Eccentric Aperture Research Articles

Improvement of Technology for Producing Rolled Sheet from Continuously Cast Steel Slabs. Part 1. Experimental Study of Casting Using a Pressure Submersible Nozzle

It is proposed to use a new submersible nozzle with eccentric apertures in order to improve continuously-cast slab quality. Calculations show that up to 38% of the heat of steel overheating is removed in the upper part of the crystallizer. The number of equiaxed crystals increases by several factors with an increase in crystallization rate. Pilot plant approval of advanced continuous casting of low-carbon and low-alloy steels makes it possible to improve hot rolled metal strength and toughness. Forecasting low-carbon steel sheet ultimate strength and relative elongation is conducted using known experimental equations. Rolled steel quality is evaluated from slabs selected from eight melts. The slab sulfur content obtained using a nozzle with eccentric apertures is somewhat higher than in slabs cast through existing nozzles.

Strehl Ratio for Annular Eccentric Circular Aperture with Presence of Seidel Aberrations

In this research the equation of point spread function (PSF) has been derived for annular eccentric aperture optical system which is consisting of circular perture with non-central circular obscuration. The study was done with diffraction limited system and when different 1st and 3rd orders aberrations were present. Also trying to show how the presence of some 1st order errors with some of 3rd order aberrations were affected on Strehl ratio and make a balancing of aberrations which gives in turn a better image.

Cumulation of High-Current Electron Beams: Theory and Experiment

High-power electron beam cumulation in a relativistic vacuum diode with a ring-type cathode is considered. The term “electron beam cumulation” here means electron beam self-focusing accompanied with multifold beam current density increase on the beam axis compared to the average current density in the cathode-anode gap. Space-charge repulsion of electrons emitted by the explosive-emission plasma on the inner edge of the cathode is shown to be the origin of this cumulation mechanism. Current density in the vicinity of beam axis is evaluated for different cathode inner diameter values both numerically and experimentally. Cathode with eccentric apertures of different diameters is studied experimentally.

Effect of Eccentricity on the Charge Distribution by a Cylinder-Penetrated Circular Aperture

This letter considers the effect of the eccentricity on the static field and charge distribution for a circular aperture pierced by a long cylinder. The conformal mapping method is used to convert the problem of an eccentric aperture into that of a concentric aperture. The Weber transform, superposition principle, and mode matching are employed to calculate the static potential for this concentric problem. Numerical computations illustrate the behavior of potential distribution, surface charge density, and partial charges on the plane for various aperture eccentricities.

Upper gastrointestinal tract obstruction due to congenital duodenal diaphragm

The presence of incomplete upper gastrointestinal obstruction in childhood is a rare condition and usually indicates congenital anomaly. We reported a case of incomplete duodenal obstruction in a 16-year-old girl due to a congenital duodenal diaphragm. A duodenal diaphragm with an eccentric aperture was found by upper gastrointestinal series and endoscopic examination in the second part of the duodenum. The patient made an uncomplicated recovery with relief of the symptoms after duodenotomy and excision of the diaphragm. This case underlines that congenital duodenal diaphragm should be kept in mind as a possibility whenever chronic obstruction of the duodenum in childhood is diagnosed. The prognosis of congenital duodenal diaphragm is usually good after excision of the diaphragm, when not associated with other congenital anomalies.

B207 カラー偏心アパーチャを用いた微小空間における微粒子の3次元位置計測

In order to measure instantaneous three-dimensional velocity distributions in a small space, three-dimensional micro-PIV technique have to be developed. In this paper, the improved eccentric aperture method that could be conveniently applied to the three-dimensional PIV measurement in a small space is discussed. By introducing a color separation technique, the measurement distance can be expanded twice, and it can process dense tracer pictures. Some experimental examples are shown.

Antral web associated with distal antral hypertrophy and prepyloric stenosis mimicking hypertrophic pyloric stenosis

A 3-year-old boy presented with postprandial vomiting and epigastric pain for 3 wk. Barium meal study suggested hypertrophic pyloric stenosis. Ultrasound of the stomach after water loading revealed an echogenic antral web with an eccentric aperture and distal antral hypertrophy. Subsequent endoscopy confirmed the ultrasound findings. Web resection and antropyloroplasty resulted in excellent recovery. To our knowledge, the barium meal and ultrasound findings of an antral web-associated distal antral hypertrophy and prepyloric stenosis has not previously been described.

Calculating the Process of Vulcanisation of a Cylinder with an Eccentric Aperture

Calculating the Process of Vulcanisation of a Cylinder with an Eccentric Aperture

223 偏心アパーチャを用いた2カメラステレオ法による3次元位置計測

A measuring method for coordinates of distributed point-markers in a three-dimensional space is examined. The measurement system basically consists of two color cameras, and each camera equipped with an eccentric aperture plate, which enables to measure distance from the camera. As for the camera settings, a method of crossed optical axis is applied. Adding to the three-dimensional measurement of coordinates, it refers the influence of the optical thickness of a lens. The factor causes non-linearity to a relationship between object-distance and magnification, the influence becomes stronger as distance to an object becomes shorter.

243 高解像度ビデオカメラと偏心絞りを用いた距離計測法の検討

Some range sensing methods using a single camera have been proposed. Most of them utilize eccentric apertures. In these techniques, the higher the resolution of the picture, the more accurate range sensing can be achieved. In order to obtain the high spatial resolution, a HDTV camera is employed in the present system. And three eccentric apertures, which form a right-angle triangle, is placed in front of the camera lens. As the results of the calibrating experiment, the system has shown a fairly good measuring precision of about 0.2% of the picturing distance. Adding to the precision, it is found the eccentric aperture realizes the faster analysis by offering easier pattern recognition.

A new type of combined bipole deflector for a rf glow discharge ion source

In order to reduce the disturbances produced by photo-radiation and neutral particles in a rf glow discharge ion source which is used in a sputtered neutral mass spectrometer, a new type of combined bipole deflector has been developed, which consists of half-cylindrical electrodes and diaphragms with eccentric apertures. A theoretical analysis and experiments have been carried out. It has been shown that the background of photo-radiation can be reduced by six orders of magnitude with the eccentric structure. The ion beam is extracted with double deflection and focused laterally by the half-cylindrical bipoles, which results in a high ion transmission up to 20%. This deflector is suitable for coupling a plasma type of ion source with a quadrupole mass spectrometer and has extremely high ratio of signal to noise.

Month in the Patent Office

Gases to be silenced are caused to partake of a whirling motion close to the inner surface and past the reticulations of the reticulated wall of a chamber arranged within an outer casing. Substantially the whole of the gases flow past the reticulations from a relatively restricted inlet to an outlet, and the whirling motion may be imparted by a deflector plate or curved vane or by a tangential inlet. A casing 1 has at one end a portion 50 terminating in a hemispherical cap 51 with inlet 54, and at the other end a plate 3 with eccentric outlet 5 and a pipe 9 attached thereto. The interior of portion 50 is separated from the interior of the rest of the casing by a plate 2 having an eccentric aperture 4 behind which is a deflector plate 10. Within the portion 50 are hollow conical frusta 52, 53 abutting at their larger ends. The small end of frustum 52 is connected to the inlet 54, while the small end of frustum 53 is connected to the aperture 4. Within the casing 1 are a pair of frustoconical chambers 6, 7 with reticulated walls, the smaller end of chamber (5 entering the larger end of chamber 7 eccentrically, and the smaller end of chamber 7 terminating in the outlet pipe 9. The deflector plate 10, adapted to whirl the gases, is located close to the wall of chamber 6 and comprises a portion 11 inclined to the longitudinal axis of the casing with an edge in contact with the internal surface of chamber 6, and a portion 12 arranged parallel to the axis of the chamber. A similar plate is located behind the entrance to chamber 7. The spaces between the frusta 52, 53 and the outer casing are filled with sound‐absorbing material 57 such as asbestos or coke, or, alternatively, sheet asbestos may be wound round the frusta. The space between the chambers 6, 7 and the casing serves as a cushioning space and may also be filled with sound‐absorbing material such as steel wool, or fibrous asbestos or with material adapted to absorb poisonous gases. An opening 13 may be provided for the removal of solid matter. In a modification (Fig. 2) the inlet pipe 59 is secured to an end plate 58 forming the base of the conical chamber 60, the smaller end of which passes through an eccentric opening in diaphragm 2 into a cylindrical reticulated chamber 15 supported by a diaphragm 16, and is extended by a pipe 62 adapted to direct the gases on to a portion 20 of a deflector plate on the side remote from an aperture 21. The gases then pass through aperture 21 and flow along the inner surface of the chamber with a gyratory motion. A second deflector plate 22, similar to the first, is situated in the chamber 15. In both constructions, the second deflector plate may produce whirling in the same or an opposite direction to the first. In a modification, the reticulated chambers are of spherical form. In Fig. 4 gases enter the chambers 38 tangentially by a pipe 39 and leave by pipes 40, 41. In Figs. 5 to 8 (not shown) different arrangements and combinations of chambers within the casing are described, and in two of the forms, suitable for aircraft, the casing is conical and provided at its rearward or smaller end with a number of perforations to give a gradual outlet. Specification 366,257 is referred to in the Provisional Specification.

Month in the Patent Office

A casing 1 encloses conical chambers 6, 7 and has an end portion 50 enclosing a double frustoconical chamber 52, 53, the space between which and the casing is filled with sound absorbent material such as asbestos or coke, or sheet asbestos may be wrapped round the frusta. The conical passage 53 leads to an eccentric aperture 4 in the base 2 of the chamber 6 and, likewise, the chamber 6 leads to an eccentric aperture in the base of chamber 7. Behind each eccentric aperture is located a deflecting plate 10 comprising two portions 11, 12 of which 11 is inclined to the longitudinal axis of the silencer casing, while the portion 12 is parallel thereto. The deflectors may whirl the gases in the same or in opposite directions. The chamber 52, 53 allows initial expansion of the gases. Specification 366,257 is referred to.