Quantitative evaluation of multiband photographic techniques Final report

Quantitative evaluation of multiband photographic techniques using combination of black and white and color photo

Global Atmospheric Aerosol Modeling

Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models

Bremsstrahlung in alpha-Decay Reexamined

A high-statistics measurement of bremsstrahlung emitted in the alpha decay of 210Po has been performed, which allows to follow the photon spectra up to energies of ~ 500 keV. The measured differential emission probability is in good agreement with our theoretical results obtained within the quasi classical approximation as well as with the exact quantum mechanical calculation. It is shown that due to the small effective electric dipole charge of the radiating system a significant interference between the electric dipole and quadrupole contributions occurs, which is altering substantially the angular correlation between the alpha particle and the emitted photon.Comment: 10 pages, 5 figures, v2: fix of small typo

Beaverdale Neighborhood Charter Plan Update

In September of 2011, the Beaverdale Neighborhood Association (BNA) filed an application to participate in the pilot Charter Neighborhood Program in order to update its original plan that was approved in 1991 with new goals for the future. On November 21, 2011, the Des Moines City Council approved the selection of Beaverdale as one of the five neighborhoods to participate in the Charter Neighborhood Program. Neighborhoods selected for the pilot program worked with City staff as well as graduate students from Iowa State University’s Department of Community and Regional Planning (ISU Planning Team) to update their respective neighborhood plans. Over the past two decades, major goals in the first Beaverdale Neighborhood plan have been accomplished. However, new issues have emerged as well, which brings about the need to establish a strategic plan for the Beaverdale Neighborhood for the next 5 to 10 years.https://lib.dr.iastate.edu/resilientneighborhoods_plans/1003/thumbnail.jp

Diffraction microtomography with sample rotation: influence of a missing apple core in the recorded frequency space

Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives morphological information only, diffraction microtomography makes it possible to obtain the complex optical refractive index of the observed sample by mapping a three-dimensional support in the spatial frequency domain. The technique can be implemented in two configurations, namely, by varying the sample illumination with a fixed sample or by rotating the sample using a fixed illumination. In the literature, only the former method was described in detail. In this report, we precisely derive the three-dimensional frequency support that can be mapped by the sample rotation configuration. We found that, within the first-order Born approximation, the volume of the frequency domain that can be mapped exhibits a missing part, the shape of which resembles that of an apple core. The projection of the diffracted waves in the frequency space onto the set of sphere caps covered by the sample rotation does not allow for a complete mapping of the frequency along the axis of rotation due to the finite radius of the sphere caps. We present simulations of the effects of this missing information on the reconstruction of ideal objects.Comment: 7 pages, 11 figures, presented at Focus On Microscopy 200

Post-LGM environments and foragers on the move: New data from the lower Altmühl Valley (Franconian Jura, SE Germany)

After the Last Glacial Maximum, the Swabian and Franconian Jura (in SW and SE Germany, respectively) were repopulated by Magdalenian hunter-gatherers within the same communication network. However, while the Magdalenian settlement of the Swabian Jura dates to 17-14 ka cal BP, permanent Magdalenian occupations in the Franconian Jura date to 15-14 ka cal BP. In comparison with its western counterpart, the Franconian Jura was mostly excavated in the early days of archaeological research. Does this different chronology reflect the different history of research? Why did Magdalenian foragers establish permanent occupation in the Franconian Jura nearly 2 millennia after settling in Swabia, despite the fact these regions are only 150 km apart? To address these questions, we reinvestigated two sites in the Altmithl Valley with micromorphology and luminescence dating, namely Felsenhausl-Kellerhohle and Klausennische. Our data show that both sites have intact Pleistocene deposits. Among these, we identified sediments dating between 17 and 15 ka that show only rare lithic artifacts and microfeatures indicative of cold and arid conditions. Our work and published data suggest that the steady settlement of Magdalenian foragers in the Altmithl Valley starting 15 ka cal BP coincides with the end of this harsh period and the onset of cool and wetter environments. Data from the Swabian Jura demonstrated that in the Lone Valley, similar environments and Magdalenian occupations commenced earlier, starting 17 ka cal BR. Therefore, we propose that regional environments acted as a barrier against the dispersal of foragers in the Franconian Jura and determined its later Magdalenian occupation. Our research highlighted that different environments, taphonomic processes, and site uses probably coexisted across the German Jura. Therefore, it remains fundamental to expand the multisite data set proposed in this article to further test hypotheses about human/environment interaction in this region. (C) 2022 The Author(s). Published by Elsevier Ltd.info:eu-repo/semantics/publishedVersio

M32+/-1

WFPC-2 images are used to study the central structure of M31, M32, and M33. The dimmer peak, P2, of the M31 double nucleus is centered on the bulge to 0.1", implying that it is the dynamical center of M31. P2 contains a compact source discovered by King et al. (1995) at 1700 A. This source is resolved, with r_{1/2} approx0.2 pc. It dominates the nucleus at 3000 A, and is consistent with late B-early A stars. This probable cluster may consist of young stars and be an older version of the cluster of hot stars at the center of the Milky Way, or it may consist of heavier stars built up from collisions in a possible cold disk of stars orbiting P2. In M32, the central cusp rises into the HST limit with gamma approx0.5, and the central density rho_0>10^7M_sol pc^-3. The V-I and U-V color profiles are flat, and there is no sign of an inner disk, dust, or any other structure. This total lack of features seems at variance with a nominal stellar collision time of 2 X 10^10 yr, which implies that a significant fraction of the light in the central pixel should come from blue stragglers. InM33, the nucleus has an extremely steep gamma=1.49 power-law profile for 0.05"<r<0.2" that becomes shallower as the HST resolution limit is approached. The profile for r<0.04" has either a gamma approx 0.8 cusp or a small core with r_c ~<0.13 pc. The central density is rho_0 > 2 10^6M_sol pc^-3, and the implied relaxation time is only ~3 X 10^6 yr, indicating that the nucleus is highly relaxed. The accompanying short collision time of 7 X 10^9 yr predicts a central blue straggler component quantitatively consistent with the strong V-I and B-R color gradients seen with HST and from the ground.Comment: 44 pages, 22 figures (7 as separate JPEG images), submitted to The Astronomical Journal. Full postscript image available at http://www.noao.edu/noao/staff/lauer/lauer_paper