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Verifying Thermal Imager Calibration
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Water condensation may occur on the outside of the cup but will not affect the reading. Allow time for the NCT reading to settle. It should read close to 0.0°C (32°F) with little, if any, OFFSET. Generally, these devices will show a maximum OFFSET of ±0.25°C (∼0.5°F). Record this OFFSET value.
Prevention of Microbial Contamination during Manufacturing
Published in Philip A. Geis, Cosmetic Microbiology, 2020
The advantages heat sanitization are penetrating into small cracks and crevices, non-corrosivity, are non-selective, broad spectrum of antimicrobial activity, lack of residues on equipment surfaces, disruption of microbial biofilms and ready availability. However, there are some challenges to using heat sanitization. For example, heat may cause condensation problems because of the high humidity conditions that are created. If purified water is not being used to generate clean steam, there is the possibility of boiler additive residues being present on equipment surfaces after the completion of the sanitization procedure and the potential residual effects will need to be assessed. High energy costs are usually offset by reduced labor costs when compared to the cost in using chemical sanitizers.
Aircrew equipment – Thermal protection and survival
Published in Nicholas Green, Steven Gaydos, Hutchison Ewan, Edward Nicol, Handbook of Aviation and Space Medicine, 2019
Nicholas Green, Steven Gaydos, Hutchison Ewan, Edward Nicol
Protective clothing for cold should: Prevent heat loss from body by insulation.Provide insulation by trapping a large volume of dry air in small sections; minimise internal convection and cold air ingress (windproof).Enable adjustments in insulation to cater for increased/decreased metabolic heat production (use of layers, openings).Wick moisture away from body.Be vapour permeable to prevent accumulation and condensation of moisture under the clothing which reduces clothing insulation.Include head protection (due to the absence of cold constrictor fibres in blood vessels of scalp).
Establishing an air-liquid interface exposure system for exposure of lung cells to gases
Published in Inhalation Toxicology, 2022
Josée Guénette, Dalibor Breznan, Errol M Thomson
Preliminary tests uncovered a potential issue with condensation triggered by cell handling: on opening the lid post-equilibration, the 85% RH, 37 °C atmosphere suddenly experienced ambient conditions, causing condensation notably on the surfaces near the exposure chamber inlet and above the cells. Condensation in the exposure chamber can be problematic as it may introduce water droplets onto cells, compromising the ALI and potentially affecting cell viability. In addition, the presence of water droplets could affect dosimetry and reactivity of the test atmospheres. For example, water droplets can serve as a reactive surface for ozone, or they can capture particles from the airstream. When condensation occurred on the lid above the cells, it was unevenly distributed, potentially affecting the wells differentially across the carrier plate. Condensation in tubing also represents a reactive surface and a possible flow obstruction, of particular concern when downstream instruments are sensitive to condensate. It may also compromise the validity of using downstream analyses as a measure of cell dose. We addressed this issue by routinely removing the diffusion humidifier and flushing with dry air using the bypass, just before opening the CelTox Sampler lid. This terminated generation of humidity; the bypass also allowed continued airflow through the exposure chamber, rapidly flushing the system of humidity.
The ins and outs of drug-releasing vaginal rings: a literature review of expulsions and removals
Published in Expert Opinion on Drug Delivery, 2020
Peter Boyd, Ruth Merkatz, Bruce Variano, R. Karl Malcolm
Silicone elastomers for use in ring manufacture can also vary in their cure chemistries. The most common are condensation-cure systems (Femring® and the cores of Annovera™) and addition-cure systems (Estring®, Progering®, Fertiring® and the body of Annovera™) (Table 1) [1]. Condensation-cure systems are cured at relatively low temperatures (<100°C), making them particularly suitable for drugs that melt or degrade at higher temperatures. However, the tin catalyst used can be poisoned by certain chemical functional groups found in drug molecules. Addition-cure silicone elastomer systems are generally cured at higher temperatures (120–180°C) and are compatible with a wider range of drug chemistries, although reaction and binding have been observed with drug molecules containing certain unsaturated moieties [64–66]. Other cure systems are also available from silicone suppliers, including those catalyzed by peroxide species and UV light. However, these have not been used widely for drug delivery devices, due to the increased potential for drug degradation, processing/manufacturing constraints, or lack of appropriate material grades.
Bridging inhaled aerosol dosimetry to physiologically based pharmacokinetic modeling for toxicological assessment: nicotine delivery systems and beyond
Published in Critical Reviews in Toxicology, 2019
A. R. Kolli, A. K. Kuczaj, F. Martin, A. W. Hayes, M. C. Peitsch, J. Hoeng
The main physical mechanisms governing the evolution of a liquid aerosol during inhalation are evaporation (caused by dilution with inhaled air), condensation (caused by the high relative humidity in the airways), and coalescence (coagulation) (Figure 3) (Hinds 2012). Evaporation of the liquid phase decreases the particle size or, for very small particles, decreases the particle number density because some liquid particles completely evaporate, particularly particles at the lower end of a polydisperse aerosol distribution. Condensation of vapors onto existing particles increases particle size, resulting in increased upper airway RT deposition. Condensation can also result in deposition of aerosol particles on the walls of the RT, caused in particular by warm and humid conditions. It is important to mention that in the case of liquid multispecies mixtures, the physicochemical properties of the mixture (e.g. surface tension, boiling point) depend on the mixture composition itself and often cannot be superimposed as a simple function of the species properties.