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Volume 23, Issue 9
Displaying 1-11 of 11 articles from this issue
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Yoshinao BUNDO, Isamu ONO, Tadahiko OGAWA1974Volume 23Issue 9 Pages 493-497
Published: September 15, 1974
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe dissolving state of titanium potassium oxalate in aqueous solution depends on pH value. The structure of the yellow-brown titanic complex which is produced by the reaction between titanium potassium oxalate and hydrogen peroxide depends also on pH value. From these facts, titanium potassium oxalate sample solution was prepared by dissolving in distilled water. The relation between radiation dose and yield of titanic complex was obtained by γ-ray irradiation of the sample solution saturated with oxygen or nitrogen gas. From these experimental results, the production mechanism of hydrogen peroxide was possible to presume. Furthermore, it was found that the reaction velocity between OH radical and titanium potassium oxalate was 2.9×1010M-1· sec-1.View full abstractDownload PDF (524K) -
—by Autoradiography—Kazue NIIZUMA, Toru ARAKI, Yutaka KAGAYA1974Volume 23Issue 9 Pages 498-504
Published: September 15, 1974
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIn the range of the sulphur content from 0.010% to 0.060%, sulphur segregation was influenced by the casting structure and solidification condition regardless of the form of sulfide.
Naturally, in the case of the similar casting structure, the pattern of sulphur segregation was the same mode regardless of the sulphur content.
On the basis of the experiment about the origin of equiaxed crystals we made presumption as follows:
The first freezed columnar crystals were separated into fine particles by residual molten bath and dispersed uniformly in the liquid.
As a result of the above-mentioned action, the temperature distribution in molten bath was uniformalized, and then the equiaxed crystals would freeze with random orientation as crystal nucleus with fine particles.View full abstractDownload PDF (3878K) -
Shinji OKANO, Yoshio ONAI, Isao UCHIDA, Teizo TOMARU, Toraji IRIFUNE, ...1974Volume 23Issue 9 Pages 505-510
Published: September 15, 1974
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe use of positron-emitters offers significant advantages in scintigraphy. Several different types of positron cameras have been constructed and studied by Anger. The positron camera presently in use has a high sensitivity, good resolution, and tomographic effect, but disadvantages of this camera, in addition to its complicated electronic circuits, are that it overloads easily and many accidental coincidences arise, because a collimator is not employed. For the purpose of improving these disadvantages, a positron camera with a focused collimator has been constructed for trial. It consists of an image detector with the Anger camera, a coincidence detector with a sodium iodide crystal of 3-inch diameter by 3-inch thickness, a focused collimator, and electronic circuits consisting of a fast coincidence circuit, a constant fraction timing single channel analyzer, and others. Distance from the face of the focused collimator to the coincidence detector, called the focal distance, is 60 cm. An effective diameter of the coincidence detector can be varied by a small collimator. When the effective diameter is 2.5 cm, the overall resolution is independent of the distance from the face of the focused collimator to the active source, and is nearly equal to the intrinsic resolution of the Anger camera. The sensitivity of the positron camera decreases to about 1/4 by attaching the focused collimator, while the counting rates in the image detector decrease to about 1/40. This gives the same effect as the 10-fold increase in sensitivity, because the positron camera will not overload even when the amount of positron emitters administered to a patient is increased about 40 times. The usefulness of this positron camera was ascertained by its use in animals and human patients. Especially in clinical examples, it makes local diagnosis possible because of the high resolution. however, the disadvantage of this positron camera is that the field of view is very small. In order to im-prove this disadvantage, a focused collimator with a focal length of 150 cm has been constructed. This instrument will be used for routine clinical studies in the near future.View full abstractDownload PDF (2757K) -
Noboru ARIMIZU, Nobuko SAWARA, Mitsuhiro KUCHIKI, Toru MATSUMOTO1974Volume 23Issue 9 Pages 511-515
Published: September 15, 1974
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSA scintillation camera utilizing an NaI crystal of 38.7 em in diameter has been employed in examinations of 1200 patients for one year and nine months. The effective field of view is 34 cm in diameter, corresponding with approximate 70% larger areas than those of a standard scintillation camera with an NaI crystal of 30.5 cm in diameter.
The performances of the large-area scintillation camera were examined regarding its linearity, resolution and uniformity by using Co-57 sources. The resolution tests with a lead bar phantom showed image discriminations of the bars of 0.64 cm wide at 5 and 10 em distant from the collimator. The uniformity was frequently checked by gamma-ray flood exposured on the detector surface, showing spontaneous shifts of uniformity with irregular intervals.
The view of large-area scintillation camera covered bi-lateral lungs in three fourths of patients without an image distortion, which are shown with a diverging collimator. The large-area view was advantageous in a comparative study of regional respiratory functions of the bi-lateral lungs with Xe-133. The liver and spleen were also represented in one view of an A-P projection in most cases. The bi-lateral kidneys and the urinary bladder, however, came into one view only in one-fourth cases. The large-area scintillation camera was rather disadvantageous in the brain scintigrams, because they were not benefitted by the view much larger than the brain and the big detector was troublesome in fixing the head for the given projection.View full abstractDownload PDF (5959K) -
Hiyoshimaru OYAMADA, Kiyomitsu KAWACHI, Hiroyoshi ISHIBASHI, Shigemasa ...1974Volume 23Issue 9 Pages 516-522
Published: September 15, 1974
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIt is needless to say that the whole body scanner, which can survey an entire body at one performance, is very useful in the daily practice. Recently, we have manufactured the whole body scanner attached by several newly designed devices for the practical use. The fundamental structure is almost the same with the whole body scanners of other type. There are two probes, having the crystals of 5 inches in diameter, which are opposed vertically. The spacing is provided for 1.5, 3.0, 4.5, 7.5, 9.0, 15.0, and 30.0mm. The scan speed can be changed from 20cm/min to 500 cm/min. The image ratio is provided for 1/5, 1/3, and 1/1. The recording system is composed of two channels, each of which has both dot and photo recording systems, In the photo recording box, there are various slits of different sizes. The most appropriate slit is set automatically on the interrelation between the actual scan spacing and the image ratio to avoid any overlaps or openings between the scan lines exposed on the film.
The newly designed devices are 1) program scanning attachment, 2) simultaneous recording system of profile scan pattern during the scintiscanning, and 3) output system for computer processing.
The program scanning device is designed for the scanning of the area of interest, which results in saving the scanning time. This is composed of photo-luminescence diode and phototransister, and is attached to one of the dot recording heads. The area of interest is demarcated with black ink on the scintigram paper. When this attachment reaches the black line, the photo-transister recognizes changes of the brightness of reflected light on the scintigram paper, which comes from the photo-luminescence diode, resulting in advancing the space. Simultaneous recording of profile pattern is based on the integrated counts obtained from each scan line. The recorder for this purpose is specially designed not to change the pitch width even though under the condition of variable scan width. In order to obtain whole body digital image, digital output system is included in this scanner. At present, on-line system is not available because of budget problem. Digital data of every 3mm or 6mm on the scan line are punched out on the tape, which is transferred to computer, HITAC 8350, for various processings.
This scanner is now working very well and providing us very good scintigrams always.View full abstractDownload PDF (9041K) -
Masataka HIGUCHI, Masaichi OOTA, Akiko MUKADE1974Volume 23Issue 9 Pages 523-525
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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Teruo KIKUCHI, Kazumi IWAMOTO1974Volume 23Issue 9 Pages 526-528
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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Masanori MATSUMOTO1974Volume 23Issue 9 Pages 529-532
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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Hiroshi ABE, Kazufumi KIMURA1974Volume 23Issue 9 Pages 533-543
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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Monitoring System and Safety EquipmentToshinori OSHIMA1974Volume 23Issue 9 Pages 544-549
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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1974Volume 23Issue 9 Pages A1467-A1020
Published: September 15, 1974
Released on J-STAGE: July 21, 2010
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