The influence of reaction conditions and some solutes on the radiation-induced addition of 2-propanol to maleic acid

1970 ◽  
Vol 35 (5) ◽  
pp. 1335-1348 ◽  
Author(s):  
J. Kučera
Keyword(s):  
Maleic Acid ◽  
Reaction Conditions ◽  
Radiation Induced

Influence of Temperature and Oxygen Concentration on the Radiation Induced Oxidation of Phenylalanine

1995 ◽  
Vol 50 (9) ◽  
pp. 864-870 ◽  
Author(s):  
P. Krajnik ◽  
R. M. Quint ◽  
S. Solar ◽  
N. Getoff ◽  
G. Sontag
Keyword(s):  
Oxygen Concentration ◽  
Room Temperature ◽  
Degradation Process ◽  
Storage Conditions ◽  
Food Storage ◽  
Reaction Conditions ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Radiation Induced ◽  
Induced Changes

AbstractThe formation of tyrosine isomers by γ-radiolysis of neutral aqueous phenylalanine solutions was found to be strongly dependent on oxygen concentration and temperature. Changing the dose rate did not influence the degradation process. In the presence of 0.25 x 10-3 mol dm-3 oxygen at room temperature the yields of o-tyrosine as well as of m- and p-tyrosine drop from G(o-Tyr) = 0.5 and G(m-Tyr) = G(p-Tyr) = 0.4 at a dose of 0.3 kGy to 0.18 and 0.16 at 2.5 kGy, respectively. In solutions containing 1.25 x 10-3 mol dm-3 oxygen the initial yields remain unchanged but decrease at 2.5 kGy only to G(o-Tyr) = 0.3 and G(m-Tyr) = G(p-Tyr) = 0.20. Under the latter reaction conditions also 3,4-dihydroxyphenylalanine was found.Samples irradiated in frozen state did not show remarkable radiolysis of phenylalanine and tyrosine formation. In the range between 5 and 20°C no essential influence of temperature on the phenylalanine radiolysis and tyrosine yields was observable. The obtained results are important for methods using the tyrosine yields as markers for the detection of irradiated food. Storage conditions and irradiation temperature play an essential role on radiation induced changes of food.

scholarly journals Nicotine-selective radiation-induced poly(acrylamide/maleic acid) hydrogels

2001 ◽  
Vol 60 (3) ◽  
pp. 203-210 ◽  
Author(s):  
D. Saraydin ◽  
E. Karadağ ◽  
Y. Çaldiran ◽  
O. Güven
Keyword(s):  
Maleic Acid ◽  
Radiation Induced ◽  
Poly Acrylamide

Swelling characterization of gamma-radiation induced crosslinked acrylamide/maleic acid hydrogels in urea solutions

2006 ◽  
Vol 27 (7) ◽  
pp. 576-584 ◽  
Author(s):  
Erdener Karadağ ◽  
Ömer Barış Üzüm ◽  
Dursun Saraydın ◽  
Olgun Güven
Keyword(s):  
Gamma Radiation ◽  
Maleic Acid ◽  
Radiation Induced

scholarly journals Modification of Track Etchedfluorinatea Films by Radiation Induced Graft Copolymerization

2009 ◽  
Vol 3 (2) ◽  
pp. 123-128
Author(s):  
Sunita Rattan ◽  
◽  
Inderjeet Kaur ◽  
Nitika Gupta ◽  
Devesh Kumar Avasthi ◽  
...  
Keyword(s):  
Total Dose ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Spectroscopic Techniques ◽  
Reaction Conditions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Radiation Induced ◽  
Ftir Technique ◽  
Basic Characteristics

With the aim of improving the basic characteristics of Track Etched Membranes (TEMs), functionalization by graft copolymerization has been attempted in the present work. Thin films (25 μm) of poly(vinyl fluoride) (PVF) (Tedlar) were irradiated by swift heavy ions (110 MeV Si 8+ ). The irradiated films were chemically etched to form latent tracks. Atomic Force Microscopy (AFM) was used to ascertain the formation of latent tracks. Irradiation effects were studied using UV-visible spectroscopic techniques. The tracks were functionalized by gamma radiation induced grafting with 4-vinyl pyridine (4-VP). In order to anticipate the best grafting conditions, percentage of grafting was studied as a function of various reaction conditions such as (i) total dose, (ii) monomer concentration and (iii) amount of water. Maximum percentage of grafting (13.66 %) was obtained at a total dose of 57.024 kGy using 2 ml of 4-VP in 10 ml of water. The grafted films were characterized by FTIR technique

Products formed in the radiation synthesis of 5-oxo-tetrahydrofuran-3-carboxylic acid derivatives

1980 ◽  
Vol 45 (12) ◽  
pp. 3564-3570
Author(s):  
Jaromír Kučera ◽  
Jaromír Moravec
Keyword(s):  
Carboxylic Acid ◽  
Ir Spectra ◽  
Rate Constant ◽  
Maleic Acid ◽  
Isopropyl Ester ◽  
Radiation Synthesis ◽  
Primary Products ◽  
Radiation Induced ◽  
Higher Temperature ◽  
Derivatives Of

After the radiation-induced addition of 2-propanol to the diesters of cis-2-butenedioic (maleic) acid at 20 °C the reaction mixture contains not only the expected lactone-type products, i.e., the derivatives of 2,2-dimethyl-5-oxotetrahydrofuran-3-carboxylic acid (II) but also the corresponding hydroxy derivatives, i.e., the derivatives of 3-carboxy-4-methyl-4-hydroxypentanoic acid (IV). These hydroxy derivatives are formed as the primary products, however, they are not stable in the solution even in the form of their diesters. Their lactonization accompanied by the splitting off of alcohols proceeds rather slowly. The lactonization rate constant of the di-isopropyl ester of the acid IV is 1.61 . 10-5 s-1, of the di-n-octyl ester of IV it is 7.41 . 10-6 s-1 at 25 °C. At a higher temperature, e.g., during the esterification, the hydroxy derivatives of IV are partly lactonized, partly they form the respective unsaturated diesters by splitting off a molecule of water. A series of new esters of the acid II and of the triesters of its 4-(1,2-dicarboxyethyl) derivative (telomer 1 : 2) are described and the wavenumbers of the characteristic lactone bands in the region 1 777 - 1 786 cm-1 in the IR spectra of both types of lactone-esters are given.

Radiation-Induced Precipitation at Thin Foil Surfaces in Ni-Be Alloys

1982 ◽  
Vol 40 ◽  
pp. 598-599
Author(s):  
T. Mukai ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Thin Foil ◽  
Homogeneous Precipitation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Radiation Induced

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.

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