Combination Of Gamma Irradiation Research Articles

Gamma Irradiation and Exogenous Proline Enhanced the Growth, 2AP Content, and Inhibitory Effects of Selected Bioactive Compounds against α-Glucosidase and α-Amylase in Thai Rice.

Exogenous proline can improve the growth, aroma intensities, and bioactive compounds of rice. This study evaluated the effects of gamma irradiation under proline conditions on the 2-acetyl-1-pyrroline (2AP), phenolic, and flavonoid contents of rice. Moreover, the bioactive compounds of gamma-irradiated rice under proline conditions that inhibited α-glucosidase and α-amylase were evaluated by in silico study. A low gamma dose (40 Gy) induced the highest rice growth under 5 mM proline concentration. The highest 2AP content was stimulated at a gamma dose of 5－100 Gy under 10 mM proline concentration. At 500 and 1,000 Gy gamma dose, the highest flavonoid and phenolic contents of rice were stimulated. 1-(2-Hydroxy-5-methylphenyl)-ethanone, which had the highest binding affinity (-7.9 kcal/mol) against α-glucosidase, was obtained at 500 and 1,000 Gy gamma dose under 5 and 10 mM proline concentrations. Meanwhile, 6-amino-1,3,5-triazine-2,4(1H,3H)-dione, which had the highest binding affinity (-6.3 kcal/mol) against α-amylase, was obtained under 10 mM proline concentration in non-gamma-irradiated rice. The results indicate that using a combination of gamma irradiation and exogenous proline is suitable for producing new rice varieties. Moreover, the bioactive compounds that were obtained in new rice varieties exhibited health benefits, especially for diabetes mellitus treatment (inhibition of α-glucosidase and α-amylase).

Suitability of aromatic polyurethanes for use in nuclear applications

Plastic bags are used to facilitate the storage and transport of nuclear materials. In case the storage container becomes damaged, these bags act as a protection barrier against possible contamination. Polyvinyl chloride (PVC) is a polymer commonly used in such applications, but unfortunately, it contributes to the corrosion of the metal container due to HCl evolution. Thus, this work evaluated aging effects on chemical and thermo-mechanical properties of aromatic polyurethanes with the intent to find a replacement for PVC. Aromatic poly(ether)urethanes were aged for up to 21 months under combined gamma irradiation and thermal treatment conditions. A few samples were also placed into actual nuclear storage containers and aged for a similar time period. Experimental techniques, such as FT-IR, NMR, mass spectrometry, TGA, DSC, and tensile tests were employed to characterize two types of polyurethanes, one with and another one without a flame-retardant additive. Our unique aging approach shows that these aromatic polyurethanes are well placed to substitute PVC bags and thus, avoid corrosion of storage metal containers used by the nuclear industry.

Thermal, Mechanical and Tribological Properties of Gamma-Irradiated Plant-Derived Polyamide 1010.

In this study, we investigated the influence of the gamma-irradiation dose and the addition of the cross-linking agent (triallyl isocyanurate (TAIC)) on the thermal, mechanical and tribological properties of plant-derived polyamide 1010 (PA1010). PA1010 and PA1010/TAIC were extruded using a twin screw extruder and injection molded. These specimens were then irradiated with gamma-ray in air with doses of 20 and 50 kGy. After gamma-irradiation, the specimens were heat-treated to remove the free radicals generated in the polymer. The combination of gamma-irradiation and the addition of TAIC significantly changed the crystal structures of PA1010. Glass transition temperature increased with the addition of TAIC and, in particular, with increasing gamma-irradiation dose. Moreover, PA1010/TAIC showed a rubbery plateau originating from cross-links by gamma-irradiation, which was observed in the temperature regions above the melting point in DMA measurements. Mechanical properties such as strength, modulus and hardness, and tribological properties such as frictional coefficient, specific wear rate and limiting pv (pressure p × velocity v) value of PA1010 improved with change in the internal microstructure with the gamma-irradiation and addition of TAIC.

Combination of gamma irradiation and storage condition for improving mechanical and physical postharvest characteristics of fresh garlic cloves.

The aim of this study was the discrimination and optimization of irradiation effect under physical and mechanical experiments on garlic. The samples were irradiated with 0, 75, and 150 Gy doses and stored at 4 and 18°C for 5months. Physical, mechanical, and color properties were measured in the period of storage. Based on the results, all irradiated garlic samples had less quality variation than control samples. Response surface methodology (RSM) optimized dose, storage time, and temperature of the stored garlic which was 75 Gy, 2months, and 17°C, respectively. In addition, after finding the optimal dose, time, and temperature, the most effective factor as weight loss was obtained and the data were classified by the principal component analysis (PCA) approach. The results showed that the PCA method had a high ability to classify and separate the data obtained from measuring the physicochemical properties of garlic and cover 99% variance of data. Moreover, partial least square (PLS) was applied for predicting weight loss data with R2 0.9999. As well, a mechanical test was investigated for finding the best situation and duration of storage condition. Finally, irradiation prevented the destruction of garlic and saved garlic in the best quality as compared with control or nonirradiated samples. After all this, it can be decided to keep garlic in warehouses and transfer this product with minimum damage.

Temperature-Dependent Dynamic on Resistance in Gamma-Irradiated AlGaN/GaN Power HEMTs

Dynamic RON is a key parameter in terms of device reliability and the efficiency of power-switching converters. In this study, commercial off-the-shelf GaN-on-Si power high-electron-mobility transistors (HEMTs) were irradiated using different regimes of accumulative gamma rays with a 60Co source of photon energy (1.33 MeV), while a base temperature of 53 °C and 133 °C during the irradiation test was applied. This test campaign had the objective of investigating how the combination of gamma irradiation and temperature affects dynamic on-resistance (RON) behaviour. The results indicated that gate voltage bias stress affected the degradation of dynamic on-resistance when irradiation was applied, and that temperature was an accelerating factor in dynamic on-resistance degradation. Finally, we obtained a partial reduction in dynamic RON when a total ionising dose of around 140 krad(SiO2) was applied and the base temperature during the irradiation test was not high.

Quality of thyme (Thymus vulgaris L.) and black pepper (Piper nigrum L.) during storage as affected by the combination of gamma-irradiation and modified atmosphere packaging

• Irradiation under O 2 -free atmosphere totally inactivated the natural contamination. • Irradiation under MAP increased essential oil yield and DPPH scavenging activity. • Irradiation resulted in increased antimicrobial activity of thyme. • Irradiation under MAP can enhance the quality of thyme and black pepper. Thyme and black pepper are among the common herbs and spices irradiated commercially for decontamination. Irradiation performed in the air atmosphere has adverse effects on some quality aspects, and this can be minimized if the treatment is delivered under an O 2 -free atmosphere. The effects of packaging under a modified atmosphere (100% N 2 , MAP) or air (AP) prior to gamma-irradiation (at 0, 6 or 14 kGy) on total phenolic content (TPC), 2,2-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, β-carotene bleaching test-based antioxidant activity (BCLA-AA), antimicrobial activity, microbial load, color, and sensory properties of thyme and black pepper were investigated during 6-month storage. Irradiation under the MAP increased essential oil yield and DPPH scavenging activity of the samples at the beginning of the storage. Moreover, the TPC of black pepper and antimicrobial activity of thyme were increased by 14 kGy irradiation in both packages at the beginning of the storage period. Total bacterial and yeast-mold counts were reduced to below 1 log cfu/g after 14 kGy irradiation from an initial contamination level of 7.7 log and 5.2 log, respectively. Reductions in the essential oil yield, DPPH scavenging activity, and antimicrobial activity of thyme during 6-month storage were noted. The BCLA-AA of thyme was increased during the storage period, whereas that of black pepper in AP was decreased. Overall, gamma-irradiation can be applied under modified atmosphere packaging (100% N 2 ) to maintain or improve some of the functional properties of thyme and black pepper without compromising sensory and microbial quality.

Evaluation of the effect of gamma irradiation in combination with ascorbic acid on the chemical parameters and the decontamination of raw milk

Food safety and security is a global concern which requires attention. Irradiation one way to preserve food to increase the shelf life of food is to prevent damage. Among dairy products, raw milk is the main sources of food contamination. This study performed to determine the effect of irradiation in combination with ascorbic acid on the pH, acidity and microbial contamination of raw milk. The raw milk sample was divided into twelve groups. The experimental groups are as follows: The first group: without radiation and without acid, the second group: without radiation with acid, the third to seventh doses of 2–10 kGy without acid and the eighth to twelfth doses of 2–10 kGy with acid. Raw milk samples were irradiated with doses of 2–10 kGy at the dose rate of 1.19 Gy/s using acobalt60 irradiator. The pH test and acidity were performed by pH meter and titration, respectively and the total bacteria count (TBC)was conducted using the Bactoscan flow cytometry during 26 days of refrigeration at 4 ± 1 °C. The pH and acidity of irradiated raw milk samples (2–10 kGy) without ascorbic acid were determined 6.613 to 6.687 with minimum of 5.823 (0 kGy) and 14.200 to-14.967 °D with maximum 32.167 °D (0 kGy) on day 15, respectively. The pH and acidity of irradiated raw milk samples (2–10 kGy) with ascorbic acid were determined 5.497 to 5.623 with minimum of 4.880 (0 kGy) and 38.767 to 41.433 °D with maximum 58.133 °D (0 kGy) on day 15, respectively. It was found that irradiated milk (2, 4 and 10 kGy) in the presence of ascorbic acid could reduce the TBC (P < 0.05) compared to samples without ascorbic acid on 0 and 15 days can be the effectiveness in the bacterial decontamination. However, increasing acidity and decreasing pH in the presence of acid is a problem which needs to be solved in a future study.

Effects of Annealing on the Properties of Gamma-Irradiated Sago Starch.

The increase in health and safety concerns regarding chemical modification in recent years has caused a growing research interest in the modification of starch by physical techniques. There has been a growing trend toward using a combination of treatments in starch modification in producing desirable functional properties to widen the application of a specific starch. In this study, a novel combination of gamma irradiation and annealing (ANN) was used to modify sago starch (Metroxylon sagu). The starch was subjected to gamma irradiation (5, 10, 25, 50 kGy) prior to ANN at 5 °C (To-5) and 10 °C (To-10) below the gelatinization temperature. Determination of amylose content, pH, carboxyl content, FTIR (Fourier Transform Infrared) intensity ratio (R1047/1022), swelling power and solubility, thermal behavior, pasting properties, and morphology were carried out. Annealing irradiated starch at To-5 promoted more crystalline perfection as compared to To-10, particularly when combined with 25 and 50 kGy, whereby a synergistic effect was observed. Dual-modified sago starch exhibited lower swelling power, improved gel firmness, and thermal stability with an intact granular structure. Results suggested the potential of gamma irradiation and annealing to induce some novel characteristics in sago starch for extended applications.

Gamma Radiation Exposure Towards Shelf-Life Extension of Brine-Treated Indigenous Climbing Perch, Anabas testudineus

The study was conducted to evaluate the effects of gamma radiation (1.5 and 3.5 kGy) on quality and shelf-life of brine-treated (18% NaCL) cultured and indigenous Climbing perch, Anabas testudineus during storage at low temperature (4°C) through sensory (Organoleptic Score, OS), chemical (Tyrosine Value, TV) and microbial analyses (Total Bacterial Count, TBC; Total Salmonella and Shigella Count, TSS; and Total Staphylococcus Count, TSC) at weekly intervals for a period of 35 days. The quality of both cultured and indigenous perch deteriorated with the increase of time. The values of TV (23.69 – 86.20 mg/100 g) and TSS (0 – 4.43 cfu/g) were tended to be high in non-irradiated perch while the values of TBC (3.00 – 11.63 cfu/g) and TSC (2.00 – 6.52 cfu/g) showed increasing trends in irradiated samples for both stains. The findings demonstrated that the synergistic effects of brine and gamma radiation in combination with low temperature could be the most effective treatment for the shelf-life extension of perch and this technique might be applied for large scale preservation of any other local fishes of Bangladesh towards food security. Bangladesh J. Zool. 50 (1): 107-119, 2022

Degradation of Reactive Yellow 18 Using Ionizing Radiation Based Advanced Oxidation Processes: Cytotoxicity, Mutagenicity and By-Product Distribution

The degradation of Reactive Yellow 18 (RY-18), induced by gamma radiation in aqueous medium, was carried out as a function of gamma radiation dose (5–20 kGy) and concentration of hydrogen peroxide, the initial dye concentration and pH of the solution were optimized for the maximum degradation efficiency. Gamma radiations alone and in combination with H2O2 were used to degrade the RY-18. A degradation rate of 99% was achieved using an absorbed dose of 20 kGy, 0.6 mL H2O2 in acidic pH. Variations in the functional groups of untreated and treated RY-18 were determined by FTIR analysis. The LCMS technique was used to determine the intermediates formed during the degradation process. The cytotoxicity and mutagenicity of RY-18 were studied by hemolytic and Ames tests, respectively. There were significant reductions in cytotoxicity and mutagenicity in response to gamma radiation treatment. Cytotoxicity was reduced from 15.1% to 7.6% after treatment with a 20 kGy absorbed dose of gamma radiations with 0.6 mL H2O2. Mutagenicity was reduced by 81.3% and 82.3% against the bacterial strains TA98 and TA100 after treatment with a 20 kGy absorbed dose with 0.6 mL H2O2. The advanced oxidation process efficiency was evaluated using the byproduct formations, which were low-molecular-weight organic acid units, which through further oxidation were converted into carbon dioxide and water end products. Based on RY-18 degradation, cytotoxicity and mutagenicity reduction, the gamma radiation in combination with H2O2 has potential for the removal of dye from the effluents.

Quality and shelf-life extension of refrigerated (4°C) Spotted snakehead (Channa punctata) using γ-radiation and food-grade preservative

Investigations were carried out to evaluate the effect of gamma radiation (1.0 and 1.5 kGy) and food-grade preservative (2% potassium sorbate) on the shelf-life of refrigerated (4°C) Spotted snakehead, Channa punctata (Bloch, 1793). Quality assessments were evaluated by sensory (OS), chemical (TV), microbial (TBC and TCC) analyses. Based on control panel, OS was shown to be gradually decreased with the storage time. Irradiated and potassium sorbate treated samples were found acceptable (edible) up to 28 and 21 days, respectively of storage period. TV were lower in irradiated samples with dose of 1.5 kGy compared to other samples. Though microbial load of each of the irradiated samples were within the acceptable limits up to 28 days but 1.5 kGy dose was found more effective. Gamma radiation in combination with good refrigeration could be most effective treatment for the shelf-life extension and microbiological quality improvement for snakehead preservation. Moreover, this preservation technique may be applicable for other fish species to enhance food safety for public health issues.&#x0D; Jahangirnagar University J. Biol. Sci. 9(1 &amp; 2): 1-12, 2020 (June &amp; December)

Remediation and detoxification of water samples contaminated with 2, 4, 6-trichlorophenol by gamma radiation and ozonation

This paper investigates the treatment of water samples contaminated with 2, 4, 6-trichlorophenol (TCP) by gamma radiation. The effects of absorbed dose, initial pH, and chloride ions on the removal of TCP were investigated. In addition, the individual and combined effects of gamma irradiation and ozonation on the toxicity of TCP solutions were assessed. The results showed that the complete decomposition of TCP could be attained at 3.5 kGy in good agreement with previous studies. The pH of the solutions was found to affect the efficiency of the treatment, and the optimal removal of TCP was observed at pH 4.0. The addition of chloride ion to TCP solution before irradiation enhanced the removal% up to 46% depending on the absorbed dose and chloride ion source. Toxicity measurements indicated that the absorbed dose required for the detoxification was ca. 20 × higher than that required for TCP decomposition. The combination of gamma irradiation with ozonation enhanced the detoxification of TCP, and a synergistic effect was observed. This synergistic effect increases with the ozonation time and absorbed dose and led to a significant reduction in the absorbed dose required for a complete detoxification from 70 to 35 kGy.

Research on the effects of bismuth borate glass system on nuclear radiation shielding parameters

There has been an increasing number of research and development activities focusing on the use of different glass systems for their nuclear radiation shielding features. In this study a simulation study has been carried out at a wide photon energy region in order to investigate the radiation protection feature of bismuth borate glasses. This study has been conducted to evaluate the proficiency level of six different glass systems (70-x)B2O3 + xBi2O3 + 15ZnO + 15Na2O (where x = 0, 5, 10, 15, 20 and 25 mol%) exposed to photon, charged particle (H1) and (He+2) and neutron. For this investigation, transmission factors (TF), mass attenuation coefficient (MAC), half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff), effective electron density (Neff) have been computed. The results confirm that the parameters of the examined glasses MAC, HVL, TVL, MFP, Zeff, and Neff are associated with photon energy and chemical composition. In addition, neutron effective cross-sections (∑R) have been computed for bismuth borates and it was seen a good harmony. The computations for present samples have been examined over a broad energy range from 0.01 to 20 MeV and theoretical results have been obtained by using MCNPX software for transmission factors. In addition, simulation results have been calculated with the WinXCom program. Furthermore, MSP and PR calculations of the bismuth borate glass have been performed to figure out the radiation shielding features. For that reason, the SRIM code has been used to simulate H1 and He+2 particles. Considering the results obtained from this research, which examines the radiation protection of bismuth borate glasses, indicates that the best shielding achievement (while the HVL, TVL, MFP, TF have the lowest and the highest (∑R) values) is reached at 25% Bi2O3. As can be seen in the results, the addition of bismuth affirms that the use of such glass systems improves the radiation protection feature. In particular, 25%Bi2O3 glass system has been proved to show superior shielding properties for gamma radiation in combination with charged particles. Since the glass sample with the highest bismuth additive is 25%Bi2O3, the most radiation protection effect is also seen in this example. The obtained material has a satisfactory radiation shielding property as bismuth is added to the mixture.

Ameliorative effect of fractionated low-dose gamma radiation in combination with ellagic acid on nicotine-induced hormonal changes and testicular toxicity in rats.

Nicotine is an active pharmacological ingredient in cigarette smoke, which may negatively influence the male reproductive system and fertility. This study aims to investigate the effect of fractionated low-dose radiation (fractionated-LDR) and/or ellagic acid (EA) on nicotine-induced hormonal changes and testicular toxicity in rats. Nicotine was administrated orally (1mg/kg) for 30days, afterward, rats were treated with LDR (2 × 0.25Gy/1-week interval), EA (10mg/kg, 14 consecutive days p.o.), or a combination of both fractionated-LDR and EA. Rats were sacrificed 24h after the last dose of treatment, then testes were dissected for histopathology examination, along with some biochemical parameters in serum and testicular tissue were evaluated. Nicotine-induced oxidative stress was evidenced by an increase in testicular thiobarbituric acid reactive substances (TBARS) and a decrease in reduced glutathione (GSH) content. Additionally, the activities of testicular androgenic enzymes were decreased, and the activity of serum lactate dehydrogenase (LDH) was significantly increased. The hormonal changes were verified by a noticeable reduction in follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone serum levels. Histological evaluation revealed that the testicular seminiferous tubules structure was distorted. On the contrary, fractionated-LDR plus EA attenuated the negative changes caused by nicotine observed through biochemical and histological findings. Accordingly, the exposure to fractionated-LDR combined with EA may be a promising candidate for treating hormonal changes and testicular toxicity caused by nicotine.

Сomparative analysis of acridineacetate-containing compounds’ radio-sensitizing effect during malignant tumor experimental radiotherapy in a metastatic colorectal cancer model in balb/c mice

Radio-sensitizing compounds are used to increase radiotherapy effectivity and reduce negative pathologic systemic effects of radiation. These radio-sensitizers selectively pile-up in tumor tissue and enhance necrobiotic processes caused by irradiation. Unfortunately, broad introduction of radio-sensitizers into clinical practice is hampered by their low effectivity and substantial negative side effects. This what determines radio-sensitizers effectivity studies high actuality in a colorectal cancer mice model. The study involved 156 male BALB/c mice who had been transplanted with colorectal cancer. After the transplantation they were injected with acridineacetate containing compounds Cyclopherone and Procitol. A comparative assessment was undertaken of tumor growth dynamics and metastatic rate. A combination of gamma-irradiation with radio-sensitizing compounds produces a more substantial therapeutic effect according to all parameters of the experimental colorectal cancer growth and development than the isolated effect of radiotherapy or antitumor drugs. A considerable slowing down of tumor growth on the 14th and 28th day of the study was revealed as well as a reliable inhibition of lymphogenous and hematogenous metastatic spread of neoplasma during the entire study and a statistically valid increase of lifespan of the experimental animals. The radiosensitizing effect of Procitol in combination with radiotherapy turned out to be more substantial than that of Cyclopherone.

Effects of citric acid and gamma radiation on the shelf life of Labeo bata (Hamilton, 1822)

The effects of citric acid (2%) and gamma radiation (1.0 and 1.5 kGy) on the quality and shelf life extension of Bata, Labeo bata (Hamilton, 1822) stored at refrigerated temperature (4°C) for 28 days were examined. Quality assessment were made by sensory (organoleptic scores), chemical (TV) and microbiological (TBC and TCC) evaluations. Organoleptic evaluation showed that irradiated samples were more acceptable than control and citric acid treated samples which also remained acceptable upto 28 days. TV of fish muscles increased with the increase of storage periods in all the samples. The rate of increase was lower in citric acid treated samples and the lowest was observed in samples with 1.5 kGy irradiation. Irradiated samples showed the best results in microbiological assessment. Gamma radiation in combination with low temperature (4°C) could increase the shelf life, and this technique may be applied for other fish species preservation.&#x0D; Jahangirnagar University J. Biol. Sci. 8(2): 25-33, 2019 (December)

Enhanced performance of anaerobic digestion of cephalosporin C fermentation residues by gamma irradiation-induced pretreatment

Antibiotic fermentation residues is a hazardous waste due to the existence of residual antibiotics and antibiotic resistance genes (ARGs), probably leading to the induction and spread of antibiotic resistant bacteria (ARB) in the environment, which could pose potential harm to the ecosystem and human health. It is urgent to develop an effective technology to remove the residual antibiotics and ARGs. In this study, the anaerobic digestion combined with gamma irradiation was applied for the disposal and utilization of cephalosporin C fermentation residues. The experimental results showed that the antibacterial activities of cephalosporin C against Staphylococcus aureus were significantly decreased after anaerobic digestion. The removal of tolC, a multidrug resistant gene, was improved up to 100% by the combination of gamma irradiation and anaerobic digestion compared to solely anaerobic digestion process, which may be due to the changes of microbial community structures induced by gamma irradiation.

Gamma Radiation and Hydrogen Peroxide Based Advanced Oxidation Process for the Degradation of Disperse Dye in Aqueous Medium

Abstract In view of promising efficiency of advanced oxidation process (AOP), gamma radiation in combination with H2O2 was employed for the degradation of disperse red 73 (DR73) dye. Cs-137 gamma radiation source was used for dye aqueous solution irradiation. The process variables such as pH (3–9), H2O2 concentration (0.3–0.9 mL), gamma radiation absorbed dose (1–20 kGy) and DR73 initial concentration (50–150 mg/L) were optimized for maximum degradation of dye. The efficiency of AOP was evaluated on the basis of dye degradation, water quality parameters and toxicity reduction. Degradation of DR73 was achieved 69% using gamma radiation absorbed dose of 20 kGy and at the same dose 96.3% degradation was achieved in the presence of 0.9 mL/L H2O2. The dye degradation found to be dependent on dye initial concentration and pH of the medium. The radiolytic progress of DR73 was monitored by Fourier transform infrared (FTIR) and UV-Visible spectroscopy. The chemical oxygen demand (COD) and biological oxygen demand (BOD) were reduced significantly in response of treatment of dye at optimum conditions of process variables. The toxicity of treated and un-treated dye solution was monitored by haemolytic and Ames assays. Results revealed that the toxicity of DR73 dye was also reduced significantly after treatment. Findings revealed that the gamma radiation based AOPs are promising and could possibly be used for the remediation of textile wastewater contains toxic dyes.

Removal of heavy metals (Cu2+ and Cd2+) from effluent using gamma irradiation, titanium dioxide nanoparticles and methanol

Heavy metal pollution has become one of the most serious environmental problems. The aim of this study was to achieve an efficient treatment process of effluents containing 1 mM copper (Cu2+) and cadmium (Cd2+) ions using a combination of gamma irradiation, methanol and TiO2 nanoparticles under different pH values. The results showed that in acidic conditions, removal of Cu2+ and Cd2+ ions by physical adsorption was less than 15% and adsorption of Cd2+ was more than that of Cu2+. In the same condition, the Cu2+ removal percentage by irradiation was greater than that of Cd2+. In basic solutions, due to precipitation of Cd and Cu hydroxides, it was not possible to carry out adsorption experiments on Cd2+ and Cu2+ ions removal by TiO2 and gamma irradiation. Cu2+ and Cd2+ ions removal processes under different conditions could be depicted by the first order kinetics model. The combined application of TiO2 and methanol enhanced Cu2+ and Cd2+ ions removal at all pH levels examined. However, using the combination of TiO2 and methanol at acidic solutions facilitated completely removal of Cu2+ and Cd2+ ions. So that, only using 50 kGy irradiation dose with combination of TiO2 nanoparticles and methanol led to the removal of 99% of coexisting Cu2+ and Cd2+ ions from the acidic wastewater.

The investigation of the combined effects of gamma irradiation and environmental manipulation on mortality and sterility of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)

Abstract With respect to the limitations use of methyl bromide and phosphine, employing ionizing radiation to control stored product pests has attracted great attention. The aim of this study is the investigation of the combined effects of gamma irradiation as viable alternatives to synthetic insecticides and environmental management on mortality and sterility of Rhyzopertha dominica (Fabricius) in a wheat cultivar (Gascogen). The effect of doses range from 30 to 2000 Gy gamma irradiation in combination with manipulation of temperature (15, 21, 27 and 32 °C) and relative humidity (20%, 50%, 65% and 85%) on 5–10 days old adults of R. dominica in Gascogen cultivar of wheat were explored. The experiments were repeated three times and conducted in The Nuclear Agriculture Research School in Karaj and laboratory of shahid steki silo in shahre-kord. Probit analysis revealed that both temperature and relative humidity had combined effects when used with gamma irradiation. The lowest doses of gamma ray required to kill 25% (14.2 Gy) and 50% (610.8 Gy) of the population (LD25 and LD50) were recorded at 21 °C and 85% relative humidity respectively. The low dose for 99% mortality (LD99; 2386.7 Gy) was recorded for beetles maintained at 21 °C and 50% relative humidity. The effect of temperature (15, 21, 27 and 32 °C) on sterility caused by gamma irradiation was also investigated. The results showed that the F1 generation emerged only when the beetles were treated with doses of 0–100 Gy at 32 °C and 0–70 Gy at 27 °C. These results indicate that temperature and relative humidity play an important role in the susceptibility of the lesser grain beetle to gamma irradiation. The results suggest that controlling the efficiency of gamma radiation through environmental control allows the use of low doses of gamma radiation that have a less harmful effect on human health, non-target organisms and seed agronomic features.