2,410 research outputs found
Innovations in spatial planning as a social process – phases, actors, conflicts
The aim of this paper is to understand the social process of the emergence and institutionalization of innovations in spatial planning (which we describe as ‘social innovations’). The paper is based on a recently finished empirical and comparative study conducted in four distinct areas of spatial planning in Germany: urban design, neighbourhood development, urban regeneration and regional planning. The empirical cases selected in these areas encompass different topics, historical periods, degrees of maturity and spatial scales of innovation. As a temporal structure of the innovation processes in the different cases we identified five phases: ‘incubating, generating, formatting, stabilizing, adjusting’. In a cross-comparison of the case studies and along these phases, we furthermore found typical (groups of) actors, tensions and conflicts. In the focus of our case analyses are the following dimensions: (1) the content of the innovations, (2) actors, networks and communities involved as well as (3) institutions and institutionalization
Producing Bose condensates using optical lattices
We relate the entropies of ensembles of atoms in optical lattices to atoms in
simple traps. We then determine which ensembles of lattice-bound atoms will
adiabatically transform into a Bose condensate. This shows a feasible approach
to Bose condensation without evaporative cooling.Comment: RevTeX, 5 pages, 5 eps-figure
Relation between TMAOase activity and content of formaldehyde in fillet minces and bellyflap minces from gadoid fishes
Minced fish is a significant component of a number of frozen fishery products like fish fingers, cakes and patties. Predominately minced fish is produced from gadoid species (Alaska pollack, cod, saithe, hake and others) possessing the enzyme trimethylamine oxide demethylase (TMAOase, E.C. 4.1.2.32) (Rehbein and Schreiber 1984). TMAOase catalyses the degradation of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA), preferentially during frozen storage of products (Hultin 1992). In most gadoid species light muscle contains only low
activity of TMAOase, the activity of red muscle and bellyflaps being somewhat higher. In contrast, the TMAOase
activity in blood, kidney and other tissues, residues of which may contaminate minced fish flesh, may be higher for
several orders of magnitude (Rehbein and Schreiber 1984)
Math Pathways Reforms in Maine
For the past several years, attention has turned toward reviewing and reframing the curricular pathways in math for students, particularly at the postsecondary level. Focus has shifted not only to math preparedness, but also to redefining the curricular pathways that lead to academic and career success. In higher education, the central principle involves redefining and reorganizing coursework around defined pathways, based on academic and career interests of students. For K-12 institutions, the math pathways reforms have less clear implications. One key organization working in this area--both nationally and in Maine--is the Dana Center at the University of Texas at Austin. The Dana Center has been partnering with the Maine Community College System (MCCS) for several years now, and has supported their progress toward implementing math pathways reforms. For this project, Maine Education Policy Research Institute (MEPRI) researchers in the Center for Education Policy, Applied Research, and Evaluation (CEPARE) were asked to describe and summarize the mathematics pathways movement which is currently underway in the state of Maine, as well as in other states across the country. This study of the math pathways movement is designed as a mini-case study to document the status of the reform in progress. Findings review math pathways as a potential means of promoting individualized student learning and career readiness, of clarifying math expectations, and of reducing the need for remedial coursework at the post-secondary level. The successes of and challenges facing individual institutions--from MCCS, to the state universities, to K-12 institutions--are also reviewed. Other challenges, including mitigating issues with tracking and ownership of the reforms, are discussed. The report concludes with recommendations for policymakers
Phase-sensitive detection of Bragg scattering at 1D optical lattices
We report on the observation of Bragg scattering at 1D atomic lattices. Cold
atoms are confined by optical dipole forces at the antinodes of a standing wave
generated by the two counter-propagating modes of a laser-driven high-finesse
ring cavity. By heterodyning the Bragg-scattered light with a reference beam,
we obtain detailed information on phase shifts imparted by the Bragg scattering
process. Being deep in the Lamb-Dicke regime, the scattered light is not
broadened by the motion of individual atoms. In contrast, we have detected
signatures of global translatory motion of the atomic grating.Comment: 4 pages, 4 figure
Bloch Structures in a Rotating Bose-Einstein Condensate
A rotating Bose-Einstein condensate is shown to exhibit a Bloch band
structure without the need of periodic potential. Vortices enter the condensate
by a mechanism similar to the Bragg reflection, if the frequency of a rotating
drive or the strength of interaction is adiabatically changed. A localized
state analogous to a gap soliton in a periodic system is predicted near the
edge of the Brillouin zone.Comment: 4 pages, 3 figure
Effect of finite detection efficiency on the observation of the dipole-dipole interaction of a few Rydberg atoms
We have developed a simple analytical model describing multi-atom signals
that are measured in experiments on dipole-dipole interaction at resonant
collisions of a few Rydberg atoms. It has been shown that finite efficiency of
the selective field-ionization detector leads to the mixing up of the spectra
of resonant collisions registered for various numbers of Rydberg atoms. The
formulas which help to estimate an appropriate mean Rydberg atom number for a
given detection efficiency are presented. We have found that a measurement of
the relation between the amplitudes of collisional resonances observed in the
one- and two-atom signals provides a straightforward determination of the
absolute detection efficiency and mean Rydberg atom number. We also performed a
testing experiment on resonant collisions in a small excitation volume of a
sodium atomic beam. The resonances observed for 1 to 4 detected Rydberg atoms
have been analyzed and compared with theory.Comment: 10 pages, 4 figures; equations 8,9,18,19,23,26-31, figures 3 and
4(d), and measurements revised in version
Quantum state tomography by continuous measurement and compressed sensing
The need to perform quantum state tomography on ever larger systems has
spurred a search for methods that yield good estimates from incomplete data. We
study the performance of compressed sensing (CS) and least squares (LS)
estimators in a fast protocol based on continuous measurement on an ensemble of
cesium atomic spins. Both efficiently reconstruct nearly pure states in the
16-dimensional ground manifold, reaching average fidelities FCS = 0.92 and FLS
= 0.88 using similar amounts of incomplete data. Surprisingly, the main
advantage of CS in our protocol is an increased robustness to experimental
imperfections
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