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Stability Assessment (stability + assessment)
Selected AbstractsEvaluation of a training program to improve clinicians' assessment of patient stabilityDRUG AND ALCOHOL REVIEW, Issue 4 2009ADAM R. WINSTOCK Abstract Introduction and Aims. Public clinics in New South Wales (NSW), Australia play a central role in inducting and stabilising opioid dependent clients onto treatment before transfer to a community pharmacy. Clinical assessment of stability is a vital skill in ensuring that clients are appropriately and effectively transferred. A two-hour clinical training program was delivered to staff at 31 public clinics, that aimed to improve staff confidence in assessing client stability, and skills in negotiating the transfer of clients to community pharmacies. Design and Methods. Pre- and post-training evaluation was conducted examining self-ratings of confidence and ability in the assessment of client stability, and the perceived utility of a clinical algorithm to improve assessments. Follow-up was conducted 3 to 6 months post-training assessing individual and clinic level changes in clinical practice. Results. 205 staff completed pre- and post-training questionnaires. Staff demonstrated a moderate level of self-reported baseline knowledge and skills in assessing client stability (mean = 6.5; 1 = poor; 10 = excellent) that improved when re-assessed following the training (mean = 8.0). 76 staff responded to the follow-up questionnaire. , 75% reported some level of improvement in their approach to clinical practice regarding stability assessment, and 59% reported being more effective in identifying clients appropriate for community pharmacy transfer. Of 19 public clinics, 14 reported an increased focus on stability assessment. Nine clinics reported barriers to achieving changes in clinical practice. Discussion and Conclusions. This evaluation demonstrates that it is possible to implement a targeted clinical training package to staff that translates into positive changes in clinical practice.[Winstock AR, Lea T. Evaluation of a training program to improve clinicians' assessment of patient stability. Drug Alcohol Rev 2009;28:353,359] [source] Peak displacement demand of small to moderate magnitude earthquakes in stable continental regionsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2005Nelson Lam Abstract A theoretical fault-slip model has been developed for predicting the notional peak displacement demand (PDD) of earthquakes based on a limiting natural period of 5 s, for application in stable continental regions (SCRs). The developed theoretical expression is simple and robust. Importantly, it envelops predictions arising from a number of existing empirical and seismological (stochastic) models included in the comparison. The notional PDD prediction has been made initially for hard rock crustal conditions and at a reference source,site distance of 30 km. Factors have accordingly been introduced to correct for different distances and geological conditions in completing the PDD prediction model. Assuming displacement-controlled behaviour, the predicted notional PDD may be compared with the displacement capacity of a structure, or component, for purposes of seismic stability assessment. Copyright © 2005 John Wiley & Sons, Ltd. [source] Construction of Lyapunov function for power system based on solving linear matrix inequalityELECTRICAL ENGINEERING IN JAPAN, Issue 4 2007Atsushi Ishigame Abstract This paper presents construction of Lyapunov functions for power systems based on solving the Linear Matrix Inequality (LMI) derived from the Lyapunov stability theorem considering the dynamics of load characteristic and AVR control system. The proposed Lyapunov function is constructed as a quadratic form of state variables and an integral term which satisfies the curl equation and the sector condition. An induction machine and a synchronous machine are considered as load characteristics. One-machine one-load infinite bus system is considered taking into account the flux decay effects and AVR with one time constant of the generator. To verify the proposed Lyapunov function, the transient stability assessment is shown. The critical clearing times given by the proposed Lyapunov function are compared with those obtained by the numerical integration method, and they are shown to be practical. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 158(4): 42, 50, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20328 [source] Reliability Aspects of Microsystems for Automotive Applications,ADVANCED ENGINEERING MATERIALS, Issue 4 2009Roland Müller-Fiedler Abstract The implementation of microsystems in automotive applications is certainly one of the driving forces for the success of MEMS as an industrial technology on mass production level. In many cases, automotive systems based on microsensors are critical to safety. Consequently, microsystems have to assure an accurate, reliable, and failsafe operation during the entire lifetime of the vehicle. Since, the car represents a harsh environment for electronic or mechanical systems and components, reliability issues of MEMS have moved more and more into the focus of research and development. In particular, reliability aspects related to packaging and assembly have become a key issue in lifetime investigations. The packaging of microsystems comprises a variety of materials and material combinations, that directly affect the stability of MEMS components. Therefore, sophisticated characterization methods are needed to extract the reliability-relevant material parameters. This paper gives an introduction into investigations of the stability assessment of glass frit bonding as well as new bonding technologies based on metallic sealing of MEMS devices. [source] Energy functions analysis in voltage collapseEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2001F. Jurado Time-domain approach examines the behaviour of the system, one determines whether stability has been maintained or lost. In contrast to the time-domain approach, direct methods determine system stability based on energy functions. The basis of direct methods for the stability assessment of a system is knowledge of the stability region. During the last decade, many researches have thoroughly analysed the use of energy functions for the direct stability assessment of networks. Energy function analysis offers a different geometric view of voltage collapse. The Transient Energy Function, a technique based on Lyapunov stability theory and originally developed for direct stability analysis of power systems, has been successfully used as a voltage stability index for collapse studies. In this paper the simulation results are on the IEEE 173-bus test system. [source] Ultrasonic rheology of a monoclonal antibody (IgG2) solution: Implications for physical stability of proteins in high concentration formulationsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2007Atul Saluja Abstract The purpose of this work was to investigate if physical stability of a model monoclonal antibody (IgG2), as determined by extent of aggregation, was related to rheology of its solutions. Storage stability of the model protein was assessed at 25°C and 37°C for three months in solutions ranging from pH 4.0 to 9.0 and ionic strengths of 4 mM and 300 mM. The rheology of IgG2 solutions has been characterized at 25°C in our previous work and correlation of solution storage modulus (G,) with protein,protein interactions established. The extent of aggregation was consistent with solution rheology as understood in terms of changes in G, with protein concentration. Thermodynamic stability of native IgG2 conformation increased with increasing pH. The correlation between rheology and aggregation was also assessed at increased ionic strengths. The decrease in aggregation was consistent with change in solution rheology profile at pH 7.4 and 9.0. The results provide evidence of a relationship between solution rheology and extent of aggregation for the model protein studied. The implications of this relationship for formulation and physical stability assessment in high concentration protein solutions are discussed. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 3181,3195, 2007 [source] Stability profiles of drug products extended beyond labeled expiration datesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2006Robbe C. Lyon Abstract The American Medical Association has questioned whether expiration dating markedly underestimates the actual shelf life of drug products. Results from the shelf life extension program (SLEP) have been evaluated to provide extensive data to address this issue. The SLEP has been administered by the Food and Drug Administration for the United States Department of Defense (DOD) for 20 years. This program probably contains the most extensive source of pharmaceutical stability data extant. This report summarizes extended stability profiles for 122 different drug products (3005 different lots). The drug products were categorized into five groups based on incidence of initial extension failures and termination failures (extended lot eventually failed upon re-testing). Based on testing and stability assessment, 88% of the lots were extended at least 1 year beyond their original expiration date for an average extension of 66 months, but the additional stability period was highly variable. The SLEP data supports the assertion that many drug products, if properly stored, can be extended past the expiration date. Due to the lot-to-lot variability, the stability and quality of extended drug products can only be assured by periodic testing and systematic evaluation of each lot. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1549,1560, 2006 [source] Synthesis and characterization of high molecular weight hexafluoroisopropylidene-containing polybenzimidazole for high-temperature polymer electrolyte membrane fuel cellsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2009Guoqing Qian Abstract A high molecular weight, thermally and chemical stable hexafluoroisopropylidene containing polybenzimidazole (6F-PBI) was synthesized from 3,3,-diaminobenzidine (TAB) and 2,2-bis(4-carboxyphenyl) hexafluoropropane (6F-diacid) using polyphosphoric acid (PPA) as both the polycondensation agent and the polymerization solvent. Investigation of polymerization conditions to achieve high molecular weight polymers was explored via stepwise temperature control, monomer concentration in PPA, and final polymerization temperature. The polymer characterization included inherent viscosity (I.V.) measurement and GPC as a determination of polymer molecular weight, thermal and chemical stability assessment via thermo gravimetric analysis and Fenton test, respectively. The resulting high molecular weight polymer showed excellent thermal and chemical stability. Phosphoric acid doped 6F-PBI membranes were prepared using the PPA process. The physiochemical properties of phosphoric acid doped membranes were characterized by measuring the phosphoric acid doping level, mechanical properties, and proton conductivity. These membranes showed higher phosphoric acid doping levels and higher proton conductivities than the membranes prepared by the conventional membrane fabrication processes. These membranes had sufficient mechanical properties to be easily fabricated into membrane electrode assemblies (MEA) and the prepared MEAs were tested in single cell fuel cells under various conditions, with a focus on the high temperature performance and fuel impurity tolerance. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4064,4073, 2009 [source] Wearable Data Collection System for Online Gait Stability AnalysisNEUROMODULATION, Issue 3 2004Tomaz Karcnik DSc Abstract We had shown in our previous research that the stability assessment and control are essential for generation of faster and more energy efficient functional electrical stimulation (FES) and/or crutch-assisted gait. The objective of our recent research work has been to design a wearable and portable system for gait stability analysis with online capabilities that is also applicable to crutch-assisted gait modes. The developed wearable stability assessment system for as yet only biped gait consists of foot switches and goniometers attached to the leg joints. The instantaneous static and dynamic stability is, within the wearable system, assessed from the trajectory of the estimated body center of gravity (COGHAT) and the supporting area shape/size as derived from step length and foot-floor contact state. We used motion analysis system data as reference for testing the wearable system accuracy. The wearable system was tested on five healthy subjects and one above-knee amputee. It proved to be reasonably accurate if compared to the classical, motion analysis system based method. However, additional work is required to port the system to the FES assisted and/or crutch assisted gait. [source] | |||||||||||||