4,473 research outputs found
Emergency escape system uses self-braking mechanism on fixed cable
Slide-wire system with a twist level slide device incorporates automatic descent and braking for the safe and rapid evacuation of personnel from tall structures. This device is used on any tall structure that might require emergency evacuation. It is also used to transfer materials and equipment
Data base management system analysis and performance testing with respect to NASA requirements
Several candidate Data Base Management Systems (DBM's) that could support the NASA End-to-End Data System's Integrated Data Base Management System (IDBMS) Project, later rescoped and renamed the Packet Management System (PMS) were evaluated. The candidate DBMS systems which had to run on the Digital Equipment Corporation VAX 11/780 computer system were ORACLE, SEED and RIM. Oracle and RIM are both based on the relational data base model while SEED employs a CODASYL network approach. A single data base application which managed stratospheric temperature profiles was studied. The primary reasons for using this application were an insufficient volume of available PMS-like data, a mandate to use actual rather than simulated data, and the abundance of available temperature profile data
Probing Solar Convection
In the solar convection zone acoustic waves are scattered by turbulent sound
speed fluctuations. In this paper the scattering of waves by convective cells
is treated using Rytov's technique. Particular care is taken to include
diffraction effects which are important especially for high-degree modes that
are confined to the surface layers of the Sun. The scattering leads to damping
of the waves and causes a phase shift. Damping manifests itself in the width of
the spectral peak of p-mode eigenfrequencies. The contribution of scattering to
the line widths is estimated and the sensitivity of the results on the assumed
spectrum of the turbulence is studied. Finally the theoretical predictions are
compared with recently measured line widths of high-degree modes.Comment: 26 pages, 7 figures, accepted by MNRA
Global shallow water magnetohydrodynamic waves in the solar tachocline
We derive analytical solutions and dispersion relations of global magnetic
Poincar\'e (magneto-gravity) and magnetic Rossby waves in the approximation of
shallow water magnetohydrodynamics. The solutions are obtained in a rotating
spherical coordinate system for strongly and weakly stable stratification
separately in the presence of toroidal magnetic field. In both cases magnetic
Rossby waves split into fast and slow magnetic Rossby modes. In the case of
strongly stable stratification (valid in the radiative part of the tachocline)
all waves are slightly affected by the layer thickness and the toroidal
magnetic field, while in the case of weakly stable stratification (valid in the
upper overshoot layer of the tachocline) magnetic Poincar\'e and fast magnetic
Rossby waves are found to be concentrated near the solar equator, leading to
equatorially trapped waves. However, slow magnetic Rossby waves tend to
concentrate near the poles, leading to polar trapped waves. The frequencies of
all waves are smaller in the upper weakly stable stratification region than in
the lower strongly stable stratification one
Integration of a clinical pharmacist workforce into newly forming primary care networks: a qualitatively driven, complex systems analysis
Objective
The introduction of a new clinical pharmacist workforce via Primary Care Networks (PCNs) is a recent national policy development in the National Health Service in England. This study elicits the perspectives of people with responsibility for local implementation of this national policy package. Attention to local delivery is necessary to understand the contextual factors shaping the integration of the new clinical pharmacy workforce, and thus can be expected to influence future role development.
Design
A qualitative, interview study
Setting and participants
PCN Clinical Directors and senior pharmacists across 17 PCNs in England (n=28)
Analysis
Interviews were transcribed, coded and organised using the framework method. Thematic analysis and complex systems modelling were then undertaken iteratively to develop the themes.
Results
Findings were organised into two overarching themes: (1) local organisational innovations of a national policy under conditions of uncertainty; and (2) local multiprofessional decision-making on clinical pharmacy workforce integration and initial task assignment. Although a phased implementation of the PCN package was planned, the findings suggest that processes of PCN formation and clinical pharmacist workforce integration were closely intertwined, with underpinning decisions taking place under conditions of considerable uncertainty and workforce pressures.
Conclusions
National policy decisions that required General Practitioners to form PCNs at the same time as they integrated a new workforce risked undermining the potential of both PCNs and the new workforce. PCNs require time and support to fully form and integrate clinical pharmacists if successful role development is to occur. Efforts to incentivise delivery of PCN pharmacy services in future must be responsive to local capacity
The variation of floods in the middle reaches of the Yangtze River and its teleconnection with El Niño events
International audienceMiddle reaches of the Yangtze River are the worst flooded segments along the Yangtze River. It is important to understand and study the variations of frequency and magnitude of historical floods in this area and how were they related to or affected by EI Niño in a long historical period. We applied the statistics and time series to study and analyze historical floods (1470-2000) and EI Niño events (1525-1995). The results show that the more floods occurred in the latest 200 years. The power-spectral analysis suggests the main cycle of flood variation is longer than that of EI Niño events. El Nino shows the fluctuations of about 2-year and 3~4 year period while the flood variation is not so significant but can also be identified in the period of 2, 8 and 40 years (it exceeds the level of confidence 0.03). Time series analyses of the fluctuation of flood and El Nino indicate that there is a significant correlation between the two at both high and moderate frequency sections. The result shows that the response of the floods along the middle reaches of the Yangtze River to the effects of El Nino events is not only delayed one or more than one year as suggested by many Chinese scientists, but it also can be somewhat longer delayed up to about 8 years. The result also indicates that the shorter the interval of EI Niño events, the sooner the flood events follows. In other words, flood could be delayed with longer time if the interval time of EI Niño events is longer
Wigner Measures and Coherent Quantum Control
We introduce Wigner measures for infinite-dimensional open quantum systems; important examples of such systems are encountered in quantum control theory. In addition, we propose an axiomatic definition of coherent quantum feedback
Feynman, Wigner, and Hamiltonian Structures Describing the Dynamics of Open Quantum Systems
This paper discusses several methods for describing the dynamics of open
quantum systems, where the environment of the open system is
infinite-dimensional. These are purifications, phase space forms, master
equation and liouville equation forms. The main contribution is in using
Feynman-Kac formalisms to describe the infinite-demsional components
Wick's theorem for q-deformed boson operators
In this paper combinatorial aspects of normal ordering arbitrary words in the
creation and annihilation operators of the q-deformed boson are discussed. In
particular, it is shown how by introducing appropriate q-weights for the
associated ``Feynman diagrams'' the normally ordered form of a general
expression in the creation and annihilation operators can be written as a sum
over all q-weighted Feynman diagrams, representing Wick's theorem in the
present context.Comment: 9 page
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