Methods of Thermal Treatment of Radioactive Waste

Throughout the world, and especially in the European Union, numerous technologies for the thermal treatment of radioactive waste are available or being developed. These technologies can be applied to a large range of different radioactive waste streams, including non-standard types of waste that present specific waste management challenges. Thermal treatment can result in a significant reduction in volume and hazard, which are beneficial for safe storage and disposal. Thermal treatment also removes organic material that can form complexing agents and increase the mobility of radionuclides in the landfill. In the paper, basic thermal techniques are presented, and some examples of the installations are shown. Common knowledge of these methods may result in an increased public acceptance of nuclear energy in a country just introducing it, as Poland is.

Zein-Based Films Containing Monolaurin/Eugenol or Essential Oils with Potential for Bioactive Packaging Application

Zein is renewable plant protein with valuable film-forming properties that can be used as a packaging material. It is known that the addition of natural cross-linkers can enhance a film’s tensile properties. In this study, we aimed to prepare antimicrobial zein-based films enriched with monolaurin, eugenol, oregano, and thyme essential oil. Films were prepared using the solvent casting technique from ethanol solution. Their physicochemical properties were investigated using structural, morphological, and thermal techniques. Polar and dispersive components were analyzed using two models to evaluate the effects on the surface free energy values. The antimicrobial activity was proven using a disk diffusion method and the suppression of bacterial growth was confirmed via a growth kinetics study with the Gompertz function. The films’ morphological characteristics led to systems with uniform distribution of essential oils or eugenol droplets combined with a flat-plated structure of monolaurin. A unique combination of polyphenolic eugenol and amphiphilic monoglyceride provided highly stretchable films with enhanced barrier properties and efficiency against Gram-positive and Gram-negative bacteria, yeasts, and molds. The prepared zein-based films with tunable surface properties represent an alternative to non-renewable resources with a potential application as active packaging materials.

Thermally Stimulated Depolarisation Studies of Methyl Acrylic Acid (MAA) Doped Ethyl Cellulose (EC)

Thermally stimulated depolarisation current (TSDC) of polarised samples of methyl acrylic acid (MAA) doped ethyl cellulose (EC) films of about 25 µm thickness has been recorded as a function of temperature, electric field, heating rates and storage times. Two current maxima in positive direction and found around 60 and 110oC for doped sample with ethyl cellulose. FTIR of doped EC are represented the different phenomena of TSDC. Thermal sampling technique showed that the relaxation is distributed. Differentia thermal analysis gave a second-order transition at bout 345K because of good correlation between both thermal techniques it is concluded that the TSD peak is associated with glass transition of the polymer, and therefore it involves the motion of large parts of the polymer chains.

Emerging Non-thermal Technologies for the Extraction of Grape Anthocyanins

Anthocyanins are flavonoid pigments broadly distributed in plants with great potential to be used as food colorants due to their range of colors, innocuous nature, and positive impact on human health. However, these molecules are unstable and affected by pH changes, oxidation and high temperatures, making it very important to extract them using gentle non-thermal technologies. The use of emerging non-thermal techniques such as High Hydrostatic Pressure (HHP), Ultra High Pressure Homogenization (UHPH), Pulsed Electric Fields (PEFs), Ultrasound (US), irradiation, and Pulsed Light (PL) is currently increasing for many applications in food technology. This article reviews their application, features, advantages and drawbacks in the extraction of anthocyanins from grapes. It shows how extraction can be significantly increased with many of these techniques, while decreasing extraction times and maintaining antioxidant capacity.

THERMAL AND NON-THERMAL METHODS OF TREATMENT OF PATIENTS WITH PRIMARY VARICOSЕ DISEASES OF THE LOWER LIMBS OF STAGE C2

Treatment results of primary varicose disorders has been shown. The experience of using of thermal (endovenous laser ablation) and non-thermal methods (endovenous mechanochemical ablation, echo-controlled introduction of bioglue) in treatment of stage C2 chronic venous is shown. The purpose of this work is to evaluate the efficiency of endovenous ablation techniques. The treatment of 58 patients was analyzed. In the group of patients who underwent endovenous laser obliteration, reflux was not detected. In the group of patients with mechanochemical obliteration, reflux was determined in 3 patients (27.2%) at follow-up after 3 months required supplementation with foam sclerobliteration. In the group of patients with the introduction of bio glue, reflux was determined in 1 patient (20%) at the examination after 3 months. The received results lead to conclusion, that endovenous laser coagulation of affected veins is a reliable method of threatment, the gold standard. The advantage of non-thermal methods is the absence of thermal effects on the paravenous structures, respectively, patients have no pain during the procedure, increases comfort, and there is no risk of damage to the paravenous nerves. Another advantage of non-thermal techniques is no need to use of tumescent anesthesia, since only one puncture is required for the operation, which is comfortable for patients. The use of adhesive vein obliteration is justified in patients with signs of a short reflux duration and has an advantage for the patient due to the absence of the need for compression in the postoperative period. Non-thermal methods require further research and widespread implementation in practice.

Non-destructive Testing of Wooden Elements

Examining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a significant part of the structure. To achieve acceptable results, test methods should take into account the anisotropic nature of wood, which includes the shape of annual rings, as well as the location of the core in crosssection. To adopt methods based on physical effects, profound knowledge of wood physics is needed, particularly of interdependence. Apart from simple tests such as a visual inspection or tapping that are used to determine near-surface defects, non-destructive testing (NDT) plays an important role in the process. This paper presents the methods of non-destructive testing of wooden elements. These methods include tests conducted with ground penetrating radar (GPR), thermal techniques, microwaves, acoustic emission, ultrasonic tomography, and X-ray tomography. The paper summarises the use of non-destructive methods, indicating their advantages, disadvantages as well as some limitations.

Exploring the composition and volatility of secondary organic aerosols in mixed anthropogenic and biogenic precursor systems

Secondary organic aerosol (SOA) formation from mixtures of volatile precursors may be influenced by the molecular interactions of the components of the mixture. Here, we report measurements of the volatility distribution of SOA formed from the photo-oxidation of o-cresol, α-pinene, and their mixtures, representative anthropogenic and biogenic precursors, in an atmospheric simulation chamber. The combination of two independent thermal techniques (thermal denuder, TD, and the Filter Inlet for Gases and Aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer, FIGAERO-CIMS) to measure the particle volatility, along with detailed gas- and particle-phase composition measurements, provides links between the chemical composition of the mixture and the resultant SOA particle volatility. The SOA particle volatility obtained by the two independent techniques showed substantial discrepancies. The particle volatility obtained by the TD was wider, spanning across the LVOC and SVOC range, while the respective FIGAERO-CIMS derived using two different methods (i.e. calibrated Tmax and partitioning calculations) was substantially higher (mainly in the SVOC and IVOC, respectively) and narrow. Although the quantification of the SOA particle volatility was challenging, both techniques and methods showed similar trends, with the volatility of the SOA formed from the photo-oxidation of α-pinene being higher than that measured in the o-cresol system, while the volatility of the SOA particles of the mixture was between those measured at the single-precursor systems. This behaviour could be explained by two opposite effects, the scavenging of the larger molecules with lower volatility produced in the single-precursor experiments that led to an increase in the average volatility and the formation of unique-to-the-mixture products that had higher O:C, MW, OSc‾ and, consequently, lower volatility compared to those derived from the individual precursors. We further discuss the potential limitations of FIGAERO-CIMS to report quantitative volatilities and their implications for the reported results, and we show that the particle volatility changes can be qualitatively assessed, while caution should be taken when linking the chemical composition to the particle volatility. These results present the first detailed observations of SOA particle volatility and composition in mixed anthropogenic and biogenic systems and provide an analytical context that can be used to explore particle volatility in chamber experiments.

John Edwin Field. 20 September 1936—21 October 2020

John Field was a brilliant experimental physicist who made major contributions to the physics and chemistry of solids. His research interests spanned a very wide range of topics, most of them involving energetic phenomena. These areas included the strength properties of solids, fracture growth, impact and erosion phenomena, shock physics, reactivity of solids, explosive initiation, lasers, acoustics and medical physics. Within the Physics and Chemistry of Solids Group in the Cavendish Laboratory, he developed the best-equipped high-speed camera facility in any university in Europe, including seven that achieved frame rates in excess of 10 6 frames per second. In addition to the cameras, extensive use was made of ultrasonics, optical and electron microscopy, mass spectroscopy and thermal techniques. He played an important national role in advising the Ministry of Defence on a wide range of topics in energetic phenomena and materials science, which led to practical engineering solutions. He was an outstanding supervisor of doctoral students, who remember him fondly.