Experimental verification of theoretical relations between total gas absorptivities and total gas emissivities for CO

An experimental study has been carried out for the purpose of verifying theoretical predictions concerning the relations between total absorptivities and total emissivities for transparent gases. The experimental conditions have been designed in such a way as to permit a direct check of theoretical relations derived for (a) nonoverlapping dispersion lines and (b) spectral lines with sufficient pressure broadening to permit neglect of the rotational fine structure. A comparison between the emissivities derived from absorptivity measurements and emissivities calculated from the spectroscopic constants of CO shows a good agreement (within 20% for most of the temperature range). The apparatus for the measurement of total gas absorptivities is described. Results for total absorptivities of carbon monoxide measured at temperatures between 300 and 500°K are given and total emissivities have been calculated in the temperature range of 300 to 1600°K. The range of total gas pressure is 0 to 515 psia

Statistics of statisticians: Critical mass of statistics and operational research groups in the UK

Using a recently developed model, inspired by mean field theory in statistical physics, and data from the UK's Research Assessment Exercise, we analyse the relationship between the quality of statistics and operational research groups and the quantity researchers in them. Similar to other academic disciplines, we provide evidence for a linear dependency of quality on quantity up to an upper critical mass, which is interpreted as the average maximum number of colleagues with whom a researcher can communicate meaningfully within a research group. The model also predicts a lower critical mass, which research groups should strive to achieve to avoid extinction. For statistics and operational research, the lower critical mass is estimated to be 9 $\pm$ 3. The upper critical mass, beyond which research quality does not significantly depend on group size, is about twice this value

The Waters are Rising! Why Isn\u27t My Tax Basis Sinking? Why Coastal Land Should be a Depreciable Asset in Light of Global Warming and the Rise in Sea Level

Depreciation deductions are the Internal Revenue Code\u27s method of allowing taxpayers to take deductions on long-term investments. Unlike normal deductions, depreciation requires the taxpayer to apportion the expense over the life of the asset. While most assets used for the production of income may be depreciated, the Internal Revenue Service and courts have never allowed land to be depreciated. The treatment of land as a non-depreciable asset is deeply rooted in the idea that it does not have a useful life -- it lasts forever. However, global temperature has risen rapidly over the past fifty years and is expected to grow even faster in the future. This causes ice caps to melt and oceans to expand, which leads to a rise in sea level. The rise in sea level means that many coastal property owners will see a decrease in their property size as the sea inundates the dry land. This is because the public trust doctrine converts navigable waters into public property. As such, coastal property is now a wasting asset because private lands are becoming public once they are underwater. This note argues that in light of global warming, coastal property should be a depreciable asset. By looking at existing tax doctrine and drawing comparisons to other types of depreciable property, this note explains why coastal property should be depreciable and how this change could be implemented under existing tax policy. Finally, this note argues that even if coastal property is not depreciable, coastal property owners should, in the alternative, be allowed to take depletion deductions

When does noise increase the quantum capacity?

Superactivation is the property that two channels with zero quantum capacity can be used together to yield positive capacity. Here we demonstrate that this effect exists for a wide class of inequivalent channels, none of which can simulate each other. We also consider the case where one of two zero capacity channels are applied, but the sender is ignorant of which one is applied. We find examples where the greater the entropy of mixing of the channels, the greater the lower bound for the capacity. Finally, we show that the effect of superactivation is rather generic by providing example of superactivation using the depolarizing channel.Comment: Corrected minor typo

Unconditional privacy over channels which cannot convey quantum information

By sending systems in specially prepared quantum states, two parties can communicate without an eavesdropper being able to listen. The technique, called quantum cryptography, enables one to verify that the state of the quantum system has not been tampered with, and thus one can obtain privacy regardless of the power of the eavesdropper. All previous protocols relied on the ability to faithfully send quantum states. In fact, until recently, they could all be reduced to a single protocol where security is ensured though sharing maximally entangled states. Here we show this need not be the case -- one can obtain verifiable privacy even through some channels which cannot be used to reliably send quantum states.Comment: Related to quant-ph/0608195 and for a more general audienc

The Polish Church Examines Its Conscience

Focuses on the conference entitled `Examination of Conscience: the Polish church Confronts Anti-Semitism, 1989-1999,\u27 held on January 20 at the Loyola Marymount University in Los Angeles, California

Are the laws of entanglement theory thermodynamical?

We argue that on its face, entanglement theory satisfies laws equivalent to thermodynamics if the theory can be made reversible by adding certain bound entangled states as a free resource during entanglement manipulation. Subject to plausible assumptions, we prove that this is not the case in general, and discuss the implications of this for the thermodynamics of entanglement.Comment: 4 pages, 1 figure, Revtex4; to appear in Phys. Rev. Let

Are there phase transitions in information space?

The interplay between two basic quantities -- quantum communication and information -- is investigated. Quantum communication is an important resource for quantum states shared by two parties and is directly related to entanglement. Recently, the amount of local information that can be drawn from a state has been shown to be closely related to the non-local properties of the state. Here we consider both formation and extraction processes, and analyze informational resources as a function of quantum communication. The resulting diagrams in information space allow us to observe phase-like transitions when correlations become classical.Comment: 4 pages, 3 epsi figures, to appear in Phys. Rev. Let

Reactant Jetting in Unstable Detonation

We note the common existence of a supersonic jet structure locally embedded within a surrounding transonic flow field in the hitherto unrelated phenomena of unstable gaseous detonation and hypervelocity blunt body shock wave interaction. Extending prior results that demonstrate the consequences of reduced endothermic reaction rate for the supersonic jet fluid in the blunt body case, we provide an explanation for observations of locally reduced OH PLIF signal in images of the keystone reaction zone structure of weakly unstable detonations. Modeling these flow features as exothermically reacting jets with similarly reduced reaction rates, we demonstrate a mechanism for jetting of bulk pockets of unreacted fluid with potentially differing kinetic pathways into the region behind the primary detonation front of strongly unstable mixtures. We examine the impact of mono-atomic and diatomic diluents on transverse structure. The results yield insight into the mechanisms of transition and characteristic features of both weakly and strongly unstable mixtures