Application of digital computer techniques to rectification and enhancement of astronomical images

An image processing program is reported to analyze the high resolution images obtained by the balloon borne 36 in. diameter stratoscope 2 telescope. A film recording device is described which is capable of converting numerical data from the computer into photographic images

An inversion in the atmosphere of Titan

A very detailed greenhouse model derives a methane to hydrogen ratio of unity and a minimum surface pressure of 0.4 atm. Based on a surface gravity g = 140 cm sec/2, the minimum CH4 abundance is 30-40 km-A and the minimum H2 abundance varies from 15 to 85 km-A. A model of the atmosphere of Titan is proposed which seems to be consistent with observations and requires a much smaller CH4 abundance (of the order or 2 km-atm). Although no H2 is required, the presence of some H2 is readily accommodated. In this model, a temperature inversion exists in the atmosphere due to absorption of blue and ultraviolet solar radiation by small particles. The absorbed radiation is re-radiated by the dust and by molecules having long wavelength bands such as CH4 7.7 micrometer and ethane at 12.2 micrometer. The brightness temperature at 20 micrometer is primarily due to re-radiation by the dust

Vibrational Feshbach Resonances Mediated by Nondipole Positron-Molecule Interactions

Measurements of energy-resolved positron-molecule annihilation show the existence of positron binding and vibrational Feshbach resonances. The existing theory describes this phenomenon successfully for the case of infrared-active vibrational modes which allow dipole coupling between the incident positron and the vibrational motion. Presented here are measurements of positron-molecule annihilation made using a recently developed cryogenic positron beam capable of significantly improved energy resolution. The results provide evidence of resonances associated with infrared-inactive vibrational modes, indicating that positron-molecule bound states may be populated by nondipole interactions. The anticipated ingredients for a theoretical description of such interactions are discussed.Comment: 5 pages, 2 figures, Phys. Rev. Lett. (in press

High resolution vertical profiles of wind, temperature and humidity obtained by computer processing and digital filtering of radiosonde and radar tracking data from the ITCZ experiment of 1977

Results are presented from computer processing and digital filtering of radiosonde and radar tracking data obtained during the ITCZ experiment when coordinated measurements were taken daily over a 16 day period across the Panama Canal Zone. The temperature relative humidity and wind velocity profiles are discussed

Mode coupling and multiquantum vibrational excitations in Feshbach-resonant positron annihilation in molecules

The dominant mechanism of low-energy positron annihilation in polyatomic molecules is through positron capture in vibrational Feshbach resonances (VFR). In this paper we investigate theoretically the effect of anharmonic terms in the vibrational Hamiltonian on the positron annihilation rates. Such interactions enable positron capture in VFRs associated with multiquantum vibrational excitations, leading to enhanced annihilation. Mode coupling can also lead to faster depopulation of VFRs, thereby reducing their contribution to the annihlation rates. To analyze this complex picture, we use coupled-cluster methods to calculate the anharmonic vibrational spectra and dipole transition amplitudes for chloroform, chloroform-$d_1$, 1,1-dichloroethylene, and methanol, and use these data to compute positron resonant annihilation rates for these molecules. Theoretical predictions are compared with the annihilation rates measured as a function of incident positron energy. The results demonstrate the importance of mode coupling in both enhancement and suppression of the VFR. There is also experimental evidence for the direct excitation of multimode VFR. Their contribution is analyzed using a statistical approach, with an outlook towards more accurate treatment of this phenomenon.Comment: 16 pages, 10 figures, submitted to Phys. Rev.

Obtaining the Quantum Fourier Transform from the Classical FFT with QR Decomposition

We present the detailed process of converting the classical Fourier Transform algorithm into the quantum one by using QR decomposition. This provides an example of a technique for building quantum algorithms using classical ones. The Quantum Fourier Transform is one of the most important quantum subroutines known at present, used in most algorithms that have exponential speed up compared to the classical ones. We briefly review Fast Fourier Transform and then make explicit all the steps that led to the quantum formulation of the algorithm, generalizing Coppersmith's work.Comment: 12 pages, 1 figure (generated within LaTeX). To appear in Journal of Computational and Applied Mathematic

Cultural heritage compensation: Approaches to transformation of sites with cultural values and architectural qualities

This proceeding is the last part of a research project investigating how compensation is expressed in designing detailed development plans in areas with heritage values and architectural qualities. The overall objective of the research project has been to produce new knowledge about heritage compensation as a concept, method and tool in planning processes. The researh project have been granted funding from the Swedish National Heritage Board’s R&D.The proceeding presents the third part of the project – the international workshop – called Architecture, cultural environment and compensation in planning processes. The workshop took place at Chalmers University of Technology in Gothenburg, 16-17 September 2019, and was organized as a joint venture between Kulturlandskapet (a cooperative heritage consultancy) and Building Design, Department of Architecture and Civil Engineering, Chalmers University of Technology. The theme in the invitation was summarized in the following way: On compensation as a concept, method and professional practice by architects, architectural conservators and archaeologists in planning processes. Ten scholars from contribute to the proceeding: Tom Davies, \ua0Athanasios Kouzelis, Mathilde Kirkegaard, Anders Larsson, Urban Nilsson, David Ross, Magnus R\uf6nn, Jennie Sj\uf6holm and Helena Ter\ue4v\ue4inen

Electrical properties of magnesium silicide and magnesium germanide

Single crystals of Mg2Si and Mg2Ge, of high purity, on the order of 1 mm x 1 mm x 1 em in size were obtained, and measurements were made of their electrical resistivities and Hall coefficients in the temperature range 60°K- 1000°K. Both compounds behaved typically as excess impurity semiconductors and exhibited apparent intrinsic conduction above 450°K