Shaft Size Research Articles

Congenital lymphedema of the penis: A method of reconstruction

Congenital lymphedema of the genitalia has profound physical and psychological consequences for the growing child. Extensive resection of this tissue and reconstruction by skin grafting offers a less than satisfactory cosmetic result. Over the past year we have employed a method of total excision of the lymphedematous tissue of the penile shaft with cosmetic reconstruction without skin grafting. A circumferential incision was made 5-10 mm from the coronal sulcus and deepened to the level of Buck's fascia. The skin and subcutaneous tissue were then completely dissected away from the penis. The skin was everted and all of the abnormal lymphedematous tissue excised up to the dermal skin margin. The skin was then tailored to the size of the penile shaft and reapproximated. This method has been employed in two patients with the advantages of (1) shorter hospitalization, (2) lack of morbidity associated with the skin donor site, and (3) satisfactory cosmetic results.

Root morphogenesis in ectopically transplanted pleurodont teeth of the iguana

A study was made to determine the behavior and fate of transplanted reptilian teeth with a pleurodont type of attachment. The purpose was to compare this attachment with the behavior of other types of attachments, when they are transplanted, and to determine which portions of the ankylosed tooth are controlled by intrinsic factors. 50 small green iguanas were used. Autologous transplants of both individual buds of a known stage of development and small blocks of the entire upper or lower jaw were placed in the gular region or anterior chamber of the eye. The transplants and the jaws were examined at intervals from 0 to 180 days. Tooth buds transplanted with or without the jaw were capable of growth to normal size and shape. New bud formation also began after transplant acceptance, and buds were more protected from epithelial injury than previously reported amphibian tooth transplants. The ankylosed adult tooth began the process of shedding almost immediately. While lack of normal environment and lack of underlying bone did not prevent formation of a normal root shaft with dentin, there was little evidence of induction of the ‘bone of attachment’ and underlying jaw bone by the growing buds. The root shaft size and shape were, therefore, intrinsic features of the pleurodont tooth.

Comparison of Application Capabilities of U and T Rated Motors

The inception of the T-frame line in the mid 1960's as the new standard integral horsepower induction motor has frequently raised the question among users as to the relative application capability of these motors to previous U-frame motors with which users have good application familiarity. This question has been asked and answered in numerous technical presentations and conferences. The aspects of the topic that have aroused most interest are: 1) insulation systems, temperature rating standards, and relative insulation life expectancy, 2) effect of overloads, 3) effect of over- and undervoltage, 4) effect of unbalanced voltage, and 5) bearing and shaft sizes.

An Experimental Study and Analysis of Turbulent Film Tilted Pad Bearings

Velocity profiles and pressure distributions are reported for turbulent flow under tilted pads in a large scale bearing model (6-ft shaft size, with air as the working fluid). Results are extended analytically to other bearing sizes and aspect ratios.

Tungsten ball microelectrode for extracellular single-unit recording

An electrolytic method is described for manufacturing ball-tipped tungsten microelectrodes. The tungsten ball is produced by slowly withdrawing the electrode from the etching solution until the wire mells and tungsten metal forms a ball at the end of the shaft. The size of the ball is related to both the size of the wire shaft and the amount of current being passed. Smaller balled tips are produced when wire of smaller shaft diameter is induced to spark and melt. Higher voltages and larger shaft diameters at sparking yield larger balled tips. Ball-tipped electrodes are produced easily and reliably by this method and require little training. Such electrodes are sturdy and capable of stably recording activity of either single cells or multiple-units with good signal-to-noise ratio. They can record extracellular perikaryal responses from neurons at several levels of the nervous system. Responses of single nerve fibers are not isolated by these electrodes.

Basis for the design of smoke shafts

How do you determine the required size of smoke shafts, and what is a proper application of them? These are questions examined by the authors.

On the Critical Speeds of a Continuous Shaft-Disk System

The effect of gyroscopic moments on the critical speeds of a shaft-disk system mounted in short end bearings is investigated. Representation of the shaft as having continuously distributed mass and elasticity allows accurate determination of higher critical speeds. Frequency equations are obtained for the critical speeds associated with both backward and forward whirling modes. The first four critical speeds (backward and forward whirling modes) are given for a range of shaft and disk sizes and for various disk locations on the shaft. Experimental verification is given for the first and second critical speeds.

Production and Detection of Solitary Macroscopic Quantized Vortices in Helium II

Ultrasonic cavitation was induced in liquid helium using plane and cylindrical standing-wave systems resonant at 89 and 53 kc/sec, respectively. The threshold voltage for cavitation noise was measured at different rotation rates of a shaft, with and without an attached paddle, rotating in the vicinity of the sound field. Below the $\ensuremath{\lambda}$ point the threshold was found to be lowered sharply at a critical rotation rate ${\ensuremath{\omega}}_{c}$. The experiments were repeated with five different shaft sizes, and ${\ensuremath{\omega}}_{c}$ was found to be inversely proportional to ${r}^{2}$, where $r$ is the radius of the shaft. The constant of proportionality was found to be $\frac{\ensuremath{\hbar}}{m}$, where $m$ is the mass of one helium atom. Further, smaller threshold reductions were observed at rotation rates of $2{\ensuremath{\omega}}_{c}$, with the largest shaft sizes. These results are consistent with the theory of quantized vortex formation and appear to indicate that such vortices play a role in the cavitation nucleation process.

Torsional instability from frictional oscillations

Rotational systems are often required to maintain steady angular motion with slow velocities. Under these circumstances, sustained torsional oscillations (self-excited) may easily occur, basically caused by the fact that the static coefficient of friction is appreciably higher than the kinetic coefficient of friction. Such oscillations are in-tolerable in a system requiring steady motion. An analytical solution of the system of Fig. 3 is given, which is then put into an analog computer, giving numerical results shown in Figs. 8(a) to 8(f) for various shaft sizes and friction coefficients. It has been possible to assemble all this information in a single dimensionless diagram Fig. 9 which shows the minimum unstable rotational speed of Fig. 8 for values of flywheel inertia, shaft stiffness, friction coefficients and internal damping. It is believed that Fig. 9 will be found useful in the design of slowly rotating shaft systems.

Rating of high-temperature induction motors

The advent of new high-temperature insulating materials, such as the silicones, gives new freedoms to the motor designer. It is probable, however, that factors other than insulation will limit the desirable motor-temperature rise to values well below the endurance limits of these materials. It is, therefore, desirable to recognize that the size of an induction motor is measured electrically by its breakdown torque, and mechanically by the size of shaft and bearings, the temperature rise being only a secondary factor. Calculations are presented, pased on idealized assumptions, which indicate that the optimum temperature rise for continuous rated induction motors is Delow 80 degrees centigrade, whatever the insulating materials used.

Rating of High-Temperature Induction Motors

The advent of new high-temperature insulating materials, such as the silicones, gives new freedoms to the motor designer. It is probable, however, that factors other than insulation will limit the desirable motor-temperature rise to values well below the endurance limits of these materials. It is, therefore, desirable to recognize that the size of an induction motor is measured electrically by its breakdown torque, and mechanically by the size of shaft and bearings, the temperature rise being only a secondary factor. Calculations are presented, based on idealized assumptions, which indicate that the optimum temperature rise for continuous rated induction motors is below 80 degrees centigrade, whatever the insulating materials used.

Investigation of formulæ for determining the proper size of shafts and piston rods

Investigation of formulæ for determining the proper size of shafts and piston rods