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The objective of this study is to investigate an appropriate breast prosthesis of pattern with center of gravity that exerts less clothing pressure on women who are breast cancer patients.

From November 2018, clothing pressure was measured with silk fabric breast prosthesis (SBP) of three different patterns above an affected breast (AB) by the force-sensitive resistance (FSR) sensor.

When wearing SBP above the AB, clothing pressure was significantly different in the healthy breast (HB) and the AB; the highest clothing pressure was at the center of nipple in the AB. Meanwhile, the top of the nipple area in the HB experienced higher clothing pressure than before wearing it. Because wearing heavy breast prosthesis presses down, influencing the HB as well. However, below the bottom of the breast bra curve in the AB, clothing pressure becomes lower than before wearing it. Because when the breast prosthesis was inserted into the bra, the clothing pressure not only increased generally but also the clothing pressure divided at some areas. Also, when comparing three different patterns of SBP, the result indicated a significant difference in clothing pressure only inside of breast cap and the center of gravity of the lower breast prosthesis has the lowest clothing pressure.

A comparison in pressure based on a circuit design (FSR sensors) and an air pack (AP) device was presented. Further work will be focused on the generation of pressure clothing for breast cancer patients.

The paper demonstrates that wearing breast prosthesis with a center of gravity in the lower position from the nipple area has less effect on breast cancer women. The results of this paper facilitate the pattern design of clothing for patients.

The main purpose of the study is to develop a theoretical model being capable of analysing the sealing and hydrodynamic‐hydrostatic lubrication mechanisms occuring between the mating surfaces of mechanical face seals.

The theoretical model developed is based on solving the governing basic lubrication equation (Reynolds differential equation) by employing a finite difference method. The main lubrication machanism is assumed to be converging‐diverging wedge which is formed by the relative tilt of the sealing surfaces. The non‐dimensional Reynolds equation was solved to give the pressure distribution and consequently the load and moment acting on the movable seal ring. The aim of the model is to predict the non‐dimensional hydrodynamic and hydrostatic load carrying capacity of the system.

Theoretical model developed is capable of estimating the hydrodynamic and hydrostatic behaviour of mechanical radial face seals. It is shown that a converging‐diverging wedge mechanism produces hydrodynamic pressure which in turn maintains the seperation of the surfaces. The tilt appears to be caused mainly by bearing misalignment. It has been shown that hydrostatic load or pressure centre is an important parameter for load balance of moving seal ring. It is easy and useful to calculate the dimensional parameters defined taking into account the different geometrical and operating parameters.

This paper offers a quick and easy opportunity to examine the hydrodynamic behaviour of movable seal ring of a mechanical face seal and provides a considerable contribution to the lubrication and sealing research area. With the general theoretical model developed, the behaviour of the seal ring can be modelled and estimated.

IN a series of articles entitled “Tailless Aircraft and Flying Wings”, concluded last month, the evolution of the tailless aeroplane and the flying wing was treated. The different trends of the development were classified, and a short discussion of the difficulties which had been experienced during experimental work given.

The treatment of Reynolds equation when the film thickness is unknown and the center of pressure is known, together with the energy and the bending equation, allows a realistic simulation of the performance of large thrust bearing. In a spring‐supported thrust‐pad bearing the distortion caused by the generated pressure thermal gradient yields a surface profile of opposite shapes. The thermoelastic analysis performed here makes it possible to determine the resultant film shape of the thrust pad.

An estimate is made of the effect of adding a small forward fin on the lift and centre of pressure of a slender wing‐body combination. The fin is assumed to discharge a trailing vortex which interacts with the main lifting surface. Design charts permit rapid estimation of lift loss and centre of pressure movement for a delta wing plus body. At the lower angles of attack, the lift loss on the wing is approximately equal to the lift of the forward surface itself. Most of the lift is lost at the front of the wing, and so wing centre of pressure moves aft with addition of the forward fin. Theoretical estimates are in general agreement with experimental results at Mach numbers 1·65 and 2·41.

This paper aims to present the slip/no-slip design in two-dimensional water-lubricated tilting pad thrust bearings (TPTBs) considering the turbulence effect and shifting of pressure centers.

A numerical model is established to analyze the slip condition and the effect of turbulence according to a Reynolds number defined in terms of the slip condition. Simulations are carried out for eccentrically and centrally pivoted bearings and the influence of different slip parameters is discussed.

A considerable enhancement in load capacity, as well as a reduction in friction, can be achieved by heterogeneous slip/no-slip surface designs for lubricated sliding contacts, especially for near parallel pad configurations. The optimized design largely depends on the pivot position. The load capacity increases by 174 per cent for eccentrically pivoted bearings and 159 per cent for centrally pivoted bearings for a suitable design. When slip zone locates at the middle of the radial direction or close to the inner edge, the performance of the TPTB is better.

The simplification of slip effect on the turbulence (definition of Reynolds number) can only describe the trend of the increasing turbulence due to slip condition. The accurate turbulence expression considering the boundary slip needs further explorations.

The shifting of pressure center due to the slip/no-slip design for TPTBs is investigated in this study. The turbulence effect and influence of slip parameters is discussed for large water-lubricated bearings.

The breakdown of laminar flow in the clearance space of a journal is considered, and the point of transition is considered in relation to experiments carried out with ‘bearings’ of large clearance. Experiments involving flow visualization with very large clearance ratios of 0.05 to 0.3 show that the laminar regime gives way to cellular or ring vertices at the critical Reynolds number predicted by G. I. Taylor for concentric cylinders even in the presence of an axial flow and at a rather higher Reynolds number in the case of eccentric cylinders. The effect of the transition on the axial flow between the cylinders is small. The critical speed for transition as deduced by Taylor, is little affected by moderate axial flows and is increased by eccentricity. The effect of critical condition on the axial‐flow characteristics of the bearing system appears to be negligible, again for moderate axial flows. Assuming that the results can be extrapolated to clearances applicable to bearing operation, the main conclusion of this paper is that the breakdown of laminar flow, which is a practical possibility in very high‐speed bearings, is delayed by eccentric operation.

This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact on a variety of factors to improve its grease lubrication properties.

Based on the simplified geometrical model, the research of grease lubrication properties of the TSUC was analyzed, and compared with oil lubrication in same parameters. Then the effects of effective radius, frequency (vehicle speed) and amplitude (angle between intermediate shaft and input shaft) on grease isothermal lubrication properties are theoretically investigated by using multigrid methods.

The results indicate that the grease isothermal elastohydrodynamic lubrication (EHL) film thickness shape and pressure distribution shape of the TSUC are similar to the oil lubrication, but the film thickness of grease lubrication is less than that of oil lubrication. Higher effective radius results in a wider pressure distribution, a lower center pressure and a thicker lubricating film. Higher frequency (vehicle speed) results in a remarkable second pressure peak and a thicker lubricating film. The effects of amplitude (angle between intermediate shaft and input shaft) and frequency have similar tendencies.

The numerical analysis research on grease lubrication properties of the TSUC is significant because the automotive transmission shaft is widely used. And it provides a new direction in designing TSUCs.

Fig. 2 shows a blade carried by a head of the kind described in Specification. 435,818. The root of the blade comprises a steel tube 32 provided with a fairing 33, Fig. 3, which is a sliding fit over supporting arm 30 and is rotatable to vary the blade pitch. The outer end of tube 32 is secured to blade spar proper 34. The blade is anchored to the hub by a torsionally resilient tie rod 35 screwed at its outer end into spar 34 and secured by a nut and tapered collet device 36. At the inner end rod 35 is secured into arm 30 and secured by a screwed plug and taper pin assembly 37. The blade is of lancet shape and is arranged so that axis B—B of the spar intersects the flapping and drag pivot axes and in the normal mean position of the blade intersects the axis of rotation at the mean centre of oscillation F of the blade pitch control gear. The masses and aerofoil sections of the blade are such that the centres of mass and mean centres of pressure of all the sections lie along axis B—B. The construction of the blade is such that the “ neutral torsional axis,” defined as the locus of points in the chord at which an applied vertical thrust produces equal degrees of flexure of the leading and trailing edges, is at or slightly in front of the axis B—B. In the latter case increase in lift tends to decrease the angle of incidence of the blade as is shown in Fig. 6 wherein C is the centre of pressure, L the lift force, and 0 the neutral torsional axis. In either arrangement aerofoil sections having a stable centre of pressure travel may be employed. In order to bring the neutral axis forward, the nose portion of the blade, in the case of hollow stressed‐skin construction, may be reinforced by additional layers of material or may comprise material having a higher modulus of elasticity than the remainder. In order to compensate the resulting forward movement of the centre of mass, a small amount of non‐structural mass may bo incorporated in the blade. In one form in which the neutral torsional axis is coincident with the B—B axis, the blade comprises a spar and an aerofoil‐shaped fairing of material of the synthetic resin or plastic group of which the modulus of elasticity is so much lower than that of the spar as not to relieve the latter appreciably of its loads. Fig. 7 shows the method of construction of such a blade comprising a steel spar having a moulded fairing. A first mould comprises upper and lower dies 1, 2 and an interposed core 3. Spar 4 is located by pegs 5 and by rows of spaced raised points 6, and is also fluted to key the moulding. Steel wires 8, 9 are strung in the spaces forming the leading and trailing edges. The blade is formed with a solid nose and with internal ribs 10 and webs 11, the latter being produced by slots formed in the upper side of core die 3. After moulding as shown, dies 2 and 3 are removed, pegs 5 cut off, countersunk, and plugged, Fig. 9, and a lower die 13 placed in position and heat applied to unite the lower skin to ribs 10 and to seal the trailing edge. A suitable plastic material is stated to be “ plastic glass.”

The purpose of this paper is to investigate how the center of pressure (COP) changes depending on the type and wearing method of baby carriers, which is fundamental research for the development of smart baby carriers. In addition, the most comfortable and least burdensome type and method of wearing baby carriers is suggested.

The COP and muscle fatigue were measured depending on the three types and wearing method of baby carriers. And then, the subjective stability, comfort, and fatigue were analyzed.

The results of this study show that horizontal changes to the COP are greater and when baby carriers are worn loosely, subjective comfort is worse. Furthermore, when the shoulder straps are worn loosely, the center of mass moves downwards, lowering the muscle fatigue of the shoulders, but greatly raising the muscle fatigue of the waist and thighs. Comparison of the shapes of baby carriers showed that X-type produced greater muscle fatigue in the shoulders, waist, and thighs, as well as greater subjective fatigue in the shoulders. However, subjective fatigue in the waist decreases when baby carriers without waist support are worn.

It is expected that changes in COP values based on the type and method of wearing baby carriers will be applied as fundamental data for the development of automatic-adjusting smart baby carriers that prevent muscular pain and concentrated pressure.