China
Africa
Explore chapters and articles related to this topic
Work-Related Ill Health
Published in Céline McKeown, Office Ergonomics and Human Factors, 2018
This condition is centred in the wrist area and relates to an inflammation in the lining of the synovial sheath in which a tendon is enclosed. Figure 11.4 shows the tendons in the hand and the synovial sheaths. Tendons are the means by which muscle attaches to bone and across which the muscle transmits forces that result in movement of the individual bone and the limb as a whole. Under normal circumstances, the tendons can move smoothly within the sheath, and this is assisted by the presence of some lubrication. The sheaths are intended to offer protection to the tendons as they pass under ligaments or as the wrist is bent and the tendon is pressed against the bones of the wrist.
Work-Related III Health
Published in Céline McKeown, Office Ergonomics, 2007
This condition is centered in the wrist area and relates to an inflammation in the lining of the synovial sheath in which a tendon is enclosed. Figure 11.4 shows the tendons in the hand and the synovial sheaths. Tendons are the means by which muscle attaches to bone and across which the muscle transmits forces that result in movement of the individual bone and the limb as a whole. Under normal circumstances, the tendons can move smoothly within the sheath, and this is assisted by the presence of some lubrication. The sheaths are intended to offer protection to the tendons as they pass under ligaments or as the wrist is bent and the tendon is pressed against the bones of the wrist.
Electrical Installation Methocs, Procecures And Recuirements
Published in Peter Roberts, Electrical Installation Work, 2017
Domestic properties are largely installed using a PVC sheathed and insulated cable (Figure 4.22), which use thermoplastic material around the inner cable conductors and its outer sheath. It is very important to realise that the actual sheath is what protects the cable from any potential physical damage and this is known as providing mechanical protection.
Coolant Channel Design for Additively Manufactured Reactor Cores
Published in Nuclear Science and Engineering, 2022
Justin Weinmeister, Casey J. Jesse, Prashant Jain, Brian J. Ade, Danny Schappel
These geometries all modeled the fuel as a homogeneous matrix of SiC and UN-TRISO with physical properties set as a mixture of the two based upon the estimated packing fraction of UN-TRISO within the fuel form. This homogenization was consistent with neutronics analysis that showed that the simplified model did not have large effects on power deposition rates.20 However, the shell material of the fuel elements, which is the original green part from the binder jet process, was modeled separately as solely 3-D printed SiC. The density and thermal conductivity values were taken from Terrani et al.,21 while the specific heats were taken from Snead et al.22 The thermal conductivity of the material can change significantly under irradiation and depending on grain size, but the values used in this study are valid for unirradiated binder jet SiC. The thin shell region and interior fuel matrix region can be seen in the cross-sectional view in Fig. 5. For the moderators, the stainless steel sheath and the YH were modeled explicitly. The center hole in the moderator was given helium properties, but it was modeled as a solid for the current work as any natural circulation within the moderator rods would beneficially redistribute heat. This beneficial effect did not need to be credited for the safety analysis of the current design, so it was ignored.
Development of Conceptual Lead Cartridge Design to Perform Irradiation Experiments in VTR
Published in Nuclear Science and Engineering, 2022
Seung Jun Kim, Keith Woloshun, Joshua Richard, Jack Galloway, Cetin Unal, Jeffrey Arndt, Michael Ickes, Paolo Ferroni, Richard Wright, Osman Anderoglu, Cemal Cakez, Khaled Talaat, Shuprio Ghosh, Brandon Bohannon
An ECFM can be built in a few different configurations. A probe-type detector is fully submerged in a molten metal, and the metal flows around the exterior of a hermetically sealed enclosure. This device can be sealed with a protective metal sheath (e.g., stainless steel, Inconel, etc.) or can be sealed with nonporous ceramic (e.g., alumina). Implementation of a metal sheath is called a dry probe, and the use of a ceramic coating is called a wet probe. A dry probe–type sensor was ultimately selected and implemented in FFTF (Ref. 6). An alternative configuration is a flow-through–type detector.7 As the name implies, the fluid traverses through the center of a coil rather than around the exterior of a probe. Figure 10 shows examples of probe-type detectors and a flow-through detector used in FFTF.
Analysis of Crystallization Fouling Durability of Novel Heating Elements for Electric Water Heating
Published in Heat Transfer Engineering, 2022
Alexander Janzen, Eugeny Y. Kenig
Electrical heating appliances have been used for many years in water heating. There are primarily two heating systems manufactured in large quantities, which are based either on tubular or bare-wire heating elements. The tubular heating element is an electrical resistance heater in a sheath made of copper, stainless steel, or steel. A heating wire is embedded inside the metal tube and electrically insulated with highly compressed magnesium oxide. The heating fluid has no contact with the heating wire. Owing to the poor thermal conductivity of magnesium oxide, the surface temperature of the heating wire increases. Because it is highly susceptible to crystalline deposits, its lifetime is limited. Tubular heating elements are not affected by air dissolved in water and are suitable for soft water conditions. Bare-wire heating elements operate in an electrically insulated block. Inside the block, the electric heating elements are placed directly in the fluid without any electrical insulation of the heating surface from the fluid. Insulation resistance is ensured by long and narrow channels in front of and behind the electric heating elements. This resistance depends on the properties of the fluid flowing through the long and narrow channels, and the channel geometry. Figure 1 shows some conventional electric heating elements.