Types Of Radiation Research Articles

Development of empirical models for calculating global and diffuse erythemal weighted solar ultraviolet radiation under clear sky conditions in Thailand

This study introduced semi-empirical models for calculating hourly global and diffuse erythemal weighted ultraviolet (EUV) solar radiation under clear sky conditions in Thailand. To develop these models, global and diffuse erythemal ultraviolet data collected over a decade (2011–2020) from four solar monitoring stations situated in the main regions of Thailand were used. The data was classified into two groups. The first group (2011–2018) was used for modeling, while the second group (2019–2020) was reserved for model validation. The global and diffuse EUV radiation models revolve around semi-empirical functions. These functions express both types of EUV radiation in terms of normalized variables, specifically the total ozone column, aerosol optical depth, and air mass. To assess the accuracy of the proposed models, their outputs for hourly global and diffuse EUV radiation were calculated at the four monitoring stations. These outputs were then compared against actual measurements to validate the effectiveness of the models. The evaluation revealed a root mean square difference of 15.8% for global EUV radiation and 14.9% for diffuse EUV radiation when compared to the mean measured values.

Crime radiation theory: the co-production of crime patterns through opportunity creation and exploitation

AbstractConsiderable research shows that crime is concentrated at a few proprietary places: addresses and facilities. Emerging research suggests that proprietary places may radiate crime: activities at a place increase the risk of crime in the area around it. Weaknesses in the research create uncertainty about radiation, so we need more rigorous research. To conduct this research, we need a theory of crime radiation that operates at two spatial levels: the proprietary place and the area. This paper describes such a theory. Our theory states that crime radiation stems from the interaction between place management decisions at the place and offenders searching for opportunities in the area. Place managers create crime opportunities inside and outside their places. Offenders exploit place managers’ creations by deliberately searching for opportunities or by chancing upon the opportunities. The ways place managers and offenders interact gives rise to three types of crime radiation: hot dot, veiled dot, and cold dot. Finally, we propose questions crime scientists should answer to better understand crime radiation.

Unveiling the shielding potential: Exploring photon and neutron attenuation in a novel lead-free XCr2Se4 chalcogenide Spinals alloys with MCNP 4C code

The study covers shielding properties of three promising lead-free XCr2Se4 alloys, where X represents Mn, Cu, or Ag, across a spectrum of energies between 0.02 MeV and 15 MeV. MCNP4C was employed to simulate the mass attenuation coefficient (MAC) for the three selected alloys. After being prepared using the conventional solid-state reaction method, the samples displayed densities ranging from 5.45 g cm−3to 6.22 g cm−3. The simulated results obtained from the MCNP4C are then benchmarked with data obtained using different software such as Phy-X, Py-MLBUF, EPIXS, and GRASP. Upon comparing the acquired results with the Phy-X data, a notable correlation was observed with a relative difference ranging from 0.11% to 8.57%. The accuracy of the simulated data was additionally validated through the Kolmogorov-Smirnov test. From the simulated MAC, different ionizing radiation shielding properties including linear attenuation coefficient (LAC), half-value layer (HVL), mean-free path (MFP), transmission factor (TF), radiation protection efficiency (RPE), and fast neutron removal cross section (FNRCS) were calculated to provide a comprehensive analysis of the samples' efficacy in dealing with different types of radiation. The LAC for neutrons at different energies is also examined. HVL analysis indicates the radiation-blocking capacity of the samples. The TF shows the alloys’ ability to either permit or restrain the transfer of radiation. Additionally, RPE and FNRCS give indication of the shielding potential of the studied samples. This study is important for nuclear physicians and researchers and serves as useful data for the development of superior shielding materials.

A comprehensive review of radiation shielding concrete: Properties, design, evaluation, and applications

AbstractThis review paper provides a comprehensive analysis of radiation shielding concrete, covering its properties, design, evaluation, and applications. It begins with an introduction, stating the objective and scope. The paper explores radiation shielding basics, including ionizing radiation, shielding principles, and materials used for shielding. Concrete's properties relevant to shielding, radiation attenuation mechanisms, and factors affecting its efficiency are discussed. Different types of radiation shielding concrete are examined, along with their applications. The design and formulation of shielding concrete, including mix proportions, optimization techniques, and quality control, are presented. Evaluation methods and standards are discussed. Lastly, challenges, future directions, and emerging technologies are outlined. This review paper serves as a valuable resource for professionals involved in radiation shielding. The review on radiation shielding concrete highlighted its effectiveness in attenuating ionizing radiation, emphasizing material composition, density, and thickness as key design factors. Evaluation methods, such as gamma spectroscopy and Monte Carlo simulations, are discussed, demonstrating its versatile applications in nuclear facilities, healthcare, and space exploration.

CYRAD: a translational study assessing immune response to radiotherapy by photons or protons in postoperative head and neck cancer patients through circulating leukocyte subpopulations and cytokine levels

BackgroundRadiotherapy has both immunostimulant and immunosuppressive effects, particularly in radiation-induced lymphopenia. Proton therapy has demonstrated potential in mitigating this lymphopenia, yet the mechanisms by which different types of radiation affect the immune system function are not fully characterized. The Circulating Immunes Cells, Cytokines and Brain Radiotherapy (CYRAD) trial aims to compare the effects of postoperative X-ray and proton radiotherapy on circulating leukocyte subpopulations and cytokine levels in patients with head and neck (CNS and ear nose throat) cancer.MethodsCYRAD is a prospective, non-randomized, single-center non interventional study assessing changes in the circulating leukocyte subpopulations and cytokine levels in head and neck cancer patients receiving X-ray or proton radiotherapy following tumor resection. Dosimetry parameters, including dose deposited to organs-at-risk such as the blood and cervical lymph nodes, are computed. Participants undergo 29 to 35 radiotherapy sessions over 40 to 50 days, followed by a 3-month follow-up. Blood samples are collected before starting radiotherapy (baseline), before the 11th (D15) and 30th sessions (D40), and three months after completing radiotherapy. The study will be conducted with 40 patients, in 2 groups of 20 patients per modality of radiotherapy (proton therapy and photon therapy). Statistical analyses will assess the absolute and relative relationship between variations (depletion, recovery) in immune cells, biomarkers, dosimetry parameters and early outcomes.DiscussionPrevious research has primarily focused on radiation-induced lymphopenia, paying less attention to the specific impacts of radiation on different lymphoid and myeloid cell types. Early studies indicate that X-ray and proton irradiation may lead to divergent outcomes in leukocyte subpopulations within the bloodstream. Based on these preliminary findings, this study aims to refine our understanding of how proton therapy can better preserve immune function in postoperative (macroscopic tumor-free) head and neck cancer patients, potentially improving treatment outcomes.Protocol versionVersion 2.1 dated from January 18, 2023.Trial registrationThe CYRAD trial is registered from October 19, 2021, at the US National Library of Medicine, ClinicalTrials.gov ID NCT05082961.

Optimization of test methods and algorithms for assessing the resistance of field-effect transistors to various types of radiation using promising test equipment

Optimization of test methods and algorithms for assessing the resistance of field-effect transistors to various types of radiation using promising test equipment

Arterial prophylactic occlusion technique in the application of surgery for locally advanced pancreatic cancer with arterial involvement after conversion therapy

Objective: To investigate and compare the clinical outcomes of the arterial pre-occlusion technique(APOT) and the traditional technique in the surgery of locally advanced pancreatic cancer with arterial involvement after conversion therapy. Methods: This is a retrospective cohort study. The clinical data of 145 patients with locally advanced pancreatic cancer with arterial involvement admitted to the Department of Hepato-Biliary-Pancreatic Surgery of the First Hospital Affiliated to Naval Medical University,from January 2020 to December 2022 were retrospectively analyzed. All patients completed neoadjuvant therapy for tumors, and the feasibility of radical surgical treatment was determined by a multidisciplinary collaborative team evaluation before surgery. According to whether the intraoperative artery was pre-occluded, 145 patients were divided into two groups, including 28 cases in the APOT group(16 males, 12 females, aged (59.0±9.4) years), and 117 cases in the routine surgery group(76 males, 41 females, aged (55.1±8.2) years). To ensure comparability of baseline data between the APOT group and the routine surgery group, a 1∶2 match was performed using the propensity score matching method, and the caliper value was 0.006 45. The t-test,the Mann-Whitney U test, χ2 test or Fisher's exact test were used to compare the data between the two groups,respectively. Results: After matching the propensity score,there were 28 cases in the APOT group and 56 cases in the routine surgery group. There were no significant differences in gender,age,preoperative comorbidities,preoperative body mass index,surgical approaches,chemotherapy regimen,stereotactic body radiation therapy ratio,tumor markers,and type of invaded artery between the two groups (all P>0.05).The arterial occlusion time M(IQR) in the APOT group was 7.0(3.8)minutes(range:3 to 15 minutes),and no ischemic manifestations were observed in the distal target organs that blocked blood vessels after surgery. The operation time was (170.3±57.7)minutes in the APOT group and (235.0±80.2)minutes in the routine surgery group,and the difference was statistically significant (t=-3.800,P<0.01). The APOT group also experienced less intraoperative blood loss(650(588)ml vs. 800(600)ml;U=1 026.500,P=0.021). No significant differences were found between the groups in combined vein resection and reconstruction,celiac trunk resection,early postoperative complications, readmission rates at 30 days,and postoperative length of stay(all P>0.05). Extra-arterial dissection was performed in all patients,with arterial resection and reconstruction in 3 cases: 2 cases in the APOT group(1 case involving the superior mesenteric artery and 1 case involving the common hepatic artery) and 1 case in the routine group(involving the common hepatic artery). Postoperative abdominal bleeding occurred in 4 cases,with 3 cases in the routine group,1 case in the routine group. The R0 resection rate was 85.7%(24/28) in the APOT group and 80.4%(45/56) in the routine group,without significant differences between the groups(P=0.763). The median overall survival time was 27.6 months for the APOT group and 22.5 months for the routine group,while the median disease-free survival was 11.7 months and 16.8 months,respectively,with no significant differences between the two groups(P=0.532,P=0.927). Conclusion: The arterial pre-occlusion technique can be used for extra-arterial dissection in patients with locally advanced pancreatic cancer involving the arteries,reducing surgery time and intraoperative blood loss.

Biological effectiveness of combined exposure to neutrons and gamma radiation applied in two orders of sequence: Relevance for biological dosimetry after nuclear emergencies

ObjectiveAfter a nuclear detonation, people will be exposed to varying mixtures of neutrons and gamma radiation and the biological effectiveness of mixed beams is not well known. Additionally, it is not known how far both radiation types interact, a question that is relevant for generating calibration curves for the purpose of biological dosimetry. The objective of this study was to investigate the potential impact of two different combinations of neutron and gamma radiation on gene expression and dicentric chromosomes in peripheral blood mononuclear cells (PBMC). MethodsWhole blood from 3 human donors was exposed to neutrons with an energy spectrum similar to that of the Hiroshima uranium bomb, to gamma radiation from a 60Co source and to a 50:50 combination of both radiations, given in two orders of sequence. In all cases the total doses were 0.5, 0.75 and 1.0 Gy. Dicentric chromosomes were analyzed by light microscopy and the expression of six known radiation-responsive genes BBC3, CDKN1A, FDXR, GADD45A, MDM2, and XPC were analyzed by RT-qPCR. ResultsPer unit dose, exposure to neutrons lead to a higher level of dicentrics and gene expression as compared to gamma radiation. Dose-response relationships for both endpoints were linear, allowing calculating the expected outcome of combined exposure by arithmetic. For dicentric chromosomes, the RBE values for 60Co→neutrons, neutrons→60Co and neutrons were 4.05, 3.62 and 7.30 respectively. For gene expression the RBE values were gene-specific, but showed values in the range of 1.14–3.01 for 60Co→neutrons, 1.33–2.68 for neutrons→60Co and 1.39–3.91 for neutrons. ConclusionsThe results demonstrate that combined exposure to neutrons and gamma radiation, regardless of the order of sequence, leads to an additive response at both endpoints. This indicates that calibration curves for mixed beams can be constructed from dose response relationships of the single beam components.

Study of the Accuracy and Reliability of Dosimetric Measurements for X-ray Beams with Radiation Qualities N-40, N-100, N-200

Radiation dosimetry is a critical aspect of medical, industrial, and scientific applications involving ionizing radiation. Accurate measurements of radiation doses ensure the safety and effectiveness of radiological practices, which is essential for protecting patients in medical procedures, maintaining safety in industrial applications, and ensuring accuracy in scientific research. Leading international organizations conduct research aimed at improving measurement accuracy and the dissemination of measurement units. One of the methods contributing to this effort is various international projects. The National Scientific Centre “Institute of Metrology” has participated in one such international project. This international project, involving several National Metrology Institutes (NMIs), aimed to improve the accuracy and consistency of radiation dosimetry across Europe. By standardizing measurement and calibration procedures, the project seeks to create a unified system for measuring radiation doses, thereby improving the reliability of ionizing radiation dosimetry. This project is particularly significant given the continuous increase in radiation-based technologies across various fields. For example, precise measurements of ionizing quantities are crucial in the medical field, especially for radiotherapy, to ensure that patients receive the necessary dose with minimal exposure to surrounding healthy tissues. Similarly, in industrial radiography, accurate dosimetry is essential for meeting safety standards and preventing excessive radiation exposure to workers. The international project, with the Physikalisch-Technische Bundesanstalt (PTB) and the Central Office of Measures (GUM) as leading organizations, aims to improve key factors in ionizing radiation dosimetry. These include developing reliable calibration protocols for various types of radiation, establishing traceability chains to ensure measurement accuracy, and sharing best dosimetry practices among project participants. Preliminary comparisons were performed between NMIs, with two control participants serving as references while other NMIs participated anonymously (knowing only their number and the numbers of the reference participants). Each participant had the opportunity to compare their obtained values with the reference values and make adjustments for future measurements. The collaborative nature of such cooperation also promotes knowledge and experience exchange, fostering innovation and improvement in dosimetry techniques. The NSC “Institute of Metrology”, a leading organization in the field of the ionizing radiation metrology, has actively participated in this project as a representative from Ukraine. The paper presents the results of international comparisons for X-ray beams with the radiation qualities N-40, N-100, N-200.

Characterization of Molecular Subtypes of Rat Mammary Cancer and Their Association With Environmental Exposures.

Breast cancer is a heterogeneous disease with many subtypes, and the association between these subtypes and exposure to environmental factors such as radiation remains controversial. Although the rat is used widely for research into human breast cancer, the heterogeneity and subtype definitions are unclear. Here, we leveraged an archive of rat mammary cancer samples and gene expression microarray data to classify tumors and examine their association with exposures. Eighty-four mammary cancer and 12 normal mammary tissue samples were obtained from previous experiments in which rats were exposed to different types of radiation, chemical carcinogens, and diets. Tumors were then subjected to immunohistochemical (IHC) analysis of conventional biomarkers, as well as gene expression profiling; they were then classified by three approaches based on IHC results, the PAM50 classifier algorithm, and unsupervised clustering of gene expression profiles. IHC identified four subtypes (luminal A-like, luminal B-like 1, luminal B-like 2, and triple-negative), while PAM50 identified six (luminal A, luminal B, basal-like, HER2-enriched, normal-like, and claudin-low). Unsupervised clustering divided the tumors into three large, statistically significant, groups (named "luminal A", "luminal B", and "non-luminal" clusters). The results of the three approaches were significantly associated with each other. Exposure to radiation and chemical carcinogens during post-pubertal development was significantly associated with an increased risk of developing luminal A tumors, whereas exposure to a high corn-oil diet was associated with a higher likelihood of luminal B tumors. Rat mammary cancer subtypes resemble those in humans and are related to environmental factors.

Radiation Detectors and Sensors in Medical Imaging.

Medical imaging instrumentation design and construction is based on radiation sources and radiation detectors/sensors. This review focuses on the detectors and sensors of medical imaging systems. These systems are subdivided into various categories depending on their structure, the type of radiation they capture, how the radiation is measured, how the images are formed, and the medical goals they serve. Related to medical goals, detectors fall into two major areas: (i) anatomical imaging, which mainly concerns the techniques of diagnostic radiology, and (ii) functional-molecular imaging, which mainly concerns nuclear medicine. An important parameter in the evaluation of the detectors is the combination of the quality of the diagnostic result they offer and the burden of the patient with radiation dose. The latter has to be minimized; thus, the input signal (radiation photon flux) must be kept at low levels. For this reason, the detective quantum efficiency (DQE), expressing signal-to-noise ratio transfer through an imaging system, is of primary importance. In diagnostic radiology, image quality is better than in nuclear medicine; however, in most cases, the dose is higher. On the other hand, nuclear medicine focuses on the detection of functional findings and not on the accurate spatial determination of anatomical data. Detectors are integrated into projection or tomographic imaging systems and are based on the use of scintillators with optical sensors, photoconductors, or semiconductors. Analysis and modeling of such systems can be performed employing theoretical models developed in the framework of cascaded linear systems analysis (LCSA), as well as within the signal detection theory (SDT) and information theory.

A study on the interaction parameters of charged and uncharged radiation types with some indoor plants

This study investigates how gamma rays, neutrons, and electrons interact with five commonly found indoor plants: Spathiphyllum wallisii (SW), Ficus elastica (FE), Dieffenbachia camilla (DC), Schefflera arboricola (SA), and Ficus benjamina (FB). Utilizing experimental measurements (with HPGe detector), Monte Carlo simulations (GEANT4 and FLUKA), and theoretical calculations (ESTAR and WinXCOM), some radiation interaction parameters for gamma rays, fast neutrons, thermal neutrons, and electrons were determined. Secondary particle generation was also analyzed to provide a comprehensive assessment. The determined linear attenuation coefficients with the help of the WinXCOM are 0.1376, 0.1662, 0.1385, 0.1651 and 0.1698 cm-1 for SW, FE, DC, SA and FB, respectively. The calculated total macroscopic cross sections for indoor plants in the same sample order are 2.0290, 2.0350, 2.0285, 2.0363 and 2.0362 cm-1. Among the investigated plants, FB exhibited the highest gamma ray interaction, while SA and FB showed superior interaction against fast neutrons compared to SW and DC. The findings reveal significant variations in interaction effectiveness and secondary radiation production across these plants, offering valuable insights for radiation safety and environmental health evaluations.

Variation of surface solar radiation components from 2016 to 2020 in China: Perspective from geostationary satellite observation with a high spatiotemporal resolution

At present, traditional satellite datasets still grapple with inadequacies in terms of capturing solar radiation with fine spatiotemporal granularity. This study utilizes the high spatiotemporal resolution of CARE data, which is developed based on geostationary satellite observations, and employs multivariate analysis techniques to conduct an in-depth investigation into the multidimensional spatiotemporal variations of different types of solar radiation across various regions in China from 2016 to 2020. In addition, the potential of solar energy resources was also assessed using cluster analysis method. The results revealed an upward trend in different components of solar radiation across most of China, with shortwave radiation exhibiting a significantly negative correlation with PM2.5 concentrations (R = −0.91, p < 0.05). This finding suggests that the increase in SWR may be attributed to the effective implementation of China's Air Pollution Prevention and Control Action Plan. It suggests that China's endeavors to mitigate air pollution have not only resulted in improvements in national air quality but have also had an indirect positive effect on enhancing the potential for photovoltaic power generation. The assessment of solar energy resources potential indicated, with 99 % statistical confidence, that western China constitutes the core region for solar energy resources development, whereas northeastern and southeastern regions face certain constraints in solar energy resources utilization. Furthermore, we examined the specific influence of atmospheric circulation patterns on solar energy resources, uncovering that the El Niño phenomenon, by altering cloud distribution and variability, indirectly affects solar radiation intensity in specific regions. This study aids in understanding China's solar radiation variations, crucial for shaping effective energy policies towards carbon neutrality.

Study of resin coating adhesion on GFRP laminate surfaces after UV degradation

This paper describes research on the effect of UV radiation on the surface of a GFRP (Glass Fiber Reinforced Polymer) laminate in the context of increasing the adhesion between the laminate and polymer resin coatings. GFRP composite samples were prepared using the hand lay-up method. The samples were then exposed to various types of ultraviolet radiation (UVA, UVB, UVC) for 1000 h, with surface roughness measurements every 100 h. The flexural strength of laminates after photoaging was tested, which showed an increase in the strength of aged laminates compared to the reference sample by approximately 5–10 %. Coatings of various thicknesses were applied to the surface of the aged laminates and their adhesion to the substrate material was tested using the mandrel bending method alongside the cross-cut technique. The greatest change in surface roughness was observed on the sample exposed to UVC radiation, where the roughness increased approximately twice in relation to the reference sample. Coating adhesion tests have additionally shown that degradation under the influence of UVC has a positive effect on the adhesion of coatings to the laminate.

Experimental and clinical combined photodynamic therapy for malignant and premalignant lesions using various types of radiation

The aim of the study was to present various types of radiation that can increase the effectiveness of combined photodynamic therapy (PDT) for malignant and premalignant lesions. Material and Methods. The Web of Science, Scopus, MedLine, Library, and RSCI databases were used for finding publications on this topic, mainly over the last 10 years. Of 230 sources, 64 were included in the review. Results. Photodynamic therapy is a new cancer treatment technology that has become increasingly popular in recent years. It is often an alternative method of treating cancer when there is a high risk of side effects and complications during traditional treatments such as surgery, radiation therapy and chemotherapy. PDT requires a photosensitizer, light energy, and oxygen to create reactive oxygen species that destroy cancer cells. This review examines the basic principles and mechanisms of PDT used alone and in combination with other traditional therapies. Despite the fact that PDT is an effective and non-invasive cancer treatment, it has some limitations, such as low light penetration depth, ineffective photosensitizers and tumor hypoxia. Our study examines new strategies that use other energy sources, such as infrared- and x-rays, ultrasound, as well as electric and magnetic fields, to enhance the PDT effect and overcome its limitations. Great hopes are also associated with the use of a combination of PDT and neutron capture therapy (NСT). Currently, chlorin derivatives associated with boron carriers have been developed. They can be used for both fluorescence diagnostics and PDT, as well as for NСT. The synthesized compounds have a high selectivity of accumulation in the tumor. To date, encouraging preclinical results of high efficiency of combined use of NСT and PDT have already been obtained. Conclusion. Combination with various energy sources is a key factor for further development of PDT. Future research aimed at overcoming the limitations of PDT will contribute to unlocking the full potential of this technology in clinical practice.

Reconstructing Failure: Assessing Surgical and Patient Reported Outcomes Following Loss of Initial Breast Reconstruction.

Breast reconstruction failure, defined as the removal of a prosthetic device or flap without immediate replacement, can be traumatic for patients. We aim to describe the progression of patients who experience tissue expander (TE), implant, or autologous breast reconstructive failure and assess the patient reported outcomes (PROs) among patients who undergo additional reconstruction. Patients undergoing TE, implant, or autologous breast reconstruction between 2017 and 2022 were included, and patients with reconstructive failures were identified. Outcomes of interests included (1) receipt of additional reconstruction and (2) BREAST-Q scores 1-year after reconstructive failure. We also performed a propensity-matched analysis between patients who undergo secondary reconstruction and patients who had an uncomplicated reconstruction. 4,258 TE, 4,420 implant, and 1,545 autologous breast reconstruction patients were included. Of patients who experienced reconstructive failures, 49.5% of TE, 4.8% of implant, and 53.8% of autologous patients underwent secondary reconstruction. Age, psychiatric diagnosis, chemotherapy, radiation, and mastectomy type were associated with increased likelihood of secondary reconstruction. Between patients with and without additional reconstruction, higher Psychosocial Well-being trended towards the former cohort (61 [Interquartile Range: 56, 80] vs 50 [46, 65], p=0.085). Propensity-matched analysis demonstrated comparable PROs at 1-year after definite reconstruction. Less than half of reconstructive failure patients undergo an additional reconstruction. Patients with secondary reconstruction may have improved Psychosocial Well-being than those who do not and comparable PROs to those who had uncomplicated initial reconstruction. Surgeons should counsel patients with reconstructive failures that although traumatizing, secondary reconstruction may be beneficial.

Photodegradation of Amoxicillin in Aqueous Systems: A Review.

Amoxicillin (AMX) is utilized in the treatment of several infectious diseases, and its concentration in wastewater has increased quite significantly over the years, posing high health hazards for humans and other living organisms. Investigations are in progress globally to eliminate AMX and other related pollutants using several methods that include adsorption, photolysis, photocatalytic degradation, photoelectrocatalytic degradation, and electrochemical conversion. AMX can be eliminated efficiently from the environment using photodegradation, either by photolysis or a photocatalytic process. Several types of semiconductor NMs have been used to eliminate AMX and other related drugs present in wastewater. This review spans the photodegradation studies conducted during the years 2018-2024 to degrade and eliminate AMX in aquatic systems. Several studies have been reported to eliminate AMX from different water streams. These studies are categorized into TiO2-containing and non-TiO2-based catalysts for better comparison. A section on photolysis is also included, showing the use of UV alone or with H2O2 or PS without using any nanomaterial. A tabulated summary of both types of catalysts showing the catalysts, reaction conditions, and degradation efficiency is presented. Researchers have used a variety of reaction conditions that include radiation types (UV, solar, and visible), pH of the solution, concentration of AMX, number of nanomaterials, presence of other additives and activators such as H2O2 as oxidant, and the influence of different salts like NaCl and CaCl2 on the photodegradation efficiency. TiO2 was the best nanomaterial found that achieved the highest degradation of AMX in ultraviolet irradiation. TiO2 doped with other nanomaterials showed very good performance under visible light. WO3 was also used by several investigators and found quite effective for AMX degradation. Other metal oxides used for AMX elimination were derived from molybdenum, zinc, manganese, copper, cerium, silver, etc. Some researchers have used UV and/or visible irradiation or sunlight, without using solid catalysts, in the presence of oxidants such as H2O2. A summarized description of earlier published reviews is also presented.

Flexible and Ecological Cotton-Based Dosimeter for 2D UV Surface Dose Distribution Measurements.

This work presents a 2D radiochromic dosimeter for ultraviolet (UV) radiation measurements, based on cotton fabric volume-modified with nitroblue tetrazolium chloride (NBT) as a radiation-sensitive compound. The developed dosimeter is flexible, which allows it to adapt to various shapes and show a color change from yellowish to purple-brown during irradiation. The intensity of the color change depends on the type of UV radiation and is the highest for UVC (253.7 nm). It has been shown that the developed dosimeters (i) can be used for UVC radiation dose measurements in the range of up to 10 J/cm2; (ii) can be measured in 2D using a flatbed scanner; and (iii) can have the obtained images after scanning be filtered with a medium filter to improve their quality by reducing noise from the fabric structure. The developed cotton-NBT dosimeters can measure UVC-absorbed radiation doses on objects of various shapes, and when combined with a dedicated computer software package and a data processing method, they form a comprehensive system for measuring dose distributions for objects with complex shapes. The developed system can also serve as a comprehensive method for assessing the quality and control of UV radiation sources used in various industrial processes.

Characterization of the image plate multi-scan response to mono-energetic x-rays.

Image plates (IPs), or phosphor storage screens, are a technology employed frequently in inertial confinement fusion (ICF) and high energy density plasma (HEDP) diagnostics because of their sensitivity to many types of radiation, including, x rays, protons, alphas, beta particles, and neutrons. Prior studies characterizing IPs are predicated on the signal level remaining below the scanner saturation threshold. Since the scanning process removes some signal from the IP via photostimulated luminescence, repeatedly scanning an IP can bring the signal level below the scanner saturation threshold. This process, in turn, raises concerns about the signal response of IPs after an arbitrary number of scans and whether such a process yields, for example, a constant ratio of signal between the nth and n + 1st scan. Here, the sensitivity of IPs is investigated when scanned multiple times. It is demonstrated that the ratio of signal decay is not a constant with the number of scans and that the signal decay depends on the x-ray energy. As such, repeatedly scanning an IP with a mixture of signal types (e.g., x ray, neutron, and protons) enables ICF and HEDP diagnostics employing IPs to better isolate a particular signal type.

Image plate multi-scan response to fusion protons in the range of 1-14 MeV.

Image plates (IPs) are a quickly recoverable and reusable radiation detector often used to measure proton and x-ray fluence in laser-driven experiments. Recently, IPs have been used in a proton radiography detector stack on the OMEGA laser, a diagnostic historically implemented with CR-39, or radiochromic film. The IPs used in this and other diagnostics detect charged particles, neutrons, and x-rays indiscriminately. IPs detect radiation using a photo-stimulated luminescence (PSL) material, often phosphor, in which electrons are excited to metastable states by ionizing radiation. Protons at MeV energies deposit energy deeper into the IP compared with x rays below ∼20keV due to the Bragg peak present for protons. This property is exploited to discriminate between radiation types. Doses of mono-energetic protons between 1.7 and 14MeV are applied to IPs using the MIT linear electrostatic ion accelerator. This paper presents the results from consecutive scans of IPs irradiated with different proton energies. The PSL ratios between subsequent scans are shown to depend on proton energy, with higher energy protons having lower PSL ratios for each scan. This finding is separate from the known energy dependence in the absolute sensitivity of IPs. The results can be compared to complimentary work on x rays, showing a difference between protons and x rays, forging a path to discriminate between proton and x-ray fluence in mixed radiation environments.