December 1947 EMSA meeting. The micrograph in fig. 1 is one of several which were presented at the meeting. This micrograph also appeared on the cover of the January 1949 issue of Journal of Applied Physics. These were exciting times in electron microscopy; it seemed that almost everything that happened was new. Our opportunities to publish were limited to patents because Mr. Farrand envisaged a commercial instrument. Regrettably, a commercial version of our laboratory microscope was not produced.


Author(s):  
P.M. Houpt ◽  
A. Draaijer

In confocal microscopy, the object is scanned by the coinciding focal points (confocal) of a point light source and a point detector both focused on a certain plane in the object. Only light coming from the focal point is detected and, even more important, out-of-focus light is rejected.This makes it possible to slice up optically the ‘volume of interest’ in the object by moving it axially while scanning the focused point light source (X-Y) laterally. The successive confocal sections can be stored in a computer and used to reconstruct the object in a 3D image display.The instrument described is able to scan the object laterally with an Ar ion laser (488 nm) at video rates. The image of one confocal section of an object can be displayed within 40 milliseconds (1000 х 1000 pixels). The time to record the total information within the ‘volume of interest’ normally depends on the number of slices needed to cover it, but rarely exceeds a few seconds.


2008 ◽  
Vol 17 (2) ◽  
pp. 62-68 ◽  
Author(s):  
Cathy Binger

Abstract Many children who use AAC experience difficulties with acquiring grammar. At the 9th Annual Conference of ASHA's Special Interest Division 12, Augmentative and Alternative Communication, Binger presented recent research results from an intervention program designed to facilitate the bound morpheme acquisition of three school-aged children who used augmentative and alternative communication (AAC). Results indicated that the children quickly began to use the bound morphemes that were taught; however, the morphemes were not maintained until a contrastive approach to intervention was introduced. After the research results were presented, the conference participants discussed a wide variety of issues relating to grammar acquisition for children who use AAC. Some of the main topics of discussion included the following: provision of supports for grammar comprehension and expression, intervention techniques to support grammatical morpheme acquisition, and issues relating to AAC device use when teaching grammatical morpheme use.


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