5,748 research outputs found
Numerical recovery of material parameters in Euler-Bernoulli beam models
A fully Sinc-Galerkin method for recovering the spatially varying stiffness parameter in fourth-order time-dependence problems with fixed and cantilever boundary conditions is presented. The forward problems are discretized with a sinc basis in both the spatial and temporal domains. This yields an approximation solution which converges exponentially and is valid on the infinite time interval. When the forward methods are applied to parameter recovery problems, the resulting inverse problems are ill-posed. Tikhonov regularization is applied and the resulting minimization problems are solved via a quasi-Newton/trust region algorithm. The L-curve method is used to determine an appropriate value of the regularization parameter. Numerical results which highlight the method are given for problems with both fixed and cantilever boundary conditions
The effects of isometric work on heart rate, blood pressure, and net oxygen cost
Isometric exercise effects on heart rate, blood pressure, and net oxygen cos
A fully Galerkin method for the recovery of stiffness and damping parameters in Euler-Bernoulli beam models
A fully Sinc-Galerkin method for recovering the spatially varying stiffness and damping parameters in Euler-Bernoulli beam models is presented. The forward problems are discretized with a sinc basis in both the spatial and temporal domains thus yielding an approximate solution which converges exponentially and is valid on the infinite time interval. Hence the method avoids the time-stepping which is characteristic of many of the forward schemes which are used in parameter recovery algorithms. Tikhonov regularization is used to stabilize the resulting inverse problem, and the L-curve method for determining an appropriate value of the regularization parameter is briefly discussed. Numerical examples are given which demonstrate the applicability of the method for both individual and simultaneous recovery of the material parameters
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Morale is high in acute inpatient psychiatry
Background: Morale on acute psychiatric wards has been considered to be problematic, and is reported to contribute to low quality patient care.
Aim: To assess the relationship of staff morale to patient, service environment, physical environment, patient routines, conflict, containment, staff demographics, and staff group variables.
Method: A multivariate cross sectional study was undertaken collecting data on morale and other variables on 136 acute admission psychiatric wards in England.
Results: Morale was higher than published comparison samples. Length of time in post was correlated with low morale, and qualified nurses had higher emotional exhaustion but also higher personal accomplishment. The level of verbal abuse on a ward was associated with low morale, as was a higher level of social deprivation among patients. Higher levels of order and organisation correlated with better morale.
Conclusions: Clear policies relating to the management of verbal abuse by patients, high levels of order and organisation, and staff rotation and education, may all support high morale. Acute inpatient psychiatry is generally a happy and rewarding work environment, and identified problems are likely to be due to other factors
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Approval Ratings of Inpatient Coercive Interventions in a National Sample of Mental Health Service Users and Staff in England
Objective: To ascertain the degree of approval amongst service users and staff for various coercive measures commonly used in acute mental health care.
Methods: A cross-sectional design was adopted. The Attitudes to Containment Measures Questionnaire (ACMQ) was completed by 1,361 service users and 1,226 staff in acute care mental health services from three regions of England. This provided evaluation of eleven coercive measures (e.g. seclusion) on six dimensions of approval (e.g. indignity, safety) in a large national sample. Comparisons between groups were tested using independent samples t-tests, χ2 or Spearman correlations.
Results: Both service users and staff disapproved strongly of mechanical restraint and expressed a relative preference for compulsory intramuscular medication and seclusion. Male staff, older service users and staff who had been involved in implementing coercion expressed greater approval of coercive measures.
Conclusion: Mechanical restraint remains highly objectionable to staff and service users in English mental health services despite its widespread acceptance elsewhere in the world
Multiaxis thrust vectoring using axisymmetric nozzles and postexit vanes on an F/A-18 configuration vehicle
A ground-based investigation was conducted on an operational system of multiaxis thrust vectoring using postexit vanes around an axisymmetric nozzle. This thrust vectoring system will be tested on the NASA F/A-18 High Alpha Research Vehicle (HARV) aircraft. The system provides thrust vectoring capability in both pitch and yaw. Ground based data were gathered from two separate tests at NASA Langley Research Center. The first was a static test in the 16-foot Transonic Tunnel Cold-Jet Facility with a 14.25 percent scale model of the axisymmetric nozzle and the postexit vanes. The second test was conducted in the 30 by 60 foot wind tunnel with a 16 percent F/A-18 complete configuration model. Data from the two sets are being used to develop models of jet plume deflection and thrust loss as a function of vane deflection. In addition, an aerodynamic interaction model based on plume deflection angles will be developed. Results from the scale model nozzle test showed that increased vane deflection caused exhaust plume turning. Aerodynamic interaction effects consisted primarily of favorable interaction of moments and unfavorable interaction of forces caused by the vectored jet plume
Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures
Boron implantation with in-situ dynamic annealing is used to produce highly
conductive sub-surface layers in type IIa (100) diamond plates for the search
of a superconducting phase transition. Here we demonstrate that high-fluence
MeV ion-implantation, at elevated temperatures avoids graphitization and can be
used to achieve doping densities of 6 at.%. In order to quantify the diamond
crystal damage associated with implantation Raman spectroscopy was performed,
demonstrating high temperature annealing recovers the lattice. Additionally,
low-temperature electronic transport measurements show evidence of charge
carrier densities close to the metal-insulator-transition. After electronic
characterization, secondary ion mass spectrometry was performed to map out the
ion profile of the implanted plates. The analysis shows close agreement with
the simulated ion-profile assuming scaling factors that take into account an
average change in diamond density due to device fabrication. Finally, the data
show that boron diffusion is negligible during the high temperature annealing
process.Comment: 22 pages, 6 figures, submitted to JA
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Identifying Key Factors Associated with Aggression on Acute Inpatient Psychiatric Wards
Aggressive behaviour is a critical issue for modern acute psychiatric services, not just because of the adverse impact it has on patients and staff, but also because it puts a financial strain on service providers. The aim of this study was to assess the relationship of patient violence to other variables: patient characteristics, features of the service and physical environment, patient routines, staff factors, the use of containment methods, and other patient behaviours. A multivariate cross sectional design was utilised. Data were collected for a six month period on 136 acute psychiatric wards in 26 NHS Trusts in England. Multilevel modelling was conducted to ascertain those factors most strongly associated with verbal aggression, aggression toward objects, and physical aggression against others. High levels of aggression were associated with a high proportion of patients formally detained under mental health legislation, high patient turnover, alcohol use by patients, ward doors being locked, and higher staffing numbers (especially qualified nurses). The findings suggest that the imposition of restrictions on patients exacerbates the problem of violence, and that alcohol management strategies may be a productive intervention. Insufficient evidence is available to draw conclusions about the nature of the link between staffing numbers and violence
A fully Sinc-Galerkin method for Euler-Bernoulli beam models
A fully Sinc-Galerkin method in both space and time is presented for fourth-order time-dependent partial differential equations with fixed and cantilever boundary conditions. The Sinc discretizations for the second-order temporal problem and the fourth-order spatial problems are presented. Alternate formulations for variable parameter fourth-order problems are given which prove to be especially useful when applying the forward techniques to parameter recovery problems. The discrete system which corresponds to the time-dependent partial differential equations of interest are then formulated. Computational issues are discussed and a robust and efficient algorithm for solving the resulting matrix system is outlined. Numerical results which highlight the method are given for problems with both analytic and singular solutions as well as fixed and cantilever boundary conditions
Discovery of Enhanced Germanium Abundances in Planetary Nebulae with FUSE
We report the discovery of Ge III 1088.46 in the planetary nebulae
(PNe) SwSt 1, BD+303639, NGC 3132, and IC 4593, observed with the Far
Ultraviolet Spectroscopic Explorer. This is the first astronomical detection of
this line and the first measurement of Ge (Z = 32) in PNe. We estimate Ge
abundances using S and Fe as reference elements, for a range of assumptions
about gas-phase depletions. The results indicate that Ge, which is synthesized
in the initial steps of the s-process and therefore can be self-enriched in
PNe, is enhanced by factors of > 3-10. The strongest evidence for enrichment is
seen for PNe with Wolf-Rayet central stars, which are likely to contain heavily
processed material.Comment: 11 pages, 1 figure, accepted for publication in ApJ Letter
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