Tube Holder Research Articles

Sound bar type percussive musical instrument

In construction of a sound bar type percussive musical instrument, the center sections of tube holders are firmly coupled to the center sections of the front and rear walls of the base frame in order to block the tube holders against undesirable center flexion due to weight of resonator tubes, thereby assuring uniform gaps for all sound bars and resonator tubes.

A centrifuge head for back-and-forth centrifugation to improve specimen infiltration by viscous plastics

For embedding of small pieces of tissue a special centrifuge head was designed for back-and-forth centrifugation of the tissue to speed up infiltration of the tissue by a viscous plastic which is poorly miscible with the solvent used for dehydration. The centrifuge head was designed in such a way that the tube holders flip between two positions with a difference in orientation of close to 180° by varying the speed. This way the tissue moves back and forth in the centrifuge tube with the surfaces of the pieces of tissue being exposed continuously to virtually fresh plastic. This way a steep concentration gradient solvent-plastic is constantly maintained at the surface of the tissue. This centrifugation—infiltration procedure is also useful whenever plastics of high viscosity are used even when the plastic and the solvent used for dehydration are easily miscible.

A simplified fundamental parameters method for quantitative energy‐dispersive X‐ray fluorescence analysis

AbstractStephenson's CORSET method has been adapted and expanded to the newer energy‐dispersive method to take advantage of its ability simultaneously to detect all elements (Z > 10) present (anticipated or not). Parameters such as the mass absorption coefficients and energies of absorption edges and emission lines of all elements are calculated as in Myklebust and Heinrich's FRAME program. The X‐ray intensities of pure elements versus atomic number of the elements for a given line (Kα or Lα) forms smooth curves as reported by Blum and Brandt. Because of the exceptional stability of energy‐dispersive methods (no moving parts, long tube life, etc.) and known overall spectrometer efficiency of these systems, they can be ‘standardized’ at installation by measuring (for a given tube, voltage and specimen holder configuration) several pure intensities (e.g. 6–10 covering the periodic table). Stored, these constants allow the calculation of the effective pure element intensity and the original intensity of the most effective excitation energy for any element that may be encountered. For an unknown sample, the program integrates net peak intensities (stripping away spectrum background and peak overlaps) and converts them to percentages with an iterative calculation. The accuracies are not as good as can be achieved with appropriate multiple standards. The compensating advantages are speed, flexibility and convenience. The entire program runs on‐line in a 16K, 16 bit minicomputer.

プラスチックライニング鋼管現地継手部の新防食工法

It has become the recent trend to adopt corrosionfree plastics for pipeline coating. This report describes two new protection methods for field coating of uncoated pipe joint sections of plastic coated pipe. The first method is sealing of uncoated pipe joint sections by means of the automatic shrinker using shrinkable tubes. In this method, shrinkable tube is held by the tube holder over the uncoated pipe joint sections of plastic coated pipe. Hot air from a propane gas burner of the automatic shrinker is blown onto the shrinkable tube while the automatic shrinker moves along the pipe. The shrinkable tube is subject to contraction and then attached to the pipe. The second method involves sheet wrapping. Uncoated joint sections of plastic coated pipe are sealed by applying heat-shrink type sheet. One side of the sheet is coated with butyl type undercoating and end of the sheet with hot melt type adhesive. After heat-shrink type sheet thus applied is heated by spuare heat element or blowtorch, it is subject to contraction and then attached to the pipe.

Density gradient fractionation by piston displacement

A method for the fractionation of centrifuged density gradients is described. A piston forced into the centrifuge tube from above displaces the gradient, while its tip collects liquid from the small volume immediately below it without disturbing the unfractionated part of the gradient. The centrifuge tube holder permits sensitive visual detection of bands of light scattering particles which may then be rapidly and precisely extracted. Continuous fractionation of the entire gradient is also possible.

Endotracheal Tube Holder

An endotracheal tube holder for restraining an endotracheal tube in a patient's mouth includes a base that is strapped to the patient's head. The base includes a tube-securing block and clip-securing blocks. A separate, U-shaped clip is engagable in ratchet fashion to the base between the tube-securing block and the clip restraining blocks to secure the endotracheal tube to the tube-securing block.

Analytical measurements of isopycnic density in the preparative ultacentrifuge with application to FeLV and FeLV-RNA

A procedure for determining the buoyant density of nucleic acids and/or other biological macromolecules using the preparative ultracentrifuge and a recording spectrophotometer via a specially adapted tube holder is described. The procedure gives buoyant density values, precise to ±0.004 gm cm −3, which is comparable to determinations made in the analytical ultracentrifuge. With this system, the buoyant densities of the feline leukemia virus (FeLV) and its ribonucleic acid (FeLV-RNA) were found to be 1.184 ± 0.002 gm cm −3 and 1.641 ± 0.006 gm cm −3 in CsCl and Cs 2SO 4, respectively.

The haematocrit centrifuge for the detection of trypanosomes in blood.

A capillary tube holder, devised to minimize shadow effects during microscopic examination of haematocrit capillary tubes for trypanosomes, is described. A blood dispenser, designed to remove trypanosomes from centrifuged tubes, resulted in thinner smears of trypanosomes covering a smaller area. The anterior end of centrifuged trypanosomes was abnormally thickened and the kinetoplast displaced posteriorly.

Modifications in a French pressure cell-laboratory press system.

Two removable steel plates, a shortened valve handle, lengthened outlet nozzle, and an added test tube holder facilitate use of a cell disruption system.

Modifications in a French Pressure Cell-Laboratory Press System

Two removable steel plates, a shortened valve handle, lengthened outlet nozzle, and an added test tube holder facilitate use of a cell disruption system.

Permanent turbidity standards.

Permanent turbidity reference standards suitable for measurement of microbial suspensions were prepared by suspending finely divided titanium dioxide in aryl sulfonamide-formaldehyde or methylstyrene resins. Turbidities of these standards, adjusted to a useful range for microbiological and immunological studies, were compared with other reference standards in use today. Tube holders for a Coleman Photonephelometer and a Nepho-Colorimeter were modified to eliminate the water well and to allow use of optically standardized 10-, 16-, or 18-mm test tubes. The standards and the tube holders have been used satisfactorily for more than 12 years.

Permanent Turbidity-Standards

Permanent turbidity reference standards suitable for measurement of microbial suspensions were prepared by suspending finely divided titanium dioxide in aryl sulfonamide-formaldehyde or methylstyrene resins. Turbidities of these standards, adjusted to a useful range for microbiological and immunological studies, were compared with other reference standards in use today. Tube holders for a Coleman Photonephelometer and a Nepho-Colorimeter were modified to eliminate the water well and to allow use of optically standardized 10-, 16-, or 18-mm test tubes. The standards and the tube holders have been used satisfactorily for more than 12 years.

An ampoule freeze-dryer for microbiological research

The construction and operation of an ampoule freeze-dryer for drying suspensions of micro-organisms in 72 tubes at controlled temperatures in the range -50° to 20°C are described. In the apparatus the suspensions can be frozen in situ by placing the tube holder in thermal contact with the condenser. Means of obtaining reasonably uniform temperatures in different suspending fluids in the same experiment, and of maintaining constant low temperatures in slow drying suspensions are discussed.

New method for holding nasal tubes in position.

A problem common to most patients subjected to nasal intubation for the purpose of either suction or long-time feeding is the difficulty involved in maintaining the tube in a fixed position. The usual method of fixation is the use of adhesive tape for adhering the tube to the nose, the cheek, or the forehead. This method is far from ideal, because adhesive tape quickly loses its effectiveness, becoming stretched or loosened by perspiration, thereby allowing the tube to move in and out as the patient swallows. This motion and the obvious pressure against the alar rim of the nose creates an unpleasant irritation or cellulitis which eventually leads to ulceration if the condition is not corrected. A new tube holder has been developed which is easily affixed to the nose, with no discomfort to the patient. It is constructed of a thin malleable aluminum, approximately 0.005 mm. in thickness, and

Thermocouple tube holders for the measurement of hot steel temperatures by immersion

A production process for thermocouple holders to be immersed into hot steel has been devised the characteristic of that process being the use of hydrostatic compression. A protecting magnesite coat is applied to the carborundum portion of thermocouple holders made for long-time immersion into steel and basic slag.

The Distribution of C14 in the Root and Shoot Apices of Young Corn Plants

Concentration of P32 in the meristematic regions of plants has been reported by a number of investigators (3, 5, 6). Rabideau and Burr (5) have given evidence for a gradient in concentration of C13-labeled compounds in the stem tips of bean plants. Belkengren (2) showed rapid movement of carbon-13-labeled materials to bean root tips after exposure of the leaves to C1302 and light. Gustafsson et al. (4) demonstrated accumulation of P32 in the meristematic regions of barley roots. These findings and other considerations have emphasized the desirability of having more information concerning the movement of carbon from leaf-fed carbon dioxide into the meristematic regions of both shoots and roots. In relation to many questions pertaining to growth and development it would be desirable to have information not only with respect to the concentration of carbon in meristematic regions but also with respect to the incorporation of labeled carbon into specific compounds and the distribution of these compounds in the growing regions. The present study was designed to yield information on the concentration of C14 in meristematic regions, the nature of the C14-labeled fractions, and the distribution of these fractions in root and shoot apices of young corn plants. Seedlings of an inbred line of corn, University of Texas number 859, were grown in sand in a greenhouse until they were three to five inches tall (8 to 10 days). They were then transferred to a black lucite disk which served as a plant holder (fig. 1). This holder was perforated with 15 holes in which two-inch lengths of glass tubing were cemented to serve as plant supports. The plants were held in these glass tube supports with a cotton plug in the lower part of the tube. The holder was placed over a desiccator bottom so that the roots of the seedlings dipped into a Shive nutrient solution. This solution was aerated continuously and black cloth was tied around the desiccator as a light screen. The plants were grown in this container for five days. At the end of the fifth day the plants were sealed in the glass tube holders by pouring melted beeswax on top of each cotton plug. When poured at 50? C, this wax caused no detectable damage to the plants. A bell jar of 10 liters volume was placed over the leaves of the plants and sealed to the lucite plant holder with grease. It was held tightly against the lucite disk with several steel springs.

Reminiscences of Roentgenology During the Last War, 1917–1919

THE unfortunate events which are taking place abroad have stimulated our national defense program to such an extent that this is perhaps an opportune time for reviewing World War number one experiences and the problems which we were forced to meet under the most difficult roentgenological conditions. It is to be regretted that “old man military roentgenology” had to be so rudely awakened after twenty-four years of peaceful slumber. This report embodies the medical experiences of St. Louis Base Hospital No. 21 (Washington University Unit) after assuming the duties of the evacuated British General Hospital No. 12, at Rouen, France. Although the conclusions were crystallized under the stress of war conditions, nevertheless the original recommendations of 1917 and 1918 may be of interest to many who may be privileged in the near future to engage in similar activities. Modified foreign body localization methods, roentgenologic procedures in the management of war-wounded, and combination floor trochoscopic and radiographic apparatus were described by me in a paper sent for publication to the A merican Journal of Roentgenology during the Christmas holidays of 1917, but this was, perhaps, lost during a period of unusually active submarine warfare and may today be deposited in Davy Jones' locker of the Atlantic. I will attempt to present these data, together with the original recommendations made in 1917 (recently resurrected from an old dust-laden army trunk) relative to the scope and limitations of the unforseen problems of a British Base Hospital. When I use the term “x-ray plates,” you will understand my reason for so doing, since films were an unknown quantity in our area. A small group of the 1,000-bed hospital units can be seen in the foreground of the accompanying photograph (Fig. 1) taken from the famous Rouen, France, racecourse grand-stand. The x-ray department was indeed fortunate in being housed in portable wooden huts (Fig. 2) instead of tents. The x-ray equipment allotted to us, however, was limited to one 6-inch “Butts” x-ray coil, Zenith mercury gas interrupter, wooden x-ray tube holder, and table. The current was supplied by eight one-inch-square celluloid wet storage batteries and these were, in turn, charged several times a day by a small one-cylinder gasoline engine. Both the gasoline engine and the Macalaster Wiggin gas x-ray tube proved to be, at times, temperamental—either the gas engine wouldn't turn over or the x-ray tube became “cranky.” The combined space of the eight small batteries was less than an average-size automobile battery of today. The full output of this apparatus, except when the x-ray tube was very “soft,” never registered beyond two milliamperes. For fluoroscopic work less than half of that amount was employed. Two milliamperes of current was the maximum output for radiographic work at 50 cm. focal plate distance, and the one-milliampere technic was limited to fluoroscopic observations.

A Dosage Chart for X-ray Therapy

ACCORDING to the recommendations of the Radiological Society of North America and of the American Roentgen Ray Society, through their Standardization Committees, x-ray machines in America are calibrated according to their output in air at some specified distance, usually 50 cm. The International Committee for Radiological Units, at the Fifth International Congress of Radiology (Chicago, 1937), made the additional recommendation that x-ray doses should be specified in terms of the numbers of roentgens delivered to the various skin fields. In order to obtain from calibration data the number of roentgens delivered to the skin in a given time, or the time required for the administration of a specified number of roentgens, it is necessary to have available a table of back-scatter values for any qualities of radiation and fields which may be used, and to perform two or three simple arithmetical operations. It is customary in many radiation departments to tabulate the irradiation times for the most frequently used distances, fields, and doses. A different table is necessary for each machine, unless two happen to have the same output. Such a table must be prepared or revised every time the output is changed for any reason, and it seldom covers a complete range of distances and fields. It was thought that a chart which would supply the time required for the delivery of any specified dose, either in air or on a skin field of any size, for any target-skin distance, would be a convenience. Such a chart is given in Figure 1. The chart looks complicated, but it consists in reality of three simple sections, each of which can be used independently or in conjunction with the others. The fact that logarithmic scales are used makes the spacing appear unusual, but, since actual values and not logarithms are indicated, no confusion need arise for this reason. Section A consists of parallel straight lines which provide for the determination of the roentgens per minute delivered in air at any distance, provided the output is known for any other distance, within the range in which the inverse square law holds. (This usually means in practice from about 10 to 15 cm. outside the tube holder, up to any desired distance.) The operation performed by this section, therefore, is that of applying the inverse square law to the air calibration, if treatment is to be administered at some distance other than that for which the calibration was made. To use this section for this purpose, the distance at which the calibration was made is found on the scale at the bottom of the section, and the corresponding r per minute on the scale at the side. The point thus determined will lie on (or near) one of the oblique lines. Other points on this oblique line indicate the r per minute at other distances, for the particular set-up in question.

The Focalograph

MANY methods have been proposed for the examination of the target of an x-ray tube. It must be conceded that any method which provides a permanent record for comparison has advantages over methods which do not have this feature. The device described, the Focalograph, as proposed by Sergeant Black is a simple, economical, and efficient apparatus for: (a) Providing a record of the appearance of the target of a roentgen tube. (By enlargement obtained by increasing the grid-film distance it is possible to see minute defects plainly.) (b) Demonstrating the effect of angular position of the target of a roentgen tube upon the effective ray. (c) Checking the effective area, actual area and minimum projected area of the focal spot of a roentgen tube. This is especially valuable in checking performance of tubes against specification claims. (d) Determining the maximum ray divergence and minimum focal film distance for various types of tubes as they are affected by the angle of the target face. The apparatus described consists of a simple wood-constructed tube holder for the roentgen tube with a special accurately perforated lead diaphragm placed on an arc between the tube and a film which is to be exposed for record (Fig. 1-A). It is also possible to study the lateral divergence by use of grids constructed in that plane. It is conceivable that many methods of grid construction may be applied to the basic apparatus in the future. The grid shown is the best found as yet for comparison studies, as it is possible to obtain several exposures on the same film. The tube is enervated from a regular x-ray machine in the usual manner. The arc of the film and of the lead diaphragm is so constructed that the appearance of the film exposed is the same as the composite image obtained by many horizontally placed films exposed with the target placed at various angles. The saving in film for experimental purposes in this procedure is obvious. It is recommended that the following technic be used in making the records described: kv.p., 40; ma., 10; sec. 10. The distance of the target to the lead grid is not to exceed 4 inches; the usual film distance is set by the apparatus. Cardboard film holders are used. Enlargements may be made by increasing the distance to the film. Under no circumstances may the kilovolt peak be increased above 40, as the danger of spark-over through the lead grid is imminent. Descriptive Data 1. Westinghouse Treatment Tube, tungsten disc (Fig. 1): Dark ring— Actual focal spot. Lighter halo— Margin of focal spot. Wide halo— Outside edge of entire anode. 2. Universal Broad Focus, solid tungsten anode (Fig. 2): Dark center— A crater on surface. Light ring— Flat surface. Dappled outer dark ring— Melted raised areas on target. Outer halo— Outer margin of anode. 3. Universal Medium Focus, solid tungsten anode: good condition (Fig. 3): Dark— Actual focal spot. Halo— Anode. 4. Universal Fine Focus, solid tungsten anode: good condition (Fig. 4): Dark— Actual focal spot.

Note on a Method of Running an X-Ray Tube on the “Earthed” System to Prevent Leakage to the Tube Box or Holder

ArticlesNote on a Method of Running an X-Ray Tube on the “Earthed” System to Prevent Leakage to the Tube Box or HolderJ. A. Shorten and T. W. BarnardJ. A. ShortenSearch for more papers by this author and T. W. BarnardSearch for more papers by this authorPublished Online18 Mar 2014https://doi.org/10.1259/are.1919.0049SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail About Previous article Next article FiguresReferencesRelatedDetails Volume 24, Issue 6November 1919Pages: 173-208 Copyright © 1919, The British Institute of Radiology History Published onlineMarch 18,2014 Metrics Download PDF