Acrylic Cylinder Research Articles

Combination of external beam irradiation and multiple-site perineal applicator (MUPIT) for treatment of locally advanced or recurrent prostatic, anorectal, and gynecologic malignancies

We have devised a single after-loading applicator, the Martinez Universal Perineal Interstitial Template (MUPIT), which has been used in combination with external beam irradiation to treat 104 patients with either locally advanced or recurrent malignancies of the cervix, vagina, female urethra, prostate, or anorectal region. Twenty-six patients treated for prostate cancer are excluded because of their short follow-up. Local failure developed in 13 of the 78 remaining patients (16.6%)—major complications developed in 4 patients (5.1%). Follow-up has been 1 year to 71 2 years; 60 78 patients have been followed for more than 2 years. All local recurrences and complications occurred before 18 months. The device consists of two acrylic cylinders, an acrylic template with an array of holes that serve as guides for trocars, and a cover plate. In use, the cylinders are placed in the vagina and/or rectum or both and then fastened to the template so that a fixed geometric relationship among the tumor volume, normal structures, and source placement is preserved throughout the course of the implantation. Appropriate computer programs have been developed to calculate the dose from these implants. The advantages of the system are (a) greater control of the placement of sources relative to the tumor volume and critical structures, as a result of the fixed geometry provided by the template and cylinders, and (b) improved dose-rate distributions obtained by means of computerized optimization of the source placement and strength during the planning phase. We conclude that the local control rate (83.4%) with low morbidity (5.1%) achieved with the combination of external beam irradiation and MUPIT applicator in these patients with locally advanced malignancies represents an improvement over previous published results with other applicators.

Effects of disturbance and anisotropy on path of crack propagation under biaxial tension.

Effect of disturbance due to material inhomogeneity and that of anisotropy on the path of crack propagation in brittle material are analyzed by the body force method. Disturbance is characterized by two factors, i.e. one is the magnitude and the other is the density of disturbance in materials. When a straight crack on x-axis propagates in a plate under biaxial tension (σx∞, σy∞), the path of crack propagation is influenced by both the ratio of σx∞ to σy∞ and the disturbance. When σx∞/σy∞≥10, the total path of crack propagation is almost entirely determined by the magnitude of disturbance at the start of propagation. When σx∞/σy∞<cong>5, the intermediate phenomena between σx∞/σy∞=2 and 10 occur. Even the weak anisotropy of KIC remarkably influences the path of crack propagation. The experimentally obtained path of fracture of a circumferential surface crack in a pressurized acrylic cylinder can be explained only by considering the anisotropy of KIC.

A multiple-site perineal applicator (MUPIT) for treatment of prostatic, anorectal, and gynecologic malignancies.

Recently, transperineal interstitial-intracavitary applicators have been used to treat locally limited and advanced perineal and gynecologic malignancies. We have developed a single afterloading applicator, referred to as the "MUPIT" (Martinez Universal Perineal Interstitial Template), which with its prototypes has been utilized to treat 78 patients with malignancies of the cervix, vagina, female urethra, perineum, prostate, and anorectal region. The device basically consists of two acrylic cylinders, an acrylic template with a predrilled array of holes that serve as guides for trocars, and a cover plate. Some of the guide holes on the template are angled outward to permit a wide lateral coverage without danger of striking the ischium. The cylinders have an axial hole large enough to pass a central tandem or a suction tube for the drainage of secretions. Thus, the device allows for the interstitial placement of 192Ir ribbons as well as the intracavitary placement of either 137Cs tubes or 192Ir ribbons. In use, the cylinders are placed in the vagina and rectum and then fastened to the template, so that a fixed geometric relationship among the tumor volume, normal structures, and source placement is preserved throughout the course of the implantation. Hollow, closed-end, stainless steel trocars are then inserted through the guide holes that produce optimal coverage of the treatment volume. Appropriate computer programs also have been developed on a minicomputer for the corresponding dose-rate computations. These programs run with sufficient speed that they may be used for both the planning of the source placement beforehand and the computation of the actual dose-rate distribution obtained. The advantages of the system are (1) greater control of the placement of sources relative to the tumor volume and critical structures owing to the fixed geometry provided by the template and cylinders, and (2) improved dose-rate distributions obtained by means of computer-assisted optimization of the source placement and strength during the planning phase.

The Rapid Carbonate Analyzer

Abstract A gasometric method is proposed for measuring soil carbonate content. The device consists of an enclosed acrylic cylinder in which soil carbonate reacts with acid to produce carbon dioxide gas. For a constant volume reactor, the carbon dioxide gas pressure is directly related to the soil carbonate content at completion of the reaction. The effect of several variables, including particle size, acid concentration, and carbonate mineralogy, on the reaction time is considered. This method has the advantages of accuracy to within ±5%, high analytical speed, low cost, and minimal operator skill. It is well suited for both laboratory and field use.

Measurement of Oil Film Thickness for Application to Elastomeric Stirling Engine Rod Seals

This paper describes an experimental program concerned with the elasto-hydrodynamic behavior of sliding elastomeric seals for the Stirling engine. During this program, an experimental apparatus was designed, built, and used to measure the oil film thickness distribution. For this oil film thickness measurement, an optical interferometric procedure was developed. Tests were conducted on commercial elastomeric seals having a 76 mm o.d. Testing conditions included seal durometers of 70 and 90, a sliding velocity of 0.8 m/s, and no pressure gradient across the seal. An acrylic cylinder and a typical synthetic base automotive lubricant were used. The work produced a first-time comparison of analytical and experimental oil film profiles for an elastomeric seal in a reciprocating environment. This comparison shows an overall qualitative agreement.

ウンシュウミカン果実の成熟に及ぼす果実温度の影響

The effect of fruit temperatures on the growth and compositon of satsuma mandarin fruits was investigated during maturation stage, by enclosing fruits on the tree grown under natural conditions in transparent acrylic cylinders whose inside temperatures were regulated at 15°C, 23°C and 30°C, respectively.Both a whole fruit and peel weights were greatest at 23°C and least at 30°C. But specific gravity of a whole fruit was much less at 15°C and 23°C then 30°C. Free acid content in the juice decreased more rapidly with an increase in fruit temperature. Total soluble solid and sugar content in the juice was highest at 23°C, followed by 30°C and 15°C in this order. In the peel, the lower the fruit temperature, the earlier the chlorophyll degradation and carotenoid accumulation occurred. However, chlorophyll degradation was inhibited and little carotenoid pigments developted at 30°C. ABA levels in the peel, also, began to rise at lower fruit temperatures and were lowest at 30°C. Coincident patterns of free ABA level and carotenoid content at respective treatments, particularly, indicate that ABA level in the peel may be involved in carotenoid synthesis which is affected by fruit temperatures. On the other hand, GA-like activities were not affected by fruit temperatures. These results suggest that temperature has influence on the maturation of satsuma mandarin fruits partly through its direct effect on fruits per se.

A modified system for in vitro perfusion of isolated renal tubules.

A modified system for the in vitro perfusion of isolated tubule segments is presented. The system consists of four holders each of which carries an acrylic cylinder. The acrylic cylinders are used to fix the glass pipettes in a concentric position. The four holders are mounted onto a support consisting of two holding pieces and three steel rods. Three of the holders contain ball-races so that they can slide on the rods with high accuracy and little friction. The holders to which the sylgard pipette and the perfusion pipette are attached are moved by electric motors. Compared with the classical V-track system this modification has the advantage of higher precision. Once the different pipettes are centered, concentricity is maintained even when the pipettes are moved forward or backward. Thus, this equipment facilitates the cannulation of tubules and increases the number of successful experiments.

Viral transport through soil columns under conditions of saturated flow

Movement of poliovirus 1, reovirus 3, and bacteriophage OX174 was studied in 8 different soils. Soils were sampled to a depth of 100 cm in three 33 cm profiles, and packed into acrylic cylinders, 10 cm in dia. and 33.66 and 100 cm in length according to the vertical distribution and bulk density of the soil as found in the field. Sequential flooding of the columns with wastewater and distilled water resulted in a cyclical pattern of viral release in column percolates. The total number of viruses detected in percolates differed among the soils tested. This was due to the differences among soil properties. Poliovirus recovery correlated most favorably with low soil cation exchange capacity and high organic carbon and clay content. The recovery of OX174 was related to low soil organic carbon and residence time of liquid within a column in combination with either high soil pH or per cent clay. As with poliovirus, detection of reovirus in soil column percolates was negatively correlated with soil cation exchange capacity.

Dynamic response of fluid coupled coaxial cylinders to seismic excitation

This study deals with the overall dynamic behavior of concentric flexible cylinders coupled with fluid in the annular region, subjected to both sinusoidal and seismic excitations. Three different combinations of acrylic cylinders are used, i.e., one outside cylinder and three inside cylinders with different inside diameters. The cylinders have the same thickness and length, which when paired with the outer cylinder provide three annular gap sizes. To determine the sinusoidal response of the system the outside cylinder is point‐excited and the natural frequencies and corresponding mode shapes are determined. For the seismic tests, the three coaxial setups are mounted on a rigid steel support frame. The support frame is suspended from the ceiling by flexible rods and excited by a hydraulic shaker with a simulated seismic input. Two distinct responses are observed, i.e., either in‐phase or out‐of‐phase breathing modes between the inner and outer cylinders. The out‐of‐phase modes approach some limiting value as the gap size decreases, while the in‐phase modes increase in frequency as the gap becomes smaller. Comparison between the inner and outer cylinder displacement responses from the seismic loadings shows the ratios of the averaged peak responses varies as a function of the gap between the inner and outer cylinder. Similar trends were observed on the spectral densities of the responses. It also appears that the gap size has a strong influence in the frequency response of the system.

A New Plankton Sampler for Coral Reefs

. A new self-contained Horizontal Plankton Sampler (HOPLASA) collects near-reef plankton that is not captured by conventional net tows and emergence traps. An electrical motor-propeller assembly inside a large acrylic cylinder drives water past an in-line flowmeter and through a rigidly attached plankton net. When positioned in the coral reef environment this sampling gear filters known quantities of bottom water. Larvae and developmental stages of many invertebrates and some fishes that never migrate to upper water layers but constitute an important fraction of the food chain are captured. Larvae of sponges, corals, and gorgonians, the most important animal reef builders, are obtained live and undamaged and can be cultured in the laboratory for identification after metamorphosis.

THE OPTICAL FUNCTION OF KERATOPROSTHESES

The optical function of acrylic cylinders used in keratoprostheses is demonstrated by using a water-filled minicamera as a model of the aphakic human eye. Lengths and diameters of the optical cylinders are important factors influencing the visual fields. The dimensions to be chosen, depends on the thickness of the cornea and the supporting tissues. The most suitable combination of visual field, magnification and diameter of the retinal image field is obtained with optical cylinders with a concave posterior surface. Using a fixed radius of curvature of the posterior surface, the radius of the anterior surfaces are calculated to make the eye emmetropic. With such a cylinder of length 4.5 mm and diameter 2.1 mm a circular visual field of 48 degrees is obtained. With cylinder length 6.0 mm the visual field is at least 35 degrees. The retinal image is about 19% larger than that of the normal phakic eye. Cylinder length exceeding 6.0 mm require a greater diameter to provide an adequate visual field. With cylinder lengths up to 6.0 mm and diameters not less than 2.1 mm, the diameter of the retinal image field is at least 12.0 mm. Accidental obliquity of the optical cylinder or off-center implantation give the possibility of undesired projection of the image field outside the macula. The obliquity or degree of off-center implantation tolerance is calculated. The retinal image may be improved by darkening the side of the cylinder.

In situ measurements of rapidly fluctuating, high sediment concentrations

A new instrument — an almometer — has been developed which measures, instantaneously and continuously, changes in the vertical density distribution of sediment. The almometer consists of two acrylic cylinders, one contains a fluorescent lamp, the other 64 photo-electric cells placed at 1 - or 2-cm intervals. These two tubes are anchored perpendicular to the bottom 30 cm apart. The amount of sediment that can be measured ranges from 10 to 500 g of sediment per liter of water. Calibration shows that differences in sediment size or mineralogy have little effect on the concentration resistance relationship if the size mean is within the sand range and the sediment is not monomineralic.

Reclamation of Soils Contaminated with Radioactive Strontium

AbstractEvesboro loamy sand, Sassafras sandy loam, and Fort Collins silt loam were treated with a mixed Ca‐Sr solution to give about 95% saturation with Ca and 5% saturation with Sr. Samples of these soils were placed in acrylic cylinders and leached with 0.06N CaCl2 to remove Sr. The leachings were mechanically controlled at various rates for different periods of time. Extracting the leached soil samples with 1N HCl yielded residual Sr equal to 0.43, 0.47, and 0% of the Sr exchange capacity of the Evesboro, Sassafras, and Fort Collins soils, respectively. There was general agreement between Sr concentrations measured at various depths and those calculated on the basis of the Lapidus‐Amundson equation, especially so with heavier soils. The Evesboro and Fort Collins soils were also tagged with carrier‐free 85Sr and, mounted in columns, leached with 0.06N solutions of either CaCl2 or SrCl2. The removal of 85Sr was more complete from the Evesboro than from the Fort Collins soil, and from the center than from the edge of the columns. Short‐term leaching capability of SrCl2 exceeded that of CaCl2 where 85Sr was present in amounts small enough to be adsorbed mostly on specific soil adsorption sites. Where larger amounts of 85Sr had been adsorbed, Ca was equally effective as Sr in replacing the contaminant.

An elntriation apparatus for macroinvertebrates1

An inexpensive hydropneumatic apparatus screens macroinvertebrates from bottom samples containing silt, mud, or clay. The elutriator, an acrylic cylinder with screened windows, cemented on an upright plastic funnel, retains benthic fauna while the sediment is washed away. The apparatus yields clean samples and has reduced the time required to sort benthos sediments by more than 80%.

A Precision Dispenser for Dry Fertilizer Materials

AbstractEquipment for the rapid and accurate dispensing of dry fertilizer materials is described. The dispensers consist of acrylic plastic cylinders containing a cylindrical cavity and are powered by a combination of hydraulic cylinders and solenoid valves. Hydraulic and electrical power are supplied by the transporting tractor. Three dispensing cylinders of different sizes are assembled to form a unit. One such unit is used for each row. The cylinders are designed with adjustable volume and may be used in various combinations, thus giving a high degree of flexibility. The amount of material dispensed with this equipment, though less precise than obtained by weighing, is more precise than obtained by using hand‐manipulated containers. The use of this equipment has sharply reduced the time and labor required to apply treatments.With the system described, either three rates of the same material or three different materials may be dispensed for application to each of four rows. Because of the modular design of the system, adaptations for specific needs can be constructed.

The acquired pellicle: immunofluorescent demonstration of specific proteins.

Abstract. Sterile polished slabs of bovine enamel, mounted in small acrylic cylinders, were held in the mouth for 2 hours. The acquired pellicles deposited on the enamel surfaces were examined in situ on the slabs or after transfer to microscope slides. Indirect immunofluorescent staining in situ afforded positive identification of IgA and lysozyme in pellicles. The preferred technique required acid separation of the pellicle from the enamel, transfer to a microscope slide, and fixation in cold ethanol. Histochemically, this pellicle appeared to he predominantly basic. Results of indirect immunofluorescent tracing indicated that IgA and lysozyme were regular constituents of the pellicle, amylase and IgG were less consistently detected, and albumin and fibrinogen were rarely encountered.

An Experimental study of the Effect of Loads on Frost Heaving and Soil Moisture Migration

The application of the artificial freezing of soil to civil engineering has been developed and well utilized in Japan since 1962. The application, however, involves some difficult problems in spite of its benefits. Part of them has been solved on the practical as well as theoretical base mainly by the present authors. One of the most significant problems which remain unsolved, is the frost heave problem. The present paper discusses the problem under various conditions of load pressure in the open system.Undisturbed soil sample, 10 cm in both diameter and height was enclosed in an acrylic acid resin cylinder of the apparatus (Fig. 1). The lower part of the cylinder contains an end cup filled with water. The surface of the water in the end cup was made to contact the bottom of the soil sample through the porous plate. The soil sample was sufficiently precooled at 0°C, and then cooled from the upper side at -2.5°C. The water in the end cup was kept at 0 °C during the freezing.The following results were obtained : 1. The soil system discharges water during freezing when the load pressure exceeds a certain value (Fig. 3, 4).2. The amount of frost heave decreases in accordance with the increase of load pressure (Fig. 7). The relation between the heave ratio (h), which means the ratio of the maximum heave amount to the initial height of sample, and the load pressure (p) is approximated as follows; h= h0+ c/p, where h0 and c are constants.It is understood from this equation that complete elimination of heave action will be difficult, because it is assumed that h0 is due to freeze-expansion of adsorbed water around soil particles behind the freezing front. 3. The relation between the amount of heave (Vh) and the amount of migrated water (Vw) is expressed by the following equation; Vh= (1-α) ΓVwo± (1 +Γ) Vw where, Γ is the coefficient of volume expansion of water changing into ice, Vwo is the volume of water in soil before freezing and a is a constant (0<α<1). Therefore, when soil moisture is discharged from the soil system (Vw< 0), the frost heave decreases in amount. The value of α was calculated as 0.3-0.4 in the present experiment (Figs. 9-12).

Mixing device for generating simple chromatographic gradients

A linear gradient device consisting of two concentric reservoirs of equal cross-sectional area, in which the initial and limiting eluent solutions are maintained in hydrostatic equilibrium, may be constructed from several combinations of commercial acrylic resin cylinders. By the use of nesting cylinders, the areas of the reservoirs may be reduced independently, allowing an assortment of nonlinear gradients to be produced by simple adjustment of the area ratio of the two reservoirs.

Keratoprosthesis : Acrylic Optical Cylinder with Supporting Intralamellar Plate

Keratoprosthesis : Acrylic Optical Cylinder with Supporting Intralamellar Plate