Three atmospheric dispersion experiments involving oil fog plumes measured by lidar

The Wave Propagation Lab. participated with the U.S. Environmental Protection Agency in a series of experiments with the goal of developing and validating dispersion models that perform substantially better that models currently available. The lidar systems deployed and the data processing procedures used in these experiments are briefly described. Highlights are presented of conclusions drawn thus far from the lidar data

A Model-Based Reconstruction Method for Incomplete Projection Industrial Computed Tomography Imaging

In computerized tomography, the cross-sectioned image of an object can be reconstructed from a set of projection data. It provides the ability to image internal structure which can not be inspected effectively with alternate techniques. Based on the Fourier slice theorem[l], projections in a full angular range and with sufficiently fine angular spacing are required to reconstruct a unique image. In some situations, however, complete projections are not available due to physical limitations in the data acquisition process. Image quality is degraded by the absence of complete data. Because most manufactured parts were built from a designer’s blueprint or solid modeling electronic database, a great deal is known about the physical structure of the part. Incorporating a priori information extracted from the CAD model has the potential to enhance incomplete projection CT image quality. In this paper, a model-based CT reconstruction method is presented. The a priori information used to enhance incomplete projection CT image quality is extracted from a 3-D solid modeling electronic database. Engineering database matching is conducted to extract the proper 2D cross-sectioned model image corresponding to the CT projection plane. A moment-based registration method is applied to ensure proper use of a priori information for model-based CT reconstruction. Furthermore, a projection substitution scheme, including projection alignment and automatic scaling method, is developed so that the projection data in the missing angular range calculated from a model image can be automatically rescaled to match the projection data in the available angular range. Experimental results of applying the model-based CT reconstruction method to an industrial part in both the limited-angle and the penetration-limited incomplete projection situations are presented and described. It is shown that the use of a priori information from solid models is a powerful technique for enhancing the quality of incomplete data CT images

The aging male: investigation, treatment and monitoring of late-onset hypogonadism in males

Androgen deficiency in the aging male has become a topic of increasing interest and debate throughout the world. The demographics clearly demonstrate the increasing percentage of the population that is in the older age groups. The data also support the concept that testosterone falls progressively with age and that a significant percentage of men over the age of 60 years have serum testosterone levels that are below the lower limits of young adults (age 20-30 years) men. The principal questions raised by these observations are whether older hypogonadal men will benefit from testosterone treatment and what will be the risks associated with such intervention. The past decade has brought evidence of benefit of androgen treatment on multiple target organs of hypogonadal men and recent studies show short-term beneficial effects of testosterone in older men that are similar to those in younger men. Long-term data on the effects of testosterone treatment in the older population are limited and specific risk data on the prostate and cardiovascular systems are needed. Answers to key questions of functional benefits that may retard frailty of the elderly are not yet available. The recommendations described below were prepared for the International Society of Andrology (ISA) and the International Society for the Study of the Aging Male (ISSAM) following a panel discussion with active participation from the audience sponsored by the ISA on the topic at the 4th ISSAM Congress in Prague in February 2004.peer-reviewe

Strict detector-efficiency bounds for n-site Clauser-Horne inequalities

An analysis of detector-efficiency in many-site Clauser-Horne inequalities is presented, for the case of perfect visibility. It is shown that there is a violation of the presented n-site Clauser-Horne inequalities if and only if the efficiency is greater than n/(2n-1). Thus, for a two-site two-setting experiment there are no quantum-mechanical predictions that violate local realism unless the efficiency is greater than 2/3. Secondly, there are n-site experiments for which the quantum-mechanical predictions violate local realism whenever the efficiency exceeds 1/2.Comment: revtex, 5 pages, 1 figure (typesetting changes only

Improved Experimental Limits on the Production of Magnetic Monopoles

We present new limits on low mass accelerator-produced point-like Dirac magnetic monopoles trapped and bound in matter surrounding the D\O collision region of the Tevatron at Fermilab (experiment E-882). In the context of a Drell-Yan mechanism, we obtain cross section limits for the production of monopoles with magnetic charge values of 1, 2, 3, and 6 times the minimum Dirac charge of the order of picobarns, some hundred times smaller than found in similar previous Fermilab searches. Mass limits inferred from these cross section limits are presented.Comment: 5 pages, 4 eps figures, REVTe

The no-signaling condition and quantum dynamics

We show that the basic dynamical rules of quantum physics can be derived from its static properties and the condition that superluminal communication is forbidden. More precisely, the fact that the dynamics has to be described by linear completely positive maps on density matrices is derived from the following assumptions: (1) physical states are described by rays in a Hilbert space, (2) probabilities for measurement outcomes at any given time are calculated according to the usual trace rule, (3) superluminal communication is excluded. This result also constrains possible non-linear modifications of quantum physics.Comment: 4 page

Search for Magnetic Monopoles Trapped in Matter

There have been many searches for magnetic monopoles in flight, but few for monopoles in matter. We have searched for magnetic monopoles in meteorites, schists, ferromanganese nodules, iron ores and other materials. The detector was a superconducting induction coil connected to a SQUID (Superconducting Quantum Interference Device) with a room temperature bore 15 cm in diameter. We tested a total of more than 331 kg of material including 112 kg of meteorites. We found no monopole and conclude the overall monopole/nucleon ratio in the samples is $<1.2 \times 10^{-29}$ with a 90\% confidence level.Comment: 6 pages, rev tex, no figure

Quantum entanglement with acousto-optic modulators: 2-photon beatings and Bell experiments with moving beamsplitters

We present an experiment testing quantum correlations with frequency shifted photons. We test Bell inequality with 2-photon interferometry where we replace the beamsplitters by acousto-optic modulators, which are equivalent to moving beamsplitters. We measure the 2-photon beatings induced by the frequency shifts, and we propose a cryptographic scheme in relation. Finally, setting the experiment in a relativistic configuration, we demonstrate that the quantum correlations are not only independent of the distance but also of the time ordering between the two single-photon measurements.Comment: 14 pages, 16 figure