RADIATION CHEMISTRY OF ALKALI THIOSULFATES

1965 ◽  
Vol 43 (3) ◽  
pp. 614-623 ◽  
Author(s):  
R. L. Eager ◽  
D. S. Mahadevappa
Keyword(s):  
Low Temperature ◽  
Gamma Rays ◽  
Room Temperature ◽  
Absorbed Dose ◽  
Radiation Chemistry ◽  
Sulfate Ions ◽  
Sodium Salts ◽  
Colloidal Sulfur ◽  
Central Oxygen ◽  
Annealing Experiments

The salts Na2S2O3, Na2S2O3•5H2O, K2S2O3, and [Formula: see text] were irradiated at room temperature with 60Co gamma rays. When the irradiated salts were dissolved in water, sulfite and sulfate ions, H2S gas, colloidal sulfur, and a relatively small quantity of acid were found among the irradiation products. The dependence of yields on the absorbed dose was studied. G-values of approximately unity were found. Using 35S as a label, it was found that the inner sulfur (the central, oxygen-bonded sulfur atom of the complex) appears in the sulfite and sulfate whereas the outer sulfur (the sulfur linked only to the central sulfur and not to oxygen) appears in the H2S and colloidal sulfur. Annealing experiments using irradiated Na2S2O3 and K2S2O3 showed that the yields of sulfite, sulfate, and H2S were decreased by heating. The sodium salts were also irradiated at 77°K. The yields of sulfate and H2S were higher for the low temperature irradiations as compared to room temperature irradiations, whereas the yields of sulfite were lower. A tentative mechanism which partially explains the results is proposed.

Radiation Chemistry of Dithionates

1971 ◽  
Vol 49 (22) ◽  
pp. 3733-3738 ◽  
Author(s):  
G. S. Murthy ◽  
R. L. Eager ◽  
K. J. McCallum
Keyword(s):  
Thermal Annealing ◽  
Gamma Rays ◽  
Room Temperature ◽  
Absorbed Dose ◽  
Radiation Chemistry ◽  
Radical Ions ◽  
Slight Effect ◽  
Sulfate Ions ◽  
Product Yields ◽  
Sulfite Ions

The salts Na2S2O6, Na2S2O6•2H2O, K2S2O6, BaS2O6, and BaS2O6•2H2O were irradiated at room temperature with 60Co gamma rays. When the irradiated salts were dissolved in water sulfite ions, sulfate ions, and acid were found as irradiation products. The dependence of yield upon absorbed dose was studied. The G-values found ranged from unity to 20. Thermal annealing of the irradiated salts had only a slight effect on product yields. For BaS2O6 there is a large increase in product yields after a dose of 28.3 × 1022 eV per mol has been absorbed. A mechanism involving SO3− and S2O6− radical ions is proposed.

The radiation chemistry of glassy n -propanol

1970 ◽  
Vol 320 (1540) ◽  
pp. 1-22 ◽  
Keyword(s):  
Gas Chromatography ◽  
Low Temperature ◽  
Room Temperature ◽  
Equilibrium Configuration ◽  
Radiation Chemistry ◽  
First Order ◽  
Gaseous Products ◽  
Radical Concentration ◽  
Thermal Bleaching ◽  
Solvent Molecules

The irradiation of glassy n -propanol at 77 K with 60 Co γ -rays has been investigated by the use of low temperature optical and e.s.r. spectroscopy to identify intermediates and gas chromatography to measure yields of gaseous products. Trapped electrons (e t - ) are formed with a yield G (e t - ) = 1.7 ± 0.2. Controlled warming and illumination with light λ > λ max suggest that electrons are initially immobilized in cavities surrounded by a non-equilibrium configuration of solvent molecules. The decay of e t - at 100 to 110 K is first-order, the Arrhenius parameters being lg A (s -1 ) = 12.5 ± 1.5 and E a = 31.3 ± 2.9kJ/mol. For photobleaching with light λ 509nm , ( ɸє ) 509 = 460 ± 501 mol -1 cm -1 independent of the fraction of e t - bleached. Unlike thermal bleaching, photobleaching does not change the total radical concentration as observed by e.s.r. The thermal and photolytic destruction of e t - are explained by the following reactions: e t - → EtCH 2 O - + H 2 e t - + hv →EtCHOH + EtCH 2 O - + H 2 →EtCHO - . + H 2 , and the effects of additives are discussed. The thermal decay of the u.v. absorption after complete photobleaching of e t - showed evidence of a species stable at 120 K but which decayed slowly at room temperature. An assignment of the u.v. absorptions to the species EtCHOH and EtCHO - is discussed. Some results are presented on the photolysis of γ -irradiated glasses with light of λ 254 nm.

Reduction of Interface Traps and Enhancement of Channel Mobility in n-Channel 6H-SiC MOSFETs by Irradiation with Gamma-Rays

2008 ◽  
Vol 600-603 ◽  
pp. 703-706 ◽  
Author(s):  
Shigeomi Hishiki ◽  
Sergey A. Reshanov ◽  
Takeshi Ohshima ◽  
Hisayoshi Itoh ◽  
Gerhard Pensl
Keyword(s):  
Gamma Rays ◽  
Room Temperature ◽  
Inversion Layer ◽  
Absorbed Dose ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Similar Increase ◽  
Channel Mobility ◽  
Hall Effect Measurements ◽  
Effective Channel

N-channel MOSFETs are irradiated with gamma-rays (g-rays) up to 3.16 MGy(SiO2) at room temperature. Above 1 MGy, the effective channel mobility increases with increasing absorbed dose. A similar increase is observed for the Hall mobility in the inversion layer. In addition, the Hall-effect measurements indicate a reduction of the interface trap density.

Survival of mouse blastocysts after low-temperature preservation under high pressure

2004 ◽  
Vol 52 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Cs. Pribenszky ◽  
M. Molnár ◽  
S. Cseh ◽  
L. Solti
Keyword(s):  
Phase Transition ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
High Hydrostatic Pressure ◽  
Room Temperature ◽  
Freezing Point ◽  
Significant Loss ◽  
Embryo Cryopreservation ◽  
Subzero Temperatures ◽  
Survival Capacity

Cryoinjuries are almost inevitable during the freezing of embryos. The present study examines the possibility of using high hydrostatic pressure to reduce substantially the freezing point of the embryo-holding solution, in order to preserve embryos at subzero temperatures, thus avoiding all the disadvantages of freezing. The pressure of 210 MPa lowers the phase transition temperature of water to -21°C. According to the results of this study, embryos can survive in high hydrostatic pressure environment at room temperature; the time embryos spend under pressure without significant loss in their survival could be lengthened by gradual decompression. Pressurisation at 0°C significantly reduced the survival capacity of the embryos; gradual decompression had no beneficial effect on survival at that stage. Based on the findings, the use of the phenomena is not applicable in this form, since pressure and low temperature together proved to be lethal to the embryos in these experiments. The application of hydrostatic pressure in embryo cryopreservation requires more detailed research, although the experience gained in this study can be applied usefully in different circumstances.

Photophysical properties of N719 and Z907 dyes, benchmark sensitizers for dye-sensitized solar cells, at room and low temperature

2021 ◽  
Vol 23 (10) ◽  
pp. 6182-6189
Author(s):  
Dariusz M. Niedzwiedzki
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
Optical Spectroscopy ◽  
Room Temperature ◽  
Photophysical Properties ◽  
Dye Sensitized Solar Cells ◽  
Time Resolved ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Photophysical properties of N719 and Z907, benchmark Ru-dyes used as sensitizers in dye-sensitized solar cells, were studied by static and time-resolved optical spectroscopy at room temperature and 160 K.

Transition Insulator-Metal and Antiferromagnetic-Paramagnetic Cu Doped in La0.47Ca0.53MnO3

2015 ◽  
Vol 1123 ◽  
pp. 73-77 ◽  
Author(s):  
Yohanes Edi Gunanto ◽  
K. Sinaga ◽  
B. Kurniawan ◽  
S. Poertadji ◽  
H. Tanaka ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Magnetic Structure ◽  
Room Temperature ◽  
Paramagnetic Phase ◽  
Perovskite Manganites ◽  
Antiferromagnetic Phase ◽  
Temperature Transition ◽  
Cu Doping ◽  
Metal State

The study of the perovskite manganites La0.47Ca0.53Mn1-xCuxO3 with x = 0, 0.06, 0.09, and 0.13 has been done. The magnetic structure was determined using high-resolution neutron scattering at room temperature and low temperature. All samples were paramagnetic at room temperature and antiferromagnetic at low temperature. Using the SQUID Quantum Design, the samples showed that the doping of the insulating antiferromagnetic phase La0.47Ca0.53MnO3 with Cu doping resulted in the temperature transition from an insulator to metal state, and an antiferromagnetic to paramagnetic phase. The temperature transition from an insulator to metal state ranged from 23 to 100 K and from 200 to 230 K for the transition from an antiferromagnetic to paramagnetic phase.

Radiation chemistry of ices of planetological interest at low temperature

1995 ◽  
Vol 16 (2) ◽  
pp. 61-71 ◽  
Author(s):  
G. Strazzulla ◽  
M. Arena ◽  
G.A. Baratta ◽  
C.A. Castorina ◽  
G. Celi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Radiation Chemistry

Molecule-Based Magnets—An Overview

MRS Bulletin ◽  
2000 ◽  
Vol 25 (11) ◽  
pp. 21-30 ◽  
Author(s):  
Joel S. Miller ◽  
Arthur J. Epstein
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Magnetic Ordering ◽  
Low Density ◽  
Materials Properties ◽  
The Common ◽  
New Processing ◽  
Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

Sign in / Sign up

Export Citation Format

Share Document