757 research outputs found
Orbiting Geophysical Observatory Attitude Control Subsystem Design Survey. NASA/ERC Design Criteria Program, Guidance and Control
This design survey summarizes the history of the Orbiting Geophysical Observatories' (OGO) Attitude Control Subsystem (ACS) from the proposal phase through current flight experience. Problems encountered in design, fabrication, test, and on orbit are discussed. It is hoped that the experiences of the OGO program related here will aid future designers
Orbiting Geophysical Observatory Attitude Control Subsystem design survey
Development history and design modifications for attitude control subsystem of OG
Kajian Ekonomi Politik Riau Televisi melalui Program Detak Riau dalam Memenuhi Kebutuhan Informasi Masyarakat Riau
Detak Riau an actual news program that raised about the incident in Riau, Pekanbaru and its surroundings especially in Detak Riau program is divided into several program again. In Detak Riau program also featured speakers who are competent in the form of direct talk show, so the audience can interact with the contact person provided. The purpose of this study was to determine how the program Detak Riau, the study of political economy, as well as see the audience\u27s response to the program Detak Riau.This study uses descriptive qualitative theory of political economy media. Data collection techniques used by realities on the ground through observation, interviews, and documentation. Informants in this study amounted to 6 people consisting of Editor in Chief, Field Coordinator, two journalists, PR Pemko Pekanbaru and 4 people in the audience selected based on purposive sampling. As for data validity checking researcher using triangulation techniques. This study aims to determine program Detak Riau as well as the audience\u27s response and to look at the political economy model of the program.The results showed that process of serving program Detak Riau uses the concept POAC this planning, organizing, actuating and controlling in the management of material news. Most of the audience gave a positive response about the information displayed then there is also a negative response on the news that is always discussed about government in general. This relates to the model of political economy in program Detak Riau, namely the commodification, spatialization, and Structuration. So most of the news content displayed is determined by economic interests and the interests of the owner some the political elite. Detak Riau beating of media institutional renewal through horizontal, while the RTV structuration under the auspices of Jawa Pos Group and Riau Pos Group is not so great, because investors or stock investor is not involved in politics
Scaling Relations for Logarithmic Corrections
Multiplicative logarithmic corrections to scaling are frequently encountered
in the critical behavior of certain statistical-mechanical systems. Here, a
Lee-Yang zero approach is used to systematically analyse the exponents of such
logarithms and to propose scaling relations between them. These proposed
relations are then confronted with a variety of results from the literature.Comment: 4 page
Anomalous Fisher-like zeros for the canonical partition function of noninteracting fermions
Noninteracting fermions, placed in a system with a continuous density of
states, may have zeros in the -fermion canonical partition function on the
positive real axis (or very close to it), even for a small number of
particles. This results in a singular free energy, and instability in other
thermal properties of the system. In the context of trapped fermions in a
harmonic oscillator, these zeros are shown to be unphysical. By contrast,
similar bosonic calculations with continuous density of states yield sensible
results.Noninteracting fermions, placed in a system with a continuous density
of states yield sensible results.Comment: 5 pages and 5 figure
Fermion loop simulation of the lattice Gross-Neveu model
We present a numerical simulation of the Gross-Neveu model on the lattice
using a new representation in terms of fermion loops. In the loop
representation all signs due to Pauli statistics are eliminated completely and
the partition function is a sum over closed loops with only positive weights.
We demonstrate that the new formulation allows to simulate volumes which are
two orders of magnitude larger than those accessible with standard methods
Universal finite-size scaling for percolation theory in high dimensions
We present a unifying, consistent, finite-size-scaling picture for
percolation theory bringing it into the framework of a general,
renormalization-group-based, scaling scheme for systems above their upper
critical dimensions . Behaviour at the critical point is non-universal in
dimensions. Proliferation of the largest clusters, with fractal
dimension , is associated with the breakdown of hyperscaling there when free
boundary conditions are used. But when the boundary conditions are periodic,
the maximal clusters have dimension , and obey random-graph
asymptotics. Universality is instead manifest at the pseudocritical point,
where the failure of hyperscaling in its traditional form is universally
associated with random-graph-type asymptotics for critical cluster sizes,
independent of boundary conditions.Comment: Revised version, 26 pages, no figure
Selective excision of the centromere chromatin complex from Saccharomyces cerevisiae.
We have taken advantage of the known structural parameters associated with centromere DNA in vivo to construct a CEN fragment that can be selectively excised from the chromatin DNA with restriction endonucleases. CEN3 DNA is organized in chromatin such that a 220-250- bp region encompassing the elements of centromere homology is resistant to nuclease digestion. Restriction enzyme linkers encoding the Bam HI- recognition site were ligated to a 289 base pair DNA segment that spans the 220-250-bp protected core (Bloom et al., 1984). Replacement of this CEN3-Bam HI linker cassette into a chromosome or plasmid results in formation of a complete structural and functional centromeric unit. A centromere core complex that retains its protected chromatin conformation can be selectively excised from intact nuclei by restriction with the enzyme Bam HI. The centromeric protein-DNA complex is therefore not dependent upon the intact torsional constrains on linear chromosomes for its structural integrity. Isolation of this complex provides a novel approach to characterizing authentic centromeric proteins bound to DNA in their native state
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