scholarly journals SERAPAN OPTIK POLIMER FILM PVA-TCA-MB YANG DIRADIASI SINAR GAMMA

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
Ni Nyoman Sri Putu Verawati

Abstrak: Pengaruh radiasi sinar gamma terhadap sifat optik dari poli vinil alkohol (PVA) yang dicampur dengan trichloro acetid acid (TCA) dan pewarna methilen blue (MB) dapat digunakan pada dosimetri dan pengukuran dosis radiasi sinar gamma telah dipelajari dengan menggunakan metode spektrofotometer. dosimeter telah diradiasi sampai dosis 14 kGy dengan menggunakan sinar gamma 60Co. Polimer  film mengalami perubahan warna dari biru keunguan ke kuning akibat radiasi sinar gamma. Perubahan warna ini mengindikasikan terbentuknya asam kuat, dengan kenaikan dosis radiasi banyak ion klorin putus dari rantai karbon TCA dan akibat radiasi menyebabkan ion H+ dan OH- menjadi radikal bebas yang dihasilkan dari proses hidrolisis air dari molekul sampel, kemudian berkombinasi dalam bentuk asam. spektrum serapan telah diukur menggunakan spektrofotometer Uv-Vis pada rentang panjang gelombang 200-700 nm, menghasilkan penurunan serapan pada puncak 360 dan 440 nm dengan peningkatan dosis dan kenaikan serapan optik pada puncak 560 nm dengan kenaikan dosis radiasi.  Kata kunci : Sifat optik, radiasi sinar gamma, polimer film PVA-TCA-MB, spektrum serapan optik. Abstract: The effect of gamma irradiation on optical properties  of methylene-blue dyed poly vinyl alcohol (PVA) blended with trichloroacetid acid (TCA) for use in dosimetry and measurement of radiation dose in gamma rays have been studied using Uv-Visible spectrophotometer method. The dosimeters were irradiated for doses up 14 kGy using 60Co gamma rays source at a constant dose rate. The polymeric films undergo colour change from blue purplish to yellow due to radiation-induced. The changes of this colour indicated strong acid, by the increasing of radiation dose caused more chlorine ions break from carbon of TCA and radiation-induced H+ and OH- free radicals are generated from the hydrolysis of water molecules, they then combined to form acid. The absorption spectra were measured using Uv-Visible spectrophotometer in the wavelength range 200-700 nm, resulting in a decrease of the absorbance at 360 and 440 nm band peak with increasing dose and an increases of the absorbance at 560 nm band peak with increasing dose. Keywords: Optical properties, gamma irradiation, polymer film PVA-TCA-MB, optical absorption spectra.

2014 ◽  
Vol 979 ◽  
pp. 343-346 ◽  
Author(s):  
Natthakridta Chanthima ◽  
Jakrapong Kaewkhao

Borophosphate glasses have been synthesized with a Bi2O3concentration of 15.0 to 25.0 mol%, added 2.5 mol% for each concentration, by the normal melt quenching technique at 1200 °C. The physical and optical properties of bismuth borophosphate glass systems have been studied. The glasses are characterized for their physical and optical properties. The density and molar volume of these glasses were found in the range 3.4391 to 3.9338 g/cm3and 52.2515 to 55.7557 cm3/mol, respectively. It was observed that the density and molar volume of these glasses was increased with increasing the concentration of Bi2O3. The absorption spectra of these glasses were recorded in the UV-Visible range. It has been found that, the absorption spectra were shifted to longer wavelength with higher Bi2O3concentration. In addition, the oxygen packing density of glass samples have been also investigated.


1983 ◽  
Vol 61 (5) ◽  
pp. 1448-1455 ◽  
Author(s):  
Janine Schaeverbeke-Sacré ◽  
Béatrice Matheron

DNA and RNA contents are studied in Jerusalem artichoke tuber explants cultured in vitro after gamma irradiation (0–5 × 105 rads (1 rad = 10 mGy)). The lower part of the explants is stimulated as soon as in contact with the medium. This stimulated area is still able to synthesize DNA and RNA up to 104 rads. An histological and cytological study shows that tissue neoformations can be observed up to 6000 rads in this outer area and that gamma rays seem to keep the cells in a "premitotic" state for a longer or shorter period according to the applied radiation dose.


2014 ◽  
Vol 979 ◽  
pp. 135-138 ◽  
Author(s):  
Yotsakit Ruangtaweep ◽  
Jakrapong Kaewkhao

In this work, the physical and optical properties of soda-lime-borate glasses doped with V2O5 concentration of 0.0 to 2.5 in mol% have been investigated. The glass samples were prepared by the normal melt-quench technique. The results show that the density and refractive index decreased with additional 0.5 mol% content of V2O5. Then both results increased with increasing V2O5 content from 1.0-2.5 mol%. The optical absorption spectra of glass samples were measured by UV-visible spectrophotometer in the wavelength range 300-1100 nm and color coordinate in CIEL*a*b* system. The absorption peaks locate around 605 and 960 nm for all V2O5 concentration that are associated to V4+ ions and produce the brown color.


2012 ◽  
Vol 585 ◽  
pp. 532-536 ◽  
Author(s):  
B. Lakshmeesha Rao ◽  
O. Mahadevaiah ◽  
Y. Sangappa ◽  
S. Asha ◽  
R. Somashekar

The radiation-induced changes in Poly (vinyl alcohol) (PVA) polymer films exposed to electron irradiation were investigated for different radiation dose. Polymer film samples were irradiated in air at room temperature by an electron beam accelerator at different doses: 0, 100, 150 and 200 kGy. The microstructural and surface properties of the irradiated PVA films were characterized by X-ray diffraction (XRD) and Atomic force microscopy (AFM). An unirradiated PVA film was used as reference. Electron irradiation was found to induce changes in structural and surface properties of polymer films and such changes vary depending on the radiation dose.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 33-38 ◽  
Author(s):  
Orhan Arslan ◽  
Şenol Bal ◽  
Semra Mirici ◽  
Nilgün Yenice

SUMMARYThe effect of gamma rays on meiosis in the M2 generation has been studied in sunflower (Helianthus annuus L.) variety Ekiz 1. Seeds were irradiated with gamma rays at 10, 20, 30, 40 and 50 kR doses. Radiation induced meotic abnormalities. The chromosomal aberrations included univalents, multivalents and stickiness at diakinesis, laggards and stickiness at metaphase I, bridges and laggards at anaphase and telophase I-II, micronuclei at telophase II. The percentage frequencies of anomalies increased generally with the increasing dose of radiation.


2019 ◽  
Vol 127 (9) ◽  
pp. 420
Author(s):  
Р.М. Сардарлы ◽  
Ф.Т. Салманов ◽  
Н.А. Алиева

The effect of gamma irradiation on the optical properties of layered TlGaSe2 and TlInS2 crystals in the wavelength range of 400–1,100 nm at 300 K is studied. From the analysis of optical absorption spectra, the energies of direct and indirect optical interband transitions before and after gamma irradiation are determined. It is shown that as the gamma-irradiation dose is accumulated in the range of 0–25 Mrad by TlGaSe2 and TlInS2 single crystals, the energies of direct and indirect allowed optical transitions increase from Egd = 2.06 eV and Egi = 1.90 eV at D = 0 Mrad to Egd = 2.11 eV and Egi = 1.98 eV at D = 25 Mrad for TlGaSe2 and Egd = 2.32 eV crystals and Egi = 2.27 eV at D = 0 Mrad to Egd = 2.35 and Egi = 2.32 eV at D = 25 Mrad for TlInS2 crystals. A decrease in the transmittance at doses from 0 to 5 Mrad and a further increase in the transmittance at the radiation dose D = 25 Mrad are observed.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Asmalina Mohamed Saat ◽  
Mohd Rafie Johan

Partially phosphorylated polyvinyl alcohol (PPVA) films were prepared at five mole ratios of phosphoric acid (PA) using solution casting technique. The optical properties of the PPVA films were examined using UV-visible (UV) and photoluminescence (PL) spectroscopy. The UV absorption spectra reveal that the absorption peaks are blue-shifted with an increase in PA concentration added to the pure PVA. The PL spectra show the presence of peaks which are characteristic of isotactic (389–398, 460–462 nm), syndiotactic (418–420 nm), and atactic (440–446 nm) configurations of the PPVA. The results also show the peak of O–P–O bonding at a wavelength range of 481–489 nm.


2018 ◽  
Vol 15 (35) ◽  
pp. 24-28
Author(s):  
Saba J. Kadhem

PMMA/TiO2 homogeneous thin films were deposited by using plasma jet system under normal atmospheric pressure and room temperature. PMMA/TiO2 nanocomposite thin film synthesized by plasma polymerization. Titanium oxide was mixed with Methyl Methacrylate Monomer (MMA) with specific weight ratios (1, 3 and 5 grams of TiO2 per 100 ml of MMA). Optical properties of PMMA/TiO2 nanocomposite thin films were characterized by UV-Visible absorption spectra using a double beam UV-Vis-NIR Spectrophotometer. The thin films surface morphological analysis is carried out by employing SEM. The structure analysis are achieved by X-ray diffraction. UV-Visible absorption spectra shows that the increasing the concentration of titanium oxide added to the polymer leads to shift the peak position (λmax) toward the infrared region of the electromagnetic spectrum. Also the peak width increases when the concentration of TiO2 increases. It can be controlled optical energy band gap of PMMA/TiO2 nanocomposite thin films by changing concentration of TiO2. SEM indicate a uniform distribution of titanium oxide particles in PMMA matrix. The x-ray diffraction pattern indicated that the thin films have amorphous structure.


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