Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

1982 ◽  
Vol 40 ◽  
pp. 78-79
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Inelastic Scattering ◽  
Temperature Dependence ◽  
Structural Damage ◽  
Direct Result ◽  
Second Step ◽  
Strong Temperature Dependence ◽  
Electron Dose ◽  
Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Modification of the Electron Microscope for Investigation of Fully Hydrated Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 418-419 ◽  
Author(s):  
R. C. Moretz ◽  
D. F. Parsons
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Structural Damage ◽  
Lower Percentage ◽  
Vacuum Drying ◽  
Total Removal ◽  
Total Absence ◽  
Biological Studies ◽  
Electron Microscopes ◽  
Beam Damage

Short lifetime or total absence of electron diffraction of ordered biological specimens is an indication that the specimen undergoes extensive molecular structural damage in the electron microscope. The specimen damage is due to the interaction of the electron beam (40-100 kV) with the specimen and the total removal of water from the structure by vacuum drying. The lower percentage of inelastic scattering at 1 MeV makes it possible to minimize the beam damage to the specimen. The elimination of vacuum drying by modification of the electron microscope is expected to allow more meaningful investigations of biological specimens at 100 kV until 1 MeV electron microscopes become more readily available. One modification, two-film microchambers, has been explored for both biological and non-biological studies.

Effect of electron beam irradiation on phytochemical composition, lipase activity and fatty acid of quinoa

2021 ◽  
Vol 98 ◽  
pp. 103161
Author(s):  
Xiaohu Luo ◽  
Zhihong Du ◽  
Kai Yang ◽  
Jing Wang ◽  
Jing Zhou ◽  
...  
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Lipase Activity ◽  
Electron Beam Irradiation ◽  
Beam Irradiation ◽  
Phytochemical Composition

scholarly journals Post-process optimization of 3D printed poly(lactic-co-glycolic acid) dental implant scaffold for enhanced structure and mechanical properties: effects of sonication duration and power

2021 ◽  
Vol 32 (8) ◽  
Author(s):  
R. N. V. C. Virinthorn ◽  
M. Chandrasekaran ◽  
K. Wang ◽  
K. L. Goh
Keyword(s):  
Structural Damage ◽  
Glycolic Acid ◽  
Solvent Mixture ◽  
Ultrasonic Waves ◽  
Poly Vinyl Alcohol ◽  
Covalent Bonds ◽  
Process Stage ◽  
Post Process ◽  
3D Printed ◽  
Ft Ir

AbstractWe described a technique of a post-process stage to partially remove the poly(vinyl alcohol) (PVA) binder in Poly(lactic-co-glycolic acid) (PLGA) dental scaffolds. The scaffolds were exposed to ultrasonic waves while immersed in an ethanol/acetone solvent mixture that possessed both polar and nonpolar properties. A factorial experiment was conducted in which the scaffolds were treated to three levels of sonication power (pW): 0, 20% (22 W) and 40% (44 W), and soaking duration (t): 5, 15, and 30 min. The treated scaffolds were characterized by FT-IR, optical microscopy, and mechanical (compressive) testing. FT-IR revealed that the amount of PVA decreased with increasing pW and t. Two-way ANOVA revealed that increasing pW and t, respectively, resulted in increasing scaffold surface area to volume (SVR). Sonication and solvent caused structural damage (i.e., unevenness) on the scaffold surface, but the damage was minimal at 20% pW and 30 min. The optimal values of pW and t resulting in enhanced fracture strength, strain and toughness were 20% and 30 min, respectively, which corroborated the findings of minimal structural damage. However, sonication had no significant effects on the scaffold stiffness. Mechanistic analysis of the effects of sonication predicted that the ultrasonic energy absorbed by the scaffold was sufficient to disrupt the van Der Waals bonds between the PVA and PLGA but not high enough to disrupt the covalent bonds within the PLGA. This technique is promising as it can partially remove the PVA from the scaffold, and mitigate problematic issues down the line, such as thermal degradation during sterilization, and undue delay/variability in biodegradation.

scholarly journals Determining the helicity structure of the nucleon at the Electron Ion Collider in China

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Daniele Paolo Anderle ◽  
Tie-Jiun Hou ◽  
Hongxi Xing ◽  
Mengshi Yan ◽  
C.-P. Yuan ◽  
...  
Keyword(s):  
Electron Beam ◽  
Inelastic Scattering ◽  
Scattering Data ◽  
Leading Order ◽  
Specific Topic ◽  
Good Separation ◽  
Effective Electron ◽  
Deep Inelastic Scattering Data ◽  
Polarized Proton ◽  
Helicity Structure

Abstract Understanding how sea quarks behave inside a nucleon is one of the most important physics goals of the proposed Electron-Ion Collider in China (EicC), which is designed to have a 3.5 GeV polarized electron beam (80% polarization) colliding with a 20 GeV polarized proton beam (70% polarization) at instantaneous luminosity of 2 × 1033cm−2s−1. A specific topic at EicC is to understand the polarization of individual quarks inside a longitudinally polarized nucleon. The potential of various future EicC data, including the inclusive and semi-inclusive deep inelastic scattering data from both doubly polarized electron-proton and electron-3He collisions, to reduce the uncertainties of parton helicity distributions is explored at the next-to-leading order in QCD, using the Error PDF Updating Method Package (ePump) which is based on the Hessian profiling method. We show that the semi-inclusive data are well able to provide good separation between flavour distributions, and to constrain their uncertainties in the x > 0.005 region, especially when electron-3He collisions, acting as effective electron-neutron collisions, are taken into account. To enable this study, we have generated a Hessian representation of the DSSV14 set of PDF replicas, named DSSV14H PDFs.

Temperature Dependence of Electron Beam Induced Epitaxial Crystallization of Silicon

1990 ◽  
Vol 122 (1) ◽  
pp. K35-K37 ◽  
Author(s):  
D. Hoehl ◽  
V. Heera ◽  
H. Bartsch ◽  
K. Wollschläger ◽  
W. Skorupa ◽  
...  
Keyword(s):  
Electron Beam ◽  
Temperature Dependence ◽  
Epitaxial Crystallization

scholarly journals Temperature-Driven Spin Reorientation Transition in CoPt/AlN Multilayer Films

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Wupeng Cai ◽  
Shinji Muraishi ◽  
Ji Shi ◽  
Yoshio Nakamura ◽  
Wei Liu ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Mean Field ◽  
Multilayer Films ◽  
Spin Reorientation ◽  
Strong Temperature Dependence ◽  
Mean Field Model ◽  
Spin Reorientation Transition ◽  
Magnetoelastic Effect ◽  
Out Of Plane ◽  
Interface Anisotropy

Spin reorientation transition phenomena from out-of-plane to in-plane direction with increasing temperature are observed for the 500°C annealed CoPt/AlN multilayer films with different CoPt layer thicknesses. CoPt-AlN interface and volume anisotropy contributions, favoring out-of-plane and in-plane magnetization, respectively, are separately determined at various temperatures. Interface anisotropy exhibits much stronger temperature dependence than volume contribution, hence the temperature-driven spin reorientation transition occurs. Interface anisotropy in this work consists of Néel interface anisotropy and magnetoelastic effect. Magnetoelastic effect degrades rapidly and changes its sign from positive to negative above 200°C, because of the involvement of stress state in CoPt films with temperature. By contrast, Néel interface anisotropy decays slowly, estimated from a Néel mean field model. Thus, the strong temperature dependence of CoPt-AlN interface anisotropy is dominated by the change of magnetoelastic effect.

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