A CALORIMETRIC DETERMINATION OF THE OXIDATION YIELD OF THE FRICKE DOSIMETER AT HIGH DOSE RATES OF ELECTRONS1a

1962 ◽  
Vol 66 (1) ◽  
pp. 180-182 ◽  
Author(s):  
A. R. Anderson
Keyword(s):  
High Dose ◽  
Dose Rates ◽  
Calorimetric Determination

scholarly journals Diffraction before destruction

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130313 ◽  
Author(s):  
Henry N. Chapman ◽  
Carl Caleman ◽  
Nicusor Timneanu
Keyword(s):  
Diffraction Pattern ◽  
Structure Determination ◽  
High Dose ◽  
X Ray ◽  
Dose Rates ◽  
Structure Factors ◽  
Serial Crystallography ◽  
The Many ◽  
Dose Tolerance

X-ray free-electron lasers have opened up the possibility of structure determination of protein crystals at room temperature, free of radiation damage. The femtosecond-duration pulses of these sources enable diffraction signals to be collected from samples at doses of 1000 MGy or higher. The sample is vaporized by the intense pulse, but not before the scattering that gives rise to the diffraction pattern takes place. Consequently, only a single flash diffraction pattern can be recorded from a crystal, giving rise to the method of serial crystallography where tens of thousands of patterns are collected from individual crystals that flow across the beam and the patterns are indexed and aggregated into a set of structure factors. The high-dose tolerance and the many-crystal averaging approach allow data to be collected from much smaller crystals than have been examined at synchrotron radiation facilities, even from radiation-sensitive samples. Here, we review the interaction of intense femtosecond X-ray pulses with materials and discuss the implications for structure determination. We identify various dose regimes and conclude that the strongest achievable signals for a given sample are attained at the highest possible dose rates, from highest possible pulse intensities.

Electron Beam Damage of Biomolecules Assessed by Energy Loss Spectroscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 61-69
Author(s):  
M. Isaacson ◽  
M.L. Collins ◽  
M. Listvan
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Structural Integrity ◽  
Analytical Electron Microscopy ◽  
High Dose ◽  
Dose Rates ◽  
Special Cases ◽  
Analytical Electron ◽  
Atom Migration ◽  
Beam Damage

Over the past five years it has become evident that radiation damage provides the fundamental limit to the study of blomolecular structure by electron microscopy. In some special cases structural determinations at very low doses can be achieved through superposition techniques to study periodic (Unwin & Henderson, 1975) and nonperiodic (Saxton & Frank, 1977) specimens. In addition, protection methods such as glucose embedding (Unwin & Henderson, 1975) and maintenance of specimen hydration at low temperatures (Taylor & Glaeser, 1976) have also shown promise. Despite these successes, the basic nature of radiation damage in the electron microscope is far from clear. In general we cannot predict exactly how different structures will behave during electron Irradiation at high dose rates. Moreover, with the rapid rise of analytical electron microscopy over the last few years, nvicroscopists are becoming concerned with questions of compositional as well as structural integrity. It is important to measure changes in elemental composition arising from atom migration in or loss from the specimen as a result of electron bombardment.

Electron-diffraction studies in synthetic polymer materials

1983 ◽  
Vol 41 ◽  
pp. 362-365
Author(s):  
D.T. Grubb
Keyword(s):  
Electron Diffraction ◽  
Synthetic Polymer ◽  
Polymer Materials ◽  
Crystallographic Structure ◽  
High Dose ◽  
Electron Dose ◽  
Dose Rates ◽  
First Case ◽  
Diffraction Patterns ◽  
The Many

Diffraction studies in polymeric and other beam sensitive materials may bring to mind the many experiments where diffracted intensity has been used as a measure of the electron dose required to destroy fine structure in the TEM. But this paper is concerned with a range of cases where the diffraction pattern itself contains the important information.In the first case, electron diffraction from paraffins, degraded polyethylene and polyethylene single crystals, all the samples are highly ordered, and their crystallographic structure is well known. The diffraction patterns fade on irradiation and may also change considerably in a-spacing, increasing the unit cell volume on irradiation. The effect is large and continuous far C94H190 paraffin and for PE, while for shorter chains to C 28H58 the change is less, levelling off at high dose, Fig.l. It is also found that the change in a-spacing increases at higher dose rates and at higher irradiation temperatures.

Zur Thermodynamik der hydrophoben Wechselwirkung; die Systeme Wasser + Glycin+ Harnstoff und Wasser + Alanin+ Harnstoff bei 25 °C / Thermodynamics of Hydrophobie Interaction in the Systems Water + Glycin + Urea and Water + Alanin + Urea at 25 °C

1973 ◽  
Vol 28 (9-10) ◽  
pp. 533-554 ◽  
Author(s):  
Lothar Rafflenbeul ◽  
Wa-Ming Pang ◽  
Hansjürgen Schönert ◽  
Klaus Haberle
Keyword(s):  
Amino Acid ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Pressure Measurements ◽  
Free Enthalpy ◽  
Heat Of Dilution ◽  
Ternary Solutions ◽  
Vapor Pressure Measurements ◽  
Calorimetric Determination

Abstract Isopiestic vapor pressure measurements and calorimetric determination of the heat of dilution have been performed and evaluated with respect to enthalpy, entropy and free enthalpy in the ternary solutions water+ glycin+ urea and water+ alanin + urea. The free enthalpy of transfer for the process: Amino acid from water to water+ urea, which can be derived from these measurements, does not agree with the value calculated from solubility measurements. The reason for this discrepancy and the values of entropy and enthalpy in terms of hydrophobic interaction are discussed. Supplementary measurements of the proton magnetic resonance in these solutions are included.

scholarly journals Commissioning of a clinical pencil beam scanning proton therapy unit for ultra‐high dose rates (FLASH)

2021 ◽  
Author(s):  
Konrad P. Nesteruk ◽  
Michele Togno ◽  
Martin Grossmann ◽  
Anthony J. Lomax ◽  
Damien C. Weber ◽  
...  
Keyword(s):  
Proton Therapy ◽  
High Dose ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Dose Rates ◽  
Pencil Beam Scanning

OC-0634: Correction for ion recombination in a built-in monitor chamber at ultra-high dose rates

2020 ◽  
Vol 152 ◽  
pp. S353-S354
Author(s):  
E. Konradsson ◽  
M. Lempart ◽  
B. Blad ◽  
C. Ceberg ◽  
K. Petersson
Keyword(s):  
High Dose ◽  
Dose Rates ◽  
Ion Recombination

Calorimetric determination of fragility in glass forming liquids: Tf vs. Tg-onset methods

2014 ◽  
Vol 37 (6) ◽  
Author(s):  
Zeming Chen ◽  
Zijing Li ◽  
Yaqi Zhang ◽  
Riping Liu ◽  
Yongjun Tian ◽  
...  
Keyword(s):  
Glass Forming ◽  
Calorimetric Determination

Survival of mammalian cells exposed to X rays at ultra-high dose-rates

1969 ◽  
Vol 42 (494) ◽  
pp. 102-107 ◽  
Author(s):  
Roger J. Berry ◽  
Eric J. Hall ◽  
David W. Forster ◽  
Thomas H. Storr ◽  
Michael J. Goodman
Keyword(s):  
Mammalian Cells ◽  
High Dose ◽  
X Rays ◽  
Dose Rates
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