A possible additional role of mineral oil in successful flash cooling

2005 ◽  
Vol 38 (6) ◽  
pp. 945-950 ◽  
Author(s):  
Lokesh Gakhar ◽  
John M. Wiencek
Keyword(s):  
Liquid Nitrogen ◽  
Nucleate Boiling ◽  
Mineral Oil ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Full Potential ◽  
Surface Cooling ◽  
Flash Cooling ◽  
Leidenfrost Temperature ◽  
Additional Role

Traditional explanations for the efficacy of mineral oil in successful flash cooling of a protein crystal correctly point to the removal of excess liquid around the crystal to prevent external ice formation. Based on the physics of the well known Leidenfrost phenomenon, an additional role that mineral oil possibly plays in aiding vitrification is suggested: that of improving cooling rates for a protein crystal plunged into liquid nitrogen. The full potential of liquid heat transfer when using liquid nitrogen is not realized in conventional cooling techniques due to film boiling that occurs around larger protein crystals. However, a thin layer of an insulating material, such as a mineral oil, around the protein crystal can prevent this vapor film from forming by raising the Leidenfrost temperature. Surface cooling then occurs in the more efficient nucleate boiling regime where liquid nitrogen is in contact with the crystal throughout the quench. Using bare and coated thermocouples, the validity of a predictive Leidenfrost temperature equation for use in liquid-nitrogen plunge cooling of protein crystals is demonstrated.

scholarly journals Approaches to automated protein crystal harvesting

2014 ◽  
Vol 70 (2) ◽  
pp. 133-155 ◽  
Author(s):  
Marc C. Deller ◽  
Bernhard Rupp
Keyword(s):  
Data Collection ◽  
Single Step ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Optical Traps ◽  
Fourth Generation ◽  
Flash Cooling ◽  
Harvesting Systems ◽  
Harvesting Process

The harvesting of protein crystals is almost always a necessary step in the determination of a protein structure using X-ray crystallographic techniques. However, protein crystals are usually fragile and susceptible to damage during the harvesting process. For this reason, protein crystal harvesting is the single step that remains entirely dependent on skilled human intervention. Automation has been implemented in the majority of other stages of the structure-determination pipeline, including cloning, expression, purification, crystallization and data collection. The gap in automation between crystallization and data collection results in a bottleneck in throughput and presents unfortunate opportunities for crystal damage. Several automated protein crystal harvesting systems have been developed, including systems utilizing microcapillaries, microtools, microgrippers, acoustic droplet ejection and optical traps. However, these systems have yet to be commonly deployed in the majority of crystallography laboratories owing to a variety of technical and cost-related issues. Automation of protein crystal harvesting remains essential for harnessing the full benefits of fourth-generation synchrotrons, free-electron lasers and microfocus beamlines. Furthermore, automation of protein crystal harvesting offers several benefits when compared with traditional manual approaches, including the ability to harvest microcrystals, improved flash-cooling procedures and increased throughput.

scholarly journals A step towards long-wavelength protein crystallography: subjecting protein crystals to a vacuum

2015 ◽  
Vol 48 (3) ◽  
pp. 913-916 ◽  
Author(s):  
Santosh Panjikar ◽  
Lars Thomsen ◽  
Kane Michael O'Donnell ◽  
Alan Riboldi-Tunnicliffe
Keyword(s):  
Data Collection ◽  
Data Quality ◽  
Crystal Lattice ◽  
Liquid Nitrogen ◽  
Proteinase K ◽  
Protein Crystals ◽  
X Ray ◽  
Long Wavelength ◽  
Flash Cooling

Using the UHV experimental endstation on the soft X-ray beamline at the Australian Synchrotron, lysozyme and proteinase K crystals have been exposed to a vacuum of 10−5 mbar, prior to flash-cooling in a bath of liquid nitrogen. Subsequent data collection on the MX2 beamline at the Australian Synchrotron demonstrated that, for lysozyme and proteinase K, it is possible to subject these mounted crystals to a vacuum pressure of 10−5 mbar without destroying the crystal lattice. Despite the lower data quality of the vacuum-pumped crystals compared with control crystals, it is demonstrated that the protein crystals can survive in a vacuum under suitable conditions.

Nucleation of protein crystals – a nanoscopic perspective

Nanoscale ◽  
2018 ◽  
Vol 10 (26) ◽  
pp. 12256-12267 ◽  
Author(s):  
Mike Sleutel ◽  
Alexander E. S. Van Driessche
Keyword(s):  
State Of The Art ◽  
Crystal Nucleation ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Historical Overview ◽  
Art Analysis

A historical overview and state-of-the-art analysis of the mechanism of protein crystal nucleation from an experimentalist's perspective.

[11] Two-dimensional protein crystals in aid of three-dimensional protein crystal growth

1997 ◽  
pp. 166-171
Author(s):  
Aled M. Edwards ◽  
Seth A. Darst ◽  
Sally A. Hemming ◽  
Francisco J. Asturias ◽  
Peter R. David ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Three Dimensional ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Two Dimensional ◽  
Protein Crystal Growth

An Experimental Study on Cryogenic Spray Quenching of a Circular Metal Disk II. Chilldown Efficiency and Effects of Coating and Flow Pulsing

2021 ◽  
Author(s):  
Jun Dong ◽  
Hao Wang ◽  
Samuel Darr ◽  
Jason Hartwig ◽  
Jacob Chung
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Liquid Nitrogen ◽  
Mass Flow ◽  
Flow Rate ◽  
Continuous Flow ◽  
Nucleate Boiling ◽  
Film Boiling ◽  
Teflon Coating ◽  
Bare Surface

Abstract This is the second part of a two-part series that presents the results of liquid nitrogen spray quenching of a Stainless Steel disc. The results of continuous-flow spray chilldown of a bare surface disc are summarized first that serves as the baseline information for evaluating the effects of disc surface coating and pulse flow. We found that for continuous-flow spray chilldown of a bare surface disc, the chilldown efficiency is mainly a function of the average mass flow rate with the trend of decreasing efficiency with increasing mass flow rate. Additional experiments were performed to evaluate the enhancement of cryogenic spray quenching by three techniques: 1. Using intermittent pulse sprays on SS bare surface, 2. Coating the SS surface with a layer of low thermal conductivity Teflon film, and 3. Spraying liquid nitrogen intermittently on the coated SS surface. In general, the results indicate that all three methods effectively produced higher spray thermal efficiencies and reduced liquid nitrogen mass consumption. However, it was also found that the Teflon coating was more effective than the flow pulsing due to that the Teflon coating induced a large surface temperature drop at the beginning of the chilldown that allowed the quenching to move quickly from poor heat transfer film boiling to efficient heat transfer transition and nucleate boiling regimes. This quick transition shortens the film boiling period, thus facilitates the switch to much higher heat transfer transition boiling and nucleate boiling periods earlier to complete the chilldown process faster.

scholarly journals Microscope detection options for colorless protein crystals grown in lipidic cubic phases

2003 ◽  
Vol 36 (5) ◽  
pp. 1295-1296 ◽  
Author(s):  
Peter Nollert
Keyword(s):  
Membrane Proteins ◽  
Crystal Nucleation ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Cubic Phase ◽  
Polarization Microscopy ◽  
Cubic Phases ◽  
Lipidic Cubic Phase ◽  
Surface Distortions ◽  
Microscopic Techniques

The use of lipidic cubic phases as crystal nucleation and growth matrices is becoming popular and has yielded crystals of soluble and membrane proteins. So far, all of the membrane proteins crystallized by this method have been colored. This feature has facilitated the detection of the often encountered microcrystals in initial screening rounds. Indeed, small colorless protein crystals have poor optical contrast as a result of the small differences in refractive index of the protein crystal and the surrounding lipidic cubic phase. While a perfect preparation of a lipidic cubic phase is transparent and optically isotropic, in a crystallization setup it frequently disguises crystals due to cracks, inclusions, surface distortions and phase boundaries. Here, several specialized microscopic techniques and illumination conditions are compared and it is found that sufficient contrast is generated by cross polarization microscopy and by Hoffman modulation contrast microscopy for the detection of colorless protein crystals.

Synthesis of luminescent lanthanide complexes within crosslinked protein crystal matrices

CrystEngComm ◽  
2018 ◽  
Vol 20 (16) ◽  
pp. 2267-2277 ◽  
Author(s):  
Yu Zhang ◽  
Xiaoting Zhang ◽  
Jianguo Tang ◽  
Christopher D. Snow ◽  
Guotao Sun ◽  
...  
Keyword(s):  
Lanthanide Complexes ◽  
Protein Crystal ◽  
Protein Crystals

Eu(TTA)3phen was synthesized inside of crosslinked protein crystals. And we characterized the volumetric changes quantitatively induced by DMSO.

Two-Phase Pipe Quenching Correlations for Liquid Nitrogen and Liquid Hydrogen

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
S. R. Darr ◽  
J. W. Hartwig ◽  
J. Dong ◽  
H. Wang ◽  
A. K. Majumdar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Liquid Nitrogen ◽  
Critical Heat Flux ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Liquid Hydrogen ◽  
Two Phase ◽  
Cryogenic Flow ◽  
Two Phase Heat Transfer

Recently, two-phase cryogenic flow boiling data in liquid nitrogen (LN2) and liquid hydrogen (LH2) were compared to the most popular two-phase correlations, as well as correlations used in two of the most widely used commercially available thermal/fluid design codes in Hartwig et al. (2016, “Assessment of Existing Two Phase Heat Transfer Coefficient and Critical Heat Flux on Cryogenic Flow Boiling Quenching Experiments,” Int. J. Heat Mass Transfer, 93, pp. 441–463). Results uncovered that the correlations performed poorly, with predictions significantly higher than the data. Disparity is primarily due to the fact that most two-phase correlations are based on room temperature fluids, and for the heating configuration, not the quenching configuration. The penalty for such poor predictive tools is higher margin, safety factor, and cost. Before control algorithms for cryogenic transfer systems can be implemented, it is first required to develop a set of low-error, fundamental two-phase heat transfer correlations that match available cryogenic data. This paper presents the background for developing a new set of quenching/chilldown correlations for cryogenic pipe flow on thin, shorter lines, including the results of an exhaustive literature review of 61 sources. New correlations are presented which are based on the consolidated database of 79,915 quenching points for a 1.27 cm diameter line, covering a wide range of inlet subcooling, mass flux, pressure, equilibrium quality, flow direction, and even gravity level. Functional forms are presented for LN2 and LH2 chilldown correlations, including film, transition, and nucleate boiling, critical heat flux, and the Leidenfrost point.

scholarly journals Methods for Obtaining Better Diffractive Protein Crystals: From Sample Evaluation to Space Crystallization

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 78
Author(s):  
Yoshinobu Hashizume ◽  
Koji Inaka ◽  
Naoki Furubayashi ◽  
Masayuki Kamo ◽  
Sachiko Takahashi ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Quality Evaluation ◽  
Protein Crystallization ◽  
Protein Crystals ◽  
Microgravity Environment ◽  
Theoretical Understanding ◽  
Protein Sample ◽  
Space Experiments ◽  
Flash Cooling ◽  
Crystallization Conditions

In this paper, we present a summary on how to obtain protein crystals from which better diffraction images can be produced. In particular, we describe, in detail, quality evaluation of the protein sample, the crystallization conditions and methods, flash-cooling protection of the crystal, and crystallization under a microgravity environment. Our approach to protein crystallization relies on a theoretical understanding of the mechanisms of crystal growth. They are useful not only for space experiments, but also for crystallization in the laboratory.

Rewet Temperature Correlations for Liquid Nitrogen Boiling Pipe Flows Across Varying Flow Conditions and Orientations

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
S. R. Darr ◽  
J. Dong ◽  
N. Glikin ◽  
J. W. Hartwig ◽  
J. N. Chung
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Liquid Nitrogen ◽  
Heat Transfer Process ◽  
Transport Processes ◽  
Liquid Oxygen ◽  
Cryogenic Fluids ◽  
Wide Range ◽  
Leidenfrost Temperature ◽  
Phase Change Heat Transfer

In many convective liquid–vapor phase-change heat transfer engineering applications, cryogenic fluids are widely used in industrial processes, spacecraft and cryosurgery systems, and so on. For example, cryogens are usually used as liquid fuels such as liquid hydrogen, liquid methane, and liquid oxygen in the rocket industry, liquid nitrogen and helium are frequently used to cool superconducting magnetic device for medical applications. In these systems, proper transport, handling, and storage of cryogenic fluids are of extreme importance. Among all the cryogenic transport processes performed in room temperatures, quenching, also termed chilldown, is an unavoidable initial, transient phase-change heat transfer process that brings the system down to the cryogenic condition. The Leidenfrost temperature or rewet temperature that signals the end of film boiling is practically considered the completion point of a quenching process. Therefore, rewet temperature has been considered the most important parameter for the engineering design of cryogenic thermal management systems. As most of the previous correlations for predicting the Leidenfrost temperature and the rewet temperature have been developed for water, they are shown to disagree with recent liquid nitrogen pipe chilldown experiments in upward and downward flow directions over a wide range of flow rates, pressures, and degrees of inlet subcooling. In addition to a complete review of the literature, two modified correlations are presented, one based on bubble growth and another based on the theoretical maximum limit of superheat. Each correlation performs well over the entire dataset.

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