Strategies for the Control of Visible Particles in Sterile Devices

Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.

Study on modeling of the air ionization process in the technology of long-term storage of fruit and grape

This article presents the results of modeling the process of air ionization in the technology of long-term storage of fruits and grapes in fruit storage facilities.Also was determined the main forces acting on ions in the ionization zone, in the volume of the fruit storage and on the surface of the processed product in order to establish the ionization modes and design the discharge gap of the ionizer. Based on the results of the research, the issues of the ionizer placement in the volume of the fruit storage have been resolved. The results of theoretical studies have been verified experimentally and the corresponding dependencies of the parameters of ionized air was obtained.

The NMIJ air kerma primary standard for high energy X-ray beams in 300-450 kV

Accurate radiation dosimetry is required for radiation protection in various environments. Therefore, dosemeters and dose-rate meters must be calibrated in standard radiation fields. The National Metrology Institute of Japan (NMIJ) expands the energy range of X-ray reference field measurement up to 450 kV using a cylindrical graphite-walled cavity ionization chamber. Departure from the condition of the Spencer-Attix cavity theory was evaluated by comparing the measurement results obtained using the cavity ionization and the free-air ionization chambers, which are used as the primary standard up to a tube voltage of 250 kV. The calibration coefficients found using the spherical ionization chamber were in good agreement with those obtained by the free-air ionization chamber within relative standard uncertainties (k = 1) for N-200 and N-250 X-ray fields. Consistent calibration coefficients were obtained in the energy range 300–450 kV.

Application of air ionization in refrigerant storage of grapes refuse, boiled with starch syrup, in marshmallow technology

Experimental data on the change in the number and species composition of microorganisms in the atmosphere have been provided. These includes the changes on the walls of refrigeration chambers and on the surface of berries of the grape varieties Preobrazhenie and Livia when stored in a refrigerating chamber with a normal and ionized atmosphere. It was shown that the use of an ionized atmosphere with a concentration of positive aeroions of 0.25… 0.48 × 1 × 103 cm3 and negative aeroions of 0.11… 0.25 × 1 × 103 cm3 helped to reduce the overall microbiota contamination in a storage atmosphere by 94.7%. This happened on the surface of the walls and structures of the refrigerating chamber by 100% and on the surface of berries of the grape varieties Preobrazhenie and Livia by 95.6% and 97.1%, respectively.

Nature of Relationships Between Atmospheric Electricity Parameters at Ground Surface and Air Ionization on the Basis of Nuclear Accidents in Power Plants and Weapons Tests

In this work we present an analysis of selected atmospheric electricity parameters, measured at the Geophysical Observatory in Świder (near Warsaw, Poland), in a review of the major events that resulted in the release of a significant amount of artificial radioactive substances in the Earth’s atmosphere: the radioactive accident in Fukushima, Japan, beginning 12 March 2011, followed by the 9.0 earthquake and tsunami; Chernobyl disaster (27 April 1986); and nuclear weapons testing (1958–1965). The physical mechanisms of the impact of radioactive sources on the electrical parameters of the atmosphere are analyzed. The formation of free charge (small ions, represented by electric air conductivity) and bound-induced charges (measured vertical electric field and current) by radioactive aerosol and cloud nuclei were taken into account. The values of electric field Ez, atmospheric air conductivity λ, and aerosol concentrations measured at a certain site depend on the time and space location of the released radioactive materials in relation to the measurement site and the meteorological situation. A frontal inflow of air masses containing radioactive substances may be noticeable at a large distance from the atmospheric electricity measuring site in fair weather conditions (Chernobyl disaster). Atmospheric precipitation plays a very important role in the transport of radioactive substances to the ground level (nuclear weapons testing). The relationship between the ionospheric potential Vi and the electric field near ground level Ez resulting from the Global Electric Circuit (GEC) concept for the presence of a strongly ionized air layer in the lower stratosphere and the ground level was disturbed in nuclear weapons testing time. The aim of this work is a qualitative characterization of discussed events. Future modeling works are needed to investigate the dependence of quantitative GEC parameters in situations of global or regional high air ionization. For this purpose, available measurements of recorded atmospheric electricity parameters will be used.