Increase In Gamma Dose Research Articles

Impact of gamma irradiation on optical and nonlinear properties of Indium chloride phthalocyanine thin films

This study investigates the impact of gamma radiation on indium chloride phthalocyanine (lnPcCl) thin films, which were prepared via vacuum thermal evaporation. x-ray diffraction revealed the amorphous structure of the films, with increasing gamma doses causing more noticeable structural disorders. Optical analysis showed a slight decrease in the optical band gap energy and a significant reduction in the fundamental band gap energy. Additionally, higher gamma doses led to decreased transmittance and increased reflectance. The study also observed substantial enhancements in nonlinear optical parameters, such as third-order nonlinear susceptibility (χ(3)) and nonlinear refractive index (n 2). These findings suggest the potential of gamma-irradiated lnPcCl films for advanced optoelectronic and nonlinear optical applications.

Fabrication, photovoltaic analysis, and electrical characterization of Au/ZnTPyP/p-Si/Ag heterojunction under gamma radiation effect for solar cell applications

The main objective of the current study is to investigate the impact of gamma rays on the characteristics and behavior of a fabricated heterojunction device based on tetra pyridyl-porphine zinc (ZnTPyP). The importance of this study includes determining critical parameters such as conversion efficiency (η). A cobalt-60 gamma source has been employed to investigate the effects of gamma exposure dosages ranging from 0 to 5 kGy on the morphological and optical features of the studied material. An atomic force microscope (AFM) was used to examine the morphological characteristics of the ZnTPyP film that formed on the glass substrate. The thin film’s optical characteristics were investigated on quartz for both as-deposited and irradiated films at various gamma doses (1 kGy and 3 kGy). Additionally, ZnTPyP is evaporated on p-type silicon substrates to create ZnTPyP/p-Si heterojunction. The current–voltage (I–V) curves at various doses of gamma radiation at 0, 1, 3, and 5 kGy for Au/ ZnTPyP /p-Si/Ag heterojunction device are experimentally measured. The predominant conduction processes are the thermionic emission and single-trap space-charge-limited current (SCLC). Furthermore, the values of the barrier height φB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\varphi_{B} } \\right)$$\\end{document} are estimated using two different methods, including I–V method and Norde’s equations at different doses, and their values are comparable. Under illumination at 0 kGy, we found the values of short-circuit current (Isc), open-circuit voltage (Voc), and photoconversion efficiency (η) to be 0.92 mA, 0.41 V, and 4.28%, respectively. On the hand, some important optical parameters are determined for both as-deposited and irradiated ZnTPyP films, such as skin depth (δ), and found that δ values reduce with increasing gamma doses, reflecting the efficiency and performance of photovoltaic cells. Finally, the study indicated the alteration in the studied optical parameters and slightly enhanced the Au/ZnTPyP/p-Si/Ag heterojunction efficiency when subjected to gamma radiation.

Identification of gamma irradiated polycarbonate-polybutylene terephthalate stiff polymer blend products using HS-GC/MS, FTIR and UV/Vis spectroscopy

In this study, the fragmentation products of Makro-blend stiff polymer due to gamma exposure were identified using Head space (HS), Gas Chromatography, and Mass Spectrometry (HS-GC/MS) techniques and Fourier Transform Infra-Red (FTIR) spectroscopy. As well the electronic transitions due to gamma exposure were examined using UV/Vis spectroscopy. For the un-irradiated and 10 kGy irradiated samples, one product was detected by (HS-GC/MS) method with a clear peak of Dimethoxyethane (MW = 90), which has a peak area percentage of 98.58% and 97.13%, respectively. With increasing gamma doses the number of identified components was increased. At 1200 kGy, ten components were detected: Biethylene (MW = 54), Dimethoxyethane (MW = 90), 1,1-Dimethoxy-2-propanone (MW = 118), 1,1-Dimethoxy-2-propanol (MW = 120), 1,1-Dimethoxycyclopentane (MW = 130), 1,1-Dimethoxyheptane (MW = 160), 1,1-Dimethoxyoctane (MW = 174), Dimethyl terephthalate (MW = 194), 4-(Diethoxymethyl) benzaldehyde (MW = 208), and Terephthalate dihexyl (MW = 334), which have peaks area percentages of 4.22, 2.98, 25.84, 2.2, 10.65, 38.86, 1.57, 5.91, 1.22, and 6.48, respectively. The recorded mass spectrum of each component confirms the molecular ion peak. The FTIR measurements demonstrate the decrease in the detected band intensities following gamma radiation. Accordingly, a chain scission occurs, which causes the carbonate bond to scission, resulting in the creation of a hydroxyl group and the (–H) abstraction from the backbone of the irradiation blend samples. The absorbance edge of the gamma-exposed samples shifted towards a higher wavelength. This pattern shows that the band gap energy is declining. The use of FTIR and HS-GC/MS in mass spectrometry analysis will be useful tools for examining radiation-induced polymeric fragments and advancing our understanding of the process underlying the creation of these fragments in polymers.

Effect of gamma irradiation on the linear and non-linear optical properties of magnetron Co-sputtered CdO–SnO2 thin films

In this work, CdO–SnO2 thin films were deposited using the magnetron Co-sputtering technique. The presence of single-phase Cadmium Stannate (Cd2SnO4) films was verified by X-ray diffraction (XRD) of the as-prepared and irradiated films. The obtained results reveal that crystallite size (D) increasing by gamma irradiation up to 50 kGY and then seem to be not affected by increasing the dose of gamma radiation for the different phases. The resulting dislocation density (δ) and number of crystallites per unit area (N) decreased irradiation of gamma till 50 kGY and seem to be not affected by increasing gamma irradiation. The microstrain εc did not show systematic variations with gamma dose. The refractive index of un-irradiated and irradiated films showed normal dispersion. Aurbach tail Eu, plasma frequency (ωp), and third order susceptibility χ(3) increased by irradiation and seem to be not affected by increasing gamma dose beyond 50 kGY. In contrast, the optical energy gap Eop found to be decrease by irradiation and seem to be not affected by increasing gamma dose beyond 50 kGY. Other optical parameters, including the absorption coefficient, and dispersion energies, are investigated before and after gamma irradiation.

Effects of Gamma-Synthesized Chitosan on Morphological, Thermal, Mechanical, and Heavy-Metal Removal Properties in Natural Rubber Foam as Sustainable and Eco-Friendly Heavy Metal Sorbents

The properties of natural rubber foam (NRF) containing gamma-synthesized chitosan (CS) powder were investigated to address the growing demand for efficient methods to treat industrial wastewater contaminated with heavy metals. The CS powder was prepared by irradiating chitin (CT) powder with varying doses of gamma rays (0–100 kGy), followed by deacetylation using 40% sodium hydroxide (NaOH) at 100 °C for 1 h. The resulting CS powders were then mixed with natural rubber latex (NRL) at different contents (0, 3, 6, and 9 parts per hundred parts of rubber by weight; phr) and processed using Dunlop techniques to prepare the foam samples. The experimental findings indicated that the degree of deacetylation (%DD) of the CS powder increased initially with gamma doses up to 60 kGy but then decreased at 80 and 100 kGy. In addition, when the CS powder was incorporated into the NRF samples, there were increases in total surface area, density, compression set, and hardness (shore OO), with increasing gamma doses and CS contents. Furthermore, the determination of heavy metal adsorption properties for Cu, Pb, Zn, and Cd showed that the developed NRF sample exhibited high adsorption capacities. For instance, their removal efficiencies reached 94.9%, 82.5%, 91.4%, and 97.0%, respectively, in NRF containing 9 phr of 60 kGy CS. Notably, all adsorption measurements were determined using 3 cm × 3 cm × 2.5 cm specimens submerged in respective metal solutions, with an initial concentration of 25 mg/L. However, the removal capacity per unit mass of the sample (mg/g) showed less dependencies on CS contents, probably due to the higher density of CS/NRF composites in comparison to pristine NRF, resulting in a smaller volume of the former being submerged in the solution, subsequently suppressing the effects from CS in the adsorption. Lastly, tests on the reusability of the developed NRF indicated that the samples could be reused for up to three cycles, with the Cu removal capacity remaining relatively high (83%) in the sample containing 9 phr of 60 kGy CS. The overall outcomes implied that the developed NRF with the addition of gamma-synthesized CS not only offered effective and eco-friendly heavy metal adsorption capacity to improve public health safety and the environment from industrial wastewater but also promoted greener and safer procedures for the synthesis/modification of similar substances through radiation technologies.

Effects of gamma radiation on the optical properties of ultrafine iron particle/polystyrene composites

The present research studied the influence of gamma radiation doses on the optical properties and parameters of the tested composite samples consisting of polystyrene polymer as a matrix filled with different concentrations of ultrafine iron particles (0, 10, 20, and 30 wt.%) with an average thickness of 2 µm. Using a UV-1800 Shimadzu spectrophotometer, the optical absorbance and transmittance values of the tested composite samples were measured at room temperature in the wavelength range of 200–800 nm. Optical parameters such as the excitation energy for electronic transitions, optical energy gap, dispersion energy, static dielectric constant, static refractive index, moments of the optical spectrum, optical oscillator strengths, linear optical susceptibility, third-order nonlinear optical susceptibility, carrier concentration to the effective mass ratio, high-frequency dielectric constant, nonlinear refractive index, plasma frequency and long wavelength refractive index were calculated and discussed at different doses of gamma radiation (1, 2, and 6 kGy). The results demonstrate that the optical properties and parameters of the gamma-irradiated composites vary with increasing gamma doses. This variation in values was observed after increased irradiation due to enhanced metal–polymer bonding and due to an increase in the density of the free charges within the metal polymer composites.

Spectroscopic and electrical changes in Lr-115 type II nuclear track detector before and after gamma radiation

In this research, the changes in the structural, spectroscopic, and electrical properties of the Lr-115 type II nuclear track detector were investigated before and after gamma irradiation. The FT-IR, X-ray, and UV–Visible spectra were recorded and studied in detail before and after irradiation process. We have arrived at the following results, the X-ray diffraction reveals that irradiated Lr-115 diffraction displays an increase in peak intensity and width at half maximum which is commonly associated with polymer crystallinity. After irradiation, the IR bands at 1447 cm−1 assigned to O-NO2 rapidly decreased, and the band at 802 cm−1 due to C–O–C shifted to 784 cm−1. From UV–Visible measurements, as irradiated doses increase, the surface plasmon absorption in irradiated samples causes the extinction coefficient (k) of the sample peak at = 199 nm to increase with increasing wavelength up to 221 nm. With increasing gamma dose, the obtained data revealed a decrease in the optical energy gap (Eg) and increases of the number of carbon atoms in a formed cluster. Increasing of the gamma doses caused an increase in the AC electrical conductivity. Furthermore, the dielectric constant was studied at room temperature as a function of the dose variation. The results indicate that gamma-ray irradiations improve the optical and electrical properties of Lr-115.

Effect of gamma rays irradiation in the structure, optical, and electrical properties of samarium doped bismuth titanate ceramics

AbstractCeramics have enormous potential in several emerging technologies, including nuclear reactors. Materials with chemical inertness, high-temperature operation, and physical properties stability under applied radiation with high energy are all desired in this field of technology. Given these broad specifications, bismuth titanate ceramics may prove to be a valuable material. Regarding this task, the effect of gamma rays on the structural, optical, and ferroelectric properties of samarium-modified bismuth titanate ceramics was investigated. The Bi3.15Sm0.85Ti3O12(BSmT) compound was irradiated for 0, 50, 100, and 200 kGy using a60Co gamma source at a dose rate of 10 kGy h−1. The phase structure confirmed the orthorhombic, single-phase nature even after gamma irradiation. The results show that the unit cell volume decreases from 966.39 to 962.38 Å3with an increase in gamma dose from 0 to 200 kGy. The X-ray photoelectron spectroscopy study shows an irradiation-induced defect in the host matrix. The results show that the bandgap energy, dielectric constant, Curie temperatures, and remnant polarization slightly decreased with an increase in gamma irradiation. According to the findings of this study, the BSmT exhibits adequate stability against gamma irradiation, which offers tremendous promise in their utilization in nuclear reactor technology.

Effect of Component Position and Inward–Outward Rotation on the Wear of Different Ultra-High Molecular Weight Polyethylenes in an Orbital Bearing Type Hip Joint Simulator

The orbital bearing machine is the world’s most widely used hip joint simulator design for wear testing of prosthetic hips. It has been used with inverted and anatomic component position and with and without inward–outward rotation. Still the effect of component position on the wear of the most widely used bearing material, ultrahigh molecular weight polyethylene (UHMWPE), has not been studied directly. With a modified orbital bearing machine, the effects of the component position, anatomic versus inverted, and of the inward–outward rotation, present versus absent, on polyethylene wear were studied for the first time. Acetabular liners made from different ultra-high molecular weight polyethylenes articulated against alumina femoral heads in alpha calf serum. The inverted position resulted in the most realistic, burnished appearance of the polyethylene bearing surfaces. In the inverted position, the wear rate decreased with increasing gamma dose that is known to improve wear resistance by cross-linking. In the anatomic position, the bearing surface was not always entirely burnished. The wear was similar with and without inward–outward rotation. The mean wear rate of vitamin E stabilized highly cross-linked ultra-high molecular weight polyethylene was close to clinical observations. Clinically relevant wear could be produced with the orbital bearing machine for both established and advanced bearing materials. The inverted position appeared preferable in the orbital bearing machine. Inward–outward rotation did not appear important.

Green synthesis of MgO nanoparticles and its antibacterial properties.

Magnesium oxide nanostructured particles (NP) were prepared using a simple solution combustion technique using different leaf extracts such as Mangifera indica (Mango - Ma), Azadirachta indica (Neem-Ne), and Carica papaya (Papaya-Pa) as surfactants. The highly crystalline phase of MgO nanostructures was confirmed by PXRD and FTIR studies for 2h 500°C calcined samples. To analyze the characteristics of obtained material-MaNP, NeNP, and PaNP for dosimetry applications, thermoluminescence (TL) studies were carried out for Co-60 gamma rays irradiated samples in the dose range 10-50KGy; PaNP and NeNP exhibited well-defined glow curve when compared with MaNP samples. In addition, it was observed that the TL intensity decreases, with increase in gamma dose and the glow peak temperature is shifted towards the higher temperature with the increase in heating rate. The glow peak was segregated using glow curve deconvolution and thermal cleaning method. Kinetic parameters estimated using Chen's method, trap depth (E), and frequency factor (s) were found to be 0.699, 7.408, 0.4929, and 38.71, 11.008, and 10.71 for PaNP, NeNP, and MaNP respectively. The well-resolved glow curve, good linear behavior in the dose range of 10-50, KGy, and less fading were observed in PaNP as compared with MaNP and NeNP. Further, the antibacterial activity was checked against human pathogens such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. A visible zone of clearance was observed at 200 and 100μg/mL by the PaNP and NeNP, indicating the death of colonies by the nanoparticles. Therefore, PaNP nanomaterial is a potential phosphor material for dosimetry and antibacterial application compared to NeNP and MaNP.

Gamma rays induced modifications in the structural, optical and photoemission properties of PVA/TiO2 nanocomposite films

In the present study, nanocomposite films made of TiO2 (0.01 wt%) nanoparticles (NPs) embedded in polyvinyl alcohol (PVA) polymers were prepared via the solution casting technique. The PVA/TiO2 nanocomposite films were irradiated with several doses of gamma-ray, ranging from 10–90 kGy. The unirradiated/irradiated nanocomposite films were investigated using FTIR spectroscopy, scanning electron microscope (SEM), roughness testing, UV–Vis spectroscopy, refractometry, densitometry, and photoluminescence spectroscopy. The results were then compared to the pure PVA polymer. FTIR spectra showed a decrease in intensity and a broadening of absorption bands due to interactions between the host PVA polymer atoms/molecules and the TiO2 NPs. SEM showed homogeneous dispersion of the TiO2 NPs in the PVA matrix. Gamma irradiation resulted in more significant morphological alterations and changing the roughness characteristics, the magnitude of which depended on the dose. UV–vis spectra showed the absorption edge significantly changing with increasing gamma doses. The optical energy gap band, Urbach’s energy, and the number of carbon clusters of the PVA/TiO2 nanocomposite films before and after gamma radiation were changed in comparison to the pure PVA sample. The refractive index and optical density improved due to the addition of TiO2 and γ-irradiation. The photoluminescence emission results emphasized the PVA/TiO2 film’s high sensitivity to γ-rays, especially at high doses, resulting in strong fluorescence peaks due to increased defects in the irradiated films. All in all, the results prove that there are alterations in the PVA polymer after the addition of TiO2 and γ-irradiation, making these films good candidates for a variety of industrial applications, including γ-ray dosimeters.

Validation of γ-radiation and their effect on phenolic compounds, antioxidant activity, and microbial load of fennel (Foeniculum vulgare) seeds and cinnamon (Cinnamomum verum) sticks.

The aim of this study was to validate the optimum doses of γ-radiation and its effect on the antioxidant capacity and microbial load of fennel seeds and cinnamon sticks. Gamma irradiation was applied in different doses 0.0, 2.5, 5.0, 7.5, 10, and 15 kGy. The findings stated that increasing gamma dose significantly (p< .05) increased the total phenolic content of the fennel seeds; however, it was decreased in cinnamon at doses higher than 5kGy. The total flavonoid content was found higher after treatments at 5kGy or more minor. After the gamma irradiation treatments, the antioxidant activities were enhanced. The microbial load of these spices was reduced after treatment. Doses more than 10.0kGy are required to lower the bacterial load in samples, while only 5.0kGy is sufficient to eliminate fungi growth. The partial least squares regression analysis stated the application of 7.5kGy and reflects the most valid treatment doses for radiation treatments of fennel seeds and cinnamon sticks. Accordingly, it can be discovered that the γ-radiation at a dose of 7.5kGy could be considered a suitable dose for the preservation and decontamination of these spices and also for enhancing its antioxidant capacity. Three spices were subjected to gamma irradiation at different doses. The application of gamma radiation significantly reduces the level of the microbial load in the spices. Gamma irradiation improved the antioxidant capacity of the spices. Gamma irradiation can be applied as an effective preservative method in the food industries.

Influence of gamma rays on the electrical properties of CuPbI3 perovskite thin films

The CuPbI3 perovskite thin films were studied in this research as a function of gamma ray doses. In more details, the effect of gamma radiation on the electrical transportation and structural properties of CuPbI3/p-Si heterostructure is studied to investigate the radiation detection and dosimetric ability of this perovskite material. The material was successfully deposited on silicon substrate by spin coating technique. The deposition was carried out at room temperature under ambient conditions. The deposited films on a silicon substrate were then annealed at 200 °C. Then, all samples were irradiated by high gamma radiation using 60Co source in the range of 0–100 kGy at room temperature. For low gamma rays dose test, the pristine sample was exposed to a low activity 137Cs source for different time duration in order to vary the range of gamma rays doses. The X-ray diffraction (XRD) results of pristine and irradiated thin films confirmed the right structure of CuPbI3 and to evaluate the impact of the incident gamma rays. Current-voltage (I–V) characterization was performed at different low gamma ray doses to assess whether the impact of gamma rays is temporary or permanent. There was an increase in the value of the forward current with increasing gamma dose. The ideality factor of the samples is greater than unity, whereas barrier height and saturation current for the samples changed with radiation because of density of defect induced by gamma and charge carrier trapping on interface layer. The results clearly showed a significant impact of gamma irradiation dose on the structure and electrical properties of CuPbI3 perovskite thin films, which may open a new channel to study the effect of irradiation on this material using different substrates.

Enhanced linear and nonlinear optical properties of erbium/ytterbium lead phosphate glass by gamma irradiation for optoelectronics applications

Herein, this study intends to reveal the impact of gamma irradiation on the structural, linear, and nonlinear optical characteristics of 47P2O5−23Na2O−6Al2O3−22PbO−0.5Er2O3−1.5Yb2O3 glass. The Er/Yb-doped lead phosphate glass samples were produced using the traditional melt quenching procedure and then treated to different doses of gamma irradiation (0, 20, 50, and 100) kGy. The amorphous phase structure of the Er/Yb-doped lead phosphate glass samples was verified through XRD patterns. Also, the shift of the FTIR peaks due to the change in bond angles, and the change in the bond length of the P–O–P bridges means the glass network stability against radiation. With increasing irradiation dosages, the energy gap dropped from 4.11 eV to 3.42 eV and then enhanced to 3.48 at 100 kGy. At the same time, the Urbach energy enhanced from 10.23 eV to 37.03 eV. The oscillator energy Eo was found between 1.55 and 1.62 eV. Also, the dispersion energy Ed varied between 2.11 eV at 100 kGy and 2.71 eV at the dose of 50 kGy. The percentage of free carrier ions to effective mass (N/m*) is in the range (4.82–8.66) × 1047 cm3/g. Besides, the lattice dielectric constant ({varepsilon }_{l}) increased from 5.54 to 6.63 as the gamma dosages increased. Furthermore, increasing gamma doses up to 50 kGy promotes susceptibility, which subsequently declines at 100 kGy, suggesting that increasing gamma doses over 50 kGy weakens polarizability potential. While the increasing gamma doses up to 50 kGy reduces the nonlinear refractive index and then improves at 100 kGy. Overall, the nonlinear and linear research revealed that Er/Yb lead phosphate glass is being used as a promising material for gain media and optical amplifiers.

Thermoluminescence response and trap features of gamma-irradiated Sr2Al2SiO7:Dy3+ phosphors

This study mainly focuses on the thermoluminescence features and trap parameter analysis of Sr2Al2SiO7:Dy3+ phosphors prepared via the low-temperature combustion method. The phase confirmation, structural and morphological studies are performed using XRD, FTIR, SEM and EDX characterizations. The energy gap of pure and Dy3+ doped phosphors is calculated. And the band gap decrease with doping. The optimum concentration was 3 mol% from the emission spectra; hence, this sample was irradiated with 3 Gy–5 kGy gamma doses. The samples showed high sensitivity and the MDD value is 0.21 mGy. The trap parameters were determined following deconvolution of the glow curves. Four traps were found in the samples, and the trap lifetime increased with increasing gamma dose. The trap depth increased The linear response from 3 Gy to 250 Gy implies that the prepared samples could be used as γ dosimeters within this range.

Gamma ray–induced tissue responses and improved secondary metabolites accumulation in Catharanthus roseus

The present study investigated the impact of gamma ray irradiation on callus biomass growth and the yield of vincristine and vinblastine of in vitro grown tissues of Catharanthus roseus. The biochemical alteration underlying the synthesis of secondary metabolites has also been studied and a comparison of yield was prepared. The embryogenic tissues were exposed to 20, 40, 60, 80, and 100Gy gamma ray doses and the callus biomass fresh weight, the embryogenesis (the embryo numbers, germination, plant regeneration), the alteration of protein, proline, and sugar attributes at different morphogenetic stages were monitored. The callus biomass growth was maximum (1.65g) in 20Gy exposed tissues and was less in 100Gy treatment (0.33g). The gamma-irradiated embryogenic tissues differentiated into embryos but the embryogenesis % and somatic embryo number per culture reduced with increasing doses. It was least in 80Gy where very low numbers of embryos were formed (3.45 and 3.30 mean torpedo and cotyledonary embryo numbers per callus mass, respectively) which later germinated into plantlets. Protein, proline, sugar, and different antioxidant enzymes, i.e., superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) activities, were investigated as the tissues were exposed to gamma ray elicitation/signaling, evoking cellular stress. Increased 80Gy gamma dose inhibited a 42.73% decrease in protein accumulation at initiation stages of embryogenic tissue. Soluble sugar level also declined gradually being least in 80Gy treated tissues (14.51mg gm-1 FW) compared to control (20.2mg gm-1 FW). Proline content, however, increased with increasing gamma doses, maximum at 80Gy (8.28mg gm-1 FW). The SOD, APX, and CAT activity increased linearly with enhanced level of gamma doses and maximum, i.e., 3.91 EU min-1mg-1, 1.71 EU min-1mg-1, and 4.89 EU min-1mg-1, protein activity was noted for SOD, APX, and CAT, respectively, at 80Gy gamma rays treated tissues. The quantification of vinblastine and vincristine in gamma ray elicitated tissues was made by using high-pressure thin layer chromatography (HPTLC). Somatic embryo-regenerated plant's leaves had the maximum yield of vinblastine (15.13 µgm gm-1 DW) at 40Gy irradiation dose compared to control (13.30 µgm gm-1 DW)-the increased yield % is 13.75. The stem is also rich source producing 11.98 µgm gm-1 DW of vinblastine. Among the various developmental stages of embryos, vinblastine content was highest in germinating stage of embryos (10.14 µgm gm-1 DW) compared to other three, i.e., initiation, proliferation, and maturation embryo stages. Similarly, highest accumulation of vincristine (6.32µg gm-1 DW) was noted at low gamma irradiation dose (20Gy) in leaf tissues. The present study indicates that the synthesis of vinblastine and vincristine was growth- and development-specific and the lower 20-40Gy gamma levels were more effective in enriching alkaloids while higher doses declined yield. KEY POINTS: • Vinblastine and vincristine yield was quantified in in vitro grown tissues and leaves of embryo regenerated Catharanthus roseus after gamma ray treatment. • The accumulation of vinblastine and vincristine was maximum in regenerated leaves; low doses were more efficient in improving yield. • Gamma ray irradiation impacted biochemical profiles, caused cellular stress, and perhaps responsible for improved alkaloid yield.

IN VITRO MUTAGENESIS AND PROPAGATION OF PAULOWNIA TOMENTOSA (THUMB) FOR SALT TOLERANCE

The study aimed to refine a protocol for micropropagation and to develop the plant's ability to withstand salinity by the use of physical and chemical mutations, so that it can be cultivated in new lands that are not suitable for other crops. Shoot tips and stem segments of Paulownia tomentosa were firstly sterilized and cultured on different media types containing benzyl amino purine (BAP) at 0, 0.1, 0.25, 0.5, and 1.0 mg/l to choose the best combination for explant growth and proliferation. To examine the plant's ability to withstand salinity, Paulownia tomentosa shoots were first irradiated with the doses of gamma rays at 0.0, 30, 60, 90, 120, and 150 Gray (Gy) and secondly, cultured on a WPM medium containing sodium azide "NaN3" at 0.0, 0.1, 0.2, 0.4, 0.8. and 1.0 mM for 5 min. Both irradiated and NaN3-treated shoots were cultured on different levels of NaCl. Inter Simple Sequence Repeats (ISSR) technique was used to detect variations caused by gamma rays and NaN3. Results showed that at 120 Gy of gamma-ray, one fragment with primer UBC824 vanished and one fragment with primer 17898B at 150 Gy appeared. In comparison, one fragment with primer either UBC873 or UBC867 at 1.0 mM and 0.8 mM of NaN3, respectively, can be considered a positive marker of Paulownia salt tolerance. Treated shoots gave the greatest number of roots/shoot (6.0) on WPM half strength with NAA at 2.0 mg/l. Increasing gamma doses or NaN3 concentrations decreased survival rate. Variation created by mutation provides the raw material for natural selection and is a driving force in evolution.

Effect of Gamma Irradiation on the Structural, Optical, Electrical, and Ferroelectric Characterizations of Bismuth-Modified Barium Titanate Ceramics.

Materials with ferroelectric properties, low bandgap energies, high polarization, low loss, and thermal stability are essential for future solar-cell applications. Researchers have attempted to obtain such materials by using several approaches. In this vein, a novel approach is reported in this work using gamma ray irradiation. The effect of gamma radiation on the structural, optical, and ferroelectric characterizations of bismuth (Bi)-doped barium titanate (BaTiO3 (BT)), namely Ba0.95Bi0.05TiO3 ceramics (abbreviated as (Bi:BT)), was investigated. X-ray diffraction, structure refinement, and Raman study revealed the presence of a perovskite structure with a tetragonal phase in all investigated samples. Morphological study revealed a nonuniform grain size and some porosity. Gamma irradiation-induced combined effects were proved by a detailed analysis of bond lengths, bond angles, octahedral distortions, oxygen vacancies, and charge compensations. Electron paramagnetic resonance (EPR) study gave direct evidence of oxygen vacancies in the irradiated samples. After gamma irradiation, UV–vis study indicated a decrease in the bandgap from 3.14 to 2.80 eV and a significant increase in visible light absorption. Cole–Cole plots confirm as an increase in gamma-ray dose results in higher levels of electron hopping. Study of the P–E hysteresis loop demonstrated that ferroelectric properties could be maintained after gamma irradiation, with a slight decrease in remnant polarization. The behaviour of the P–E was correlated with increasing gamma dose in the investigated ceramics, demonstrating a strong gamma dependence in the loops’ profile. We guess that the present approach may be a promising technique for enhancing the multifunctionality of electronic devices.

Effects of Boron Application and Gamma Ray Irradiation On Yield of Sugar Beet (Beta Vulgaris L.) Grown in Sandy Soil

Effects of boron as an essential nutrient for sugar beet along with gamma irradiation was traced under field conditions. Data demonstrated that the fresh and dry root yields of sugar beet significantly increased with the increase either gamma dose or boron levels comparing to the non-irradiated and born-untreated plants. It seems that root dry weight tended to increase gradually with increasing gamma dose 0 to 100 Gy, then tended to decrease with 200 Gy dose but it still increased with gradual increases of boron levels. In this regard, the best value of root dry weight was achieved with 100 Gy dose interacted with 2.40 kg/ ha of boron addition. On the other hand, plants exposed to 50 Gy and treated with 2.40 kg/ ha reflected the highest shoot dry matter yield compared to other treatments. Relatively, this treatment increased shoot dry weight by about one fold, two folds and near to two folds for the same sequence. Behavior of NPK uptake by shoots has the same trend. Plants irradiated with 100 Gy together with 2.40 kg boric acid ha-1 yielded the highest total soluble solids (TSS%) and produced the best per cent of sucrose. Bangladesh J. Bot. 50(4): 1041-1049, 2021 (December)

Natural dye solar cell: Conductive transparent oxide, photo anode, sensitizers, electrolyte, and γ-radiation response

ABSTRACT This article represents the gamma irradiation effects on the experimental details of prepared natural dye solar cell (NDSC) components. The optical absorption and physical characteristics of NDSC components were investigated by using different techniques such as Fourier Transform Infrared, Electron Paramagnetic Resonance, Scanning Electron Microscope, and UV−Vis absorption Spectroscopy. The average optical energy gap of the natural fruit dyes was found 2.1 ± 0.3 eV. The transmittance onset of conductive transparent oxide was blue shifted with the increase of gamma dose. Optical energy gap of the electrolyte was calculated to have a value of 2.61 eV. The maximum peaks of incident photon to current efficiency spectrum were found for SnO2 (undoped) film at 515 nm and for SnO2:Sb (doped) film at 550 nm. The short current and open voltage were found to be 0.92 mA and 0.44 V, respectively, for doped film.