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Search Results (148)

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Keywords = air dose rate

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10 pages, 480 KiB  
Article
Aerosol Characteristics of Nebulized Tranexamic Acid 100 mg/mL for Hemoptysis Treatment—Proof-of-Concept Study
by Gerrit Seifert, Frank Erdnüß, Wolfgang Kamin and Irene Krämer
J. Pharm. BioTech Ind. 2025, 2(3), 12; https://doi.org/10.3390/jpbi2030012 - 28 Jul 2025
Viewed by 222
Abstract
Background: Off-label nebulization of tranexamic acid (TXA) solution is common practice for the treatment of hemoptysis. However, data regarding nebulization protocols, resulting aerodynamic parameters of the generated aerosol, and corresponding biopharmaceutical parameters are missing. The aim of this in vitro study was to [...] Read more.
Background: Off-label nebulization of tranexamic acid (TXA) solution is common practice for the treatment of hemoptysis. However, data regarding nebulization protocols, resulting aerodynamic parameters of the generated aerosol, and corresponding biopharmaceutical parameters are missing. The aim of this in vitro study was to investigate the aerosol characteristics of nebulized sterile, aqueous TXA solution. Methods: TXA solution 100 mg/mL was nebulized for 2 min by a multi-dose vibrating mesh nebulizer using 15 L/min and 30 L/min air flow rates. The generated aerosol was analyzed by a Next Generation Cascade Impactor. For each air flow rate, the mean Fine Particle Dose (FPD), Fine Particle Fraction (FPF), the Mass Median Aerodynamic Diameter (MMAD), and Geometric Standard Deviation (GSD) were quantified. Results: Nebulization at 15 L/min air flow rate resulted in a MMAD of 6.68 ± 0.23 µm and GSD of 2.02 ± 0.16. The FPD < 5 µm was 16.56 ± 0.45 mg, the FPF < 5 µm 28.91 ± 3.40%. Nebulization at 30 L/min air flow rate revealed a MMAD of 5.18 ± 0.12 µm and GSD of 2.14 ± 0.10. The FPD < 5 µm was 16.30 ± 1.38 mg, the FPF < 5 µm 35.43 ± 0.59%. Conclusions: Nebulization of TXA 100 mg/mL solution by a specified vibrating mesh nebulizer generated an aerosol particle distribution and deposition pattern suitable for the treatment of hemoptysis with bronchial origin. Full article
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14 pages, 1884 KiB  
Article
Study of Radon Radiation in the Area of the Akchatau Polymetallic Mine, Republic of Kazakhstan
by Yuriy Pak, Dmitriy Pak, Vladimir Matonin, Diana Ibragimova, Pavel Timoshenko, Yuriy Barkov, Anar Tebayeva and Pavel Medvedev
Atmosphere 2025, 16(7), 769; https://doi.org/10.3390/atmos16070769 - 23 Jun 2025
Viewed by 317
Abstract
The data on the volumetric radon activity of the Akchatau territory were systematized in the context of radioecological safety. Radon (Rn222 and Rn220) and indoor radon (isotopes Po, Pb, and Bi) make a significant contribution to radon radiation in residential [...] Read more.
The data on the volumetric radon activity of the Akchatau territory were systematized in the context of radioecological safety. Radon (Rn222 and Rn220) and indoor radon (isotopes Po, Pb, and Bi) make a significant contribution to radon radiation in residential and industrial premises. Increased radon concentration in a number of areas is associated with the Akchatau tungsten–molybdenum mine. The source of radon in geological terms is acid leucocratic granites in the northwestern and southeastern parts of the studied territory. Seasonal assessment of radon radiation was carried out using modern devices “Alfarad Plus” and “Ramon-Radon”. Frequency analysis of the average annual equivalent equilibrium concentration (EEC) in 181 premises showed that only in 47.5% of the premises does the volumetric radon activity not exceed the current standards (200 Bq/m3). Differentiated values of radon concentration were obtained in cases where daily and seasonal observations were carried out. In 43.1% of premises, the effective dose varies from 6.6 mSv/year to 33 mSv/year, and for 9.4% of premises, from 33 mSv/year to 680 mSv/year. The increased radon concentration is caused by high exhalation from the soil surface, the radioactivity of building materials, and low air exchange in the surveyed premises. In the northwestern part of Akchatau, anomalous zones were found where the exposure dose rate of gamma radiation exceeds 0.6 mkSv/hour. An objective assessment of radon largely depends on a number of factors that take into account the geological, technical, atmospheric, and climatic conditions of the region. Therefore, when planning an optimal radon rehabilitation strategy, it is necessary to take the following factors into account: the design features of residential premises and socio-economic conditions. Practical recommendations are given for radiation-ecological and hygienic monitoring of radon safety levels in the environment to reduce effective doses on the population. Full article
(This article belongs to the Section Air Quality)
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21 pages, 10366 KiB  
Article
An Assessment of the Impact of Gypsum Deposit Development on Changes in the Radiation Environment
by Alexander I. Malov, Vitaliy A. Nakhod, Sergey V. Druzhinin and Elena N. Zykova
Appl. Sci. 2025, 15(12), 6639; https://doi.org/10.3390/app15126639 - 12 Jun 2025
Viewed by 489
Abstract
The aim of the conducted research was to assess the impact of gypsum deposit development on changes in the radiation levels of the abiotic components of the environment. For this purpose, a study of the radioactivity of water, bottom sediment, soil, gypsum and [...] Read more.
The aim of the conducted research was to assess the impact of gypsum deposit development on changes in the radiation levels of the abiotic components of the environment. For this purpose, a study of the radioactivity of water, bottom sediment, soil, gypsum and loam samples was performed. Ground-based studies of the distribution of the values of the ambient dose equivalent rate of gamma radiation and radon flux density were also carried out. It was shown that due to the high solubility of gypsum, the degree of karstification of the territory increases under the influence of meteoric waters, and as a result of the intensification of anthropogenic impact, the degree of chemical weathering of rocks increases. This leads to a coordinated change in not only the chemical but also the radiation conditions. In particular, radioactive contamination of quarry waters and areas of increased radon flux density in soil air were established. In bottom sediments, the significant correlations of 137Cs, 238U and 234U activity concentrations with carbonates, organic matter and soluble salts contents, as well as Fe, Zn, Cu, Cr, Pb, Ni, Mo, Cd, Co, Ti and V, indicate a significant role of the anthropogenic factor in the accumulation in bottom sediments. This factor is associated with both regional atmospheric transport (137Cs) and the activity of the mining enterprise in the study area (238U and 234U). Full article
(This article belongs to the Special Issue Advances in Environmental Radioactivity Monitoring and Measurement)
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14 pages, 1409 KiB  
Article
Production, Validation, and Exposure Dose Measurement of [13N]Ammonia Under Academic Good Manufacturing Practice Environments
by Katsumi Tomiyoshi, Yuta Namiki, David J. Yang and Tomio Inoue
Pharmaceutics 2025, 17(5), 667; https://doi.org/10.3390/pharmaceutics17050667 - 19 May 2025
Viewed by 542
Abstract
Objective: Current good manufacturing practice (cGMP) guidance for positron emission tomography (PET) drugs has been established in Europe and the United States. In Japan, the Pharmaceuticals and Medical Devices Agency (PMDA) approved the use of radiosynthesizers as medical devices for the in-house manufacturing [...] Read more.
Objective: Current good manufacturing practice (cGMP) guidance for positron emission tomography (PET) drugs has been established in Europe and the United States. In Japan, the Pharmaceuticals and Medical Devices Agency (PMDA) approved the use of radiosynthesizers as medical devices for the in-house manufacturing of PET drugs in hospitals and clinics, regardless of the cGMP environment. Without adequate facilities, equipment, and personnel required by cGMP regulations, the quality assurance (QA) and clinical effectiveness of PET drugs largely depend on the radiosynthesizers themselves. To bridge the gap between radiochemistry standardization and site qualification, the Japanese Society of Nuclear Medicine (JSNM) has issued guidance for the in-house manufacturing of small-scale PET drugs under academic GMP (a-GMP) environments. The goals of cGMP and a-GMP are different: cGMP focuses on process optimization, certification, and commercialization, while a-GMP facilitates the small-scale, in-house production of PET drugs for clinical trials and patient-specific standard of care. Among PET isotopes, N-13 has a short half-life (10 min) and must be synthesized on site. [13N]Ammonia ([13N]NH3) is used for myocardial perfusion imaging under the Japan Health Insurance System (JHIS) and was thus selected as a working example for the manufacturing of PET drugs in an a-GMP environment. Methods: A [13N]NH3-radiosynthesizer was installed in a hot cell within an a-GMP-compliant radiopharmacy unit. To comply with a-GMP regulations, the air flow was adjusted through HEPA filters. All cabinets and cells were disinfected to ensure sterility once a month. Standard operating procedures (SOPs) were applied, including analytical methods. Batch records, QA data, and radiation exposure to staff in the synthesis of [13N]NH3 were measured and documented. Results: 2.52 GBq of [13N]NH3 end-of-synthesis (EOS) was obtained in an average of 13.5 min in 15 production runs. The radiochemical purity was more than 99%. Exposure doses were 11 µSv for one production run and 22 µSv for two production runs. The pre-irradiation background dose rate was 0.12 µSv/h. After irradiation, the exposed dosage in the front of the hot cell was 0.15 µSv/h. The leakage dosage measured at the bench was 0.16 µSv/h. The exposure and leakage dosages in the manufacturing of [13N]NH3 were similar to the background level as measured by radiation monitoring systems in an a-GMP environments. All QAs, environmental data, bacteria assays, and particulates met a-GMP compliance standards. Conclusions: In-house a-GMP environments require dedicated radiosynthesizers, documentation for batch records, validation schedules, radiation protection monitoring, air and particulate systems, and accountable personnel. In this study, the in-house manufacturing of [13N]NH3 under a-GMP conditions was successfully demonstrated. These findings support the international harmonization of small-scale PET drug manufacturing in hospitals and clinics for future multi-center clinical trials and the development of a standard of care. Full article
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21 pages, 6034 KiB  
Article
Silver-Modified Biochar: Investigating NO2 Adsorption and Reduction Efficiency at Different Temperatures
by Flavia Tavares, Fernanda F. Camilo, Mohamed Zbair, Lionel Limousy and Jocelyne Brendle
Catalysts 2025, 15(4), 392; https://doi.org/10.3390/catal15040392 - 17 Apr 2025
Viewed by 527
Abstract
This study investigates the adsorption and reduction of NO2 on biochar (BCC) and silver-modified biochar (Ag-BCC) in a continuous flow. Ag-BCC showed a higher NO2 adsorption capacity (11.78 mg/g) than BCC (11.04 mg/g) at 200 °C, despite its lower surface area [...] Read more.
This study investigates the adsorption and reduction of NO2 on biochar (BCC) and silver-modified biochar (Ag-BCC) in a continuous flow. Ag-BCC showed a higher NO2 adsorption capacity (11.78 mg/g) than BCC (11.04 mg/g) at 200 °C, despite its lower surface area (345 vs. 402 m2/g). While neither material decomposed NO2 at 22 °C, Ag-BCC achieved a NO/NO2 ratio of 20% (vs. 9% for BCC) at 200 °C, highlighting the catalytic role of silver in NO2 conversion. Breakthrough curve modeling identified the Dose–Response model as optimal, accurately describing adsorption kinetics at all temperatures (22–200 °C). Adsorption rate constants decreased with increasing temperature, confirming exothermicity. Overall, the results highlight the enhanced performance of Ag-BCC for NO2 capture and conversion, underlining the potential of surface-modified biochars in the sustainable mitigation of air pollution. Full article
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13 pages, 2235 KiB  
Article
Optimization of DD-110 Neutron Generator Output for Boron Neutron Capture Therapy Using Monte Carlo Simulation
by Hossam Donya and Muhammed Umer
Quantum Beam Sci. 2025, 9(2), 12; https://doi.org/10.3390/qubs9020012 - 15 Apr 2025
Cited by 2 | Viewed by 1428
Abstract
Boron neutron capture therapy (BNCT) is a specialized cancer treatment that leverages the high absorption cross-section of boron for thermal neutrons. When boron captures neutrons, it undergoes a nuclear reaction that produces alpha particles and lithium ions, which have high linear energy transfer [...] Read more.
Boron neutron capture therapy (BNCT) is a specialized cancer treatment that leverages the high absorption cross-section of boron for thermal neutrons. When boron captures neutrons, it undergoes a nuclear reaction that produces alpha particles and lithium ions, which have high linear energy transfer (LET) and can effectively damage nearby cancer cells while minimizing harm to surrounding healthy tissues. This targeted approach makes BNCT particularly advantageous for treating tumors situated in sensitive areas where traditional radiation therapies may pose risks to critical structures. In this study, the deuterium–deuterium (DD) neutron generator, specifically the DD-110 model (neutron yield Y = 1 × 1010 n/s), served as the neutron source for BNCT. The fast neutrons produced by this generator were thermalized to the epithermal energy range using a beam-shaping assembly (BSA). The BSA was designed with a moderator composed of 32 cm of MgF2, a reflector made of 76 cm of Pb, and filters including 3 cm of Pb and 1.52 cm of Bi. A collimator, featuring a 10 cm high Pb cone frustum with a 12 cm aperture diameter, was also employed to optimize beam characteristics. The entire system’s performance was modeled and simulated using the MCNPX code, focusing on parameters both in-air and in-phantom to evaluate its efficacy. The findings indicated that the BSA configuration yielded an optimal thermal-to-epithermal flux ratio (φther/φepth) of 0.19, a current-to-flux ratio of 0.87, and a gamma dose-to-epithermal flux ratio of 1.71 × 10−13 Gy/cm2, all aligning with IAEA recommendations. The simulated system showed acceptable ratios for φther/φepth, gamma dose to epithermal flux, and beam collimation. Notably, the advantage depth was recorded at 5.5 cm, with an advantage ratio of 2.29 and an advantage depth dose rate of 4.1 × 10−4 Gy.Eq/min. The epithermal neutron flux of D110 exceeded D109, but D110’s fast neutron contamination increased ~6.6 times. On the other hand, D110’s gamma contamination decreased by 30%. Based on these findings, optimizing neutron source characteristics is crucial for BNCT efficacy. Future research should focus on developing advanced neutron generators that balance these factors, aiming to produce optimal neutron yields for enhanced treatment outcomes and broader applicability. Full article
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20 pages, 2521 KiB  
Article
Radioactive Assessment and Th-, Nb-Ta-, Zr-, REE-Bearing Minerals in Alkaline Syenite: Environmental Implications for Radiological Safety
by Ahmed E. Abdel Gawad, Elena G. Panova, Mohamed M. Ghoneim, Svetlana Y. Yanson, Sultan J. Alsufyani, A. Saftah, Nadi Mlihan Alresheedi and Mohamed Y. Hanfi
Geosciences 2025, 15(4), 138; https://doi.org/10.3390/geosciences15040138 - 4 Apr 2025
Cited by 2 | Viewed by 453
Abstract
This study focused on identifying Th-, Nb-Ta-, Zr-, and REE-bearing minerals with a multivariate statistical approach in alkaline syenite to evaluate their radiological risks, at Nikeiba, Egypt. Through microchemical analyses, by utilizing electron probe microanalysis, horite, microlite, monazite, zircon, columbite, and fergusonite were [...] Read more.
This study focused on identifying Th-, Nb-Ta-, Zr-, and REE-bearing minerals with a multivariate statistical approach in alkaline syenite to evaluate their radiological risks, at Nikeiba, Egypt. Through microchemical analyses, by utilizing electron probe microanalysis, horite, microlite, monazite, zircon, columbite, and fergusonite were shown to bear uranium and thorium. These minerals have played an important role in higher radioactive zones in the studied alkaline syenite. REE-minerals comprising bastnäsite, monazite, and fluorite and apatite are well recorded. The total rare earth elements (TREE2O3) reveal higher concentrations in bastnäsite than monazite, with averages 74.87 and 63.8 wt%. Ce is considered the most predominant LREE in the analyzed bastnäsite and monazite. The mean values of radionuclide activity concentrations of 238U, 232Th, and 40K are 108 ± 20 Bq/kg, 107 ± 9 Bq/kg, and 1255 ± 166 Bq/kg, respectively. Radiological assessments revealed a radium equivalent activity of 357 Bq/kg, below global limits, but an air-absorbed dose rate (166 nGy/h) and annual effective doses (0.81 mSv/y indoors, 0.20 mSv/y outdoors) exceeding safe thresholds. Additionally, the excess lifetime cancer risk (ELCR) was calculated at 0.00071, surpassing the acceptable limit of 0.00029, making these rocks unsafe for construction use. Statistical analyses further underscored the relationships between radionuclide concentrations and associated risks, highlighting the necessity for continuous monitoring and mitigation. Full article
(This article belongs to the Section Geochemistry)
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20 pages, 3188 KiB  
Article
Volatile Organic Compounds in Early Childhood Education Facilities: Simultaneous Indoor and Outdoor Measurements in the Haifa Bay Area
by Ran Darzi, Merav Bareket, Yuval and Yael Dubowski
Atmosphere 2025, 16(2), 181; https://doi.org/10.3390/atmos16020181 - 5 Feb 2025
Viewed by 599
Abstract
Indoor air quality (IAQ) is of great importance, as people spend up to 90% of their time indoors, leading to significant exposure to air pollutants. The IAQ in early childhood education (ECE) facilities is of particular interest since young children are more vulnerable [...] Read more.
Indoor air quality (IAQ) is of great importance, as people spend up to 90% of their time indoors, leading to significant exposure to air pollutants. The IAQ in early childhood education (ECE) facilities is of particular interest since young children are more vulnerable and poor air quality may have possible long-lasting impacts on them. In the present study, simultaneous indoor and outdoor VOC measurements were carried out in three ECE facilities in the Haifa Bay area, Israel. Three sampling campaigns were utilized, each lasted for a minimum of one week, encompassing four consecutive working days and at least one weekend. During working days, sampling was performed during daytime activity hours and at nighttime (off hours). Twenty-three VOCs were identified, quantified, and classified into six chemical groups—aromatic hydrocarbons, aliphatic alkanes, terpenes, alcohols, carbonyls, and “others”. The total outdoor VOC concentration was 23 μg m−3 during the daytime and 22 μg m−3 at night, with carbonyls and aromatic hydrocarbons accounting for ~80% of it. Despite the heterogeneity of the study area, outdoor concentrations depicted a smaller spatial and temporal variability than was observed indoors. In the ECE facilities, the total VOC reached 134 and 204 μg m−3 during the daytime and nighttime, respectively, and were strongly impacted by the air exchange rate. Carbonyls, alcohols, and terpenes were more prevalent indoors, accounting for 77.5–81.1% of the total. Their high indoor/outdoor ratios, especially for formaldehyde and limonene, suggest a significant contribution from indoor emission sources. Exposure calculations were compared to reference values for carcinogenic and non-carcinogenic effects. While the lifetime average daily dose (LADD) did not exceed the available reference values, the upper-limit estimates of continuous lifetime exposure to measured indoor levels indicate that formaldehyde and acetaldehyde surpassed their respective limits by factors of 10 and 3, respectively. Full article
(This article belongs to the Section Air Quality)
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15 pages, 893 KiB  
Article
Analysis of Volatile Compounds in a Value-Added Jerky by Incorporating Ajwain and Thyme Essential Oils
by Elaine Anit, Helga Hernández, Jan Banout and Klára Urbanová
Appl. Sci. 2025, 15(2), 550; https://doi.org/10.3390/app15020550 - 8 Jan 2025
Viewed by 883
Abstract
Ajwain essential oil and thyme essential oil naturally contain important bioactive compounds. Various researchers have discovered that these compounds contribute biological benefits for living things such as humans and animals. Bioactive compounds found in essential oils, such as terpenes and terpenoids, possess antibacterial [...] Read more.
Ajwain essential oil and thyme essential oil naturally contain important bioactive compounds. Various researchers have discovered that these compounds contribute biological benefits for living things such as humans and animals. Bioactive compounds found in essential oils, such as terpenes and terpenoids, possess antibacterial and flavouring qualities, making them promising natural preservatives in the food business. This study investigates the effect of essential oil treatment methods on their incorporation into dehydrated beef and its subsequent sensory acceptability. The meat samples underwent hot air blanching and oil treatment with doses of 0.75 mL and 1.5 mL, respectively. Subsequently, the samples were dried at 55 °C for 6 h after each treatment. The identification and quantification of volatile chemicals were performed using headspace solid-phase microextraction and gas chromatography–mass spectrometry. Thymol, γ-terpinene, p-cymene, and β-pinene were the predominant compounds before and after the treatments. The findings revealed that the application of ajwain and thyme essential oil treatments resulted in significant differences in the final concentration of monoterpenes. However, the sensory evaluation indicated that the ajwain and thyme essential oil samples received similar overall ratings. Consequently, ajwain essential oil could be a suitable alternative to thyme in beef jerky. Full article
(This article belongs to the Special Issue Advances in Food Analysis and Processing)
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12 pages, 2228 KiB  
Article
The Radon Exhalation Rate and Dose Assessment of Granite Used as a Building Material in Serbia
by Fathya Shabek, Božidar Obradović, Igor Čeliković, Mirjana Đurašević, Aleksandra Samolov, Predrag Kolarž and Aco Janićijević
Atmosphere 2024, 15(12), 1495; https://doi.org/10.3390/atmos15121495 - 15 Dec 2024
Cited by 1 | Viewed by 1283
Abstract
The application of energy-saving policies in buildings could lead to a decrease in the air exchange rate in dwellings, which could consequently lead to an increase in indoor radon concentration and, therefore, to an increase in resident exposure to ionizing radiation. The aim [...] Read more.
The application of energy-saving policies in buildings could lead to a decrease in the air exchange rate in dwellings, which could consequently lead to an increase in indoor radon concentration and, therefore, to an increase in resident exposure to ionizing radiation. The aim of the research presented in this paper is to investigate radiological exposure to residents due to the usage of different granites commonly used in Serbia as a building material. From the total of 10 analysed granite samples, a wide range of radon and thoron exhalation rates were found: from <161 μBq m−2 s−1 to 5220 ± 200 μBq m−2 s−1 and from <7 mBq m−2 s−1 to 5140 ± 320 mBq m−2 s−1, respectively. Assuming a low air exchange rate of 0.2 h−1, the contribution of the measured granite material to the indoor radon concentration could go up to 150 Bq m−3. The estimated annual effective doses due to exposure to radon and thoron exhalation from the granite samples were (0.05–3.79) mSv and (<0.01–1.74) mSv, respectively. The specific activity of radionuclides ranged from 6.6 ± 0.5 Bq kg−1 to 131.8 ± 9.4 Bq kg−1 for 226Ra, from 0.5 ± 0.1 Bq kg−1 to 120.8 ± 6.5 Bq kg−1 for 232Th, and from 0.22 ± 0.01 Bq kg−1 to 1321 ± 86 Bq kg−1 for 40K. The obtained external hazard index ranged from 0.03 to 1.48, with three samples above or very close to the accepted safety limit of 1. In particular, dwellings with a low air exchange rate (causing elevated radon) could lead to an elevated risk of radiation exposure. Full article
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23 pages, 4305 KiB  
Article
The Study of Radioactive Fallout Source of Low-Equivalent Nuclear Bursts Based on Nuclear Cloud Simulation Using the CFD-DPM
by Yangchao Li, Qiang Liu, Wei Liu, Wenshuang Xian, Feifei Li and Kai Zhang
Atmosphere 2024, 15(12), 1421; https://doi.org/10.3390/atmos15121421 - 26 Nov 2024
Viewed by 1386
Abstract
The activity-height distribution of radioactive particles in the stabilization cloud of a nuclear burst plays a crucial role in the radioactive fallout prediction model, serving as the source for transport, diffusion, and dose rate calculation modules. A gas-particle multiphase flow solver was developed [...] Read more.
The activity-height distribution of radioactive particles in the stabilization cloud of a nuclear burst plays a crucial role in the radioactive fallout prediction model, serving as the source for transport, diffusion, and dose rate calculation modules. A gas-particle multiphase flow solver was developed using the OpenFOAM Computational Fluid Dynamics (CFD) library and discrete phase method (DPM) library under a two-way coupling regime to simulate the U.S. standard atmosphere of 1976 with good stability. The accuracy of the numerical model was verified through low-equivalent nuclear weapons tests, including RANGER-Able and BUSTER-JANGLE-Sugar, depicting reasonable spatio-temporal changes in cloud profiles. The initialization module of the Defense Land Fallout Interpretative Code (DELFIC) and activity-size distribution, which considered fractionation, were employed for nuclear fireball and radioactive particle initialization. Simulations indicated that the activity-height distribution of the stabilization cloud mainly concentrated on the lower third of air burst cloud caps, while settling near the burst center for surface or near-surface bursts. This study has confirmed the effectiveness of the gas-particle flow solver based on the CFD-DPM method in simulating low-equivalent nuclear clouds and enriching research on radioactive fallout prediction models. Full article
(This article belongs to the Special Issue Numerical Simulation of Aerosol Microphysical Processes (2nd Edition))
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12 pages, 5357 KiB  
Article
Microbial Contamination and Sterilization Methods in an Air Circulation-Type Geothermal Ventilation System
by Hyuntae Kim
Environments 2024, 11(11), 254; https://doi.org/10.3390/environments11110254 - 14 Nov 2024
Viewed by 976
Abstract
A simulated system was created to evaluate an air circulation-type geothermal ventilation system, focusing on measuring microbial contamination levels on the surface of the heat exchange unit. Additionally, this study examined sterilization methods using UV lamps on the surface of the heat exchanger. [...] Read more.
A simulated system was created to evaluate an air circulation-type geothermal ventilation system, focusing on measuring microbial contamination levels on the surface of the heat exchange unit. Additionally, this study examined sterilization methods using UV lamps on the surface of the heat exchanger. The fungal concentration on the surface of the heat exchanger showed a tendency to increase over time. Although direct comparison is challenging due to the varying concentrations of outdoor air fungi at different measurement times, the surface fungal concentration was highest at a minimum airflow rate of 150 m3/h compared to other conditions. However, since the adhesion of contaminants from outdoor air to the surface of the heat exchanger is influenced not only by airflow but also by outdoor temperature and relative humidity conditions, future research needs to consider these factors. According to the ATP measurement results, microbial contamination was evaluated as “slightly dirty” after 24 h and “dirty” after 48 h of operating the experimental apparatus. Therefore, it is advisable to clean the internal surfaces of the geothermal ventilation system every 1–2 days. The results of the sterilization experiments using UV lamps indicated that irradiation for approximately 30 min inactivated 94.5%-to-96.1% of microorganisms derived from outdoor air. However, since the sterilization dose varies depending on the type of microorganism, it is necessary to determine the optimal irradiation time based on the target microorganisms and the UV lamp’s irradiation intensity. Full article
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13 pages, 4605 KiB  
Article
Toxicity of Piper hispidinervum Essential Oil to Callosobruchus maculatus and Cowpea Bean Quality
by Maria Suely Siqueira Ferraz, Lêda Rita D’Antonino Faroni, Adalberto Hipólito de Sousa, Fernanda Fernandes Heleno, Marcus Vinicius de Assis Silva and Ernandes Rodrigues de Alencar
Plants 2024, 13(22), 3148; https://doi.org/10.3390/plants13223148 - 9 Nov 2024
Cited by 1 | Viewed by 1001
Abstract
Essential oils and their major compounds have been studied to protect stored grains, especially for the control of insects. In this context, this research aimed to investigate the fumigation and contact toxicities of the essential oil of Piper hispidinervum C. DC. (Piperaceae [...] Read more.
Essential oils and their major compounds have been studied to protect stored grains, especially for the control of insects. In this context, this research aimed to investigate the fumigation and contact toxicities of the essential oil of Piper hispidinervum C. DC. (Piperaceae) (sin. Piper hispidum Sw.) to Callosobruchus maculatus adult individuals and the effect on insect progeny. We also assessed the essential oil’s effect on stored-cowpea quality. The fumigation bioassay used essential oil at 14.3, 57.1, 100.0, 142.9, and 185.7 µL/L of air, whereas the contact bioassay tested concentrations of 60, 80, 100, 120, and 140 µL/kg. Insect mortality was appraised after four days (fumigation) or one day (contact). In turn, oviposition and emergence rates were evaluated after seven (fumigation) or fifty (contact) days of storage. Grain quality was also analyzed after 50 days of storage. Safrole was confirmed as the primary compound of the essential oil. P. hispidinervum essential oil proved its fumigant and contact toxicities to C. maculatus adult individuals. The concentrations lethal to 50 and 95% of the population were, respectively, 91.23 and 242.59 µL/L of air (fumigation) and 101.51 and 208.52 µL/kg of cowpeas (contact). In both application forms, C. maculatus oviposition and progeny rates declined with the increase in the essential oil concentration. Furthermore, cowpea bean quality was preserved even at sublethal doses. Full article
(This article belongs to the Special Issue Green Insect Control: The Potential Impact of Plant Essential Oils)
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13 pages, 2349 KiB  
Article
Fluoroscopy-Guided Percutaneous Transthoracic Needle Lung Biopsy with the Aid of Planning Cone-Beam CT: Diagnostic Accuracy and Complications
by Sang Hyun Cho, Hyun Jung Yoon, Young Lee, Injoong Kim, Je Ryung Gil and Yeo Jin Kim
Diagnostics 2024, 14(21), 2441; https://doi.org/10.3390/diagnostics14212441 - 31 Oct 2024
Cited by 1 | Viewed by 1146
Abstract
Background: Fluoroscopy-guided PTNB for fluoroscopy-identifiable lung lesions has been suggested as a useful method for the pathological diagnosis of lung lesions; however, it is lacking in accuracy and safety compared to CT-guided PTNB. Thus, we aimed to investigate the diagnostic accuracy and complications [...] Read more.
Background: Fluoroscopy-guided PTNB for fluoroscopy-identifiable lung lesions has been suggested as a useful method for the pathological diagnosis of lung lesions; however, it is lacking in accuracy and safety compared to CT-guided PTNB. Thus, we aimed to investigate the diagnostic accuracy and complications of fluoroscopy-guided percutaneous transthoracic needle biopsy (PTNB) with the aid of pre-procedural planning cone-beam computed tomography (CBCT) in order to take advantage of their respective strengths. Methods: A total of 255 fluoroscopy-guided PTNBs with the aid of planning CBCT were performed. Pre-procedural planning CBCT was conducted to calculate the shortest length from the skin puncture site to the margin of the target lesion for the needle trajectory. No intra-procedural CBCT was performed. The diagnostic performance of fluoroscopy-guided PTNB with the aid of planning CBCT was calculated. The prognostic factors for diagnostic failures and complications were evaluated using logistic regression analysis. Results: The accuracy, sensitivity, specificity, PPV, and NPV were 97.3%, 88.0%, 90.9%, 100%, and 62.5%, respectively. There were 29 diagnostic failures (11.8%), and the multivariable analysis showed that a longer lesion depth on CBCT and a shorter specimen length were each associated with diagnostic failure (p = 0.010 and 0.012, respectively). Complications occurred in 34 PTNBs (13.3%). The multivariable analysis showed that an increased total number of biopsies per lesion, a longer length of lung aeration via needle insertion, a smaller lesion size on CT imaging (≤20 mm), and the presence of an air bronchogram were associated with the occurrence of complications (p = 0.027, <0.001, 0.003, and 0.020, respectively). Conclusions: Excellent diagnostic accuracy was obtained by fluoroscopy-guided PTNB with the aid of planning CBCT. Compared to that of CT- or CBCT-guided PTNB, the procedure-related complication rate was acceptably low, but the radiation dose to patients could be potentially reduced. Full article
(This article belongs to the Special Issue Diagnosis of Cardio-Thoracic Diseases)
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20 pages, 3444 KiB  
Article
The Cross-Verification of Different Methods for Soil Erosion Assessment of Natural and Agricultural Low Slopes in the Southern Cis-Ural Region of Russia
by Mikhail Komissarov, Valentin Golosov, Andrey Zhidkin, Daria Fomicheva and Alexei Konoplev
Land 2024, 13(11), 1767; https://doi.org/10.3390/land13111767 - 28 Oct 2024
Cited by 5 | Viewed by 1639
Abstract
The conventional measuring methods (runoff plots and soil morphological comparison) and models (WaTEM/SEDEM and regional model of Russian State Hydrological Institute (SHI)) were tested with regard to the Southern Cis-Ural region of Russia, along with data from rainfall simulation for assessing soil erosion. [...] Read more.
The conventional measuring methods (runoff plots and soil morphological comparison) and models (WaTEM/SEDEM and regional model of Russian State Hydrological Institute (SHI)) were tested with regard to the Southern Cis-Ural region of Russia, along with data from rainfall simulation for assessing soil erosion. Compared with conventional methods, which require long-running field observations, using erosion models and rainfall simulation is less time-consuming and is found to be fairly accurate for assessing long-term average rates of soil erosion and deposition. In this context, 137Cs can also be used as a marker of soil redistribution on the slope. The data of soil loss and sedimentation rates obtained by using conventional measuring methods were in agreement with the data based on the used contemporary modeling approaches. According to the erosion model calculations and data on the fallout of radionuclides in the Southern Cis-Ural (54°50–25′ N and 55°44–50′ E), the average long-term annual soil losses were ~1.3 t·ha−1 yr−1 in moderate (5°) arable slopes and ~0.2 t·ha−1 yr−1 in meadows. In forests, surface erosion is negligible, or its rates are similar to the rate of soil formation of clay–illuvial chernozems. The rates of soil erosion and sediment deposition on the arable land obtained using different methods were found to be very close. All the methods, including the WaTEM/SEDEM, allowed us to measure both soil erosion and intra-slope sedimentation. The regional SHI model fairly accurately assesses soil erosion in the years when erosion events occurred; however, soil erosion as a result of snowmelt did not occur every year, which should be taken into account when modeling. The concentrations of 137Cs in the topsoil layer (0–20 cm) varied from 0.9 to 9.8 Bq·kg−1, and the 137Cs inventories were 1.6–5.1 kBq·m−2, with the highest values found under the forest. The air dose rate in the forest was higher than in open areas and above the average of 0.12 μSv·h−1 on the slope (0.1 μSv·h−1 in the meadow and 0.08 μSv·h−1 on the arable land), with the value increasing from the watershed to the lower part of the slope in all the areas. The γ-background level in the studied ecosystems did not exceed the maximum permissible levels. Full article
(This article belongs to the Section Land, Soil and Water)
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