Level of Sagittal Plane Fit of Plates on the Radial Shaft: A Cadaveric Study Comparing Precontoured and Straight Titanium Plates

Background: During radial shaft fracture fixation, it is important to contour the plate appropriately to restore the radial bow in order to maintain normal forearm mechanics and motion. The aim of this study was to investigate the fit of precontoured radial shaft plates versus surgeon-contoured plates. Methods: Six 10-hole Acumed® precontoured volar and dorsolateral radius plates and twelve 10-hole Synthes straight titanium 3.5 mm LC-DCP plates were drilled with arrays of 1.5 mm diameter holes to permit measurement of the plate distance off bone. Plates were applied to 6 cadaver radii and secured with a screw on each end. Three plate conditions were tested: precontoured plates, precontoured plates with further surgeon contouring, and straight plates with surgeon contouring. Surgeon contouring time for each plate was recorded. Each plate was divided into 3 equal regions, and the average distance gaps for each region and the entire plate were calculated. Results: For the volar side, precontoured plates had a larger total gap compared to that plate with additional surgeon contouring (1.4 mm difference) and the straight surgeon-contoured plates (1.2 mm difference). On the dorsal side, there was no difference in fit between the 3 plate conditions at any location. No differences were found in plate contouring times. Conclusions: The precontoured dorsal plate fit was as good as the surgeon-contoured plates indicating this plate could potentially be used in fracture surgery without further bending. The precontoured volar plate was under-contoured, on average, and would likely require further bending to restore the radial bow.

Casimir Forces Out of Thermal Equilibrium Near A Superconducting Transition

We present a comprehensive analysis of the out-of-equilibrium Casimir pressure between two high-T c superconducting plates, each kept at a different temperature. Two interaction regimes can be distinguished. While the zero-point energy dominates in the near field, thermal effects become important at large interplate separations causing a drop in the force’s magnitude compared with the usual thermal-equilibrium case. Our detailed calculations highlight the competing role played by propagating and evanescent modes. Moreover, as one of the plates undergoes the superconducting transition, we predict a sudden discontinuity in the force for any plate distance, which has not been previously observed in other systems. The sensitivity of the dielectric function of the high-T c superconductors makes them ideal systems for a possible direct measurement of the out-of-equilibrium Casimir pressure.

Experimental Investigation on the Heat Flux Distribution and Pollutant Emissions of Slot LPG/Air Premixed Impinging Flame Array

Experiments were carried out to investigate the heat transfer and pollutants emission characteristics of a slot LPG premixed flame array impinging normally onto a flat plate. The effects of jet-to-jet spacing (S/de), nozzle-to-plate distance (H/de), and jet Reynolds number (Re) on the heat flux and emission index of CO, CO2, and NOx/NO2 were examined. In addition, the thermal and emission characteristics between slot jets and circular jets were compared under identical experimental conditions. The results show that the more uniform heat flux distribution and higher total heat flux can be obtained at moderate jet-to-jet spacing, large jet-to-plate distance, and higher Reynolds number. EICO emissions can be influenced by the combined effects of jet-to-jet spacing, jet-to-plate distance, and higher Reynolds number. For the sake of the better combustion efficiency and lower EICO emission, the moderate jet-to-jet spacing (S/de = 2.5), larger jet-to-plate distance (H/de = 4), and relatively higher Reynolds number (Re = 1500) are preferred for the slot jet flame array. Furthermore, it is found that there exists a trade-off between the EICO and EINOx of the slot LPG flame array. Compared with multiple circular flame jets, multiple slot flames jets have the higher area-averaged heat flux due to the larger heating area and more uniform heat flux distribution, while the higher EICO emission and lower EINOx emission are due to the greater jet interaction suppressing the air entrainment. Thus, it is known that the slot flame array has a better heating performance but relatively higher pollutant emissions than the circular flame array.

The Effect of Baffle Configuration on Heat Transfer and Pressure Drop Characteristics of Jet Impingement System with Cross-Flow

Use of baffles in jet impingement systems in presence of initial cross-flow disturbs boundary layer that results in rise in heat transfer. Two configurations of baffle assisted impingement systems were considered and a comparative study on heat transfer and pressure drop is carried out based on operating parameters such as baffle clearance, blow ratio and h/D ratio using commercially available CFD package. Numerical predictions showed that both heat transfer and pressure drop in segmented configuration were higher than louvered configuration for all blow ratio employed in this study. Parametric studies showed that, thermo-hydraulic performance parameter is higher only for louvered configurations at low blow ratio. When cross-flow velocity is comparable with jet velocity, segmented baffles resulted in relatively higher thermo-hydraulic performance because of its higher heat transfer rate relative to the incurring pressure drop. An increase in clearance proportionally increases performance parameter. However, as jet to plate distance increases, thermo hydraulic performance declines significantly.

Heat Transfer Characteristics of a Coaxial Inverse Diffusion Flame Jet Impingement with an Induced Swirl

Flame jet has a wide range of applications in the industries and also in domestics field. The efforts have been put to enhance the heat transfer and to reduce the emissions from the premixed and inverse diffusion flame burners. Especially, the IDF burner suffers from lack of proper air and fuel mixing, the swirl generated motion from twisted tape would improve the combustion efficiency. Therefore, an aim of experiment is to study the heat transfer characteristics of an inverse diffusion flame (IDF) jet impinging on a flat surface in a coaxial tube burner with swirl. The twisted tape of 15mm pitch creates the swirl in the flame jet (Corresponding to the twist ratio of 3 and swirl number of 0.52). An effect of swirl at air jet Reynolds number of 1000 to 2500 and surface of the burner-to-impingement plate distance (H/da) varying from 2 to 20 is studied at fixed equivalence ratio (ϕ) of 1.1. An average heat flux and peak heat flux are studied for the region of 0<r/da<3 on an impingement plate. From an investigation, it is found that the swirling in the flame jet enhances the average heat flux by up to 179.2%. The maximum average heat flux is found at the optimal burner-to-target plate distance of 8.

MATHEMATICAL MODELLING TO PREDICT ANGULAR DISTORTION IN MIG WELDING OF STAINLESS STEEL 202 PLATES

In present research, mathematical models have been established to predict the angular distortion in Metal Inert Gas(MIG) welding for 6mm plates of SS 202 grade for butt welded joints. The filler metal used was a continuously fed solid metal wire of stainless steel (304L).100% Argon gas was used to serve the purpose of shielding the weld pool from the atmosphere as it does not dissociate at high temperatures. This prevented any turbulence in the welding arc and deterioration in weld quality. To obtain experimental samples, the design matrix was developed using the statistical technique of central composite rotatable design (CCRD). Analysis of Variance (ANOVA) technique was used for the adequacy check of the models developed. The models developed can be used to find direct and interaction effect of the input parameters, namely welding speed (WS), voltage (V), nozzle to plate distance (NPD), torch angle (Ɵ) and wire feed rate (WFR) on the angular distortion.

Experimental and Numerical Investigation of Thermal Performance of Synthetic Jet Impingement

Synthetic jet potentially useful in electronics cooling is investigated both numerically and experimentally. In the present study, a confined three dimensional synthetic jet with sinusoidal moving wall is considered. Computations are carried out using the FLUENT software with the coupled user defined function describing the diaphragm movement. In this study the effect of various geometrical parameters influencing the flow field and heat transfer are investigated. The effects of change in orifice geometry (circular, square and rectangular), orifice aspect ratio, and jet-to-plate distance are studied for a given hydraulic diameter. The heat transfer results obtained from the synthetic jet is compared with the continuous jet. An electromagnetic actuator is used as an oscillating diaphragm for the generation of synthetic jet. A stainless steel foil with 0.05 mm thickness is used as the test specimen. The surface temperature of the test specimen is measured by using a thermal imaging technique during synthetic jet impingement and a constant temperature anemometer has been employed for velocity measurement. Tests are carried out for Reynolds number of 5448, varied range of jet-to-plate distance (1–18). The maximum value of the heat transfer coefficient is found to be 16 times more than the heat transfer coefficient for natural convection.

Radiation resistance of high frequency ultrasonic devices for distance measurement in the RHF

The fuel element plates of research reactors are subjected to swelling phenomena. These structure modifications impact an initial inter-plate distance of 1.8 mm. An ultrasonic device has been developed to investigate this parameter. With a 1 mm thickness, it relies on two transducers linked to an electronic system. The feasibility of the distance measurement has been proved in a previous study and the irradiation impact on the transducer components is here studied. To do so, a radiation resistance experiment was realized in the Arc-Nucleart Institute of Grenoble. It allowed the study of the influence of radiations on the device active and passive components’ characteristics.