• Title/Summary/Keyword: Infrared Irradiation

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Detection of Pulsed Photostimulated Luminescence Signals Emitted by Infrared Stimulation of Irradiated Spices during Storage under Two Conditions

  • Yi, Sang-Duk;Woo, Si-Ho;Yang, Jae-Seung
    • Preventive Nutrition and Food Science
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    • v.6 no.3
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    • pp.152-157
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    • 2001
  • Accumulated photon counts in immediate measurement after irradiation of marjoram, basil and thyme were shown to be below 625$\pm$162, 577$\pm$178 and 1261$\pm$640 Pc, respectively. The accumulated photon counts increased linearly with increasing irradiation doses up to 5 kGy and slightly increased from 5 kGy to 10 kGy. This trend was similar after storage periods. According to storage conditions, the difference of the accumulated photon counts was net clearly observed. The accumulated photon counts of irradiated spice samples decreased with increasing storage periods. The rate of decrease was higher in 5 and 10 kGy irradiated samples than that in 1 kGy, and in room conditions than that in darkroom conditions. The photon counts of the irradiated spice samples measured for 120 s were higher than those measured for 60 s. The irradiated spice samples showed higher photon counts than those of unirradiated samples in both room and darkroom conditions during all the storage periods. These results indicate that detection of irradiation was still possible after 24 weeks, although the PPSL signal of all spice samples decreased with increasing storage times.

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Effect of Electron Beam and ${\gamma}$-Ray Irradiation on the Curing of Epoxy Resin

  • Kang, Phil-Hyun;Park, Jong-Seok;Nho, Young-Chang
    • Macromolecular Research
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    • v.10 no.6
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    • pp.332-338
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    • 2002
  • The effect of an electron beam and ${\gamma}$-ray irradiation on the curing of epoxy resins was investigated. Diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) as epoxy resin were used. The epoxy resins containing 1.0-3.() wt% of triarylsulphonium hexafluoroantimonate(TASHFA) and triarylsulphonium hexafluorophosphate(TASHFP) as initiator were irradiated under nitrogen at room temperature with different dosage of EB and ${\gamma}$-rays from a Co$^{60}$ u source. The chemical and mechanical characteristics of irradiated epoxy resins were compared after curing of EB and ${\gamma}$-ray irradiation. The thermal properties of cured epoxy were investigated using dynamic mechanical thermal analysis. The chemical structures of cured epoxy were characterized using near infrared spectroscopy. Mechanical properties such as flexural strength, modulus were measured. The gel fraction of DGEBA with ${\gamma}$-ray was higher than that of the epoxy with EB at the same dose. Young's modulus of the sample irradiated by ${\gamma}$-ray is higher than that of sample cured by EB. From the result of strain at yield, it was found that the epoxy cured by ${\gamma}$-ray had a higher stiff property compared with the irradiated by EB.

Structural Characteristics of Low Molecular Weight Laminarin Prepared by Ionizing Irradiation (이온화 방사선 조사에 의해 얻어진 저분자 laminarin의 분자구조 특성)

  • Choi, Jong-Il
    • Korean Chemical Engineering Research
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    • v.51 no.6
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    • pp.780-783
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    • 2013
  • Recently, it has been reported that low molecular weight laminarin had the enhanced biological activities. In this study, molecular structure of low molecular weight laminarin prepared by ionizing irradiation was studied. Low molecular weight laminarin samples of 13.5, 8.5, 7, and 6 kDa were obtained from 15 kDa laminarin by irradiation. From gel permeation chromatography data, low molecular weight laminarin was shown to have low polydispersity. To define the changes of functional groups in laminarin with different molecular weights, Fourier-transform infrared analysis was carried out. There was found no significant changes of functional groups in low molecular weight laminarin, except the increase of carbonyl group. The granular fissures from scanning electron microscopy showed the breakage of glycosidic bond in low molecular weight laminarin. These results could be utilized for the investigation of the enhanced biological activities of low molecular weight polysaccharides including laminarin.

Effects of Far Infrared on Nitric Oxide level at a rat model of Autoimmune Arthritis Induced (원적외선이 자가면역성 관절염 흰쥐모델의 산화질소정량에 미치는 영향)

  • Kim Jae Yoon;Park Kyu Hyun;Park Young Han;Kim Jin-Sang;Park Rae Joon
    • The Journal of Korean Physical Therapy
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    • v.14 no.2
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    • pp.65-73
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    • 2002
  • OBJECTIVE: This study was Far infrared(FIR) irradiating to a rat collagen-induced autoimmune arthritis and observed nitric oxide level of spine. METHODS: Type II collagen(CII) in adjuvant was injected into rats on day 0. The results showed that rats injected with CII plus adjuvant had signs of autoimmune arthritis on day 14. Thereafter, Far infrared(FIR) irradiation was begun on day 15. The rats were irradiated FIR twice per day for 20 min each time. RESULTS: Seven days later(Day 22), the level of NO at FIR irradiated group(FRG; Arth+FIR) was decreased more than FIR-non irradiated group(FNRG; Arth). Twenty-one days later(Day 36), the level of NO at FRG was more closed to the control group's NO level than the FNRG. CONCLUSION: These results indicated that Far infrared irradiating appears to reduce the nitric oxide level at a rat model of autoimmune arthritis induced.

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Immediate Effect of Sustained Stretching Exercises with Far Infrared on the Ankle Range of Motion and Muscle Tone in Patients with Stroke

  • Youn, Pong Sub;Park, Shin Jun
    • The Journal of Korean Physical Therapy
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    • v.31 no.1
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    • pp.56-61
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    • 2019
  • Purpose: The spasticity of stroke patients decreases the ankle range of motion and increases the gastrocnemius muscle tone. This study examined the effects of stretching exercise and far infrared irradiation on the ankle function in stroke patients with spasticity. Methods: This study was conducted on 20 stroke patients admitted to Jesaeng General Hospital, who were divided into a study group (stretching exercise with far infrared) and control group (stretching exercise only). The dorsiflexion range of motion was measured using a smartphone and the medial gastrocnemius muscle tone and stiffness were measured using a Myoton pro. Results: With the exception of the non-paretic gastrocnemius muscle tone in the control group, the medial gastrocnemius muscle tone and stiffness decreased significantly in both groups. In both groups, the dorsiflexion range of motion increased significantly. In addition, the experimental group had a significantly higher dorsiflexion range of motion than the control group. On the other hand, there was no significant difference between the two groups in terms of the medial gastrocnemius muscle tone and stiffness. Conclusion: For stroke patients with spasticity, stretching exercises increased the ankle's range of motion and decreased the gastrocnemius muscle tone. The addition of heat therapy further increased the ankle's range of motion. On the other hand, as the sample size was small, future studies should include more subjects.

Effect of Far-Infrared Irradiation on the Antioxidant Activity of Extracts from Grape Seed (포도씨의 항산화능에 대한 원적외선 처리의 효과)

  • Jeong, Seok-Moon;Kim, So-Young;Ha, Jung-Uk;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.10
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    • pp.1619-1624
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    • 2005
  • The effect of far-infrared (FIR) irradiation on the antioxidant activity of extracts from grape seed (GS) was evaluated. GS (5 g) were placed in Pyrex petri dishes (8.0 cm diameter) md FIR irradiated at 150$^{\circ}C$ for 10, 20, 30, 40 or 60 min with a FIR heater. After FIR irradiation, water extract (WE) (1.0 g/10 mL), methanol extract (ME) (1.0 g/10 mL) and 70$\%$ ethanol extract (EE) (1.0 g/10 mL) of GS were prepared, and total phenol contents (TPC) and radical scavenging activity (RSA) of the extracts were determined. The antioxidant activities of GS extracts increased as FIR irradiation. For example, FIR irradiation of GS at 150$^{\circ}C$ for 10 min increased the TPC and RSA of WE from 0.95 mM to 1.84 mM and 33,87$\%$ to 58.55$\%$, respectively, compared to non-irradiated control. In the case of ME at the same conditions of FIR irradiation (150$^{\circ}C$ for 10 min), the TPC and RSA also increased from 3.4 mM to 4.52 mM and 76.55$\%$ to 89.41$\%$, respectively. The TPC and RSA of EE increased from 2.65 mM to 4.82 mM and 66.89$\%$ to 84.62$\%$, too. According to the GC/MS analysis, several low-molecular-weight phenolic compounds such as vanillic acid and 3,4-hydroxy benzoic acid were newly formed in the EE after FIR irradiated at 150$^{\circ}C$ for 10 min. There were slight differences in the kinds of phenolic compounds between EE of non irradiated control and FIR irradiated samples. These results indicated that FIR irradiation onto GS could enhance antioxidant activities of its extracts with increasing the amount of phenolic compounds.

Solvent Free Microwave Accelerated Synthesis of Heterocyclic Thiazolidin-4-ones as Antimicrobial and Antifungal Agents

  • Sekhar, Kondapalli Venkata Gowri Chandra;Rao, Vajja Sambasiva;Reddy, Aravalli Satish;Sunandini, Ravada;Satuluri, V S A Kumar
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1219-1222
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    • 2010
  • A simple and efficient method has been developed for conversion of arenecarbaldehyde-3-methylquinoxalin-2-ylhydrazones to 3-(2-methylquinoxalin-3-yl)-2-(substitutedphenyl)thiazolidin-4-ones in good yields using microwave irradiation technique on silica as solid support under solvent free conditions. The synthesized compounds were characterized by elemental microanalysis, infrared spectroscopy, $^1H$ NMR, and mass spectroscopy. All the synthesized thiazolidinones were investigated for their antimicrobial and antifungal activities. The results of the biological activities revealed that the compounds 3b, 3d, 3f and 3h exhibited excellent antibacterial activities while 3d and 3h exhibited good antifungal activity.

PDMS기판에 이온빔 처리에 따른 수평 액정의 배향 연구

  • Kim, Yeong-Hwan;O, Byeong-Yun;Kim, Byeong-Yong;Lee, Won-Gyu;Im, Ji-Hun;Na, Hyeon-Jae;Seo, Dae-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.159-159
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    • 2009
  • We characterize a flexible self-assembled liquid crystal display (LCD) fabricated from a polyimide (PI) alignment layer with polydimethylsiloxane pixel walls. Ion beam (IB) irradiation aligned LC molecules in the PI layer and bonded two flexible plastic substrates in a one-step assembly of the pixel walls. X-ray photoelectron spectroscopic analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy provided chemical and physical evidence for the formation of stable chemical bonds between the PI layer and the PDMS pixel walls in addition to the important maintenance of a uniform 6 um gap between the two substrates without the use of any epoxy resins or other polymers.

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UV-Induced Graft Polymerization of Polypropylene-g-glycidyl methacrylate Membrane in the Vapor Phase

  • Hwang, Taek-Sung;Park, Jin-Won
    • Macromolecular Research
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    • v.11 no.6
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    • pp.495-500
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    • 2003
  • UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

A Study on the Crystallinity in Silk Fibers(II) -Crystallization in Silk Fibroin by Acid Treatment and Its Photoyellowing Reduction Effect- (견의 결정성에 관한 연구(II) -견 피브로인의 산 처리에 의한 결정화와 황변억제효과에 대하여-)

  • 장정대;최석철
    • Textile Coloration and Finishing
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    • v.6 no.2
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    • pp.24-29
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    • 1994
  • In order to investigate the crystallization in silk fibroin induced by acid treatment and its photo-yellowing reduction effect. silk fibroin were immersed in PH 3.5~4.0 sulfuric acid and 0.01N hydro-chloric acid at 2$0^{\circ}C$, and the changes of crystallinity were measured by infrared spectroscopy, X-ray diffraction. Yellowness index caused by UV irradiation were also observed. The results are as follows : 1. ${\beta}$-form transition occurs when the silk fibroin are immersed at 2$0^{\circ}C$ in pH 3.5~4.0 sulfuric acid and 0.01N hydro-chloric acid. Formation of new hydrogenbond in molecules on the amorphous region induced ${\beta}$-form structure, and increased crystallinity. 2. Crystallization owing to $\beta$-form transition reduced the initial yellowness index by ultraviolet irradiation.

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