Plastic Shaft Research Articles

A New Procedure of En-Bloc Endoscopic Mucosal Resection (EMR) Using Improved Papillotomy Knife (MUCOSECTOME)

Backgrounds: En-bloc resection is beneficial for accurate histological assessment of resected specimen of endoscopic mucosal resection (EMR). Variable EMR methods were developed. Conventional EMR technique or technique using Cap device method (EMRC) is technically simple and convenient but with this procedure the size of specimen obtained from one-piece resection is very limited. Insulated tipped knife procedure (IT knife) has already reported and it is actually useful to some expert endoscopists of it, but sometimes difficult for general endoscopist to use it safely. We newly developed a safe and easy technique of the en-bloc EMR using an improved papillotomy knife (Mucosectome). Device and methods: Mucosectome is an electrosurgical device, which is improved papillotomy knife for EMR. Mucosectome is composed with flexible plastic shaft and cutting wire. Traction applied on the handle manipulates the tip of the Mucosectome to assist in the proper alignment of the cutting wire to the tissue and then procedure itself becomes safe. Results. 35 cases of early gastric cancer patients received EMR using Mucosectome. En bloc resection of the lesion succeeded in 32 cases. The size of the resected specimen varied 20 to 65mm. Dissection of the submucosa was very easily and fastly carried out. Minor bleeding including oozing occurred in 14.2% and no perforation encountered. Conclusion: Here we present a new method of EMR using improved papillotomy knife (Mucosectome), which can realize safer, easier, and less time-consuming EMR compared to previous methods.

230 小型減速装置における樹脂製すべり軸受の低摩擦化・高寿命化検討

Although the micro reducer is able to get higher output power than input, it needs to reduce friction resistance applied to bearings. Therefore, from the viewpoint of transmission efficiency and long life, the micro reducer generally uses ball bearings due to low friction. However, it is difficult to reduce the production cost and to miniaturize the size at the same time. The authors have been developing the low cost, high accuracy and long life micro reducer with the plastic plain bearing in order to solve problems above. The problems in this research and development are to complete low friction and to improve wear property for the plastic plain bearing. In this paper, the combination of materials for the plastic plain bearing and the plastic shaft with lubricants are examined.

On the linearly hardening rotating solid shaft

Abstract Analytical solutions are obtained for elastic–plastic deformations of a linearly hardening rotating solid shaft with fixed ends and with free ends. All stages of elastic–plastic deformations are studied using Tresca's yield condition and the flow rule associated with it. Expressions for the stresses, displacement and plastic strains for a perfectly plastic shaft can be deduced from the expressions of linearly hardening shaft by letting the hardening parameter vanish.

FE fatigue analysis of notched elastic–plastic shaft under multiaxial loading consisting of constant and cyclic components

This paper presents a finite element analysis for a notched shaft subjected to nonproportional synchronous multiaxial loading. A combined tension/torsion is considered. For simplicity, one loading component is kept constant while the other is cyclic. The von Mises (von Mises R. Ges. Wiss. Göttingen, math. phys. K1 1913:582–93) yield criterion in conjunction with the kinematic hardening rule of Prager and Ziegler (Prager W. Proc. Inst. Mech. Engrs 1955;169:41–57; Ziegler H. Quart. Appl. Math. 1959;17:55–60) is applied to describe the elastic–plastic material behavior of the notched shaft. The boundary value problem is solved by using the commercial finite element program system ABAQUS (Theory manual, Version 4.9, 1991; User's manual, Version 4.9, 1991). A parametrical study is carried out and numerical results are presented to show the effects of the magnitude/amplitude ratio and the starting situation on the stabilized stress–strain hysteresis of the cyclic component and the stress–strain relation of the constant component.

Multiaxial fatigue life evaluation of tubular adhesively bonded joints

The only viable method for joining plastic tubes and composite shafts is by bonding them adhesively. These structures are often subjected to complex cyclic loadings. Failure of these tubular joints not only depends on the applied loads, but also depends on the tube geometry, material properties of adhesive and tubes, and defects in the joint. The shear stress distribution in the tubular joints is obtained for joints under axial and torsional loadings using the shear lag model. Under axial loading the adhesive is assumed to carry only shear stress and adherend to carry only axial load. However, the model considers the variation of the shear stress across the adhesive thickness. The effect of a void on the maximum shear stress is obtained. A nondimensional θ a parameter is defined and it is shown that the shear stress distribution not only depends on the value of θ a but it also depends on cross sectional geometry of the tubes. For tubes with equal cross sectional area, the shear stress distribution along the bonded area is almost symmetric. For tubular joints with θ a equal or greater than 6.7, a centrally symmetrical annular void with a size of at least 50% of the overlap length has little effect on the maximum shear stress and thus the failure load. The shear stress under torsional loading is obtained by assuming the adhesive to shear in the circumferential direction only and neglecting its other deformations. The tubes are assumed to shear in the axial direction. The analysis considers the variation of the shear stress across the adhesive thickness. As in the case of axial loading, a new nondimensional parameter, θ t for tubes under torsion is defined. The results show that the shear stress in the bonded area not only depends on the 0, value, but also depends on the polar moment of inertia, J 1 and J 2, of the tubes. The effect of annular voids on the shear stress distribution is evaluated for different void sizes and θ t values. The failure locus of adhesively bonded tubular specimens under axial, torsional and combined axial and torsional loadings is obtained. Based on these results a damage model for the tubular joints under combined axial and torsional cyclic loading is proposed. It is shown that this model can predict the fatigue life of the tubular joints reasonably well.

Highly elastic carbon fiber reinforced plastic propulsion shaft

Highly elastic carbon fiber reinforced plastic propulsion shaft

Measurements of earth pressures on two HDPE plastic shafts in municipal waste fills (In German) : Pruhs, H; Alexiew, D; Frank, P GeotechnikV16, N3, 1993, P115–124

Measurements of earth pressures on two HDPE plastic shafts in municipal waste fills (In German) : Pruhs, H; Alexiew, D; Frank, P GeotechnikV16, N3, 1993, P115–124

Clinical sampling device for rapid viral diagnosis by transmission electron microscopy

AbstractA clinical sampling device useful for rapid viral diagnosis was constructed from a plastic‐shafted throat swab by excision of the cotton or alginate wool tip and heat shaping the end of the plastic shaft to accommodate a Formvar‐ and carbon‐coated grid. The device can be conveniently carried in the coat pocket and can be readily used to obtain specimens at the bedside. Various types of fluids containing virus particles may be examined by transmission electron microscopy to obtain a presumptive diagnosis, often in less than 1 hour.

Dual stiffness Malecot (Stamey) catheter.

A new catheter with a soft plastic shaft and a stiff mushroom has been developed for drainage of various fluid-filled cavities. It can be introduced with a flexible guidewire system. Its dual stiffness provides greater comfort for and acceptance by the patient.

An instrument for measuring root canal length and apex location: A rapid technique

The invention of a new instrument (the Apexfinder) for measuring the root length and apex location is reported. This instrument is an accurate and reliable tool for the apex determination. The application method is based on the insertion of a plastic, fine-tapered barbed shaft through a beveled tube into the root canal. When resistance to withdrawal is felt, which indicates that one of the barbs has engaged the apical margin, the shaft is marked at the level of the cusp tip. The distance between the mark and the barbs which caused the resistance is measured. These barbs will show apical inclination, which would be opposite to the direction of the rest of the barbs. The practitioner can rely on this technique in the majority of cases provided that a full range of plastic shafts, with different dimensions, is available for use with the outer tube.

An Animal Respirator for Use in Electrically Shielded Rooms

A portable respirator is described which operates with a sufficiently low level of noise and electrical disturbance to permit its use with sensitive electronic equipment in electrophysiological studies of the auditory and other systems. It is operated by a plastic shaft passing through the wall of an electrically shielded room to a portable driving mechanism outside. It may be used with room air or other gases without admixture of room air. Respiratory minute volume is fixed for each animal by adjusting the stroke length of the pump and selecting a suitable drive speed. The animal may be placed in any position for access to any part of its body. Dead-space air and rebreathing are determined by the design and timing of a 3-way valve and by the length of tubing from pump to animal.