scholarly journals Effect of Addition of Soybean Oil and Gamma-Ray Cross-linking on the Nanoporous HDPE Membrane

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Jong-Seok Park ◽  
Jong-Bae Choi ◽  
Hui-Jeong Gwon ◽  
Youn-Mook Lim ◽  
Myung Seob Khil ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Soybean Oil ◽  
Gamma Rays ◽  
High Density Polyethylene ◽  
Dibutyl Phthalate ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Electrochemical Stability ◽  
Cross Linking ◽  
Wet Process

A nanoporous high-density polyethylene (HDPE) membrane was prepared by a wet process. Soybean oil and dibutyl phthalate (DBP) were premixed as codiluents, and gamma-rays were used for the cross-linking of HDPE. The pore volume of the nanoporous HDPE membranes with soybean oil was affected by the extracted amount of oil. The tensile strength of the membrane improved with an increasing absorbed dose up to 60 kGy, but decreased at 80 kGy due to severe degradation. The ionic conductivity of the nanoporous HDPE membrane did not really change with an increasing absorbed dose because the pores had already been formed before the gamma-ray radiation. Finally, the electrochemical stability of the HDPE membrane increased when the absorbed dose increased up to 60 kGy.

scholarly journals Gamma Ray-Induced Polymerization and Cross-Linking for Optimization of PPy/PVP Hydrogel as Biomaterial

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 111 ◽  
Author(s):  
Jin-Oh Jeong ◽  
Jong-Seok Park ◽  
Young-Ah Kim ◽  
Su-Jin Yang ◽  
Sung-In Jeong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Viability ◽  
Gamma Rays ◽  
Biomedical Applications ◽  
Gamma Ray ◽  
The Other ◽  
Cross Linking ◽  
Gamma Ray Irradiation ◽  
Good Cell ◽  
Scanning Electron

Conducting polymer (CP)-based hydrogels exhibit the behaviors of bending or contraction/relaxation due to electrical stimulation. They are similar in some ways to biological organs and have advantages regarding manipulation and miniaturization. Thus, these hydrogels have attracted considerable interest for biomedical applications. In this study, we prepared PPy/PVP hydrogel with different concentrations and content through polymerization and cross-linking induced by gamma-ray irradiation at 25 kGy to optimize the mechanical properties of the resulting PPy/PVP hydrogel. Optimization of the PPy/PVP hydrogel was confirmed by characterization using scanning electron microscopy, gel fraction, swelling ratio, and Fourier transform infrared spectroscopy. In addition, we assessed live-cell viability using live/dead assay and CCK-8 assay, and found good cell viability regardless of the concentration and content of Py/pTS. The conductivity of PPy/PVP hydrogel was at least 13 mS/cm. The mechanical properties of PPy/PVP hydrogel are important factors in their application for biomaterials. It was found that 0.15PPy/PVP20 (51.96 ± 6.12 kPa) exhibited better compressive strength than the other samples for use in CP-based hydrogels. Therefore, it was concluded that gamma rays can be used to optimize PPy/PVP hydrogel and that biomedical applications of CP-based hydrogels will be possible.

Radiation induced degradation of murexide dye in two media for possible use in dosimetric applications

2019 ◽  
Vol 48 (6) ◽  
pp. 540-546 ◽  
Author(s):  
Sameh Mohamed Gafar ◽  
Nehad Magdy Abdel-Kader
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Chemical Yield ◽  
Radiation Sensitivity ◽  
Industrial Applications ◽  
Food Irradiation ◽  
Radiation Chemical ◽  
Content Type ◽  
Wide Range

Purpose The purpose of this paper is to study the effect of gamma-rays on murexide (Mx) dye and its possible use as radiation dosimeters in two different dosimetry systems. The first system depends on the Mx dye as a liquid dosimeter. The second dosimetry system depends also on the same dye but as in a gel form, which is more sensitive to gamma-rays. Design/methodology/approach The prepared Mx (solutions/gels) have a considerable two peaks at 324 and 521 nm that upon irradiation, the intensity of these peaks decreases with the increasing radiation dose. Findings The gamma-ray absorbed dose for these dosimeters was found to be up to 2 kGy for the solution samples and 40 Gy for the gels. Radiation chemical yield, dose response function, radiation sensitivity and before and after-irradiation stability under various conditions were discussed and studied. Practical implications It is expected that the radiolysis of the Mx dye can be used as radiation dosimeters in two different dosimetry systems; liquid and gel dosimeters. This can be applied in a wide range of gamma radiation practical industrial applications in water treatment, food irradiation dosimeters, radiotherapy and fresh food irradiation and seed production. Originality/value Both of the prepared Mx dyes, either as solutions or gel samples, can be facilely prepared from commercially, cheap, safe, available chemicals and suitable for useful applied Mx solutions and gels radiation dosimeters.

EPDM RUBBER PLASTICIZED WITH POLYMERIC SOYBEAN OIL OF DIFFERENT MOLECULAR WEIGHTS

2017 ◽  
Vol 90 (4) ◽  
pp. 667-682 ◽  
Author(s):  
Zoran S. Petrović ◽  
Jelena Milić ◽  
Mihail Ionescu ◽  
James R. Halladay
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Soybean Oil ◽  
Cross Linking ◽  
Tear Strength ◽  
Soybean Oils ◽  
Molecular Weights ◽  
Compression Set ◽  
Diene Rubber ◽  
Processing Aids

ABSTRACT Polymerization of soybean oil produces higher-viscosity liquids, which may serve as processing aids and plasticizers in certain rubbers as a replacement of petrochemical oils. Four polymerized soybean oils of different molecular weights showed good compatibility with ethylene–propylene–diene rubber (EPDM), but because of the presence of double bonds and copolymerization with EPDM, they decreased the cross-linking density when compared with paraffinic extender oil. As a consequence, polymeric soybean oils reduced tensile strength and modulus but increased elongation, tear strength, and compression set. Higher-molecular-weight plasticizers are expected to reduce sweating out of oils. Pure soybean oil was not completely compatible at the concentration tested, but it showed a strong plasticizing effect; dramatically lowered tensile strength, tear strength, and modulus; and increased elongation and compression set. No clear effect of molecular weight of polymerized soybean oils on properties was observed, but increasing the sulfur content was found to be beneficial. Using polymeric vegetable oils instead of petrochemical extenders in EPDM rubbers is economical and environmentally desirable, but the curing system requires optimization to accommodate loss of cross-linking density.

scholarly journals Mechanical and Shielding Properties of Concrete Subject to Gamma-ray

2020 ◽  
Vol 9 (1) ◽  
pp. 42-49 ◽  
Author(s):  
S. Hosein Ghasemzadeh Mosavinejad ◽  
Samira Kazemi Rad
Keyword(s):  
Tensile Strength ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Pulse Wave ◽  
Graphite Powder ◽  
Ultrasonic Pulse ◽  
Protective Material ◽  
Attenuation Coefficients ◽  
Protective Properties ◽  
Shielding Properties

 In this research, concrete with different percentages of 0, 10, 25, 50, 75 and 100 of barite powder and 10% of graphite powder were investigated for the study of gamma protective properties. The transmitted fluxes of gamma-rays that were emitted from Cs-137 source were detected by a NaI(Tl) detector and analyzed by an MCA analyzer. Then, the samples were tested for compressive strength, tensile strength, ultrasonic pulse wave velocity and the linear attenuation coefficients. By comparing the obtained samples, it was observed that a sample containing 10% barite powder plus 10% graphite powder could be used as a protective material against gamma rays.

ВЛИЯНИЕ ПРЕДВАРИТЕЛЬНОГО ОБЛУЧЕНИЯ ГАММА-КВАНТАМИ НА ОДИНОЧНЫЕ СБОИ В МИКРОСХЕМАХ ПАМЯТИ, ВОЗНИКАЮЩИЕ ПРИ ВОЗДЕЙСТВИИ НЕЙТРОНОВ ЭНЕРГИИ 14 МЭВ

2020 ◽  
Vol 96 (3s) ◽  
pp. 187-189
Author(s):  
В.П. Шукайло ◽  
О.В. Ткачев ◽  
А.С. Кустов ◽  
К.Д. Какшарова
Keyword(s):  
Dose Level ◽  
Cross Section ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Single Event ◽  
Single Event Upsets ◽  
Dielectric Layers ◽  
Gamma Ray Irradiation ◽  
Preliminary Irradiation

Исследовано влияние предварительного облучения гамма-квантами на сечение одиночных событий (ОС) в СОЗУ при воздействии нейтронов с энергией 14 МэВ. Показано, что с увеличением уровня предварительного облучения гамма-квантами сечение ОС возрастает. Рост сечения от величины поглощенной дозы обусловлен накоплением зарядов в диэлектрических слоях интегральной микросхемы. The paper explores the influence of a preliminary gamma ray irradiation on single event upsets (SEU) in SRAM at 14 MeV neutrons influence. It has been shown that there is an increase in SEU cross section with an increase of level of preliminary irradiation by gamma rays. The increase of cross section from absorbed dose level depends on accumulation of charges in dielectric layers of integrated microcircuit.

scholarly journals The influence of ionizing radiation on the properties of starch-PVA films

Nukleonika ◽  
2015 ◽  
Vol 60 (3) ◽  
pp. 669-677 ◽  
Author(s):  
Anna Abramowska ◽  
Krystyna A. Cieśla ◽  
Marek J. Buczkowski ◽  
Andrzej Nowicki ◽  
Wojciech Głuszewski
Keyword(s):  
Tensile Strength ◽  
Gamma Rays ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Absorbed Dose ◽  
Oxidation Products ◽  
Strong Interactions ◽  
Poly Vinyl Alcohol ◽  
Solution Casting ◽  
Fast Electrons

Abstract The cornstarch: poly(vinyl alcohol) (PVA) films characterized by the alternating ratio of starch:PVA (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100) and containing 30% of glycerol were prepared by solution casting. The films were irradiated with an absorbed dose of 25 kGy with gamma rays in a vacuum and with fast electrons in the air. The films characterized by a high content of starch appeared stiff, while the films characterized by a high content of PVA were highly flexible. The tensile strength and flexibility, as well as swelling and hydrophilicity, increased with the increase in the PVA content in the films. However, the tensile strength and wetting angle values achieved a minimum at an intermediate composition. It was found that irradiation enables to reduce hydrophilicity of the films accompanied by a decrease in their flexibility. No general conclusion concerning the effect of irradiation on tensile strength and swelling behavior can be derived. An increase in the homogeneity of the films and an increase in the compatibility of their components was found by scanning electron microscopy (SEM). Strong interactions of the starch and the PVA components were discovered by diffuse reflectance spectroscopy. Degradation was found to be the prevailing process occurring in the films under the influence of irradiation. The possible accompanying crosslinking is discussed in terms of the gel content in the samples. Creation of various oxidation products in the films characterized by the modified composition was observed under the influence of irradiation carried out in the air. Basing on the obtained results it can be supposed that the selected starch-PVA compositions might appear useful as packagings of the products predicted for radiation decontamination.

Electrons generated from machine sources operated at or below an energy level of 10 MeV The eV (electronvolt) is the unit of energy used to measure and describe the energy of electrons and of other types of radiation. The energy of 1 eV is equivalent to the kinetic energy acquired by an electron on being accelerated through a potential difference of 1 V. The eV is a very small unit of energy. It is therefore more common to speak of keV (kiloelectronvolt = 1000 eV) or MeV (megaelectronvolt = 1 million eV). To convert eV to units of energy one can use the conversion 1 MeV = 1.602 X 10“ J (joule). Gamma rays and x-rays are part of the electromagnetic spectrum (Fig. 1), which reaches from the low-energy, long-wavelength radiowaves to the high-energy, short-wavelength cosmic rays. Radiowaves, infrared (IR) waves, and visible light are nonionizing radiations. Ultraviolet (UV) light can ionize only certain types of molecule under specific conditions and is generally not consid­ ered as ionizing radiation. X-rays and gamma rays are identical in their physical properties and in their effect on matter; they differ in their origin. X-rays are produced by machines and exhibit a wide continuous spectrum of radiation, whereas gamma rays come from radioactive isotopes (radionuclides) in a discon­ tinuous spectrum of radiation intensities. When ionizing radiation penetrates into a medium (e.g., the irradiated food) all or part of the radiation energy is absorbed by the medium. This is called the absorbed dose. The unit in which the absorbed dose is measured is the gray (Gy); it is equal to the absorption of 1 J (joule)/kg. One kGy (kilogray) = 1000 Gy. Formerly the dose unit rad was used. It was defined as 100 erg/g. The conversion of old to new units is based on the relationship 1000 rad = 1 Gy, or 1 krad = 10 Gy, or 1 Mrad = 10 kGy. The dose accumulated per unit of time is called the dose rate. Gamma ray sources provide a relatively low dose rate (typically 100-10,000 Gy/h, whereas

1995 ◽  
pp. 28-28
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Uv Light ◽  
Absorbed Dose ◽  
Radiation Energy ◽  
Radioactive Isotopes ◽  
X Rays ◽  
Small Unit

On the possible gamma-ray source in Cygnus

1967 ◽  
Vol 31 ◽  
pp. 469-471
Author(s):  
J. G. Duthie ◽  
M. P. Savedoff ◽  
R. Cobb
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Right Ascension

A source of gamma rays has been found at right ascension 20h15m, declination +35°, with an uncertainty of 6° in each coordinate. Its flux is (1·5 ± 0·8) x 10-4photons cm-2sec-1at 100 MeV. Possible identifications are reviewed, but no conclusion is reached. The mechanism producing the radiation is also uncertain.

Solar Flare Energetic Neutral Emission Measurements in the Project Coronas-I

1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  
Keyword(s):  
Solar Flare ◽  
Energy Range ◽  
Gamma Rays ◽  
Pulse Shape ◽  
Gamma Ray ◽  
Pulse Shape Discrimination ◽  
Shape Discrimination ◽  
Solar Neutron ◽  
Low Altitude

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.

scholarly journals On a Possible Origin of the Gamma-ray Excess around the Galactic Center

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1432
Author(s):  
Dmitry O. Chernyshov ◽  
Andrei E. Egorov ◽  
Vladimir A. Dogiel ◽  
Alexei V. Ivlev
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Molecular Clouds ◽  
Alternative Explanation ◽  
Gamma Ray ◽  
Galactic Center ◽  
The Self ◽  
Large Area ◽  
Mhd Turbulence ◽  
The Standard Model

Recent observations of gamma rays with the Fermi Large Area Telescope (LAT) in the direction of the inner galaxy revealed a mysterious excess of GeV. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs) generation and propagation with a peak in the spectrum around a few GeV. Popular interpretations of this excess are that it is due to either spherically distributed annihilating dark matter (DM) or an abnormal population of millisecond pulsars. We suggest an alternative explanation of the excess through the CR interactions with molecular clouds in the Galactic Center (GC) region. We assumed that the excess could be imitated by the emission of molecular clouds with depleted density of CRs with energies below ∼10 GeV inside. A novelty of our work is in detailed elaboration of the depletion mechanism of CRs with the mentioned energies through the “barrier” near the cloud edge formed by the self-excited MHD turbulence. This depletion of CRs inside the clouds may be a reason for the deficit of gamma rays from the Central Molecular Zone (CMZ) at energies below a few GeV. This in turn changes the ratio between various emission components at those energies and may potentially absorb the GeV excess by a simple renormalization of key components.

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