scholarly journals Disinfection of Archived Material by Radiation Processing Technology Keeping the Material Integrity

2018 ◽  
Vol 33 (1-2) ◽  
pp. 1-4
Author(s):  
Md Kamruzzaman Pramanik ◽  
Abdul Bathen Miah ◽  
Md Khorshed Alam
Keyword(s):  
Tensile Strength ◽  
Radiation Dose ◽  
Ionizing Radiation ◽  
Bacterial Count ◽  
B Value ◽  
Total Bacterial Count ◽  
Elongation At Break ◽  
Colour Parameter ◽  
60Co Source ◽  
L Value

The aim of the study was to preserve paper-based archived material for a long period of time using ionizing radiation/nuclear technique. To conduct this research, old note-pad samples were selected as tentative archived material. Samples were prepared and irradiated at a series of radiation doses e.g. 0, 2.0, 4.0, 6.0, 8.0, 10.0 and 14.0 kGy at a dose rate of 12.8 kGy/h from panaromic Batch type 80 kCi 60Co source. After irradiation, different quality parameters such as microbiological (Total Viable Bacterial Count, Total Fungal Count), mechanical (Tensile Strength, Percent of Elongation at Break and Elastic Modulus) and color properties (L-value, a-value and b-value) of the samples were assessed to observe the immediate effect of ionizing radiation on these properties. Results showed that the total bacterial count of unirradiated (control) paper were 4.0X102 cfu/g and radiation dose of 2.0 kGy was enough to eliminate the microbial load completely. Among mechanical properties, tensile strength (TS) of unirradiated sample was 16.23 MPa and it was gradually increased as the dose increased and finally reached upto 18.99 MPa at a dose of 14 kGy causing the TS-change above significant level (p < 0.05). Though changes of percent of elongation at break (EB) due to irradiation was insignificant, elastic module (EM) increased as the radiation dose increased gradually. EM of non irradiated sample was 381.85N/m2 and it started changing significantly from 6.0 kGy and finally reaches upto 477.03 N/m2 at 14.0 kGy. Results showed that L-value of colour parameter changed very slightly though a and b-value changed significantly from 6.0 kGy. From these findings it can be inferred that a radiation dose of 4.0 kGy might be used to conserve the cultural heritage including valuable paper-based archived materials. Bangladesh J Microbiol, Volume 33, Number 1-2, June-Dec 2016, pp 1-4

Synthesis and Properties of Phenyl Silicone Resin Reinforced Addition Type Liquid Phenyl Silicone Rubber

2018 ◽  
Vol 926 ◽  
pp. 39-44 ◽  
Author(s):  
Dan Peng ◽  
Qiu Hong Mu ◽  
Shuo Zhang ◽  
Jin Hui Li ◽  
Feng Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Radiation Dose ◽  
Thermal Degradation ◽  
Silicone Rubber ◽  
Resin Content ◽  
Silicone Resin ◽  
Elongation At Break ◽  
Before And After ◽  
Tearing Strength

Phenyl silicone resin reinforced addition type liquid phenyl silicone rubber was prepared by vulcanization of vinyl end-capped polymethylphenylsiloxane (PVPS), phenyl MT resins and hydrogen end-capped polydiphenylsiloxane (PHPS) under Pt catalysis at 150°C for 4h. The effects of the proportion and the vinyl content of phenyl MT resins on the mechanical properties of cured products were investigated. The thermal stability was explored by thermogravimetric analysis. The changes of mechanical properties were also studied before and after irradiation. Phenyl silicone rubber with good performance was obtained when the phenyl MT resin content was 50~60 wt% and the vinyl content was at 5.5~6.6 wt%. The onset temperature of thermal degradation and the center temperature of thermal degradation were 443.7°C and 502°C, respectively. When the radiation dose increased from 0 to 300 KGy, the tensile strength decreased from 4.1MPa to 2.3MPa and the tearing strength decreased from 8.9MPa to 5.1MPa. When the radiation dose continues to increased from 300 to 900 KGy, the tensile strength increased from 2.3MPa to 6.4MPa and the tearing strength increased from 5.1MPa to 6.5MPa. During the process of radiation, the elongation at break had been kept down from 96% to 52%, and the hardness increased from 80A to 90A.

Effects of 60Co-Irradiation on Tensile Properties of Polyimide Based on 2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane

2012 ◽  
Vol 554-556 ◽  
pp. 323-326
Author(s):  
Yan Hong Zheng ◽  
Yu Zhai ◽  
Jian Mei Guo ◽  
Hong Yan Yu ◽  
Lian Cai Wang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Radiation Effects ◽  
Tensile Modulus ◽  
Elongation At Break ◽  
60Co Source ◽  
Maximum Increment ◽  
Tetracarboxylic Dianhydride

Radiation effects on polyimide (PI) films were studied with different irradiation doses by 60Co. The PI film were synthesized from 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (Bis-AP-AF) with 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (BTDA). The tensile strength, tensile modulus and elongation at break of the irradiation PI films were measured and compared in order to determine the effect of the irradiation doses on the tensile properties. The results showed that the tensile strength, tensile modulus and elongation at break of the irradiation PI film can be significantly improved by irradiation of 60Co source. The optimum irradiation doses were 50 kGy. The maximum increment of tensile strength, tensile modulus and elongation at break of the irradiation PI film is 37.8%, 45.0% and 95.2%, respectively.

Effects of Synthetic Process on the Properties of Silicone Resin Composed of Polysiloxane Block Copolymer

2021 ◽  
Vol 319 ◽  
pp. 41-46
Author(s):  
Dan Peng ◽  
Qiu Hong Mu ◽  
Jin Hui Li ◽  
Wei Ju ◽  
Feng Wang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Block Copolymer ◽  
Radiation Dose ◽  
Radiation Resistance ◽  
Room Temperature ◽  
The Other ◽  
Silicone Resin ◽  
Plastic Properties ◽  
Synthetic Process ◽  
Elongation At Break

One component room temperature vulcanized (RTV) silicone resin was prepared by combination of a kind of polydimethylsiloxane-b-phenylsilsesquioxane copolymer with crosslinker and catalyst. The effects of feeding order on properties of cured silicone resin were studied in detail. When hydroxyl terminated polydimethylsiloxane was added in three times and the D/T ratio was 2.0~2.3 during synthesis, the cured resin with the hardness over 20Shore D had the better elastic-plastic properties and heat resistance than the other two feeding orders. The tensile strength was over 3MPa and the elongation at break was above 75%. The Td5% was 416.6°C.The silicone resin also had good radiation resistance. At the radiation dose of 1500kGy, there was no obvious defect observed in the material, and the tensile strength increased to 6.83MPa, while elongation at break decreased to 26%.

Study of the radiomodifier effect of Pityrocarpa moniliformis extract

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
João Victor Torres de Moraes ◽  
Ricardo Luiz Calazans Luna Filho ◽  
Williams Nascimento de Siqueira ◽  
Hianna Arely Milca Fagundes Silva ◽  
Dewson Rocha Pereira ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Cellular Response ◽  
Biomphalaria Glabrata ◽  
Toxicity Tests ◽  
Antioxidant Compounds ◽  
Blastula Stage ◽  
Natural Substances ◽  
60Co Source ◽  
60Co Gamma ◽  
60Co Gamma Radiation

Ionizing radiation has been applied in several areas of knowledge, among them the study of the radiomodifier activity of natural substances. These substances can modify the cellular response to the damage induced by the radiation. Therefore, this work aimed to evaluate the radiomodifier action of Pityrocarpa moniliformis extract on Biomphalaria glabrata embryos exposed to 60Co gamma radiation. Initially, toxicity tests were performed on the extract against the B. glabrata embryos for the choice of concentration that did not cause death and embryonic malformation. Then, the antioxidant activity of the P. moniliformis extract with flavonoids and phenolic compounds was evaluated by means of the ABTS method. To evaluate the radiomodifier activity of the extract, embryos were selected in the blastula stage and irradiated with 7.5 Gy in a 60Co source (gammacell-Co60). Then, the embryos were exposed for 24 h to the extract of P. moniliformis at a concentration of 250 μg/mL. The results showed that the extract of P. moniliformis presents flavonoids and enzymatic inhibition by ABTS, which demonstrates the presence of antioxidant compounds. However, the tests of the radiomodifier activity did not present radioprotective effect for embryos exposed to ionizing radiation.

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