Low-level Radiation Research Articles

SISTEMA PARA EL CONTROL DE TEMPERATURA, APLICADO A LA DESHIDRATACIÓN DE MENTA MEDIANTE ACTUADORES LINEALES Y MARQUESINA DE DOBLE

The objective of this research was to determine the thermal performance of a solar dehydration system that allows controlling the temperature for the dehydration of aromatic herbs such as mint. The use of a double chamber marquee allowed obtaining high thermal values, even with low radiation levels. For temperature control, a system of vertical mobile beds was used in order to reach the programmed temperature. This temperature was monitored using an embedded Arduino-type system that allows both monitoring and controlling motors, as well as recording temperature information. It was possible to keep the temperature approximately constant at 40°C, the ideal value for drying aromatic and medicinal herbs.

Solar Radiation as an Isolated Environmental Factor in an Experimental Mesocosm Approach for Studying Photosynthetic Acclimation of Macrocystis pyrifera (Ochrophyta).

Solar radiation effects on the ecophysiology and biochemical responses of the brown macroalga Macrocystis pyrifera (L.) C. Agardh were evaluated using a mesocosm approach in Southern Chile. Treatments with different radiation attenuations were simulated with three vertical attenuation coefficients: (1) total (Kd = 0.8 m−1), (2) attenuated (Kd = 1.2 m−1), and (3) low (Kd = 1.6 m−1) radiation levels. Nutrient concentration and temperature did not show differences under the three light conditions. Photosynthetic activity was estimated by in vivo chlorophyll a (Chla) fluorescence under the three light treatments as an isolated physical factor in both in situ solar radiation in the field. This was achieved using a pulse amplitude-modulated (PAM) fluorometera—Diving PAM (in situ). Photosynthetic activity and biochemical composition were measured in winter during two daily cycles (1DC and 2DC) in different parts of the thalli of the plant: (1) canopy zone, (2) middle zone, and (3) down zone, associated with different depths in the mesocosm system. Nevertheless, the in situ electron transport rate (ETRin situ) was higher in the exposed thalli of the canopy zone, independent of the light treatment conditions. The concentration of phenolic compounds (PC) increases in the down zone in the first daily cycle, and it was higher in the middle zone in the second daily cycle. The Chla increased in the morning time under total and attenuated radiation in the first daily cycle. Solar radiation increasing at midday prompted the photoinhibition of photosynthesis in the canopy zone but also an increase in productivity and phenol content. Therefore, light attenuation in the water column drove key differences in the photo-physiological responses of M. pyrifera, with the highest productivity occurring in thalli positioned in the canopy zone when exposed to solar irradiance.

Radiation Safety and Electrophysiologists: Radiation Protection Status – Go for Zero Fluoroscopy European Heart Rhythm Association Registry

Background: The purpose of this study was to analyze electrophysiologists’ radiation-protective devices for occupational exposure across European countries. Methods: Data reported herein were gathered from the international, multicenter prospective Go for Zero Fluoroscopy registry performed in years 2018–2019. The registry encompassed 25 European electrophysiological centers from 14 countries and up to 5 operators from each center. Results: The analysis included 95 operators (median age: 39 years, 85% of male, median training time: 5 years). The most frequently used X-ray protection tools (used by ≥80% of the group) were lead aprons, thyroid shields, screens below the table, glass in the laboratory, and least often (<7%) protective gloves and cabin. No statistically significant differences regarding the number of procedures performed monthly, electrophysiologists’ experience and gender, and radiation exposure dose or radiation protection tools were observed, except lead thyroid shields and eyeglasses, which were more often used in case of fewer electrophysiological procedures performed (<20 procedures per month). Operators who were protected by >4 X-ray protection tools were exposed to lower radiation levels than those who were protected by ≤4 X-ray protection tools (median radiation exposure: 0.6 [0.2–1.1] vs. 0.2 [0.1–0.2] mSv per month, p < 0.0001; 1.1 [0.1–12.0] vs. 0.5 [0.1–1.1] mSv per year, p < 0.0001), respectively. Conclusions: Electrophysiologists’ radiation-protective devices for occupational exposure are similar across European centers and in accordance with the applicable X-ray protection protocols, irrespective of the level of experience, number of monthly performed EP procedures, and gender.

Lack of impact of radiation on blood physiology biomarkers of Chernobyl tree frogs

BackgroundHuman actions have altered natural ecosystems worldwide. Among the many pollutants released to the environment, ionizing radiation can cause severe damage at different molecular and functional levels. The accident in the Chernobyl Nuclear Power Plant (1986) caused the largest release of ionizing radiation to the environment in human history. Here, we examined the impact of the current exposure to ionizing radiation on blood physiology biomarkers of adult males of the Eastern tree frog (Hyla orientalis) inhabiting within and outside the Chernobyl Exclusion Zone. We measured the levels of eight blood parameters (sodium, potassium, chloride, ionized calcium, total carbon dioxide, glucose, urea nitrogen, and anion gap), physiological markers of homeostasis, as well as of liver and kidney function.ResultsLevels of blood physiology biomarkers did not vary in function of the current exposure of tree frogs to ionizing radiation within the Chernobyl Exclusion Zone. Physiological blood levels were similar in frogs inhabiting Chernobyl (both in areas with medium-high or low radiation) than in tree frogs living outside Chernobyl exposed only to background radiation levels.ConclusionsThe observed lack of effects of current radiation levels on blood biomarkers can be a consequence of the low levels of radiation currently experienced by Chernobyl tree frogs, but also to the fact that our sampling was restricted to active breeding males, i.e. potentially healthy adult individuals. Despite the clear absence of effects of current radiation levels on physiological blood parameters in tree frogs, more research covering different life stages and ecological scenarios is still needed to clarify the impact of ionizing radiation on the physiology, ecology, and dynamics of wildlife inhabiting radioactive-contaminated areas.

Role of meteorological factors in the transmission of SARS-CoV-2 in the United States

Improved understanding of the effects of meteorological conditions on the transmission of SARS-CoV-2, the causative agent for COVID-19 disease, is needed. Here, we estimate the relationship between air temperature, specific humidity, and ultraviolet radiation and SARS-CoV-2 transmission in 2669 U.S. counties with abundant reported cases from March 15 to December 31, 2020. Specifically, we quantify the associations of daily mean temperature, specific humidity, and ultraviolet radiation with daily estimates of the SARS-CoV-2 reproduction number (Rt) and calculate the fraction of Rt attributable to these meteorological conditions. Lower air temperature (within the 20–40 °C range), lower specific humidity, and lower ultraviolet radiation were significantly associated with increased Rt. The fraction of Rt attributable to temperature, specific humidity, and ultraviolet radiation were 3.73% (95% empirical confidence interval [eCI]: 3.66–3.76%), 9.35% (95% eCI: 9.27–9.39%), and 4.44% (95% eCI: 4.38–4.47%), respectively. In total, 17.5% of Rt was attributable to meteorological factors. The fractions attributable to meteorological factors generally were higher in northern counties than in southern counties. Our findings indicate that cold and dry weather and low levels of ultraviolet radiation are moderately associated with increased SARS-CoV-2 transmissibility, with humidity playing the largest role.

PPARγ gene expression analysis in psoriasis treatment

Introduction. PPARγ is the most studied PPAR subtype and is expressed predominantly in adipose tissue, heart, colon, kidney, spleen, intestine, skeletal muscle, liver, macrophages, and skin. In the skin, PPARγ controls the genetic regulation of gene network expression involved in cell proliferation, differentiation, and inflammatory responses. PPARγ (Peroxisome proliferator-activated receptor gamma) has only recently come to be considered a key player in the development and pathogenesis of psoriasis and psoriatic inflammatory conditions.Aim of the study. To study PPARγ gene expression in the affected skin of psoriasis patients in comparison with visually unaffected skin. To study changes in PPARγ gene expression level in psoriasis affected skin in comparison with unaffected skin in patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm.Materials and methods. Twelve patients with psoriasis participated in the study. Biopsies from unaffected skin areas were taken at a distance of about 3 cm from the affected skin. Analysis was performed by real-time PCR.Results and Discussion. We quantitatively measured PPARγ gene expression using RT-PCR in the affected skin of patients with psoriasis in comparison with visually unaffected skin in the same patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm (the short-wave part of the infrared range). The study experimentally showed a 1.3 ± 0.27-fold decrease in PPARγ gene expression in the affected skin of psoriasis patients on average. Significant increase in over-expression of PPARγ gene up to 2,13 ± 0,47 times was observed after treatment of patients with low-level laser radiation.Conclusions. PPARγ gene expression may be an indicator of the efficacy of psoriasis treatment at the molecular level, as well as become a new therapeutic target.

Investigating the consequence of chronic exposure to radiation on renal biomarkers among selected radiologic technologists

Introduction: Chronic radiation exposure, particularly among technicians using medical imaging instruments, may contribute to chronic disease, including renal dysfunction. Investigating the potential association of this exposure with biochemical changes may assist disease detection and prevention. Objectives: The study explores the risk of renal dysfunction among radiologic technologists (RTs) with ten years or more of diagnostic imaging experience to evaluate the association of accumulated radiation doses and possible renal injury. Patients and Methods: A retrospective analysis was performed on the effective accumulative radiation dose from 2009 to 2019 among RTs of radiological department at a general hospital in southern Saudi Arabia. Blood samples were collected, and key biomarkers analyzed using a fully automated biochemical analyzer. Serum levels of the following were measured; sodium, gamma-glutamyl transferase (GGT), chloride, creatine kinase (CK), calcium, albumin, urea, creatinine, lactate dehydrogenase, total protein and potassium. In statistical analysis, P&lt;0.05 was considered significant. Results: Even with exposure to only low-level radiation sources, RTs were statistically predisposed to variation in biochemical profiles. RTs exhibited GGT and CK levels higher than that of controls, while serum chloride was significantly low. Conclusion: The current study found a significant change in renal biochemical profiles among RTs who had worked in a radiological department for more than ten years. The association between GGT, CK with Kidney diseases was reported in several reports. Chronic exposure to radiation may contribute to a rise in GGT and CK levels and reduction of chloride and thus could develop the risk of renal diseases.

The potential of decorative building materials (marble) for retrospective thermoluminescence dosimetry

Among the various types of decorative materials used in Bangladeshi dwellings, the marble/marble stone is one of the most common ones that used largely for enhancing the beauty and/or aristocracy of the dwelling environment. In this study, the most commonly used, six types of marble stones, have been analyzed for retrospective accident dosimetry. With the interest of characterizing several key thermoluminescence properties to examine their potentiality for dosimetry, annealing - irradiation - readout steps have been done chronologically which comprises the analysis of glow curves, relative sensitivity, dose dependence, repeatability and fading. Considering the various TL parameters, marble 'Carrara' imported from Italy present relatively better capability for reconstruction of radiation dose in the dose range of 10–50 Gy. From fading result, it is clear that for reconstruction of absorbed dose up to four weeks of post exposure, the marble 'Carrara' is found to be the most reliable media among the studied marble types. The Zeff values for the various marble samples are found to be in the range of 13.65–19.12, comparing favorably in replace of TLD-200 (Zeff = 16.3) which can be used for low-level environmental radiation dosimetry. Present work constitutes the first study to investigate the potentials of marble stone for reconstruction of absorbed dose in the range of 10–50 Gy dose.

Enhancing the X-Ray Differential Phase Contrast Image Quality With Deep Learning Technique.

The purpose of this work is to investigate the feasibility of using deep convolutional neural network (CNN) to improve the image quality of a grating-based X-ray differential phase contrast imaging (XPCI) system. In this work, a novel deep CNN based phase signal extraction and image noise suppression algorithm (named as XP-NET) is developed. The numerical phase phantom, the ex vivo biological specimen and the ACR breast phantom are evaluated via the numerical simulations and experimental studies, separately. Moreover, images are also evaluated under different low radiation levels to verify its dose reduction capability. Compared with the conventional analytical method, the novel XP-NET algorithm is able to reduce the bias of large DPC signals and hence increasing the DPC signal accuracy by more than 15%. Additionally, the XP-NET is able to reduce DPC image noise by about 50% for low dose DPC imaging tasks. This proposed novel end-to-end supervised XP-NET has a great potential to improve the DPC signal accuracy, reduce image noise, and preserve object details. We demonstrate that the deep CNN technique provides a promising approach to improve the grating-based XPCI performance and its dose efficiency in future biomedical applications.

RADIOCHROMIC FILM CALIBRATION FOR DOSIMETRY IN CHEST CT SCANS

Phantoms can be used as quality control objects in computed tomography (CT) imaging and dosimetry in specific regions of interest. By means of phantom tests, alternatives can be created to optimize the acquisition protocols and thus modify the acquisition parameters to deposit lower levels of radiation to the patient, seeking a quality image for the diagnosis. Radiochromic films, GAFCHROMIC XR-AQ2 model, are used to measure the dose-response when exposed to radiation. The profile of the absorbed dose within a phantom is important because it allows an understanding of a larger reality. Calibration curves were obtained from radiochromic films using a cylindrical phantom made of polymethyl methacrylate (PMMA). This phantom has five openings, one central and four peripherals lagged 90°. The phantom was positioned in the isocenter of the gantry of a scanner manufactured by the Toshiba, model Asterion, using 120 and 135 kV voltage of the X-ray tube. The phantom peripheral openings were positioned similarly to positions 3, 6, 9, and 12 of the analog clock. The ionization chamber was used for the record values of the Air Kerma in PMMA, in the central and 12 positions when the central slice of the phantom was irradiated in the axial mode. The other openings were filled with rods also made of PMMA. Radiochromic film strips were placed into PMMA rods and the central and 12 openings were filled. The central area of the phantom was scanned in helical mode. The film strips were digitized and processed their images to have the calibration curve survey.

Trade-off between predation risk and behavioural thermoregulation drives resting behaviour in a cold-adapted mesocarnivore

Behavioural trade-offs arise when animals must decide to engage in one behaviour at the expense of another, potentially to the animal's detriment. Here, we investigate the existence of such a trade-off by exploring the relative influence of two important behavioural processes, thermoregulation and predation avoidance, on resting behaviour in a cold-adapted mesocarnivore, the wolverine, Gulo gulo. Using animal-borne biologgers, we evaluate the hypothesis that wolverine resting behaviour in both subnivean cavities and on surface snow beds is influenced by a combination of ambient weather conditions and predation risk. Specifically, we posit that although resting on the snow surface is more thermally advantageous in certain weather conditions, it is traded off against heightened predation risk. In support of the importance of thermoregulation, we find that wolverines rest almost exclusively in subnivean cavities at very low temperatures and low levels of solar radiation, and rest almost exclusively on the snow surface at higher temperatures and higher levels of solar radiation. In support of the importance of predation avoidance, we find that wolverines select more topographically concealed sites and are more vigilant while resting on the snow surface. We also find that wolverines are more vigilant at topographically exposed resting sites than at concealed sites. Together, these lines of evidence suggest that wolverines trade security from predators for thermal advantage at warmer ambient temperatures and higher solar radiation levels during winter, but that this trade-off is not necessary at lower temperatures when wolverines preferentially use subnivean cavities to simultaneously meet both demands. Parsing such contextually dependent trade-offs is important to understanding species' habitat selection, energy management and survival.

Low levels of ultra-violet radiation mitigate the deleterious effects of nitrate and thermal stress on coral photosynthesis

Reef ecosystems are under increasing pressure from global and local stressors. Rising seawater temperature and high ultraviolet radiation (UVR) levels are the main drivers of the disruption of the coral-dinoflagellate symbiosis (bleaching). Bleaching can also be exacerbated by nitrate contamination in coastal reefs. However, the underlying physiological mechanisms are still poorly understood. Here, we assessed the physiological and oxidative state of the scleractinian coral Pocillopora damicornis, maintained eight weeks in a crossed-factorial design including two temperatures (26 °C or 30 °C), and two nitrate (0.5 and 3 μM-enriched), and UVR (no UVR and 25/1.5 Wm−2 UVA/B) levels. Nitrate enrichment, and high temperature, significantly impaired coral photosynthesis. However, UVR alleviated the nitrate and temperature-induced decrease in photosynthesis, by increasing the coral's antioxidant capacity. The present study contributes to our understanding of the combined effects of abiotic stressors on coral bleaching susceptibility. Such information is urgently needed to refine reef management strategies.

Radiometric Performance Evaluation of FY-4A/AGRI Based on Aqua/MODIS.

Fengyun-4A (FY-4A) is the first satellite of the Chinese second-generation geostationary orbit meteorological satellites (FY-4). The Advanced Geostationary Radiation Imager (AGRI), onboard FY-4A does not load with high-precision calibration facility in visible and near infrared (VNIR) channel. As a consequence, it is necessary to comprehensively evaluate its radiometric performance and quantitatively describe the attenuation while using its VNIR data. In this paper, the radiometric performance at VNIR channels of FY-4A/AGRI is evaluated based on Aqua/MODIS data using the deep convective cloud (DCC) target. In order to reduce the influence of view angle and spectral response difference, the bi-directional reflectance distribution function (BRDF) correction and spectral matching have been performed. The evaluation result shows the radiometric performance of FY-4A/AGRI: (1) is less stable and with obvious fluctuations; (2) has a lower radiation level because of 24.99% lower compared with Aqua/MODIS; 3) has a high attenuation with 9.11% total attenuation over 2 years and 4.0% average annual attenuation rate. After the evaluation, relative radiometric normalization between AGRI and MODIS in VNIR channel is performed and the procedure is proved effective. This paper proposed a more reliable reference for the quantitative applications of FY-4A data.

Sensitivity of ENSO Simulation to the Convection Schemes in the NESM3 Climate System Model: Atmospheric Processes

The El Niño-Southern Oscillation (ENSO) is the most prominent climate system in the tropical Pacific. However, its simulation, including the amplitude, phase locking, and asymmetry of its two phases, is not well reproduced by the current climate system models. In this study, the sensitivity of the ENSO simulation to the convection schemes is discussed using the Nanjing University of Information Science and Technology Earth System version 3.0 (NESM3) model. Three convection schemes, including the default, the default coupled with the stochastic multicloud model (SMCM), and the default used in the Coupled Model Intercomparison Project Phase 6 (CMIP6), are implemented. The model results reveal that the low-level cloud cover and surface net shortwave radiation are best represented over the tropical Pacific in the model containing the SMCM. The simulations of the ENSO behavior’s response to changes in the convection scheme are not uniform. The model results reveal that the model containing the SMCM performs best in terms of simulating the seasonal cycle of the sea surface temperature anomaly along the equatorial Pacific, the phase locking, and the power spectrum of ENSO but with a modest ENSO amplitude. Compared to the model containing the default convection scheme, the coupling of the default scheme and the SMCM provides a good simulation of the ENSO’s asymmetry, while the model containing the CMIP6 convection scheme outperforms the others in terms of the simulation of the ENSO’s amplitude. Two atmospheric feedback processes were further discussed to investigate the factors controlling the ENSO’s amplitude. The analyses revealed that the strongest positive atmospheric Bjerknes feedback and the thermodynamic damping of the surface net heat flux occurred in the model containing the CMIP6 convection scheme, suggesting that the atmospheric Bjerknes feedback may overwhelm the heat flux damping feedback when determining the ENSO’s amplitude. The results of this study demonstrate that perfectly modeling and predicting the ENSO is not simple, and it is still a large challenge and issue for the entire model community in the future.

Techno-economic study of compound parabolic collector in solar water heating system in the northern hemisphere

Abstract The auxiliary requirement of a solar water heating system is an index of the end-user's cost and, thus, the feasibility of the system. Within this study several locations worldwide with high and low solar radiations and electricity prices in latitudes of 0, 15, 30, 45 and 60°N have been selected and the effect of employing a Compound Parabolic Collector (CPC) on the yearly auxiliary energy saving of a solar water heating system has been investigated numerically and compared with the energy performance of a typical flat plat collector. The yearly solar radiation in selected locations ranges from 2509 to 852 kWh/m2. Electricity prices also vary from 0.04 to 0.28 USD/kWh. According to results, in all selected locations, CPC shows an advantage over flat plate collectors in auxiliary power consumption. The yearly auxiliary heating rate decreased maximum by 27% in Shambat in Sudan and minimum by 5% in Chongqing in China. As solar radiation increases, the advantage of CPC becomes more meaningful. Regarding costs and economic feasibility of CPC, maximum net present values are all achieved in the locations with the highest electricity prices and not very high discount rates. Selected locations in Japan and Italy with maximum NPV values of 1,981 and 1,811 UDS, respectively, have the highest electricity rates of 0.28 and 0.27 USD/kWh, in respect. In both countries, the discount rate is relatively low and about 0.3. Moreover, among the selected locations, NPV of investment on CPC in Gabon, Guatemala, USA, Japan and Sweden with low levels of solar radiation, between 974 and 1,942 kWh/m2, is between 832 and 1,981 USD at the end of the project’s life time and justifies the employment of this type of solar collector in sites with high energy prices, even though not much solar radiation is available. It could be concluded that in locations with high electricity prices and not very much discount rates, even in cases of relatively low solar radiation, investment in CPC would yield the highest profits.

Ablation of cells in mice using antibody-functionalized multiwalled carbon nanotubes (Ab-MWCNTs) in combination with microwaves

This is a proof-of-principle study on the combination of microwaves and multiwalled carbon nanotubes to induce in vivo, localized hyperthermic ablation of cells as a potential methodology for the treatment of localized tumors. Compared to conventional methods, the proposed approach can create higher temperatures in a rapid and localized fashion, under low radiation levels, eliminating some of the unwanted side effects. Following successful ablation of cancer cells in cell culture and zebrafish tumor-xenograft models, it is hypothesized that a cancer treatment can be developed using safe microwave irradiation for selective ablation of tumor cells in vivo using carbon nanotube-Antibody (CNT-Ab) conjugates as a targeting agent. In this study, mice were used as an animal model for the optimization of the proposed microwave treatment strategy. The safe dose of CNT-Ab and microwave radiation levels for mice were determined. Further, CNT-Ab distribution and toxicology in mice were qualitatively determined for a time span of two weeks following microwave hyperthermia. The results indicate no toxicity associated with the CNT-Ab in the absence of microwaves. CNTs are only found in the proximity of the site of injection and have been shown to effectively cause hyperthermia induced necrosis upon exposure to microwaves with no noticeable damage to other tissues that are not in direct contact with the CNT-Ab. To understand the cellular immune response towards CNT-Abs, transgenic zebrafish with fluorescently labeled macrophages and neutrophils were used to assay for their ability to phagocytize CNT-Ab. Our results indicate that macrophages and neutrophils were able to actively phagocytose CNT-Abs shortly after injection. Taken together, this is the first study to show that CNTs can be used in combination with microwaves to cause targeted ablation of cells in mice without any side effects, which would be ideal for cancer therapies.

Controlling Photosynthetic Light Harvesting at the Single Protein Level

The light-harvesting complexes of oxygenic photosynthetic organisms have to balance two vital functions: efficient transport of photoexcitations to the photochemical reaction center under low levels of solar radiation and efficient photoprotection under intense solar radiation and other stress conditions, during which photoexcitations are rapidly dissipated as heat. Most light-harvesting proteins bind a dense arrangement of chromophores, ensuring that subtle protein conformational changes are often sufficient to switch between the complexes’ light-harvesting and photoprotective functions. Single-molecule spectroscopy allows one to follow these switches in real time. I will show how this technique has led to the discovery of new light-harvesting and photoprotective states in various photosynthetic light-harvesting complexes and how the population equilibrium between these states can be finely tuned at the single protein level by the incident photon flux, the pH, the chromophore arrangement, and by controlling the interaction with small, accessory proteins. I will also demonstrate how the light-harvesting efficiency of these complexes can be actively controlled through interactions with localized surface plasmons from metallic nanostructures to dramatically alter the radiative and nonradiative deexcitation rates.

Hourly Surface Observations Suggest Stronger Solar Dimming and Brightening at Sunrise and Sunset Over China

AbstractExploration of the diurnal pattern of global dimming and brightening has been limited by the paucity of high‐temporal resolution observations. Based on 22 years’ continuous observations of hourly surface solar radiation (SSR) over 96 stations across China for 1993–2014, this study evidences higher relative changes in diurnal SSR in terms of both frequency and magnitude at sunrise and sunset, with a longer pathway for the sun passing through the atmosphere, than the hours in between. This, in general, leads to a further shortening of the days between sunrise and sunset in the cold seasons and the polluted region of north China with low radiation levels but a further extension in the other seasons and regions with sufficient sunlight. Pollution reduction by 39.4%–69.7% during the 2014 Asia‐Pacific Economic Cooperation summit at Beijing are accompanied with a 10.4–80.0% rebound of diurnal SSR in the forenoon and late afternoon.

Using Geiger Dosimetry EKO-C Device to Detect Ionizing Radiation Emissions from Building Materials

The purpose of the article is to check and assess what radiation is emitted by particular building materials with the passage of time. The analysis was performed with the EKO-C dosimetry device from Polon-Ekolab. The scope of the work included research on sixteen selected construction materials, divided into five groups. The analysis of the results showed that samples such as bricks (first group) and hollow blocks (second group) emit the highest radiation in the tested objects. When comparing these materials, the highest value was recorded when measuring the ceramic block of 15.76 mSv·yr−1. Taking into account the bricks, the highest value of radiation was shown by a full clinker brick, 11.3 mSv·yr−1. Insulation materials and finishing boards are two other groups of building materials that have been measured. They are characterised by a low level of radiation. In the case of materials for thermal insulation, the highest condition was demonstrated by graphite polystyrene of 4.463 mSv·yr−1, while among finishing boards, the highest value of radiation was recorded for the measurement of gypsum board of 3.76 mSv·yr−1. Comparing the obtained test results to the requirements of the Regulation of the Council of Ministers on ionizing radiation dose limits applicable in Poland, it can be noted that the samples examined individually do not pose a radiation risk to humans. When working with all types of samples, the radiation doses are added up. According to the guidelines of the regulation, the total radiation dose does not exceed 50 mSv·yr−1 and does not constitute a threat to human health.

LIBERTARIAN PHILOSOPHY VERSUS PROPERTARIAN DOGMA: A FURTHER REPLY TO BLOCK

This replies to Block 2019 (B19), which responds to Lester 2014 (L14). The main issues in the, varyingly sized, sections are as follows. 1 Further explanations of critical rationalism, the theory of liberty, and problems with the non-aggression principle. 2.1 The relationships among law, morality, and libertarianism. 2.2 The objective invasiveness of low-level radiation and that it is, therefore, a proactive imposition (albeit trivial) if someone inflicts it on non-consenting people. 2.3 The objective and subjective aspects of proactive impositions; and how clashes can be resolved. 2.4 How liberty relates to risk and self-ownership. 2.5 Libertarian initial acquisition versus absolute property rights by labour-mixing. 2.6 Organisational note. 2.7 Libertarianism and mens rea. 2.8 Libertarian rectification versus lex-talionis doubling. 2.9 Indirectly clashing rights, self-preservation, trespasser-hiker, flagpole-grasper, and landmine-layer. 2.10 A logical point is not a moral point. 2.11 Pacifism and libertarianism. 3.1 A weak criticism of utilitarianism. 3.2 Hedonometers; approximate interpersonal comparisons of utility imply libertarianism; what a libertarian is; libertarian rankings. 4. Libertarian philosophy versus propertarian dogma. Coda: the need to take seriously the philosophical problems with propertarian-justificationist libertarianism. Readers that might be interested include those engaging in libertarian philosophy and those using the Rothbardian/Blockian theoretical approach to libertarianism.