Safety Considerations on Siting and Shielding
Bertil R. R. Persson, Freddy Ståhlberg in Health and Safety of Clinical NMR Examinations, 2019
To maintain the superconducting conditions, the magnet must be filled with liquid cryogens which are usually transferred into the cryostat from transport vessels (dewar) using routine top-pressure methods. During this operation one must put the cryogens in the correct inlets and not blow warm helium gas onto the magnet. These mistakes could result in a magnet quench. Liquid nitrogen consumption will be of the order of 200 to 250 ℓ/week and can be obtained from bulk storage either directly by a fixed, insulated transfer pipe or transport dewar of suitable capacity. The cryostat capacity of liquid helium is 200 to 450ℓ and typical consumption is between 50 to 100 ℓ/week with a monthly refill period. The costs of cryogens vary considerably but are in the order of 6 U.S. dollars/ℓ of liquid helium and 0.7 U.S. dollars/ℓ of liquid nitrogen. In order to reduce the cost it may be effective to install a helium recovery system. Physical data for the cryogenics are given in Table 1.
Medical and Biological Applications of Low Energy Accelerators
Vlado Valković in Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
The AMIT continued by following phases:2014–2017 The OPTIMHAC program (Spanish National funding): Beam optimization.2014–2017 CIEMAT Funds.2016–2019 The CIENTO program (Spanish Nacional funding): Cryogenics and operational optimization.2017–2021 The ARIES program (H2020): Integration as a research infrastructure.
The human oocyte: Controlled-rate cooling Controlled-rate cooling
David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham in Textbook of Assisted Reproductive Techniques, 2017
Cryobiology is the branch of biology that studies the effects of low temperatures on living systems. The basic principles of cryobiology must be well known in order to get good results. Cryopreservation requires the biological sample to be brought to cryogenic temperature (—196°C) at which biological, chemical, and physical activities come to a stop. The factors playing a fundamental role in cryopreservation are biophysical—such as cryoprotectant and speed—and morphological—such as dimensions and quality of sample. For these reasons, cryopreservation of human oocytes, because of their unique features of size and physiology, experiences several difficulties.
Co-amorphous systems for the delivery of poorly water-soluble drugs: recent advances and an update
Published in Expert Opinion on Drug Delivery, 2020
Jiawei Han, Yuanfeng Wei, Yan Lu, Runze Wang, Jianjun Zhang, Yuan Gao, Shuai Qian
Conventional ball milling is sometimes inadequate to transform crystals into amorphous solids due to heat production when milling, which may potentially induce recrystallization. Given the rise of temperature, cryomilling is generally applied to compromise the generated heat during milling process [18,124]. For cryomilling, the samples were placed and sealed in milling jars, and then immersed in liquid nitrogen, followed by milling. Due to the cryogenic temperature far below Tg of most amorphous drugs, the solids are quite brittle and easily mechanically milled into disordered state. For example, due to low Tg of atenolol, Moinuddin et al. selected cryogenic milling to prepare hydrochlorothiazide-atenolol CAM [18]. The physical mixture of hydrochlorothiazide and atenolol was placed in an airtight tube and eventually became a complete CAM up to 48 min by milling at 10 Hz. Ojarinta et al. developed indomethacin-amino acids CAMs prepared by cryomilling [125]. To avoid overheating causing degradation or solid-state transition, the milling cans were removed every 10 min and cooled in liquid nitrogen for 2 min.
It Feels Like Yesterday: Drag, Nostalgia, and Queer Affective History in The Vaudevillians
Published in Journal of Homosexuality, 2022
The Vaudevillians performance of a reparative return is also signaled through Kitty and Dan’s status as authorities of queer pastness as well as champions of a backward gaze. In order to understand the significance of this status, it is necessary to contextualize the show as a queer variation on the popular science fiction trope of the frozen time traveler. H.G. Wells’ 1895 The Time Machine established time travel as a cornerstone of fantasy fiction. In the late twentieth century, the more specific concept of “time travel” by way of accidental cryogenics developed into a popular, often comic, plot device. Films and television shows like Encino Man (1992), Demolition Man (1993), Austin Powers (1997), and Futurama (1999), among others, drew on and popularized the notion of living relics from the past who were accidentally frozen and find themselves marooned in the future (or present). In these examples, the frozen time traveler presents a variation on the fish-out-of-water story archetype. In each case, the newly thawed protagonist must deal with the temporal culture shock of a new period and assimilate to the bigger and better present/future. The Vaudevillians thus falls within the larger fantasy trope of the “frozen time traveler.” While Monsoon and Scale’s performance draws on this tradition, they also provide a distinctively queer intervention into this mainstream trope that has, traditionally, relied on a straight, albeit fantastical, depiction of time.
Ablative brain surgery: an overview
Published in International Journal of Hyperthermia, 2019
Andrea Franzini, Shayan Moosa, Domenico Servello, Isabella Small, Francesco DiMeco, Zhiyuan Xu, William Jeffrey Elias, Angelo Franzini, Francesco Prada
Physical principles used for brain ablation have included chemical agents, mechanical devices, ionizing radiation, induction of heat or cryogenics, high-intensity focused ultrasound (HIFU), electromagnetic waves and radiofrequency (RF) [4]. Currently, the four main ablative techniques that are used for brain pathologies are RF thermoablation, stereotactic radiosurgery (SRS), laser interstitial thermal therapy (LITT), and HIFU thermal ablation [3] (Table 1).
Related Knowledge Centers
- Cryobiology
- Cryopreservation
- Cryosurgery
- Helium
- Hydrocarbon
- Neon
- Oxygen
- Nitrogen
- Hydrogen
- Absolute Zero