• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.984-990
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• 2014

Polymers are the most commonly used di-electrics because of their reliability, availability, ease of fabrication and cost. The commercial and industrial demand for advanced polymeric materials which are capable of being used in harsh environment is need of the hour. The study of the effect of electron beam irradiation on polymeric materials is an area of rapidly increasing interest. This paper discusses the resultant beneficial effects of electron beam irradiation on the SiR-EPDM blend having 50:50 composition. The changes in mechanical and electrical properties of SiR-EPDM blend which are exposed to three different doses of electron beam radiation namely 5 Mrad, 15 Mrad and 25 Mrad are presented. The irradiated blends are analyzed for their electro-mechanical and physico chemical properties. The electrical changes induced by irradiation are investigated by arc resistance, surface resistivity and volume resistivity measurements as per ASTM standards. The mechanical changes are observed by the measurement of tensile strength and elongation at break. Physico chemical investigation has been done using the FTIR, in order to investigate the irradiation induced chemical changes.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.400-403
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• 2005

The effect of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from defatted soybean meal (DSM) was evaluated. DSM were placed in pyrex petri dishes (8.0 cm diameter) and irradiated at $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60 min with a FIR heater or simple heater. After FIR irradiation or simple heat treatment at same conditions, methanol extracts of DSM were prepared and total phenol contents (TPC), radical scavenging activity (RSA) and reducing power of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When DSM were FIR-irradiated at $150^{\circ}C$ for 15 min, the values of TPC, RSA, and reducing power of the extracts increased from 31.62 mg/ml to 57.51 mg/ml, 11.6% to 53.1%, and 0.068 to 0.147, respectively, compared to the untreated controls. Simple heat treatment of DSM under the same conditions ($150^{\circ}C$ for 15 min) also increased the TPC, RSA, and reducing power of the extracts from to 58.04 mg/ml, 65.2% and 0.160, respectively. The results indicated that appropriate FIR-irradiation or heat treatment on DSM increased the antioxidant activities of methanolic extracts.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.386-389
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• 2007

The antioxidant activities of Phellinus igniarius (PI) and Ganoderma lucidum (GL) extracts were evaluated after far-infrared (FIR) irradiation. PI and GL were irradiated at $120^{\circ}C$ for 30, 60, 90 and 120 min with a FIR heater (2-14 ${\mu}m$), and then extracted by distilled water for 1 hr. Total sugar contents (TSC), total phenolic contents (TPC), radical scavenging ability (RSA), and reducing power (RP) were significantly increased by FIR irradiation. When PI was irradiated for 120 min, the TSC, TPC, RSA, and RP values of the PI extracts increased from 10.1 to 25.9 mg/g, 6.1 to 13.4 mg/g, 23.8 to 51.5%, and 0.222 to 0.363, respectively, compared to the untreated controls. The GL extracts, under the same conditions ($120^{\circ}C$ for 120 min), also increased in TSC, TPC, RSA, and RP from 11.1 to 22.6 mg/g, 2.5 to 5.8 mg/g, 14.5 to 18.6%, and 0.271 to 0.296, respectively. These results indicate that appropriate FIR irradiation of PI and GL could enhance the antioxidant activities of their extracts by increasing amounts of phenolic and sugar compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1114-1117
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• 2005

The effects of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from peanut shells was evaluated. Peanut shells were placed in pyrex petri dishes (8.0cm diameter) and irradiated at $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60min with a FIR heater. After FIR irradiation or simple heat treatment at same conditions, methanol extracts of peanut shells were prepared and total phenol contents (TPC), radical scavenging activities (RSA) and reducing powers of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When peanut shells were FIR­irradiated at $150^{\circ}C$ for 5 min, the values of TPC, RSA, and reducing power of the extracts increased from 40.17mg/mL to 42.30mg/mL, $67.7\%\;to\;76.3\%$, and 0.569 to 0.639, respectively, compared to the untreated controls. Simple heat treatment of peanut shell under the same conditions $(150^{\circ}C\;for\;5min)$ also increased the TPC, RSA, and reducing power of the extracts from 40.17mg/mL to 43.52mg/mL, 67.7\%\;to\;79.3\%$ and from 0.569 to 0.623, respectively. The results indicate that appropriate FIR-irradiation or heat treatment on peanut shells could increase the antioxidant activities of methanolic extracts.

• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.223-243
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• 1996

We have constructed a line-by-line model of the A-X system of CO in order to analyze the CO bands appearing in the UV spectra of comets. The model includes electronic, rotational, vibrational transitions, excitations by solar UV radiation, and effects of neutral and electron collisions. The major bands of the A-X system occur in the $1200 - 1800{\AA}$ range where the temporal variation of solar irradiation is significant. The solar spectrum in this spectral range shows many emission lines, which cause a significant Swings effect. We derived fluorescence efficiencies of the bands as functions of heliocentric velocity and cometocentric distance using a high resolution spectrum of the sun. We compared our model with a spectrum of comet P/Halley obtained with the IUE, and estimated that the UV Swings effects are less than 20 fluorescence efficiencies for the most bands of the A-X system. We discuss the temporal variation of solar UV irradiation and its effects on the fluorescence efficiencies. The study of the A-X system also requites knowledge of vibrational and rotational fluorescent processes in the infrared and radio regions because the majority of CO molecules in the coma is in the ground rotational states. The solar infrared spectrum near 5 microns, where the fundamental band of CO occurs, contains strong absorption lines of the fundamental band and hot bands of CO and its isotopes. We derived fluorescence efficiencies of the infrared band as functions of heliocentric velocity and cometrocentric distance. The solar absorption lines near 5 microns cause a 20 reduction of the g-factor of the fundamental band at heliocentric velocities close to 0 km/sec. We discuss the effects of neutral and electron collisions on the fluorescence efficiencies of the infrared and UV bands.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.17-22
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• 2014

In this study, we prepared CdTe/CdS solar cells using a thermal vacuum evaporation method. In particular, $CdCl_2$ treatment was attempted using this same method at $400^{\circ}C$ for 30 min. The prepared CdTe/CdS solar cells were investigated using Fouier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and a solar simulator system including light absorption properties, morphological properties, and power conversion efficiency (PCE). In addition, we investigated the gamma-irradiation treatment at dose rates of 0 Gy, 500 Gy, 1 kGy, 10 kGy, and 30 kGy. The characteristics of gamma-irradiation treatment were studied based on the same method described above. In particular, it showed increased values as 0.826% higher than the non-irradiation of 0.448% from PCE analysis.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.322-327
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• 2022

Fucoidans were degraded by hydrogen peroxide under the electron beam (2.5 MeV) with various radiation doses (5 kGy, 10 kGy, 15 kGy, and 20 kGy) at room temperature. The degradation property was analyzed with a gel permeation chromatography (GPC-MALLS) method. An average molecular weight of fucoidan decreased from 99,956 at the irradiation dose of 0 kGy to 6,725 at the irradiation dose of 20 kGy. The solution viscosity of fucoidans showed a similar pattern to the molecular weight change. The number of chain breaks per molecule (N) increased with increasing the irradiation dose and concentration of hydrogen peroxide. The radiation yield of scission value markedly increased with increasing the irradiation dose up to 15 kGy. Also a 10% hydrogen peroxide concentration was more efficient than that of 5%. The structures of degraded fucoidan samples were studied with Fourier transform infrared spectroscopy (FT-IR). The results showed that the degradation process did not significantly change the chemical structure or the content of sulfate group. The sulfur content of each sample was determined with an Elemental Analyzer. With increasing the concentration of hydrogen peroxide, the ratios of sulfur/carbon, hydrogen/carbon, and nitrogen/carbon slightly decreased. The antioxidant activities of fucoidans were investigated based on hydroxyl radical scavenging activities. The ability of fucoidan to inhibit the hydroxyl radical scavenging activity was depended on its molecular weight.

• Carbon letters
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• v.16 no.3
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• pp.219-221
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• 2015

In order to study the impact of atmosphere during electron beam irradiation (EBI) of polyacrylonitrile (PAN) precursor fibers, the latter were stabilized by EBI in both air and oxygen atmospheres. Gel-fraction determination indicated that EBI-stabilization under an oxygen atmosphere leads to an enhanced cyclization in the PAN fibers. In the Fourier-transform infrared spectroscopy analysis, the PAN fibers stabilized by EBI under an oxygen atmosphere exhibited a greater decrease in the peak intensity at 2244 cm⁻¹ (C≡N vibration) and a greater increase in the peak intensity at 1628 cm⁻¹ (C=N absorption) than the corresponding PAN fibers stabilized under an air atmosphere. From the X-ray diffraction analysis it was found that oxygen uptake in PAN fibers leads to an increase in the amorphous region, produced by cyclization.

• 한국약용작물학회:학술대회논문집
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• 2011.04a
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• pp.102-103
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• 2011

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.316-317
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• 2011