Hollow Body Research Articles

Duct and electronic apparatus having the duct

[Object] To provide a duct with high sound absorbing effect and sufficient exhausting efficiency and an electronic apparatus having the duct [Solving Means] A duct 10 includes a hollow duct body 20, an inflated section 30 arranged at an intermediate part of a passage of the duct body 20, and a sponge 40 bonded on internal surfaces of the duct body 20 and the inflated section 30. The duct body 20 and the inflated section 30 have a thickness of 0.25 mm and are formed of a sheet member of paper impregnated with polymethylpentene on the surface thereof. The duct body 20 includes an intake-port side duct body 201 and an exhaust-port side duct body 202, which are connected together at an angle of 90° therebetween. To an intake port 20A of the intake-port side duct body 201, a fan is connected. The inflated section 30 is arranged in the side of the intake port 20A, and the cross-sectional area of the inflated section 30 is 1.8 times that of the duct body 20.

Occurrence of defect and Prevention in Drying Process of Slip-cast Hollow Green Body for Large Pottery

Occurrence of defect and Prevention in Drying Process of Slip-cast Hollow Green Body for Large Pottery

Beta-Utopian Order

Beta-Utopian Order

A Novel Fluidic Bellows Manipulator

A not-conventional manipulator is presented in this paper. The device consists of a bellows-like flexible and continuum structure actuated by fluid. Two balloons, placed inside of a hollow cylindrical flexible body, separated by a floating spine, may deform the flexible body thus moving the manipulator end-effector on a single plane according to an opportune inflating sequence. The description of the device, its assembling procedure and experimental characterization in terms of end-effector workspace, characteristic force-position curve, response in dynamics are addressed. Furthermore a general mathematical analysis of the robots based on the bellows-like structure is presented. The model approximates the flexible structure of the device as a series of rigid links connected by a couple of revolute and prismatic joints. The model was accurately validated by comparing the forward kinematics, static and inverse dynamics of the manipulator built with data from the analytical model.

Internal Behavior of Clayey Ground Improved by Vertical Drains in 3D-Consolidation Process

In order to establish a precise method for predicting the residual settlement, including the secondary consolidation, of clayey ground improved by vertical drains, a new consolidation test apparatus was developed. In this test apparatus, the consolidation of a hollow cylindrical body, in which the pore water flows radially toward the center, can be simulated by installing a vertical drain at the center of the specimen. The radial distributions of the radial displacement and excess pore water pressure in the specimen during the three-dimensional consolidation process also can be measured in this test apparatus. The radial displacements in the specimen were obtained by measuring the intensity of the magnetic field induced by a small magnet buried in the specimen by magnetometers set in the consolidation ring surrounding the specimen and in the vertical drain installed at the center of the specimen. From the measured results on the radial displacements in the specimen, it was found that during the three-dimensional consolidation process not only the vertical displacement but also the radial displacement occurs inside the specimen. The radial displacement developed toward the center of the specimen in the early stage of consolidation and then returned toward the outside in the later stage of consolidation but did not completely return to the original position at the end of consolidation. The mechanism of the three-dimensional consolidation by the vertical drain, which caused these behaviors, was clarified based on the test results on the radial distributions in the radial displacement and the excess pore water pressure in the specimen.

Apparatus for damping acoustic vibrations in a combustor

The present invention relates to an apparatus for damping acoustic vibrations in a combustor as well as a corresponding combustor arrangement with the apparatus. The apparatus comprises a Helmholtz resonator ( 4 ) that can be connected via a connecting channel ( 2 ) with a combustor ( 1 ). The Helmholtz resonator ( 4 ) contains a hollow body ( 6 ) the volume of which can be changed by adding or draining a fluid via a supply line ( 5 ), or is located adjacent to such a hollow body in such a way that the resonance volume ( 3 ) of the Helmholtz resonator ( 4 ) is changed when the volume of the hollow body ( 6 ) is changed. This apparatus makes it possible to adjust the resonance frequency of a Helmholtz resonator arranged inside a pressure container in accordance with the respective current operating point of the combustor to be damped, without having to pass movable components through the pressure container.

Device to improve loudspeaker enclosure duct

A waveguide for use in a loudspeaker. The waveguide is positioned within a loudspeaker enclosure and connect to a low frequency transport duct of the loudspeaker. The waveguide has a hollow body which is perforated with apertures. The body presents a high mechanical impedance to the low frequency waves increasing the duct input impedance of the loudspeaker which improves transmission of the low frequency waves to the exterior of the loudspeaker enclosure.

Advances in Dynamics and Impact Mechanics

On the dynamic collapse of circular and square tubes under axial impact On analysis of axisymmetric crushing of tubes and frusta Crushing strength of ship structures On the side impact of hollow composite rail body shells Multibody systems dynamics methodologies for crashworthiness On the numerical simulation of the progressive collapse of polymer composite sandwich beams under impact loading Simplified analysis of square plates under explosion loading Ballistic penetration and perforation of steel plates - an experimental and numerical investigation Dynamic behavior of large-scale structures due to a low speed impact Dynamic response and failure of free-free beams under impact or impulsive loading Failure behaviour of prestressed concrete beams under high-speed and impact loadings.

A novel sensor for monitoring acoustic cavitation. Part I: Concept, theory, and prototype development.

This paper describes a new concept for an ultrasonic cavitation sensor designed specifically for monitoring acoustic emissions generated by small microbubbles when driven by an applied acoustic field. Its novel features include a hollow, open-ended, cylindrical shape, with the sensor being a right circular cylinder of height 32 mm and external diameter 38 mm. The internal diameter of the sensor is 30 mm; its inner surface is fabricated from a 110-microm layer of piezoelectrically active film whose measurement bandwidth is sufficient to enable acoustic emissions up to and beyond 10 MHz to be monitored. When in use, the sensor is immersed within the liquid test medium and high frequency (megahertz) acoustic emissions occurring within the hollow body of the sensor are monitored. In order to shield the sensor response from events occurring outside the cylinder, the outer surface of the sensor cylinder is encapsulated within a special 4-mm thick polyurethane-based cavitation shield with acoustic properties specifically developed to be minimally perturbing to the 40 kHz applied acoustic field but attenuating to ultrasound generated at megahertz frequencies (plane-wave transmission loss > 30 dB at 1 MHz). This paper introduces the rationale behind the new sensor, describing details of its construction and the materials formulation program undertaken to develop the cavitation shield.

기능성 대장 내시경 로봇 시스템

Colonoscopy is an important medical procedure for the diagnosis of various diseases like cancers in the colon and rectum. But it requires a lot of time for a doctor to acquire dexterous skills necessary to perform successful colonoscopy. Moreover, to many patients, conventional colonoscopy simply takes too long time.<br/> Therefore, some studies on the development of autonomous and more convenient colonoscope are carried out.<br/> In this paper, we propose a functional colonoscope robot system that has a locomotive function with a hollow body, a steering system, and other basic functions of typical conventional colonoscope systems. The concept and each component of the functional colonoscope system are described in this paper. In order to evaluate the functional performance of the colonoscope robot, we carried out in -vitro and in-vivo tests.

Gallium-mediated growth of multiwall carbon nanotubes

Liquid gallium was used as a viable and effective solvent and template for high-yield growth of multiwall carbon nanotubes. The gallium-mediated nanotubes thus obtained differ morphologically from nanotubes obtained by using transition metals as catalysts. The nanotubes have a pin-like morphology, generally composed of an oval-shaped tip filled with liquid gallium and a tapered hollow body. The inner diameter of the tube is so large that the inner/outer diameter ratio is usually larger than 0.9. The tubes are naturally opened at both ends. These gallium-filled nanotubes may be used as a nanothermometer in the temperature range of 30 to 550 °C. This study opens an interesting route for carbon nanotube synthesis.

BEM Solution With Minimal Energy Technique for the Geometrical Inverse Heat Conduction Problem in a Doubly Connected Domain

This article addresses the use of boundary element method in conjunction with minimal energy technique for solving a geometrical inverse heat conduction problem. The problem considered in this study is to estimate the unknown inner boundary position in an irregular-shaped hollow body of which the inner boundary surface is subjected to a specified temperature condition. For solving the problem, first boundary element equations are converted into the quadratic programming problem by minimizing the energy functional with a constraint, next a hypothetical inner boundary is defined such that the actual inner boundary is located interior of the hypothetical solution domain, then temperatures at hypothetical inner boundary are determined to meet the constraints of measurement error in inner surface temperatures, and finally boundary element analysis is performed for the position of an unknown boundary. Based on these main solution procedures, an effective detection algorithm is provided. In addition, the solution method is numerically tested to investigate the effects of measurement errors on the accuracy of estimation.

Musical drinks vesels

A musical drinks vessel comprises a hollow body 10 for holding the beverage and a sound generating assembly having an electrically operated sound generating device 11,12 sealingly mounted therein. The sound generating device 11,12 is activated when the amount of light incident on a photodiode thereof exceeds a predetermined level. A shutter 21 is provided for obscuring light from the photodiode, when it is desired to deactivate the sound generating device 11,12 . The shutter enables the device 11,12 to be activated and deactivated simply and remotely, without any physical connection to the device that could allow the ingress of liquid or steam liquid when the device is being washed or sterilised.

Sports related combined noisemaker and visual display device

A sports related combined noisemaker and visual display device includes a hollow body with a rigid wall, configured to replicate the appearance of a helmet or other type of sporting equipment, a rigid partition disposed in the interior of the body so as to form a closed chamber bounded by the wall of the body and the partition, a plurality of hard pellets loosely disposed in the chamber, and handle means disposed on the body for shaking the body back and forth to cause the pellets to impact the wall and partition and produce sound. The placement of the handle and the orientation of the partition are such that the chamber functions to focus and project the sound from the wall of the body generally opposite the handle. The outer surface of the body provides an area for the application of visual displays such as decals.

Solenoidal skin vibrator energized by complex electric waveforms

A new skin vibrator converts simple or complex electrical waveforms into simple or complex mechanical waveforms or vibrations that are applied to the skin and underlying tissues for therapy or pleasure. The complex waveforms may be completely random in response to the output of a random electrical noise generator, or non-random but complex in response to music or speech. In effect, random acoustic vibrations or speech or musical vibrations are induced in the skin and underlying tissues. The vibrator comprises an oblong hollow body having a solenoidal motor mounted inside. The solenoid is partially damped at both extremes of its stroke to buffer the impact within the vibrator and thereby soften the vibration. Wires extend from the vibrator for connection with a signal generator, audio amplifier or other source of the electrical waveforms.

NON-LINEAR STOCHASTIC DYNAMICS OF TENSION LEG PLATFORMS

In this paper, a set of non-linear equations of motion for a single-tendon tension leg platform are developed. The equations of motion consist of partial differential equations representing the transverse and longitudinal response of the tendon. In addition, a mixed formulation partial differential equation describing the surge response of the hull and tendon, coupled with an ordinary differential equation for the pitch response of the rigid hull is presented. Many of the simplifying assumptions used by prior researchers have been eliminated. The hull is modelled as a hollow rigid cylindrical body, and the tendon as a hollow cylindrical beam pinned at its top to the hull and at its bottom to the template connected to the seafloor. The Extended Hamilton's Principle is applied and the Lagrangian is fully developed. Terms include the kinetic energy, bending and membrane strain energies and the potential energy due to gravity and buoyancy. The normalized equations of motion are also detailed. The full derivation with assumptions are presented. The response, analyzed for stochastic wave and current loading, is presented with a planar motion assumption. The tension leg platform will oscillate about its vertical position due to ocean waves. Current will cause a tension leg platform to oscillate about an offset position rather than its vertical position. This offset in the surge direction has a corresponding setdown, the lowering of the hull in the heave direction, which increases the buoyancy forces. This results in a higher tension in the tendons than if the tendon and hull were in a vertical position. Forces on the tendon have been neglected in much of the literature. The responses presented in this work show that the inclusion of forces on the tendon will result in both a greater amplitude and offset position when compared to studies where these forces are neglected. This offset position, which is the surge displacement from the vertical position, is significant in the operation of a tension leg platform. A Monte Carlo simulation was performed on the drag and inertia coefficients in Morison's equation. A uniform random distribution of coefficients was selected from 0.6 to 2.0 for each coefficient. Twenty computer simulations were implemented for each coefficient. The response showed that the offset position and the amplitude are both dependent on the drag coefficient. The surge of the hull shows a maximum offset approximately three times greater for the coefficient that resulted in the maximum displacement than the minimum. The response did not show a significant dependence on the inertia coefficient, however, this is not necessarily true for unsteady current, large hull and tendon diameters, ocean wave frequencies greater than 1 rad/s and low current velocity.

Structural Analysis of Railway Car Body Made of Aluminium Hollow Extrusions.

Stuctural FEM analysis on railway car bodies made of aluminium hollow extrusions under uniformly distributed normal load was carried out. For the structural analysis on hollow extrusion structure car body, the method to substitute equivalent orthogonal anisotropic plates for hollow extrusions and the character of shell elements must be considered. The equivalent orthogonal anisotropic plate is obtained through the selection of four main rigidities which describe principal deformation of car body. For the characteristics of shell elements, element division on pier panel enough to describe its shear deformation must be considered. The FEM result which is calculated with orthogonal anisotropic plates and the characteristic of shell elements are in good agreement with the load test result.

Connection structure and connection fitting for an electrode post of a battery

An electrode post connection structure for connecting a connection conductor to an electrode post of a battery through a connection fitting, which includes a lock stage portion formed on a circumference of the electrode post, a tapered portion formed at a top portion of the electrode post, a lock spring inserted in the connection fitting so as to engage with the lock stage portion to thereby lock the electrode post and the connection fitting with each other, and a hollow elastic body accommodated in the connection fitting so as to press the connection conductor to thereby connect the electrode post and the connection conductor to each other. Thus, work for connecting a connection conductor to an electrode post of a battery is simplified, and the electric characteristic and reliability of the connection are improved greatly.

Conduite à tenir face aux corps étrangers œsogastriques chez l'enfant

Various methods have been used to remove foreign bodies; hollow foreign bodies deserve special consideration. The main difficulty encountered in such situations is the anatomic obstacle of the lower and upper esophageal sphincters along with a risk of perforation.We describe a unique approach by using an esophageal balloon dilator to anchor a hollow foreign body onto an endoscope, which allows for the successful extraction of such objects with minimal risk.Case series.Shands Jacksonville and University of Florida/Jacksonville, Jacksonville, Florida.Two consecutive patients with hollow foreign bodies in the stomach that required removal.A combined approach by using an endoscope and a 20-mm by 8-cm esophageal balloon dilator to remove hollow foreign bodies from the stomach.Nonsurgical removal of hollow gastric foreign bodies.Both foreign bodies were successfully removed from the stomach and extracted by mouth with this technique. There were no complications after both procedures.The inflated esophageal balloon that anchors a hollow foreign body onto a flexible endoscopic technique is a safe and effective alternative to previously described methods for removal of such foreign bodies in the gastric cavity. This method may be applicable to the removal of other hollow objects within the gastric lumen.

Analytical 4D Infrared Tomography Using an InSb Focal Plane Array Sensor. 2. 4D Infrared Tomography (Multiwavelength Approach)

A focal plane array InSb image detector has been used for noninvasive spectroscopic infrared tomography of visually turbid polymer bodies. Tomographic images from a rotating sample, illuminated by infrared light, were taken under distinct, equidistant angular views. Several IR wavelengths were used simultaneously for illumination. This provided for each analyzed sample a four-dimensional data set consisting of three geometric dimensions (x, y, z) and the wavelength axis (λ). Concealed or secret parts inside the turbid hollow polymer body were visualized by three-dimensional numerical computer-assisted tomographic reconstruction using the back-projection algorithm. IR tomography at different wavelengths provided the possibility of differentiation between distinctly absorbing materials inside a visually turbid material. The name 4D IR tomography or spectroscopic infrared tomography is proposed for this new analytical method.