Monitoring of critical parameters of radiation sterilization process at an industrial electron accelerator

Continuous monitoring of critical parameters of an industrial electron accelerator provides quality of product processing. For that purpose, the methods of contact-free diagnostics of processing regime are developed. One of them is based on application of a wide-aperture stack-monitor for on-line measurement of beam current, electron energy, and also the mean absorbed dose over the plain of beam scanning in an irradiated object [1]. In the work, the conditions of application of cathodoluminescence (CL), accompanied action of accelerated electrons on amorphous dielectrics, for adjustment of the stack-monitor, and also for measuring in on-line mode the dose in a point of control as well as of distribution of the electron flux density on the surface of the object, is studied. It is shown, that titanium dioxide, keeping the radiation-optical yield at an accumulated dose of up to 4 MGy, can be considered as a promising material for manufacturing of CL detector.

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DETERMINATION OF EQUIVALENCE BETWEEN RADIATION STERILIZATION PROCESS AND COMMERCIAL THERMAL PROCESS FOR CURED MEATS

10.21236/ad0625252 ◽

1965 ◽

Author(s):

R. A. Greenberg ◽

B. O. Bladel ◽

W. J. Zingelmann

Keyword(s):

Thermal Process ◽

Radiation Sterilization ◽

Cured Meats ◽

Sterilization Process

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Change in Radiation Sterilization Process from Gamma Ray to X-ray

Biomedical Instrumentation & Technology ◽

10.2345/0899-8205-55.s3.78 ◽

2021 ◽

Vol 55 (s3) ◽

pp. 78-84

Author(s):

Christiane Beerlage ◽

Bjoern Wiese ◽

Annemie Rehor Kausch ◽

Milorad Arsenijevic

Keyword(s):

Material Properties ◽

Gamma Ray ◽

Orthopedic Implants ◽

Biological Evaluation ◽

Radiation Sterilization ◽

Radiation Processing ◽

X Ray ◽

Business Perspective ◽

Sterilization Process ◽

Key Steps

Abstract The terminal sterilization of sterile orthopedic implants is a key process that, in addition to providing sterility, changes the material properties of the product and packaging. These changes might be observed during functionality testing and/or biological evaluation. We are establishing an additional sterilization process that appears promising from both a technical and business perspective. Our project aims to add X-ray sterilization to the established gamma sterilization for metallic hip and shoulder implants. To limit complexity, we started with a narrow product range. The main steps of our project journey are described here. Given that X-ray sterilization remains relatively new in terms of understanding the changes that might occur for product materials and functionality compared with changes observed following gamma radiation processing, this article highlights key steps in the change from gamma ray to X-ray sterilization.

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Optical Properties of HVEM Accelerators

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114529 ◽

1975 ◽

Vol 33 ◽

pp. 180-181

Author(s):

A. Strojnik ◽

J.W. Scholl ◽

V. Bevc

Keyword(s):

Optical Properties ◽

Electron Accelerator ◽

Systematic Investigation ◽

Electron Source ◽

High Brightness ◽

The Past ◽

Wide Range ◽

Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

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Effects of sterilization modes on the mechanical strengths of plaster of paris implants

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156432 ◽

1989 ◽

Vol 47 ◽

pp. 890-891

Author(s):

K. Cowden ◽

B. Giammara ◽

T. Devine ◽

J. Hanker

Keyword(s):

Gamma Radiation ◽

Calcium Sulfate ◽

Significant Loss ◽

Potassium Sulfate ◽

Limiting Factors ◽

Radiation Sterilization ◽

Plaster Of Paris ◽

Hardness Tester ◽

Dry Heat ◽

Calcium Sulfate Hemihydrate

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).

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