Irradiated Products Research Articles

Application of certified reference materials of absorbed dose for process validation of irradiation of medical supplies and food products

At present, radiation technologies are most commonly applied for sterilization of medical supplies and irradiation of food products. The results of radiation treatment cannot be fully verified by subsequent non-destructive testing. Therefore, irradiation processes and equipment used for radiation treatment should be subject to mandatory validation and certification. In this paper, we present the results obtained during process validation of radiation-technological installations based on electron accelerators by investigating absorbed dose in irradiated products.

Effect of electron and X-ray irradiation on microbiological and chemical parameters of chilled turkey

The purpose of this work was to compare the effect of electron and X-ray irradiation on microbiological content and volatile organic compounds in chilled turkey meat. Dose ranges which significantly suppress the pathogenic microflora while maintaining the organoleptic properties of the turkey meat are different for electron and X-ray irradiation. According to the study it is recommended to treat chilled turkey using X-ray irradiation with the dose ranging from 0.5 to 0.75 kGy, while in electron irradiation permissible doses should be within 0.25–1 kGy. Three main groups of volatile compounds: alcohols, ketones, and aldehydes—were found in irradiated and non-irradiated samples of turkey meat. It was found that the total amount of aldehydes, which are responsible for the formation of a specific odor of irradiated meat products, increases exponentially with the increase in the absorbed dose for both types of irradiation. It was established that acetone can be used as a potential marker of the fact of exposure of low-fat meat products to ionizing radiation.

Assessment of biological safety of irradiated feed and food products

Assessment of biological safety of irradiated feed and food products

Radiation-Induced Solid-State Transformations of Uranyl Peroxides.

Single-crystal X-ray diffraction studies of pristine and γ-irradiated Ca2[UO2(O2)3]·9H2O reveal site-specific atomic-scale changes during the solid-state progression from a crystalline to X-ray amorphous state with increasing dose. Following γ-irradiation to 1, 1.5, and 2 MGy, the peroxide group not bonded to Ca2+ is progressively replaced by two hydroxyl groups separated by 2.7 Å (with minor changes in the unit cell), whereas the peroxide groups bonded to Ca2+ cations are largely unaffected by irradiation prior to amorphization, which occurs by a dose of 3 MGy. The conversion of peroxide to hydroxyl occurs through interaction of neighboring lattice H2O molecules and ionization of the peroxide O-O bond, which produces two hydroxyls, and allows isolation of the important monomer building block, UO2(O2)2(OH)24-, that is ubiquitous in uranyl capsule polyoxometalates. Steric crowding in the equatorial plane of the uranyl ion develops and promotes transformation to an amorphous phase. In contrast, γ-irradiation of solid Li4[(UO2)(O2)3]·10H2O results in a solid-state transformation to a well-crystallized peroxide-free uranyl oxyhydrate containing sheets of equatorial edge and vertex-sharing uranyl pentagonal bipyramids with likely Li and H2O in interlayer positions. The irradiation products of these two uranyl triperoxide monomers are compared via X-ray diffraction (single-crystal and powder) and Raman spectroscopy, with a focus on the influence of the Li+ and Ca2+ countercations. Highly hydratable and mobile Li+ yields to uranyl hydrolysis reactions, while Ca2+ provides lattice rigidity, allowing observation of the first steps of radiation-promoted transformation of uranyl triperoxide.

Femtosecond laser synthesis and comparative analysis of fluorescent carbon dots from L-lysine aqueous solution

Laser synthesis of fluorescent species from biomolecules in living cells and tissues offers unique capabilities for fluorescent bioimaging, yet little is known about its mechanisms and characteristics of products. We examine synthesis of fluorescent products from water solution of L-lysine upon irradiation by trains of femtosecond laser pulses with varying parameters. We demonstrate that irradiation products contain nanoscale carbon-based fluorescent particles (carbon dots) with multi-colour and excitation-dependent emission. Morphology, chemical composition and fluorescent characteristics of irradiation products strongly depend on laser pulses parameters.

Iodine release from high-burnup fuel structures: Separate-effect tests and simulated fuel pellets for better understanding of iodine behaviour in nuclear fuels

Iodine release modelling of nuclear fuel pellets has major uncertainties that restrict applications in current fuel performance codes. The uncertainties origin from both the chemical behaviour of iodine in the fuel pellet and the release of different chemical species. The structure of nuclear fuel pellet evolves due to neutron and fission product irradiation, thermo-mechanical loads and fission product chemical interactions. This causes extra challenges for the fuel behaviour modelling. After sufficient amount of irradiation, a new type of structure starts forming at the cylindrical pellet outer edge. The porous structure is called high-burnup structure or rim structure. The effects of high-burnup structure on fuel behaviour become more pronounced with increasing burnup. As the phenomena in the nuclear fuel pellet are diverse, experiments with simulated fuel pellets can help in understanding and limiting the problem at hand. As fission gas or iodine release behaviour from high-burnup structure is not fully understood, the current preliminary study focuses on (i) sintering of porous fuel samples with Cs and I, (ii) measurements of released species during the annealing experiments and (iii) interpretation of the iodine release results with the scope of current fission gas release models.Graphical abstract

Improvement of BIPV Efficiency by Application of Highly Reflective Surfaces at the Building Envelope

The use of concentrated solar irradiation for the improvement of electric generation improvement has been implemented on different scales, mainly in photovoltaic systems. High-concentration Fresnel lenses are widely chosen for this approach in large installations, while low-concentration systems are rather applied in medium-low scales. For the latter, the improvement on electric performance was revealed, even when no solar tracking was implemented. The presented work aims to analyse a low-concentration photovoltaic installation by a numerical approach. First, the reflective surfaces were designed geometrically considering the optimal slope determined for each month. Subsequently, different simulation techniques were used separately for prediction of solar irradiation and energy production. Three criteria were selected to analyze power generation: the highest increase in total annual solar irradiance on panels with reflective surfaces, the highest total annual solar irradiance collected, and the optimal slope of panels for the entire year. The increase in energy was found to not exceed 10% in the winter months. Whereas in the spring and summer months the energy improvement is about 15–20%. Moreover, it was observed that the temperature of the proposed concentration photovoltaic system increased significantly, reaching more than 90 °C, while for traditional PV panels it did not exceed 75 °C.

Irradiation influence on the chemical composition and morphological properties of the agricultural products

The article discusses the impact of radiation treatment of agricultural products on their chemical composition, which determines the nutritional value of products, as well as on the main properties of products. The main advantages of agricultural products that have undergone radiation treatment are given, related, inter alia, to an increase in their shelf life, prevention of diseases and insect damage. The world experience of increasing the volume of radiation processing products by type in comparison with the 2010 level is considered. The main criteria for radiation processing of food products and the levels of radiation doses required for absorption by products to achieve certain technological goals are presented. The influence of radiation doses of radiation on proteins, fats, carbohydrates and vitamins in agricultural products is indicated. The influence of radiation exposure on the growth and maturation of some crops is estimated. The possibility of the influence of changes in the structure and composition of irradiated food products on the human body is emphasized. The factors that ensure the profitability of farms that use the practice of radiation processing of agricultural products when supplying them to international markets are also given. The calculations are carried out on a model of a small farm specializing in the cultivation of cucumbers and tomatoes.

Quarantine treatment of hoa loc mango by electron beam irradiation

Using electron beam (EB) irradiation as quarantine treatment for fresh fruits in particular and foods of plant origin in general is a growing trend of the world. Our preliminary results on EB irradiation impacts on Hoa Loc mangoes showed that EB irradiation could be a suitable quarantine treatment for the Hoa Loc mango fruits having weight from 407 to 552g and thickness from 7.3 to 8.0 cm to ensure the dose uniformity ratio (DUR) among irradiated products is within limitation (DUR ≤ 2.5). Main quality parameters of irradiated mangoes were insignificantly affected by exposure to EB with the dose ranging from 0.4 to 0.8 kGy, though their weight loss, the color indices L* (lightness), a* (redness to greenness), b* (yellowness to blueness) and firmness were slightly changed in compared with the control (non-irradiated). The results also revealed that vitamin C concentration of the fruits irradiated at 1 kGy much reduced and the hue angle significant increased by the end of storage. These results suggested that EB irradiation of Hoa Loc mangoes at the generic doses of 0.4 kGy is a feasible quarantine treatment that maintains the main the fruit quality.

An investigation using a validated method based on HS-SPME-GC-MS detection for the determination of 2-dodecylcyclobutanone and 2-tetradecylcyclobutanone in X-ray irradiated dairy products

The headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technique was used to investigate 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) as X-ray induced markers in irradiated dairy products. For the first time, an intensive study on several types of milk and cheeses, was carried out to evaluate both the suitability of this analytical technique for dairy products and how different factors related to these types of food, such as matrix composition, ripening time and technological processes, can affect 2-DCB and 2-TCB extraction. The results demonstrated that these analytes were identified in all types of irradiated samples, even if 2-TCB showed a lower sensibility than 2-DCB. Moreover, for both analytes, increasing irradiation dose over the experimental range of 0.5–5.0 kGy, a linear response was observed in all the matrices studied. The minimum dose level (MDL) and limit of detection (LOD), in irradiated and spiked samples, were 0.5 kGy and 5.0 μg L−1, respectively. Furthermore, linear correlation between 2-DCB and 2-TCB contents was demonstrated. Finally, chemometric analysis highlighted the influence of ripening time and dairy technological processes on extraction capability of the two investigated analytes.

Low temperature plasma irradiation products of sodium lactate solution that induce cell death on U251SP glioblastoma cells were identified

Low-temperature plasma is being widely used in the various fields of life science, such as medicine and agriculture. Plasma-activated solutions have been proposed as potential cancer therapeutic reagents. We previously reported that plasma-activated Ringer’s lactate solution exhibited selective cancer-killing effects, and that the plasma-treated L-sodium lactate in the solution was an anti-tumor factor; however, the components that are generated through the interactions between plasma and L-sodium lactate and the components responsible for the selective killing of cancer cells remain unidentified. In this study, we quantified several major chemical products, such as pyruvate, formate, and acetate, in plasma-activated L-sodium lactate solution by nuclear magnetic resonance analysis. We further identified novel chemical products, such as glyoxylate and 2,3-dimethyltartrate, in the solution by direct infusion-electrospray ionization with tandem mass spectrometry analysis. We found that 2,3-dimethyltartrate exhibited cytotoxic effects in glioblastoma cells, but not in normal astrocytes. These findings shed light on the identities of the components that are responsible for the selective cytotoxic effect of plasma-activated solutions on cancer cells, and provide useful data for the potential development of cancer treatments using plasma-activated L-sodium lactate solution.

Rooftop photovoltaic potential in Istanbul: Calculations based on LiDAR data, measurements and verifications

Usage of solar energy is increasing steadily especially in the rooftop installations of buildings in large cities. This study contains calculations of electrical energy produced by photovoltaic panels placed on roofs of buildings for city of Istanbul using building data and verify calculated results by a mobile measurement system. Three dimensional city model utilizes light detection and ranging data that covers an area of 5400 km2 for the whole city. The main object classes such as ground, building, vegetation were derived, buildings are vectorized and a digital elevation model are used for the generation of a second level of detail. Using the geometric data of the buildings in Istanbul as input to the developed software, the electricity production of panels is calculated on the suitable roofs of the buildings considering the observed climatic conditions and solar radiation for the city. A photovoltaic weather mobile vehicle measurement system was designed and applied for verification of developed model in eight different areas of Istanbul for stationing 50 days at each location. Results of difference between measurements and calculations of solar irradiation and electrical energy production are 2.44% and 14.70%, respectively. Batch processing was performed on 39 districts of Istanbul with 1.3 million buildings and annual electrical energy production from the roofs of all buildings is calculated to be 30.8 TWh at the point of common coupling to the utility. Total rooftop electricity production of Istanbul has a potential to meet 67% of the total electricity consumption for the year 2019.

European inter-comparison studies as a tool for perfecting irradiated food detection methods

Abstract In this paper, we present the results of inter-comparison studies on identification of irradiated food carried out by the leading European laboratories from 1991 to 2018. In 1990s, the Federal Institute for Health Protection of Consumers and Veterinary Medicine in Germany played the leading role in the organization of the inter-laboratory tests on this subject. At the beginning of the present century, the Spanish Agency for Food Safety and Nutrition and Food National Spanish Centre took over this role. In total, 47 international tests were carried out in which nearly 500 samples of alimentary products were analysed in 37 laboratories from 14 European countries. The tests were aimed at proving the reliability of analytical methods – thermoluminescence (TL), photostimulated luminescence (PSL), and electron paramagnetic resonance (EPR) spectroscopy – for identification of specific irradiated food products and to control the analytical skills and experience of participating laboratories. The results made possible a discussion on why some irradiated food samples are more difficult for identification. In general, the tests showed that TL measurements of products such as herbs, nuts, peppers, and raisins, and EPR studies of fish and chicken bones, fresh strawberries, and dried fruits could be used as reliable control methods. The challenge that control laboratories are facing now, is related to the identification of complex food products such as diet supplements or biopharmaceuticals, in which only some additives are irradiated.

An improved photocatalytic activity of H2 production: a hydrothermal synthesis of TiO2 nanostructures in aqueous triethanolamine

Abstract In this study, novel hydrothermal synthesis is used to explore the impact of photocatalytic activity on H2 production using an aqueous solution of triethanolamine (TEoA) in TiO2 nanostructures designed with varying molar concentrations of HCl, and the production of molecular hydrogen is explored as a function of molar concentration. A solar simulator is utilized to assess the photocatalytic activities of methyl orange degradation under UV light irradiation and molecular H2 production. Also, XRD patterns and SEM images are explored to show agglomerated nanoparticle formation, and an EDX spectrum is employed to confirm TiO2 compositions. The band gap analysis of produced nanostructures is performed using a UV-Vis spectrometer and is found to be varying in between 2.5 and 3.0 eV, while the maximum methyl orange degradation corresponds to 1.0 M concentration of HCl, indicating an enhanced hydrogen production. To meet the foreseeable future energy crises and worsening environmental challenges, we may need sustainable energy sources, and photocatalysis molecular H2 production offers a viable alternative to fossil fuels that can be employed to tackle future difficulties.

EFFECT OF GAMMA IRRADIATION TECHNIQUE ON THE MICROBIAL AND NUTRITIONAL QUALITY OF EDIBLE BAMBOO SHOOT (Dendrocalamus asper) FOR SHELF-LIFE ENHANCEMENT

The present investigation was performed to evaluate the potential of gamma radiation as a postharvest technology to preserve bamboo shoots. For this, Dendrocalamus asper shoots were gamma irradiated in the dose range of 0.5 to 5.0 kGy followed by storage at 5 ± 2 °C temperature dipped into 2% NaCl solution. Acceptability of the irradiated product was assessed based on microbial, physicochemical, and organoleptic attributes as well as induced radioactivity (food safety parameter). Results of the study revealed that a dose of 2.5 kGy was sufficient to complete removal of microbial load from the bamboo shoot up to 4 log reductions when compared with the unirradiated sample. No significant changes were found in physicochemical parameters including protein, pH, moisture, HCN content, and minerals. Organoleptic evaluation for different parameters were was within the acceptable criteria up to 240 days, hence 2.5 kGy doses of irradiation had the best preservation effect on the bamboo shoots of D. asper. The result of this study suggests that irradiation could be a potential method for maintaining the quality of bamboo shoots during storage.

Modeling primary production: Developing the BZI model from the production-irradiance (P-I) curves

The linearity of the BZI (biomass, photic depth and irradiance) regression model for the estimate of depth-integrated primary productivity in the water column is evaluated. It is shown that the linear model can be derived from traditional production-irradiance (P-I) curves by assuming a linear production-irradiance relationship. A correction tem is obtained for water depth shallower than the photic depth. The analysis revealed that the slope of the linear BZI model is determined by the slope of the P-I curve. Following similar steps and assumptions, some of the well-known nonlinear light functions such as Steele's function, Smith's function and the Monod function were analytically integrated yielding nonlinear BZI models which go through the origin naturally allowing zero productivity at zero light. The nonlinear model integrated from Steele's function was successfully applied to three subtropical estuaries in Florida: the St. Lucie Estuary on the east coast, the Caloosahatchee River and Estuary and the Escambia Bay on the west coast. Despite being more faithful to theory (zero intercept), the non-linear version yielded only slightly better results than the linear model.

Determination of chemical and microbiological characteristics of meat products treated by radiation

Radiation treatment of food products carried out to increase their shelf life can result in chemical transformations initiated by free radicals. Volatile compounds (alcohols, aldehydes, ketones, etc.) formed, in particular, as a result of lipid oxidation, impair the organoleptic properties of products. Method of gas chromatography-mass spectrometry (GC-MS) makes it possible to identify the fact of food processing by detection of volatile marker compounds: in the case of meat products, the existing standard brings under regulation detection of 2-alkylcyclobutanones, however, the products with a reduced fat content, such as turkey and chicken, require an alternative marker. The results of GKh-MS study revealed the dependence of microbiological parameters and the content of various volatile organic substances in chilled turkey meat on the dose of electron radiation. It is shown that the total amount of alcohols, ketones and aldehydes (11 compounds) decreases exponentially with an increase in the absorbed dose. An increase in the radiation dose leads to a higher content of carbonyl compounds (aldehydes and acetone), which results in a specific taste and smell of the irradiated products. At the same time, the acetone concentration increases linearly with the absorbed dose, which makes it possible to use acetone as a potential marker of the degree of irradiation of low-fat meat products. Irradiation in the «working» doses (0.5 – 1 kGy) significantly suppresses the pathogenic microflora and keeps the organoleptic properties of the product.

Dataset for the Solar Incident Radiation and Electricity Production BIPV/BAPV System on the Northern/Southern Façade in Dense Urban Areas

The prosperous implementation of Building Integrated Photovoltaics (BIPV), as well as Building Attached Photovoltaics (BAPV), needs an accurate and detailed assessment of the potential of solar irradiation and electricity production of various commercialised technologies in different orientations on the outer skins of the building. This article presents a dataset for the solar incident radiation and electricity production of PV systems in the north and south orientations in a dense urban area (in the northern hemisphere). The solar incident radiation and the electricity production of two back-to-back PV panels with a ten-centimetre gap for one year are monitored and logged as primary data sources. Using Microsoft Excel, both panels’ efficiency is also presented as a secondary source of data. The implemented PV panels are composed of polycrystalline silicon cells with an efficiency of 16.9%. The results depicted that the actual efficiency of the south-facing panel (13–15%) is always closer to the standard efficiency of the panel compared to the actual efficiency of the north-facing panel (8–12%). Moreover, although the efficiency of the south-facing panel on sunny days of the year is almost constant, the efficiency of the north-facing panel decreases significantly in winter. This phenomenon might be linked to the spectral response of the polycrystalline silicon cells and different incident solar radiation spectrum on the panels. While the monitored data cover the radiation and system electricity production in various air conditions, the analysis is mainly conducted for sunny days, and more investigation is needed to analyse the system performance in other weather conditions (like cloudy and overcast skies). The presented database could be used to analyse the performance of polycrystalline silicon PV panels and their operational efficiency in a dense urban area and for different orientations.

Adaptive Irradiance Sampling for Many-Light Rendering of Subsurface Scattering.

Rendering a translucent material involves integrating the product of the transmittance-weighted irradiance and the BSSRDF over the surface of it. In previous methods, this spatial integral was computed by creating a dense distribution of discrete points over the surface or by importance-sampling based on the BSSRDF. Both of these approaches necessitate specifying the number of samples, which affects both the quality and the computation time for rendering. An insufficient number of samples leads to noise and artifacts in the rendered image and an excessive number results in a prohibitively long rendering time. In this article, we propose an error estimation method for translucent materials in a many-light rendering framework. Our adaptive sampling can automatically determine the number of samples so that the estimated relative error of each pixel intensity is less than a user-specified threshold. We also propose an efficient method to generate the sampling points that make large contributions to the pixel intensity taking into account the BSSRDF. This enables us to use a simple uniform sampling, instead of costly importance sampling based on the BSSRDF. The experimental results show that our method can accurately estimate the error. In addition, in comparison with the previous methods, our sampling method achieves better estimation accuracy in equal-time.

A study on UVC irradiance emitted by various types of UVGI products

There are many types of Ultra Violet Germicidal Irradiation (UVGI) products available in the market used in many applications such as sterilization and disinfection. These products are popular during the spread of pandemic COVID-19 and become an option of disinfection method for surface and air such as in office, hospital, hotel room and car. The objective of the study is to investigate the UVC lamps of the UVGI products based on their wavelength. This is to validate whether the product samples are using UVC lamp as stated in the specification which normally has 253.7 to 254 nm wavelength. Besides that, the UVC intensity level has been measured to determine the irradiance emitted by the lamps. The measurement was carried out at various distance to see the effectiveness of the UVGI in disinfection process at different size of spaces. UVC is categorised as non-ionising radiation and has potential health effects due to excessive exposure specially to eye and skin. The equipment used for the irradiance measurement is IL 1700 radiometer with UVC sensor and the measurement data recorded in microwatt/cm2. The irradiance level of the samples was compared with the permissible exposure limit to the members of public by International Commission on Non-Ionizing Radiation Protection (ICNIRP).