A proof of superlensing in the quasistatic regime, and limitations of superlenses in this regime due to anomalous localized resonance

2005 ◽  
Vol 461 (2064) ◽  
pp. 3999-4034 ◽  
Author(s):  
Graeme W Milton ◽  
Nicolae-Alexandru P Nicorovici ◽  
Ross C McPhedran ◽  
Viktor A Podolskiy
Keyword(s):  
Power Dissipation ◽  
Line Source ◽  
Applied Field ◽  
Small Extent ◽  
The Other ◽  
Special Structure ◽  
Rigorous Proof ◽  
Field Magnitude ◽  
Resonant Region ◽  
Quasistatic Regime

Enlarging upon work of Nicorovici, McPhedran & Milton ( Nicorovici et al . 1994 Phys. Rev. B 49 (12), 8479–8482), a rigorous proof is given that in the quasistatic regime a cylindrical superlens can successfully image a dipole line source in the limit as the loss in the lens tends to zero. In this limit it is proved that the field magnitude diverges to infinity in two sometimes overlapping annular anomalously locally resonant regions, one of which extends inside the lens and the other of which extends outside the lens. The wavelength of the oscillations in the locally resonant regimes is set by the geometry and the loss, and goes to zero as the loss goes to zero. If the object or source being imaged responds to an applied field it is argued that it must lie outside the resonant regions to be successfully imaged. If the image is being probed it is argued that the resonant regions created by the probe should not surround the tip of the probe. These conditions taken together make it difficult to directly probe the potential in the near vicinity of the image of a source or object having small extent. The corresponding quasistatic results for the slab lens are also derived. If the source is too close to the slab lens, i.e. lying within the resonant region, then the power dissipation in the lens tends to infinity as the loss goes to zero, which makes the lens impractical for imaging such quasistatic sources. Perfect imaging in a cylindrical superlens is shown to extend to the static equations of magnetoelectricity or thermoelectricity, provided they have a special structure which makes these equations equivalent to the quasistatic equations.

Re-adjustments for MOM calculations of microstrip and stripline power dissipation

2020 ◽  
pp. 1-11
Author(s):  
Frederick Huang
Keyword(s):  
Magnetic Field ◽  
Method Of Moments ◽  
Current Density ◽  
Power Dissipation ◽  
Finite Thickness ◽  
The Other ◽  
Integration Limit ◽  
Large Current ◽  
Large Current Density ◽  
Parallel Strips

Abstract Microstrip and stripline losses in Method of Moments (MOM) calculations have an error arising from the large current density at the strip edges, characterized by an integration limit (W/2-d) in the equation for current density in thin strips (width W), where d is a fitting parameter. It depends primarily on the width of the MOM subsection on the edge of the strip. By comparing with the integration limit (W/2-Δ) for an actual strip with finite thickness, a correction factor is estimated. The equations incorporating d are confirmed by comparing with MOM calculations of isolated stripline, uniformly spaced parallel strips, striplines and microstrips close to ground planes, and with a strip in a uniform, externally applied magnetic field. The results are also consistent with measurements with copper. This makes the accuracy of the loss estimates commensurate with the excellence of the other aspects of MOM simulations.

scholarly journals III. On unequal electric conduction-resistance at cathodes

1884 ◽  
Vol 37 (232-234) ◽  
pp. 35-36
Keyword(s):  
Small Extent ◽  
The Other ◽  
Total Resistance ◽  
Electric Conduction ◽  
Thermo Electric ◽  
Contact Potential ◽  
Chemical Action ◽  
Negative Plate ◽  
Action Films ◽  
New Phenomena

During some experiments which I have been making on the unequal resistance to the deposition of a metal upon cathodes of different metals in the same solution by the same current (see “Some New Phenomena of Electrolysis”), I have been led to investigate the resistance of cathodes of different metals to the passage of the current into them. I have found that by taking a good conducting electrolyte, immersing in it a positive sheet of zinc, and a smaller negative one of another metal, connecting the plates with a galvanometer of low resistance, reducing all the other resistances in the circuit to the minimum except that of the negative plate; then making a series of measurements of strengths of current of different couples formed by the zinc and about twelve other metals, during removal of polarisation by stirring the liquid; also making another series of measurements of the electromotive forces of the same couples during stirring; calculating from these data the total resistance in each case, then deducting the portion of resistance due to the galvanometer, also that due to the liquid itself, and to opposing contact-potential, and thermo-electric and voltaic action at the cathode and external junction, very different amounts of resistance, large in some cases, remain, and are exercised by different metals as cathodes, and those differences of resistance are only to a small extent due to heat and current absorbed in liberating hydrogen, and can only in a few cases be partly accounted for by chemical action, films, or absorption of gases at the cathode.

The Polarizability of Molecular Hydrogen H2

1936 ◽  
Vol 32 (2) ◽  
pp. 260-264 ◽  
Author(s):  
C. E. Easthope
Keyword(s):  
Wave Function ◽  
Perturbation Theory ◽  
Molecular Hydrogen ◽  
Applied Field ◽  
Minimum Energy ◽  
Wave Functions ◽  
The Other ◽  
System A ◽  
The One ◽  
Two Parameter

1. The problem of calculating the polarizability of molecular hydrogen has recently been considered by a number of investigators. Steensholt and Hirschfelder use the variational method developed by Hylleras and Hassé. For ψ0, the wave function of the unperturbed molecule when no external field is present, they take either the Rosent or the Wang wave function, while the wave functions of the perturbed molecule were considered in both the one-parameter form, ψ0 [1+A(q1 + q2)] and the two-parameter form, ψ0 [1+A(q1 + q2) + B(r1q1 + r2q2)], where A and B are parameters to be varied so as to give the system a minimum energy, q1 and q2 are the coordinates of the electrons 1 and 2 in the direction of the applied field as measured from the centre of the molecule, and r1 and r2 are their respective distances from the same point. Mrowka, on the other hand, employs a method based on the usual perturbation theory. Their numerical results are given in the following table.

scholarly journals 690 PB 262 EFFECT OF IRRIGATION ON THE YIELD AND YIELD COMPONENTS OF TOMATO

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 531f-531
Author(s):  
Daniel Smeal ◽  
E.J. Gregory ◽  
R.N. Arnold ◽  
J. Tomko
Keyword(s):  
New Mexico ◽  
Line Source ◽  
Yield Components ◽  
Fruit Yield ◽  
The Other ◽  
Regression Coefficients ◽  
Average Weight ◽  
Positive Correlation ◽  
Yield And Yield Components ◽  
Marketable Fruit

A single sprinkler line-source was used to provide irrigation treatments to three tomato (Lycopersicon escu Mill.) varieties (`Baja', `Rowpac', and `Roza') during 1988 and 1989 in northwestern New Mexico. In both years, marketable fruit yield (Y) of all varieties increased linearly with increased irrigation (1). However, the regression coefficients describing the Y vs. I relationship differed with variety and year. In 1989, `Rowpac' Y ranged from 40.3 to 114.2 Mg ha-1 at levels of 31.5 and 62.5 cm, respectively. Yields of `Baja' and `Roza', while similar to those of `Rowpac' at low I levels, were 59% and 71% of `Rowpac' Y, respectively, at the highest level of irrigation. At any given I level, Y was lower in 1988 than in 1989. While average weight per fruit (wt/fruit) and number of fruit per plant (no/plant) increased with increasing I level in all varieties, increased Y in `Rowpac' had a higher positive correlation with no/plant (40 to 90) than with wt/fruit (85 to 120 g). Increasing Y in `Baja' on the other hand, correlated much better with increased wt/plant (100 to 195 g) than no/plant (20 to 45).

scholarly journals Prasa lokalna jako źródło do badań dialektologicznych (na przykładzie kieleckich „Przemian”)

2021 ◽  
pp. 11-25
Author(s):  
Stanisław Cygan
Keyword(s):  
Small Extent ◽  
The Other ◽  
Valuable Source ◽  
Language System ◽  
The One ◽  
Printed Sources

The local press is used to a small extent for dialectological studies. In the article, I present a review and typology of press materials contained in the Kielce socio-cultural monthly „Przemiany” (Transformation, 1970–1989), which is a valuable source of language material, primarily for Polish dialectical lexicography, but also for the study of the language system of the Kielce dialects from the 1980s and 1990s. The sociolinguistic aspect is included in the description of dialects in the analyzed press texts. On the one hand, Kielce dialect materials broaden the number of printed sources for the issued Polish dialect dictionary, and on the other – they can be well used when developing a regional glossary.

scholarly journals A Mechanically Checked Proof of IEEE Compliance of the Floating Point Multiplication, Division and Square Root Algorithms of the AMD-K7™ Processor

1998 ◽  
Vol 1 ◽  
pp. 148-200 ◽  
Author(s):  
David M. Russinoff
Keyword(s):  
Register Transfer Level ◽  
The Other ◽  
Floating Point ◽  
Square Root ◽  
Rigorous Proof ◽  
Point Multiplication ◽  
Logical Operations ◽  
Other Hand ◽  
Ieee Standard ◽  
Proof Of Correctness

AbstractWe describe a mechanically verified proof of correctness of the floating point multiplication, division, and square root instructions of the AMD-K7 microprocessor. The instructions are implemented in hardware and represented here by register-transfer level specifications, the primitives of which are logical operations on bit vectors. On the other hand, the statements of correctness, derived from IEEE Standard 754, are arithmetic in nature and considerably more abstract. Therefore, we begin by developing a theory of bit vectors and their role in floating point representations and rounding. We then present the hardware model and a rigorous proof of its correctness. All of our definitions, lemmas and theorems have been formally encoded in the ACL2 logic, and every step in the proof has been mechanically checked with the ACL2 prover.

General discussion after session I

1988 ◽  
Vol 325 (1587) ◽  
pp. 439-443
Keyword(s):  
Interstellar Medium ◽  
Recent Literature ◽  
Small Extent ◽  
The Other ◽  
Stable Form ◽  
Main Question ◽  
Rich Medium ◽  
The Earth ◽  
The Subject ◽  
Abundance Anomalies

D. A. Williams ( UMIST, Manchester, U. K. ) . I wish to highlight some of the interesting and possibly controversial points that were raised. Professor Tayler gave us a very good introduction to the subject and I expect we shall discuss the questions that he raised on abundance anomalies and in particular the survival of grains. There are two particular aspects that interest me. First there is deuterium fractionation in the interstellar medium and it is, of course, known that deuterium fractionation occurs in meteorite material. That seems to indicate that material was fractionated in cold conditions and that the conditions have remained cold ever since because, if the temperature gets above ca . 200 K, that fractionation will disappear. The other point that I found particularly interesting in recent literature is the detection of diamond in the carbonaceous component of certain meteorites and again this seems to indicate a low-temperature regime for that particular material; diamond not being the most stable form of carbon. In Professor Kroto’s stimulating talk there were raised a number of questions, but not so much about chemistry of the interstellar medium as on chemistry in the laboratory or possibly chemistry in circumstellar regions; the main question that I would expect to hear discussed today is that of the applicability of what he has done. Very exciting though it is, there is some uncertainty about the applicability of his work to the problems that we are considering in this particular meeting. The conditions that you might find in the circumstellar regions are obviously not going to be quite like the conditions produced in the laboratory. The second important question that I would expect to be addressed in discussion now is the following. As material moves out of the circumstellar regions into the interstellar regions are the structures that Professor Kroto was describing expected to persist or not? He mentioned that C 60 may be formed in Bunsen burners and he also said that C 60 is very stable. If that is so why is all carbon on the earth not in the form of C 60 ? There must be some destruction mechanisms applying to these structures. Actually, if one makes amorphous carbon by having a surface in a carbon rich medium then, in fact, one does not get the sort of structures that he talked about. A mixture of diamond-like and graphitic-like regions of fairly small extent, perhaps a few tens of angstroms, is found.

scholarly journals II. On the change of absorption produced by fluorescence

1898 ◽  
Vol 191 ◽  
pp. 87-104 ◽  
Keyword(s):  
Small Extent ◽  
The Body ◽  
The Other ◽  
Fluorescent Light ◽  
Small Thickness ◽  
Similar Body ◽  
Absorption Power

About two years ago, in the spring of 1895, in the course of a conversation with Professor J. H. Poynting on the nature of the phenomenon of fluorescence, in the study of which I was at the time beginning to engage, the suggestion was thrown out by him that possibly fluorescent bodies absorb differently, according as they are fluorescing or not, the rays which they give out whilst fluorescing, thus that a body A would absorb differently, according as it is fluorescing or not, the rays from a similar body B in a state of fluorescence. Some fluorescent bodies undoubtedly do, others do not, absorb, except to a very small extent, the rays which they emit. A strong solution of fluorescin or eosin, for instance, hardly permits its fluorescent light to penetrate even a very small thickness. Glass coloured with oxide of uranium is much more transparent, but sulphate of quinine hardly absorbs these rays at all. The question was whether during the act of fluorescing any change is produced in the nature of the absorption itself, that is, whether during fluorescence there is an increase or diminution of absorption in that part of the spectrum where the emitted rays lie. For instance, with uranium glass the radiation takes place chiefly between the D and E lines, so that the absorption power for rays may be different according as the body is examined in the dark or in daylight in this part of the spectrum. Of the five bright bands of which the radiation consists, three lie between the D and E lines, the other two being of less refrangibility and of less intensity in the red and orange (Stokes, ‘Phil. Trans.,' 1852). With the spectroscope I have used I have not been able to see the band in the red, but the other four were quite distinct. The spectrum seemed to me to be of the nature of maxima and minima.

A note on viscous flow induced by half-line sources bounded by conical surfaces

2019 ◽  
Author(s):  
Prabakaran Rajamanickam ◽  
Adam D Weiss
Keyword(s):  
Radial Velocity ◽  
Line Source ◽  
Stokes Equations ◽  
Reynolds Numbers ◽  
The Other ◽  
Half Line ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Axisymmetric Solutions ◽  
Conical Surfaces

Summary In this article, axisymmetric solutions of the Navier–Stokes equations governing the flow induced by a half-line source when the fluid domain is bounded by a conical wall are discussed. Two types of boundary conditions are identified; one in which the radial velocity along the axis is prescribed, and the other in which the radial velocity along the axis is obtained as an eigenvalue of the problem. The existence of these solutions is limited to a range of Reynolds numbers, and the transition from one case to the other is discussed in detail.

The Italian line in English after Chaucer

2002 ◽  
Vol 11 (4) ◽  
pp. 291-305 ◽  
Author(s):  
Martin J. Duffell
Keyword(s):  
Small Extent ◽  
The Other ◽  
Random Deployment ◽  
Other Hand ◽  
Long Line ◽  
Iambic Pentameter ◽  
Distinguishing Features

This article argues that the English iambic pentameter (EIP) has other important features in addition to the five parameters identified by Hanson and Kiparsky’s (1996) parametric theory ( position number and size, orientation, prominence site and type). One of these features is that EIP contains a mixture of pausing (French) and running (Italian) lines, as determined by whether the syllable in position 4 is word-final. A study of the frequency with which the Italian line is used in the two centuries after Chaucer’s death reveals that Hoccleve and the Scots poets, Henryson, Dunbar and Douglas, adhered fairly closely to Chaucer’s EIP verse design. On the other hand, several generations of English poets, Lydgate, Wyatt, Surrey and Sidney, experimented with alternative types of line that might well have developed into the canonical English long-line metre. Ultimately, however, the examples of Spenser and Shakespeare proved decisive in ensuring the victory of Chaucer’s metre. Between the 17th and 19th centuries, Donne, Milton, Dryden, Pope, Wordsworth, Keats and Browning were among the major poets who consolidated that victory and exploited the Italian line in order to accommodate their own or their age’s choice of diction. The mixture of French and Italian lines in decasyllabic verse is one of the distinguishing features of EIP. Although other factors affect the proportions in this mixture to a small extent, they are primarily the result of individual poets’ aesthetic choice. Significantly, all the English poets after Spenser whose verse is analysed in this article have favoured a more evenly balanced mixture of French and Italian lines than the random deployment of their lexicon would have produced.

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