Support Columns Research Articles

Rapid Quantitative Determination of Three Active Ingredients in Liquid Antitussive Preparations by High-Speed Liquid Chromatography

Three active ingredients in liquid antitussive preparations, acetaminophen, chlorpheniramine maleate, and dextromethorphan hydrobromide, were separated by high-speed liquid chromatography on an octadecylsilane (permanently bonded to a controlled surface porosity support) column with a buffered, pH 8.8, alcohol-water mobile phase and measured with a UV photometer. Due to the relatively large excess of acetaminophen and the fixed detector wavelength (254 nm), the analysis was performed sequentially in two steps. Nonetheless, results were obtained in one-third the time required for conventional methods and instrument flexibility was maintained, thereby permitting its use for a variety of analyses. The relative standard deviations for the three components were 1.8, 0.76, and 2.0%, respectively.

Stereotaxic intraocular surgery. Use in vitreous and posterior segment surgery.

This stereotaxic micromanipulator is composed of a baseplate with head stabilization mechanism, a Flieringa ring and support column for fixation of the eye, a three dimensional stereotaxic system, a system for mechanically assisted intraocular micromanipulation, and a collet for a series of interchangeable intraocular tools. Calibrations aid the manipulation of intraocular tools when cloudy or opaque media impair visualization, but visual monitoring of intraocular movements with contact-lens surgical microscopy or indirect ophthalmoscopy is employed whenever possible. This stereotaxic micromanipulator is designed to augment present forms of intraocular surgery and to facilitate the performance of new procedures for the management of posterior segment intraocular disease.

Sealing of support columns of heat exchangers with self-curing plastic

Sealing of support columns of heat exchangers with self-curing plastic

Separation of tin from other elements by partition chromatography

Tin(IV) is separated quantitatively from many other metal ions by reversed-phase chromatography on a column of solid support impregnated with an organic liquid. When aqueous 8 M hydrochloric acid is used as the eluent, tin(IV) is retained on a column impregnated with methyl isobutyl ketone and is separated quantitatively from bismuth(III), cadmium(II), copper(II), lead(II), mercury(II) and zinc(II). For the separation of tin(IV) and molybdenum(VI) the aqueous elut ing phase is 1 M hydrochloric acid-3 M sulphuric acid. A column impregnated with isopropyl ether quantitatively retains antimony(V) from 8 M hydrochloric acid and permits tin(IV) to be eluted rapidly.

Preparative Scale Gas Chromatography. VII. Support Material and Column Shape

Preparative Scale Gas Chromatography. VII. Support Material and Column Shape

The process gas chromatography of fatty acid distillation streams. I. Analytical chemistry

AbstractIt was decided to build a process gas chromatograph to monitor the fatty acid stills. The initial work led to the development of phosphoric acid treated polyester columns for the GLC of unesterified fatty acids. The design and construction of a process analyzer for the fatty acid stills was then begun. When this gas chromatograph was completed, it was used to monitor the still. Chromatograms of the fatty acid streams are shown and discussed. Quantitative results are compared to those obtained by conventional methyl ester analysis. Work with inert support column packings is also described.

Concrete usage in Atomic Power Reactor Support

Use of a concrete structure at an atomic power plant as a support for the reactor, as a biological radiation shield, and as a missile shield is described. Reasons are given for selecting conventional-aggregate concrete, instead of heavy'' concrete, around and under the reactor to retain radioactive emissions passing through the tank walls and surrounding water. A spherical shell selected to form the vapor container is carried on a ring of support columns resting on individual footings. The columns of the reactor support pierce this sphere surrounded by gas-tight bellows seals. This construction isolates the sphere from the effects of differential expansions and settlements of the reactor structure and permits use of a relatively thin, unlined steel shell. The design basis for the concrete support is given, including effects of creep and differential settlements. Also considered are possible serious consequences of applying standard allowable unit shear values to concrete members which may be in net tension over the entire cross section because of differential settlements. (auth)

New Electrostatic Accelerator

A new electrostatic accelerator has been constructed and tested. The entire vacuum system including the accelerating tube and ion source is of bakable construction. The accelerating tube, corona tube, and support column are constructed of thin metal disks hard-soldered to alumina ceramic rings and the insulation length of each is 5 ft. Without the accelerating tube the generator has been operated at potentials in excess of 7 Mv corresponding to gradients of over 1400 kv/ft. With flat disk molybdenum electrodes usable voltage was limited to 2.1 Mv. When these electrodes were replaced by flat disk steel electrodes having smaller beam apertures and provided with side pumpout holes, the accelerator was operated for short times at potentials in excess of 4 Mv corresponding to a tube gradient of over 800 kv/ft. There was no evidence of small discharges or electron loading in the tube. During the course of these tests three tube ceramics were cracked—probably by sparking—and it is now difficult to operate the machine at potentials much above 3.5 Mv. Voltage division is accomplished by a series of negative point-to-plane corona gaps which are enclosed in a tube. The charging belt is equipped with paper staples which are charged by induction. Accelerator voltage is very stable.

Flat Slabs And Supporting Columns And walls Designed As Indeterminate Structural Frames

Flat Slabs And Supporting Columns And walls Designed As Indeterminate Structural Frames

An experimental check on edgewise arch computations

This study aims to develop a detailed computational fluid dynamics (CFD) model to investigate the flow and heat transfer characteristics in the dome of a pressurized water reactor (PWR). The upper plenum is also considered in order to simulate the possible coolant leak to the dome via the gaps of upper support plate. The essential solid components within the solution domain, including the upper core plate, the guide tube assemblies, the support columns, and the rod cluster control, are realistically modeled, instead of the porous-medium approximation. Through the detailed-geometry CFD simulation, the thermal-hydraulic features in the upper plenum, individual guide tube assembly, and the dome can be obtained. And, the temperature distribution on the reactor pressure vessel (RPV) head can be used to estimate the values of total effective degradation years (EDY) and reinspection years (RIY) for monitoring the crack initiation and growth on the head. Present calculated results also reveal that the original values of EDY and RIY using the cold-leg temperature as the head temperature by the Maanshan staff is conservative.

THE RESTORATION OF THE PERINÆUM BY A NEW METHOD.

[Read in the Section on Obstetrics and Diseases of Women.] The anatomy of the perinaeum has within the last few years become fairly well understood, and its importance demonstrated to be greater by far than was earlier supposed. The perineal body is now recognized as an anatomical entity, and is the key-stone in the arch of perineal support. Its physiological importance in parturition has been well demonstrated recently by Dr. Hart, of Edinburgh,—an understanding of which will do much to lessen the frequent occurence of perineal lacerations. The lesion when partial is often overlooked; indeed, the gynaecologist, gist, from his standpoint of observation, is inclined to feel that the injury, when it does not involve the sphincter ani, is in the majority of instances unrecognized. The two anatomical points most important to bear in mind in reference to the vagina and its value as a column of elastic support to