Effects Of Gamma-ray Irradiation Research Articles

The effect of gamma rays irradiation on diversity of Musa paradisiaca var. sapientum as revealed by ISSR molecular marker

Abstract. Due MS, Susilowati A, Yunus A. 2019. The effect of gamma rays irradiation on diversity of Musa paradisiaca var. sapientum as revealed by ISSR molecular marker. Biodiversitas 20: 1416-1422. Pisang Ambon (Musa paradisiaca var. sapientum (L.) Kunt.) is one of the horticultural commodities that have high production in Indonesia, making it a superior product. Bananas are propagated vegetatively, which hampers the production of genetic variation and requires a long generation time in the vegetative cycle. This study aimed to determine the diversity of Pisang Ambon induced by gamma radiation of various dosages (10 Gy, 20 Gy and 30 Gy) in vitro based on the ISSR (Inter-Simple Sequence Repeats) marker. The results showed that gamma-ray radiation influenced the morphological properties of plant height, stem diameter, leaf length, leaf width and leaf number based on ANOVA variance analysis. Increased growth occurs in plants with radiation doses of 10 Gy and 20 Gy. The molecular analysis of ISSR uses 6 primers, namely ISSR 835, ISSR 836, ISSR 846, ISSR 847, ISSR 848 and ISSR 855. Of the 6 primers, only 2 primers were able to produce polymorphisms above 50%. A total of 9 bands were produced, in which 8 bands showed polymorphic with a percentage of 90%. The similarity matrix ranged from 0.25-0.93, indicating the level of variation between mutants. The result of dendrogram was divided into two groups with a coefficient distance of 0.47-0.93; plants at a dose of 10 Gy have the highest diversity with the furthest coefficient of diversity distance of 0.47.

Gamma rays irradiation effects in thin film polyethylene terephthalate polymer

The effect of gamma rays irradiation on structural properties of polyethylene terephthalate (PET) has been studied using Fourier Transform Infrared Spectroscopy (FTIR), X-rays diffraction (XRD) and UV–Visible spectrophotometry techniques. The gamma rays irradiations were performed, using 60Co source with mean energy of 1.25 MeV, at Nuclear Research Centre of Algiers, Algeria. The gamma absorbed dose rate was about 1.3 kGy/h as measured using the Frick dosimeter. Several PET samples with a thickness of 6 μm were irradiated at room temperature with the presence of air atmosphere at different doses (0.05–5 MGy). The FTIR analysis reveals that the intensities of the different absorption bands decrease with increasing gamma rays dose. This is attributed to the chain scission induced by gamma rays irradiation. It is found from XRD analysis that the crystallinity is reduced after irradiation. The variation in crystallite size is also observed. The UV–vis spectra show a large absorption band extended from 310 to 355 nm assigned to the formation of extended systems of conjugate bonds with the creation of carbon clusters. The optical absorbance in this range increases linearly with the gamma rays dose. An empirical relation is established to estimate gamma dose from this correlation. Both direct and indirect energy gaps are found to decrease with increasing gamma rays dose indicating the appearance of new electronic transitions. Moreover, it is also observed that the Urbach energy increases with the gamma rays dose. This indicates the disorganization of the PET structure after irradiation.

Fabrication and Gamma-Ray Irradiation Effect on Optical and Mechanical Properties of Germano-Silicate Glass Fibers with Inner Cladding of B and F Doped Silica Glasses

ABSTRACTThe effect of glass composition, pure silica glass, boron-doped and fluorine-doped silica glasses of inner cladding, in the germano-silicate glass core fibers on optical and mechanical properties upon the γ-ray irradiation was investigated. Enhanced radiation hardening at 1,550 nm was found in both the B- and F-doped fibers after the γ-ray irradiation with dose-rate of 1.25 kGy/h. The radiation-induced attenuation (RIA) was found to increase in the order of the B-doped fiber, the F-doped fiber, and the silica fiber. While no major influence on the refractive index of the fibers after the γ-ray irradiation was found, the residual stress was slightly changed.

Effects of gamma ray irradiation on penetration hole in and fragment size from carbon fiber reinforced composite plates in hypervelocity impacts

This study examines how gamma ray irradiation affects the penetration holes in and fragment sizes from carbon fiber reinforced plastic (CFRP) plates due to hypervelocity impacts. In order to do so, quasi-isotropic CFRP plates made of unidirectional pre-impregnated sheets and 1-mm-diameter spherical projectiles made of aluminum alloy (2017-T4) were used. Witness plates (200 mm × 200 mm × 2 mm) made of copper (C1100P-1/4H) and containing a 30-mm-diameter hole were placed 50 mm in front of and behind each target to examine the fragments based on ISO 11227. The fragments collected from the impact and rear sides of the target were compared. Gamma ray irradiation had a slight effect on the penetration hole, the fragment size distributions, and the craters on the witness plates. When the gamma ray irradiation was 10 MGy, the penetration holes at impact velocities of 2.4 km/s and 5.3 km/s became slightly smaller. At the impact velocity of 2.4 km/s, perforation of the 0.5 MGy, 6.5 MGy, and 10 MGy specimens prevented the projectile from fracturing.

Effect of Gamma-Ray Irradiation on the Growth of Au Nano-Particles Embedded in the Germano-Silicate Glass Cladding of the Silica Glass Fiber and its Surface Plasmon Resonance Response.

The effect of γ-ray irradiation on the surface plasmon resonance (SPR) sensing capability of refractive index (n = 1.418–1.448) of the silica glass optical fiber comprised of germano-silicate glass cladding embedded with Au nano-particles (NPs) was investigated. As the γ-ray irradiation increased from 1 h to 3 h with the dose rate of 1190 Gy/h, the morphology of the Au NPs and the SPR spectrum were found to change. The average diameter of Au NPs increased with the aspect ratio from 1 to 2, and the nano-particles became grown to the clusters. The SPR band wavelength shifted towards a longer wavelength with the increase of total dose of γ-ray irradiation regardless of the corresponding refractive indices. The SPR sensitivities (wavelength/refractive index unit, nm/RIU) also increased from 407 nm/RIU to 3553 nm/RIU, 1483 nm/RIU, and 2335 nm/RIU after the γ-ray irradiation at a total dose of 1190 Gy, 2380 Gy, and 3570 Gy, respectively.

Radiosensitivitas Kalus Embriogenik Kopi Robusta Bp 436 Terhadap Iradiasi Sinar Gamma

<p><em>High genetic diversity is one factor that determines the success of plant breeding. Mutation induction by gamma ray irradiation is one method to improve plant genetic diversity. This study aimed to 1) obtain growth regulators composition suitable in inducing embryogenic callus, 2) determine the effect of gamma ray irradiation on the growth and development of somatic embryos, and 3) obtain lethal dose (LD) <sub>20</sub> and <sub>50</sub> values in Robusta coffee BP 436. The study was conducted at the Tissue Culture Laboratory, Industrial and Beverage Crops Research Institute, from May 2017 to December 2018. Explants used were young leaves of Robusta coffee BP 436. Callus induction used ½ MS media with 2,4-D (4.52 μM) and 2-iP (0.00; 4.93; 9.86; 14.79; and 19.72 μM) treatment. Mutation induction was performed using gamma radiation dosed at 0, 10, 20, 30, 40, and 50 Gy treatments. The regeneration media was ½ MS containing GA<sub>3</sub> (0 and 1 mg/l). The study used a complete randomized design with 10 replications. The results showed the best combination of plant growth regulator to induce the callus was 2.4-D 4.52 μM + 2-iP 19.72 μM. The fresh weight of cultures was inhibited above 30 Gy, whereas the number of somatic embryos decreased at doses above 10 Gy. Addition of GA<sub>3</sub> 1 mg/l in regeneration media increased the number of somatic embryos in torpedo phase, but not in gamma irradiation exposed calluses. The LD<sub>20</sub> and LD<sub>50</sub> of Robusta coffee BP 436 are 16.81 and 28.52 Gy, respectively.</em></p>

Effect of gamma ray irradiation on chemical composition, antioxidant, antimicrobial, and insecticidal activities of Thymus pallescens essential oil

The essential oils isolated by hydrodistillation from Thymus pallescens de Noé dried leaves exposed to γ-irradiation at dose levels of 0, 5, 10, 20, and 30 kGy were analyzed by gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (MS) and tested for their antioxidant, antimicrobial, and insecticidal activities. No qualitative change was observed in the chemical composition. Carvacrol (81.8–85.7%) was the most prominent component. Gamma-irradiation at 20 kGy affects quantitatively some components. Antioxidant activity was evaluated by four different test systems, namely, inhibition of lipid peroxidation (thiobarbituric acid reactive substance, TBARS), ferric reducing power, and scavenging of radicals DPPH• and ABTS•+. In all systems, irradiated oils at 20 and/or 30 kGy showed the most antioxidant efficiency. Overall, the antimicrobial activity conducted against seven microorganisms revealed no significant changes according to the radiation dose. Fumigation bioassays and contact method against confused flour beetle Tribolium confusum revealed that the oil irradiated at 20 kGy had highest insecticidal activity. The results showed that gamma-irradiation of T. pallescens could be not only beneficial safe decontamination perspective but also as an improvement factor of some of its properties.

Structure dependence of gamma ray irradiation effects on polyurethane and epoxy resin studied by PAL technique

Positron annihilation lifetime (PAL) technique has been employed tostudy the microstructural changes of polyurethane (PU), EUXIT 101and epoxy risen (EP), EUXIT 60 by Gamma-ray irradiation with thedose range (95.76 - 957.6) kGy. The size of the free volume hole andtheir fraction in PU and EP were determined from ortho-positroniumlifetime component and its intensity in the measured lifetime spectra.The results show that the irradiation causes significant changes in thefree volume hole size (Vh) and the fractional free volume (Fh), andthereby the microstructure of PU and EP. The results indicate thatthe γ-dose increases the crystallinity in the amorphous regions of PUand increase the cross-linking of EP.

Gamma-ray irradiation effect on ZnO bulk single crystal: Origin of low resistivity

We report the origin of low resistivity in ZnO bulk single crystals with thicknesses of 500 μm caused by gamma-ray irradiation. The crystals are irradiated at room temperature with gamma-rays of 1.17–1.33 MeV from a cobalt-60 source. The gamma-ray dose is 170 kGy. The resistivity at room temperature decreases from 4.1 × 104 Ω cm to 3.1 × 102 Ω cm by the irradiation. After the irradiation, slight increase in green luminescence at around 530 nm is observed, suggesting that zinc vacancy (VZn), oxygen vacancy (VO) and oxygen interstitial (Oi) are induced by Compton electrons emitted by the gamma-ray irradiation because this PL peak is a superposition consisting of the emissions relating to the VZn (∼490 nm), VO (∼530 nm), and Oi (∼580 nm). The PL intensity of VO is eight times larger than that of VZn. The existence of VO+ (g value is 1.996) is also observed by the electron paramagnetic resonance. This signal disappears by illuminating red LED with a wavelength of 654 nm, indicating VO+ to VO2+ transition. The existence of VZn would suggest the formation of zinc interstitial (Zni). In analogy with the low resistivity after Al-implanted ZnO, the origin of the low resistivity in gamma-ray irradiated ZnO is attributed to the Zni located at ∼30 meV below the conduction band.

Development of proton beam irradiation system for small animals using FFAG accelerator

To evaluate the biological effect of boron compounds on normal tissues in boron neutron capture therapy, it is necessary to compare the radiation effects of neutron irradiation and gamma ray irradiation on small animals in nonclinical studies. Neutron beams and gamma rays are difficult to collimate; thus, it is impossible to administer a dose on each part of the normal tissues of small animals. Therefore, we have developed a method to compare biological effects by irradiating neutrons and gamma rays after irradiating a proton beam to the point just before the threshold dose at which the biological effects occur. We aim to develop an irradiation field that irradiates proton beams locally using a fixed-field alternating-gradient (FFAG) accelerator and a small ridge filter.An aluminum scatterer, transmission dose monitor, ridge filter, range shifter, collimator, and a proton beam from the FFAG accelerator were used to form an irradiation field with a spread out Bragg peak (SOBP) with a length of 10 mm and a size of 10 mm2.Dose measurement was performed using a Gafchromic film and an ionization chamber. The irradiation system was simulated using the PHITS Monte Carlo simulation code, and simulation results were compared with experimental results.We succeeded in forming an irradiation field with a dose rate of 14.3 ± 0.24 Gy/min, an SOBP length of 10 mm, and a size of 10 mm2.

The effect of gamma rays irradiation on the growth and flavonoid content of kenikir (Cosmos caudatus Kunth.)

The aim of the research was to identify agronomical characteristics and flavonoid content of kenikir (Cosmos caudatusKunth.) irradiated by gamma rays with several dosages. Seeds of kenikir were irradiated by gamma rays in radiator chamber 4000 A using 60Co source at Isotope and Radiation Application Center, BATAN, Jakarta. Dosages of irradiation ranging from 50 Gy-300 Gy with interval 50 Gy. Subsequently, irradiated seed along with unirradiated seeds (control) were planted in Greenhouse Agriculltural Faculty, Universitas Sumatera Utara (± 32 meters above sea level). The variation of agronomical characters (plant height, leaf number, stem diameter, number of branches per plant and flowering age) were observedfrom 1st week up to 9th week after planting. Data were analyzed by t-test using minitab 18 program. The flavonoid content of leaves extract were analyzed using spektrofotometer UV-VIS in Research Laboratory, Faculty of Pharmacy, Universitas Sumatra Utara. The results showed that the mean values of M1 generation of all agronomical characters observed were lower than control plants whereas the highest flavonoid content was found in the population of gamma ray irradiated at 100 Gy.

Study of gamma-ray radiation effects on the passivation properties of atomic layer deposited Al2O3 on silicon using deep-level transient spectroscopy

Aluminum oxide (Al2O3) has emerged as a potential dielectric material and exhibited an excellent passivation property on silicon surface. However, such oxide layer is extremely sensitive to γ-ray irradiation. In this work, deep-level transient spectroscopy has been applied to study the influence of γ-ray irradiation on the passivation properties of atomic layer deposited Al2O3 on silicon. It is shown that γ-ray irradiation leads to a significant increase of interface state density (Dit). Meanwhile, its energy distribution is broadened and shifts deeper with respect to the top of valence band, and therefore evolves into more efficient recombination centers for carriers. Besides, capacitance–voltage (C–V) curves shows a progressive shift toward the negative voltages with increased radiation doses. This indicates the hole trapping in Al2O3, which can neutralize the negatively charged defects and therefore degrade its field-effect passivation. Hence, the passivation quality of Al2O3 on silicon deteriorates significantly after γ-ray radiation.

THE EFFECT OF GAMMA-RAY IRRADIATION ON MECHANICAL PROPERTIES OF EARLY-AGE CEMENT MORTAR

This study is focused on experimental investigation of the effect of gamma-ray irradiation on early-age cement mortar properties. Several working hypotheses were formulated based on the current research review. The results of the performed experiment in terms of the relative weight and the relative length change are described in detail in this study. Two observations could be made from comparison of the working hypotheses with the obtained experimental results. Firstly, the positive effect of gamma-ray irradiation in terms of the relative weight change was observed within the first 300 hours or within the equivalent absorbed irradiation dose of 450 kGy. Secondly, the shrinkage due to gamma-ray irradiation was smaller for the unsealed samples due to presence of carbon dioxide in the air, which is needed for the carbonation reaction. It is believed that the obtained experimental data themselves provide a platform for validation of related numerical models.

Effect of gamma-ray irradiation on microstructure and mechanical property of Sn63Pb37 solder joints

In order to meet the reliability requirement of solder joints for future small satellite, the effect of γ-ray irradiation on the microstructure and mechanical property of Sn63Pb37 solder joints was investigated by scanning electron microscope observation and mechanical testing. The results showed that γ-ray irradiation possessed few influence on the thickness and morphology of intermetallic compound layer of Sn63Pb37/Cu. But the mechanical properties of solder joints were reduced with micro-voids and micro-cracks appearing in Pb-based solid solution during irradiation process. Energetic electrons created by γ-ray through Compton Effect, generated dislocated atoms which eventually resulted in the formation of microscopic defects and the decrement of mechanical property. After 960 h γ-ray irradiation at the dose rate of 0.25 Gy(Si)/s, the shear force of Sn63Pb37 solder joints was decreased by 11.47%. Compared with as-soldered joint, the ductility of irradiated solder joints was reduced with more unobvious shear dimples and lower impact toughness.

Macroscopic effects and microscopic origins of gamma-ray irradiation on In-doped CdZnTe crystal

The effects of gamma-ray irradiation, exposed to a 60Co source with a dose of 2.7 kGy, on In-doped CdZnTe (CdZnTe:In) crystal were investigated. We combined the “macroscopic” electrical properties of CdZnTe:In sample, evaluated by current–voltage (I–V) measurements at different temperature, with the “microscopic” origins of electrically active defects induced by gamma-irradiation, characterized by thermally stimulated current spectroscopy. It reveals that the bulk resistivity at room temperature have increased from 2.7 × 109 Ω cm for the as-grown CdZnTe:In sample to 5.9 × 109 Ω cm for the irradiated sample. Since the microscopic origins of these macroscopic effects are linked to the electrically active defects within the material, five main defect states (I, II, III, IV and V) were characterized and identified in the CdZnTe:In crystal. In particular, the introduction of gamma-irradiation altered the trap concentrations of these defect states, such as the rapidly decreasing concentration of region I. Besides, the gamma-ray irradiation caused a further deepening of EDD level (region V) from the value of 0.717 ± 0.004 eV for the as-grown sample to the value of 0.749 ± 0.004 eV for the irradiated sample. The microscopic origin of EDD level was identified with TeCd2+ below the conduction band minimum, which is responsible for the pinning of EF level near the mid-gap, and thus for the observed high-resistivity performance of CdZnTe:In.

Study of frequency dependent characterization: applied gamma-ray irradiation on metal-polymer nanostructure

The study analyzed the effects of gamma-ray irradiation and high frequency on metal-polymer-semiconductor (MPS). The MPS structure is analyzed before and after gamma radiation source with dose of 30 kGy and 60 kGy, and the impacts of 60Co gamma-ray irradiation on the electrical characteristics of Al/Coronene/p-Si schottky diode have been reported. It has been found that barrier height, the series resistance and the density of the interface trap states strongly depend on applied gamma irradiation dose and also the value of high frequency.

Morphology change in (K0.5Na0.5)(Mn0.005Nb0.995)O3 thin films caused by gamma-ray irradiation

We investigated the effects of gamma-ray (γ) irradiation on the morphology properties of (K0.5Na0.5)(Mn0.005Nb0.995)O3 (KNMN) thin films. The KNMN thin films were prepared on Pt/Ti/SiO2/Si substrate using a chemical solution deposition method through a spin-coating process and were subject to γ radiation at various total doses from 0–3000 kGy. The grain size of the KNMN films changed visibly with an increase in the total γ irradiation dose. Williamson-Hall plot analysis revealed that the microstrain of the films increased from 0.222% (at 0 kGy) to 0.266% (at 3000 kGy) after the irradiation. The observed variation of the morphology properties on the total dose might be mainly associated with the microstrain in Mn-doped KNN thin films. In addition the migration of defects and/or impurities bound inside the grain by the gamma-ray energy in Mn-doped KNN thin films can enhance the grain size decrease process. The mobile impurities in our polycrystalline samples can congregate at the domain boundary, which can lead to partial amorphization inside the grain.

The Improvement of Phenotypic Variability and Effects of Gamma-Ray Irradiation on Growth and High Yield Character of Bambara Groundnut (Vigna subterranea (L.) Verdcourt) in M2 Generation

Mutation in plant breeding using gamma-ray irradiation is one way to improve a phenotypic variability, especially in the plant’s growth and high yield, as well as to give some effects. The effects of gamma rays include causing physiological damage and morphological changes in Bambara groundnuts. This research aims to analyze the phenotypic variability and to study the effects of gamma rays on growth and high-yield character of Bambara nuts in M2 generation. The experiment was conducted from November 2016 to April 2017 at Experimental Field of Faculty of Agriculture, Universitas Padjadjaran Jatinangor, Sumedang, Indonesia. The experimental design used was the Spatial Plan, using the method of comparative descriptive research. Accession of Bambara nuts (KB-29 (1)) were treated with gamma-ray radiation with different doses of 100 Gy, 150 Gy, and 200 Gy. The results showed that gamma rays could improve phenotypic variability value by F-test and cause chimera, dwarf plants, plant death, curled leaves, and albino. In addition, it gave a positive influence on all components of the results.

Effect of gamma-ray irradiation on the electrical characteristics of Al/C24H12/p-Si nano-structure

We have investigated the effects of 60Co gamma-ray irradiation on the electrical properties of an Al/C24H12/p-Si metal-polymer-semiconductor (MPS) Schottky diode such as series resistance (Rs), ideality factor (n) and barrier height (ΦB). The samples have been prepared using an evaporation technique and irradiated with a total dose range of 0–90 kGy at room temperature. Current-voltage (I–V) measurements have been performed before and after irradiation in the dark and at room temperature. It has been observed that the barrier height and series resistance values are decreased after irradiation while ideality factor is increased. Decreasing in Rs indicates that the product of the mobility and the free carrier concentration has increased due to the radiation defects. Experimental results show that this material can be modified using 60Co gamma-ray irradiation.

Gamma and neutron irradiation effects on multi-walled carbon nanotubes

In this study, the effects of gamma-ray and neutron radiation on multi-walled carbon nanotubes (MWCNTs) at different doses were investigated. The samples in powder form were exposed to thermal neutrons, fast neutrons, and 10 kGy and 20 kGy doses of gamma-ray radiation. Virgin and irradiated MWCNTs were investigated through structural, optical, morphological, and chemical analysis by Raman spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) to investigate the damage produced by the radiation. The Raman spectroscopy measurements show that the ID/IG ratio increased with the irradiation except for the 10 kGy gamma rays. XPS measurements display a higher degree of oxygen incorporation with the neutron irradiation. Detailed analysis of the C1s spectra also shows lower percentages of CC sp2 and higher percentages of CC sp3 in the MWCNTs irradiated by neutrons. Dark black spots were observed in the MWCNTs by irradiation, which is attributed to the formation of an amorphous structure by TEM measurements. The results show that, overall, the 10 kGy gamma irradiation dose improves the structural quality while the 20 kGy dose gamma rays, fast, and thermal neutrons caused a decrease in the degree of the structural quality of the MWCNTs.