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Competency-based assessment tools are used in regional anaesthesia to measure the performance of study participants, trainees, and consultants. This narrative review was performed to appraise currently published assessment tools for regional anaesthesia. A literature search found 397 citations of which 28 peer-reviewed studies met the inclusion criteria of primary psychometric evaluation of assessment tools for regional anaesthesia. The included studies were diverse in the type of assessment and the skill set being assessed. The types of assessments included multiple-choice questions, hand-motion analysis, cumulative sum, visuospatial and psychomotor screening, checklists, and global rating scales. The skill sets that were assessed included holistic regional anaesthesia technical and non-technical performance observed at the bedside, to isolated part-tasks, such as needle tip visualisation under ultrasound. To evaluate validity and reliability, we compared the studies against published medical education consensus statements on ideal assessment tools. We discuss the relative merits of different tools when used to assess regional anaesthesia, the importance of psychometrically robust assessment tools in competency-based anaesthesia education, and directions for future education research in regional anaesthesia.

In the two-dimensional shear deformation theories (SDT) of composite laminates, the three-dimensional plates or shells are transferred to a two-dimensional problem in the reference surface by introducing displacement fields and stress resultants along the thickness direction, the constitutive relationship is a resultant form. The multiscale analysis methods developed from SDT can not describe the periodicity along the thickness direction in composite laminated plates and shells, so it is almost impossible to accurately analyze the local stress fields surrounding the fibers based on the two scale analysis scheme. A two scale layerwise multiscale analysis method (LMAM) is established based on the Reddy’s layerwise theory (RLWT) and O(1) homogenization method for the composite laminated plates, considering the periodicity in in-plane and along the thickness direction simultaneously. The macroscopic problem of laminated plate is discretized by RLWT, while the unit cells consisted by fiber and matrix are modeling by three-dimensional finite elements. In numerical examples, the proposed LMAM is verify by using direction numerical simulation (DNS) and the O(1) homogenization method based on three-dimensional macroscopic finite elements. The unidirectional and woven composite plates are studied by the proposed LMAM; the macroscopic and microscopic stress distributions along the thickness are investigated.

The radial profile of sheath potential (φw) on tungsten surfaces has been measured in the boundary layer of Alcator C plasma using a retarding field energy analyzer. Simultaneous measurement of the electron temperature (Te) and ion temperature (Ti) profiles was also made. The φw, Te and Ti profiles are monotonically decreasing functions of radius but are much steeper on the electron drift side of the probe. Plotted as a function of Ti/Te the normalized sheath potential — eφw/kTe decrease steeply on the electron drift side but increases weakly on the ion drift side. Such a difference in characteristics was not predicted theoretically. Unipolar arcing was found on the tungsten surface examined with a scanning electron microscope. Microscopic craters were formed due to arcing. The surface density of the craters is as high as 1013 cm−2. The density and size of the craters increases with sheath potential. No sheath potential and unipolar arcing were found on the SiC surface.

We have employed a Mach-Zehnder interferometer, using a Ne-like Y x- ray laser at 155 {Angstrom} as the probe source, to study large-scale- length, high-density colliding plasmas and exploding foils. The measured density profile of counter-streaming high-density colliding plasmas falls in between the calculated profiles using collisionless and fluid approximations with the radiation hydrodynamic code LASNEX. We have also performed simultaneous measured the local gain and electron density of Y x-ray laser amplifier. Measured gains in the amplifier were found to be between 10 and 20 cm{sup {minus}1}, similar to predictions and indicating that refraction is the major cause of signal loss in long line focus lasers. Images showed that high gain was produced in spots with dimensions of {approximately} 10 {mu}m, which we believe is caused by intensity variations in the optical drive laser. Measured density variations were smooth on the 10-{mu}m scale so that temperature variations were likely the cause of the localized gain regions. We are now using the interferometry technique as a mechanism to validate and benchmark our numerical codes used for the design and analysis of high-energy-density physics experiments. 11 refs., 6 figs.

This paper provides a background for the use of Langmuir and gridded energy analyzer probes in diagnosing plasmas with varied characteristics. Theory is illustrated which governs the analysis of data from, and the design of these probes. Several probe analysis techniques and some of their typical problems are presented.

This paper presents a characterization of the Alcator C scrape-off layer (SOL) plasma during ICRF second harmonic hydrogen fast wave heating experiments. The SOL plasma parameters were measured using a multifunctional probe, Janus, which is capable of simultaneously measuring the ion and electron parameters both parallel and antiparallel with respect to the toroidal magnetic field. The probe data indicate, at low value of injected RF power, that there is direct edge heating and density increases at radii greater than that of the antenna Faraday shield. Increasing the injected RF power spreads both the temperature and density increases throughout the edge region, flattening the radial profiles. Varying the position of the resonance layer in the main plasma does not significantly change the effect of ICRF on the SOL parameters. Given this single spatial point characterization of the SOL, a crude estimate of power flow into and through the edge plasma indicate that ≈ 20% of the ICRF power launched from the antenna is absorbed directly in the SOL plasma. Additional observation of the impurity source rates confirms the conclusions of an earlier paper, which attributed increasing central densities of high-Z impurities to the increase in physical sputtering rate at both the ICRF antenna's Faraday shield.

Visual inspection of the full poloidal ring limiters of Alcator C identifies two directionally asymmetric damage regions at the high field side of the plasma: at the top location on the electron side (as defined by plasma current) and at the bottom location on the ion side. We report direct measurements of edge plasma parameters in the SOL plasma on the top location using Janus, a two-sided, multi-diagnostic edge probe. Higher ion and electron temperatures and densities at the probe location occur on the electron side under standard operating conditions. The degree of asymmetry cannot be explained by limiter configuration alone, but the direction of the toroidal field and variation of the plasma horizontal position, change the magnitude of asymmetry. Mechanisms that may cause the directional asymmetries include parallel plasma flow and asymmetric perpendicular transport into the collecting flux tubes. Measurements made by DENSEPACK, a full poloidal array of Langmuir probes, show that strong poloidal asymmetries in both plasma density and electron temperature in the scrape-off region of Alcator C exist. Such asymmetries may arise from asymmetric perpendicular transport and/or act to drive plasma flows along field lines.

SiC-coated graphite limiter material was eroded by a plasma during the plasma edge experiments in Alcator C, and redeposited on the molybdenum surface of the Janus probe. Surface morphology, composition and structure of the deposit was examined after a total exposure time of ~1000 s. The redeposited material typically showed a “layered” morphology. AES depth profiles revealed increased oxygen content in the redeposited material and an apparent diffusion of Si and C at the deposit-molybdenum interface. Two clearly distinguishable chemical states of silicon in the deposit, as observed by XPS, suggest that plasma ionized polycrystalline SiC is being redeposited as a mixture of SiC and SiO x . Preliminary examination of the near surface regions by SIMS indicated (a) the presence of deuterium in the deposit, (b) the presence of molybdenum in the first few layers of the deposit, (c) formation by the plasma of multiple states of Si x O x , Si x C x , and Si x C x O x which do not appear in the spectrum of the unexposed SiC.

Impurity source mechanisms which appear during the heating of the Alcator C tokamak by injection of lower hybrid frequency waves are described. Silicon is a dominant impurity in these experiments where SiC was the limiter surface material. At low values of injected power, the silicon source rate is dominated by physical sputtering. As the amount of injected power is raised, evaporation caused by the tail electron heat flux to the limiter becomes the primary source for impurities entering the plasma. Measurements of silicon line emission from the plasma as well as other central and edge parameters are presented as functions of injected radiofrequency power.

Janus is a multiple‐function edge probe used to diagnose the Alcator C limiter shadow plasma whose components include two sets of identical diagnostics, each set facing a different direction. Included within each set of diagnostics are a retarding‐field energy analyzer (RFEA), Langmuir probe, and calorimeter. Janus is constructed to make measurements both parallel and antiparallel to a magnetic field. It can withstand high heat fluxes and can be scanned perpendicular to the magnetic field in the limiter shadow. The RFEA can alternatively sample both the ion and electron parallel energy distribution functions during a tokamak discharge. From the Langmuir probe, one can infer electron temperature, density, and the plasma floating potential. The calorimeter independently detects the total parallel heat flux incident on an electrically floating plate. Together these three diagnostics enable detailed, localized edge plasma studies on Alcator C. This paper presents the design considerations for each of the diagnostics along with a brief summary of the analysis techniques. Some experimental results obtained using Janus will also be presented.