Functional Urban Regions in Austria

This paper sets out a regionalization of Austria into functional urban regions, each of which consists of an urban core(s) of at least 50,000 population and/or 20,000 jobs and the surrounding hinterland that is economically linked to the urban cores through commuting flows. The regionalization is based primarily on population and commuting data for 1971 and, to a lesser extent, on the geographical orientation of major highway networks. These functional urban regions are to serve as the spatial bases of data collection and of forthcoming analyses of demographic and employment change during the 1950-60 and 1960-70 periods in Austria

Development and Application of Operational Techniques for the Inventory and Monitoring of Resources and Uses for the Texas Coastal Zone

There are no author-identified significant results in this report

Functional Urban Regions and Central Place Regions in the Federal Republic of Germany and Switzerland

The first part of this paper contains a discussion of the criteria and procedures used to delimit functional urban regions in the Federal Republic of Germany. Each region consists of an urban core, containing at least 20,000 jobs and 50,000 population, and all hinterland counties that are linked to the core through journey-to-work flows from hinterland to core. The second part of the paper discusses central-place regions in Switzerland and concludes that these regions are conceptually similar to functional urban regions. These German and Swiss regions are to serve as the spatial frameworks of policy-relevant and analytical studies of regional growth and change in both countries during the 1960-70 period

The effects of repeated amphetamine exposure during adolescence on behavior and prefrontal cortex function

Cognitive impairment and altered drug sensitivity are two commonly reported behavioral outcomes of amphetamine abuse. Individuals who begin using amphetamine during adolescence may have an increased risk of developing drug-related problems because of maturational changes in mesocorticolimbic circuitry that are specific to this stage of development. The studies presented here were designed to assess long-term effects of amphetamine on cognition, dopamine receptor function, and prefrontal cortex (PFC) activity, with a focus on the consequences of drug exposure during adolescence. Chapter 1 includes a review of the literature on substance abuse and PFC dysfunction along with the specific aims of the studies described in the following chapters. Chapter 2 describes studies of drug-induced psychomotor activity and measures of working memory in rats exposed to amphetamine during adolescence or adulthood. Results suggest long-term effects of amphetamine on cognition vary according to the age of exposure. The experiments in Chapter 3 investigated the protracted effects of repeated amphetamine exposure during adolescence on psychomotor behavior and medial PFC function in young adulthood. Relative to controls, rats pre-exposed to amphetamine displayed psychomotor sensitization when challenged with amphetamine and heightened responsiveness to D1 and D2 receptor agonists. Expression of sensitization to amphetamine was attenuated in pre-exposed rats following challenges with a D1 or D2 receptor antagonist. The long-term functional impact of amphetamine on medial PFC neurons was assessed using single-unit recordings in awake behaving rats. Young adult rats were challenged with amphetamine followed by a D1 or D2 receptor antagonist. The proportion of amphetamine-responsive neurons and the pattern of spike activity was altered in animals exposed to amphetamine during adolescence relative to controls. Finally, Chapter 4 includes a general discussion on the results and implications of the experiments described in this dissertation. Taken together, the research presented here demonstrates age-dependent effects of amphetamine on cognition and highlights the long-lasting impact of amphetamine exposure on dopamine and medial PFC function

Contracting methods and risks in federal remediation projects

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.Includes bibliographical references (leaves 129-132).by Peter K. Sherrill.M.S

One-neutron knockout from 57^{57}Ni

The single-particle structure of $^{57}$Ni and level structure of $^{56}$Ni were investigated with the \mbox{$^{9}$Be ($^{57}$Ni,$^{56}$Ni+$\gamma$)$\it{X}$} reaction at 73 MeV/nucleon. An inclusive cross section of 41.4(12) mb was obtained for the reaction, compared to a theoretical prediction of 85.4 mb, hence only 48(2)% of the theoretical cross section is exhausted. This reduction in the observed spectroscopic strength is consistent with that found for lighter well-bound nuclei. One-neutron removal spectroscopic factors of 0.58(11) to the ground state and 3.7(2) to all excited states of $^{56}$Ni were deduced.Comment: Phys. Rev. C, accepte

Tensor Product Approximation (DMRG) and Coupled Cluster method in Quantum Chemistry

We present the Copupled Cluster (CC) method and the Density matrix Renormalization Grooup (DMRG) method in a unified way, from the perspective of recent developments in tensor product approximation. We present an introduction into recently developed hierarchical tensor representations, in particular tensor trains which are matrix product states in physics language. The discrete equations of full CI approximation applied to the electronic Schr\"odinger equation is casted into a tensorial framework in form of the second quantization. A further approximation is performed afterwards by tensor approximation within a hierarchical format or equivalently a tree tensor network. We establish the (differential) geometry of low rank hierarchical tensors and apply the Driac Frenkel principle to reduce the original high-dimensional problem to low dimensions. The DMRG algorithm is established as an optimization method in this format with alternating directional search. We briefly introduce the CC method and refer to our theoretical results. We compare this approach in the present discrete formulation with the CC method and its underlying exponential parametrization.Comment: 15 pages, 3 figure

Production of Radioactive Nuclides in Inverse Reaction Kinematics

Efficient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for various applications. It is particularly interesting when the isotope of interest is only a few nucleons away from a stable isotope. In this article production via charge exchange and stripping reactions in combination with a magnetic separator is explored. The relation between the separator transmission efficiency, the production yield, and the choice of beam energy is discussed. The results of some exploratory experiments will be presented.Comment: 10 pages, 4 figures, to be submitted to Nucl. Instr. and Met