Spectrometer System Research Articles

Orthogonal dispersion modeling of double-stage VIPA spectrometer in SBS system

Brillouin microscopy enables the assessment of the mechanical properties of biological tissues by mapping the Brillouin shift in three-dimensional (3D), all-optical, label-free, non-contact, and subcellular resolution. The virtually imaged phased array (VIPA) etalon is widely utilized for measuring Brillouin spectra owing to its superior light throughput, large angular dispersion, and rapid signal acquisition capabilities. The VIPA-based spectrometer plays a significant role in Brillouin microscopy, but it is highly sensitive to factors such as the tilt angle, beam radius, lens focal length, and so on. Here, we propose an orthogonal dispersion model based on paraxial wave theory. This model is employed to explore the output intensity distribution and dispersion characteristics of a double-stage VIPA spectrometer. To validate the proposed model, we develop a stimulated Brillouin scattering (SBS) system by leveraging the optimal spectrometer parameters to measure the Brillouin frequency shift in pure water. We demonstrate the capabilities of this model in mitigating spectral dispersion and enhancing spectral measurement accuracy by optimizing the spectrometer's system parameters. This work is pivotal for the future deployment of the double-stage VIPA spectrometer in SBS-based microscopy applications.

Light Output Function and Pulse-Shape Discrimination Capability of p-Terphenyl Organic Scintillator in Wide Neutron Energy Range of 1.1 to 19 MeV

In this work, we studied the light-output properties, efficiency function, as well as the pulse-shape discrimination (PSD) capability of p-Terphenyl scintillator. The selected solid cylindrical scintillation detector has a thickness of 45 mm and a diameter of 45 mm. Recently presented studies of light-output functions have only been measured for low-neutron energies. Our motivation has been to determine the light output function for p-Terphenyl scintillator more accurately over a wider neutron energy range. The measurements have been carried out with mono-energetic neutron beams in the wide energy range from 1.1 to 19 MeV. The neutron–gamma spectrometric system which we developed has been used for the measurement. The input analog signal from the detector was digitized with a fast 12-bits analog to digital converter with a sampling frequency of 1 GHz. Measured data from the detector are processed into the gamma and neutron spectra. The accurate light output function for the p-Therphenyl scintillator has been calculated. The pulse-shape discrimination capability, as well as the detection efficiency, of a p-Terphenyl scintillator are lower in comparison with a NE-213 equivalent detector.

Design of geostationary orbit ultrawide FOV long-wave infrared imaging spectrometer

The geostationary orbit imaging spectrometer offers distinct advantages for diverse applications in remote sensing. To enhance swath and data richness, there is a growing trend toward spectrometers with broader fields of view (FOV) and extended slit lengths. Optical systems equipped with these features face significant challenges in aberration correction. This paper investigates the parameters of geostationary orbits and designs a spectroscopic system capable of achieving ultrawide FOV without the need for stitching spectrograph subsystems. Additionally, it also designs a front-end telescope system that matches the spectroscopic system. The spectroscopic system features a slit length of 240 mm, employing an enhanced Offner structure for a long slit spectroscopic system, incorporating a freeform surface on the third mirror. To inhibit the effects of radiation stray light, the system's exit pupil is controlled to be positioned in front of the image plane to facilitate matching with the cold shield. The analysis indicates that the spectral resolution of the long-wave infrared imaging spectrometer system is 50 nm, with a total of 90 spectral sampling channels. The system's spatial resolution is 100 m, enabling a swath width of 400 km. Furthermore, the modulation transfer function (MTF) exceeds 0.42 at the Nyquist frequency of 8.35 lp/mm. The maximum RMS radius of the system is less than 27 μm at wavelengths ranging from 8 to 12.5 μm.

Greenhouse gas column observations from a portable spectrometer in Uganda

Abstract. The extensive terrestrial ecosystems of tropical Africa are a significant store of carbon and play a key but uncertain role in the atmospheric budgets of carbon dioxide and methane. As ground-based observations in the tropics are scarce compared with other parts of the world, recent studies have instead made use of satellite observations assimilated into atmospheric chemistry and transport models to conclude that methane emissions from this geographical region have increased since 2010 as a result of increased wetland extent, accounting for up to a third of global methane growth, and that the tropical Africa region dominates net carbon emission across the tropics. These studies critically rely on the accuracy of satellite datasets, such as those from the Orbiting Carbon Observatory-2 (OCO-2), the Greenhouse gases Observing SATellite (GOSAT), and the Sentinel-5 Precursor TROPOspheric Monitoring Instrument (TROPOMI), along with results from atmospheric transport models, over a geographical region where there are little independent data to test the robustness of published results. In this paper we present the first ground-based observations of greenhouse gas column concentrations over East Africa, obtained using a portable Bruker EM27/SUN Fourier transform infrared (FTIR) spectrometer during a deployment covering the first few months of 2020 in Jinja, Uganda. We operated the instrument near autonomously by way of an automated weatherproof enclosure and observed total atmospheric column concentrations of the greenhouse gases carbon dioxide and methane, as well as carbon monoxide, a useful proxy for emissions from incomplete combustion processes in the region. We discuss the performance of the combined enclosure and spectrometer system that we deployed in Jinja to obtain these data and show comparisons of our ground-based observations with satellite datasets from OCO-2 and Orbiting Carbon Observatory-3 (OCO-3) for carbon dioxide and TROPOMI for methane and carbon monoxide, whilst also comparing our results with concentration data from the GEOS-Chem and Copernicus Atmosphere Monitoring Service (CAMS) atmospheric inversions that provide a means of increasing spatial and temporal coverage where satellite data are not available. For our measurement period, we find mean differences in XCO2 between OCO-2 and the EM27/SUN of −0.29 % and between OCO-3 and the EM27/SUN of −0.28 %. In the case of TROPOMI, the mean difference in XCH4 that we find between TROPOMI and the EM27/SUN is −0.44 %, whilst for XCO the mean difference is −5.65 %. In each of these cases, the mean difference observed between the satellite and ground-based column concentrations is either close to or within the precision and accuracy requirements for the respective missions. With regard to the model and reanalysis comparisons with the EM27/SUN column concentrations, we see mean differences from the EM27/SUN of a global GEOS-Chem inversion for XCO2 of −0.08 %, a regional high-resolution GEOS-Chem inversion for XCH4 of −0.22 %, and the CAMS global reanalysis for XCO of −9.79 %. Our results demonstrate the value of ground-based observations of total column concentrations and show that the combined EM27/SUN and enclosure system employed would be suitable for acquisition of the longer-term observations needed to rigorously evaluate satellite observations and model and reanalysis calculations over tropical Africa.

Оценка методической погрешности измерения активности РАО разными способами для транспортных контейнеров большого объема

The article describes a method for determining the methodological error in measuring the activity of radioactive waste in containers of various types. Within the framework of the mathematical model, which takes into account the uniformity of the distribution of nuclides in the container, an assessment was made of the value of methodological error when choosing measurements using various methods using a spectrometric system with a collimated detector. The obtained results can be used in development of methods for measuring containers before sending radioactive waste for disposal to specialized organizations.

Evaluation of fluence-to-dose response function of neutron survey meter using singular value decomposition method

This paper presents the evaluation of the fluence-to-ambient dose equivalent response function (referred to as F2D response function) of the Aloka TPS-451C neutron dose equivalent rate meter (hereafter referred to as a neutron meter) based on a singular value decomposition (SVD) approach. Measurements of neutron ambient dose equivalent rates, Ḣ∗(10), using the neutron meter were conducted in various neutron standard fields of 241Am-Be source with different neutron fluence rate spectra. A series of Ḣ∗(10) values and corresponding neutron fluence rate spectra were used as the input data for unfolding the F2D response function of the neutron meter. To verify the SVD-based method, the fluence response functions of a well-known Bonner sphere spectrometer system were unfolded using the SVD method, and the results were compared with those provided in the IAEA technical report No. 403. The SVD method was then applied to determine the F2D response function of the Aloka TPS-451C neutron meter with the use of the ICRP-74 F2D response function and that predicted in a previous work as initial guesses. The consistency between initial guesses and the SVD unfolded F2D response function of the Aloka TPS-451C neutron meter implies the reliability of the SVD method for determining the response functions of neutron meters.

Characterization of Neutron Irradiator as a Source of Reference Radiation Field for Calibrating Dosemeters and Doserate Meters at PSI Laboratory

A new neutron calibration laboratory has been installed at the Paul Scherrer Institute in Switzerland. The calibration laboratory has been equipped with a newly developed neutron irradiator with two calibration benches, remote control instruments and related ancillary equipment for calibrating dosemeters and doserate meters. The actual dimensions of the calibration laboratory are 2.0 m (H) X 6.8 m (W) X 12.6 m (L). On the steel grid at a height of 2 m from the basement floor, two calibration benches are installed. A transport channel is installed in the middle of the benches for the transfer of the radiation sources. The radiation sources are moved from the safe position of the irradiator to the reference irradiation position using an air pressure unit. The reference position is at a height of 1.2 m from the grid floor. The neutron irradiator is equipped with two Am-Be sources. Characterization of neutron radiation field has been calculated in detail by the MCNPX neutron transport code as well as energy distribution of neutrons and contribution of scattered neutrons. Experimentally, it was measured with a neutron/gamma digital spectrometric system equipped with a stilbene detector. The quality of the neutron radiation field has been characterized by ambient dose equivalent rate and the shape of the Am-Be spectra has been verified with the ISO-8529 standard.

Natural Radioactivity in some Local Food Samples Consumed by Children in Iraq

This work was directed towards studying the specific activity of natural radioactivity (40k, 238U, and 232Th) in 13 samples of foodstuff that are consumed by children in Iraq. The foodstuffs such as biscuit, cocoa powder, milk powder, indomie, and soup were collected from markets in the Al-Najaf governorate. This food was analyzed in the laboratory, which belongs to the University of Kufa, using a scintillation detector (NaI(Tl)) detector (gamma spectrometer systems) and provided with software MESTRO-32. The results found that, the specific activity for potassium-40 were ranged from 52.11 Bq/kg to 619.61 Bq/kg, while the specific activity for uranium-238 ranged between 4.11 Bq/kg to 18.9 Bq/kg, but for thorium-232 were ranged from 0.39 Bq/kg to 12.06 Bq/kg. The specific activity for 40K, 238U, and 232Th for all samples was found to be within the worldwide range for radioactivity in food 420, 30, and 45 Bq/kg, respectively, except for cocoa powder samples have specific activity for 40K higher than worldwide. This study has shown that the levels of radioactivity in most samples of children food were within the limit value of organization UNSCEAR. Finally, the present study will provide data about natural radioactivity in food used by children in all governorates of the country to protect all children.

Optimization of cultivation system for Bacillus Siamese strain and its biocontrol effect on postharvest Colletotrichum gloeosporioides

In this study, we established an effective cultivation system for Bacillus Siamese (N-1), identified key antibacterial substances, and explored the underlying mechanisms of optimized N-1 fermentation for controlling pathogens. Our results demonstrate that the optimized system significantly enhanced the inhibitory effect of N-1 on five types of pathogens affecting tropical fruits. Additionally, non-targeted metabolomics analysis and ultra-high performance liquid chromatography triple quadrupole mass spectrometer system (UPLC-MS/MS) revealed the presence of lipopeptides, including Surfactin and FengycinA, in the optimized fermentation. Furthermore, in vitro experiments indicated that lipopeptide treatment (LT) at a concentration of 3.125 mg mL−1 significantly distorted the hyphae, decreased the activity of antioxidant enzymes, increased the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, and enhanced protein exosmosis rate of C. gloeosporioides. Moreover, LT markedly reduced the activities of energy metabolism-related enzymes, including succinate dehydrogenase (SDH), Na+K+-ATPase, and Ca2+Mg2+-ATPase, as well as ATP content, leading to apoptosis of C. gloeosporioides. In vivo experiments revealed that LT significantly inhibited the expansion of disease spots caused by C. gloeosporioides in mango fruit. These findings suggest that the established culture system could serve as a potential strategy to enhance biocontrol efficacy and prevent fruit decay.

Myoglobin saturation as an intracellular indicator for transfusion need in oncology patients.

This study aims to demonstrate the potential of myoglobin saturation as an indicator of oxygen delivery adequacy to help determine the need for red cell transfusion. Modern blood management approaches have been established to optimise use of red blood cells for transfusions in patients with anaemia. However, most approaches make recommendations to transfuse based on haemoglobin or haematocrit levels and do not directly address adequacy of oxygen delivery. Intracellular oxygen determined by myoglobin saturation directly measures oxygen delivery at the tissue level. A custom built spectrometer system with an optical fibre probe was used in this pilot study to measure muscle cell myoglobin saturation noninvasively from the first digital interosseous muscles in patients undergoing planned red blood cell transfusion. Patients were recruited from both the in-patient and out-patient oncology service at a major university medical centre. Measurements were made immediately before, immediately after, and 24 h following transfusion. Clinical data and tissue oxygen values from the Somanetics INVOS system were also collected. Myoglobin saturation, and thus cellular oxygen increased in some, but not all patients receiving a transfusion, and was most pronounced in patients who initially had low myoglobin saturation compared with the group as a whole. Clinical decisions to transfuse based on haemoglobin or haematocrit thresholds alone are likely insufficient to optimise use of red blood cell transfusions. The combination of haemoglobin or haematocrit with myoglobin saturation may optimally determine who will benefit physiologically from a transfusion.

Development of double-walled bellows for ITER VUV spectrometer systems

This study describes the design and development of double-walled bellows used in ITER's vacuum ultra-violet (VUV) spectrometer systems. These bellows were designed to accommodate port plug displacement resulting from the thermal expansion of the ITER vacuum vessel and other interface loads. The three VUV spectrometer systems under development—the VUV core survey spectrometer, divertor-VUV spectrometer, and VUV-edge spectrometer—are intended to measure the VUV spectrum to monitor impurity species in the plasma. While the ex-vessel components of ITER VUV spectrometers in the interspace and port cell areas, are fixed to the tokamak building, the closure plate of the port plugs, to which the sight pipes are attached, is expected to move by several centimeters both vertically and radially owing to the vacuum vessel's thermal expansion. As a result, the structural integrity of the system requires a flexible structure that can compensate for displacement caused by thermal expansion. To address this need, two types of double-walled bellows were developed, gimbal bellows for lateral displacement and axial bellows for axial displacement. These were developed in accordance with the ASME SEC.VIII code and EJMA standard to meet ITER's safety and vacuum requirements. A double wall is mandated for vacuum bellows due to their vulnerability in terms of vacuum safety. The structural integrity and functionality of the designed bellows were confirmed through functional tests on the manufactured prototype.

Riverine 129I dynamics during high-flow events on the Abukuma River in Fukushima

This study presents the riverine 129I concentrations and fluxes during high-flow events. The river water samples obtained by a previous study were subjected to 129I analyses. River water samples were collected at the midstream of the Abukuma River for five and seven times during high-flow events in July 2018 and October 2018, respectively. Suspended solids and filtered water samples were measured for 129I/127I ratios using an accelerator mass spectrometer system and for 127I concentrations using ICP-MS. Aggregated mean values of dissolved 129I concentration and 129I concentrations in suspended solids were 0.11 μBq/L (n = 12) and 0.60 mBq/kg (n = 12), respectively. Corresponding values of 129I/127I ratios were in 2.2 × 10−9 (n = 12) and 3.7 × 10−9 (n = 12), respectively. These concentrations and ratios were comparable to those at the background level before the Fukushima Dai-ichi nuclear power plant accident. Positive correlations with dissolved 137Cs and Cl− concentrations suggested that the dissolved 129I concentration decreased due to dilution of the river water during the events. A positive correlation with total carbon content suggested that organic matter contents determine 129I concentrations in suspended solids. The total 129I fluxes during JUL18 and OCT18 were 9.9 × 103 and 2.2 × 104 Bq, respectively. Although dissolved 129I was predominant under low-flow conditions, the particulate 129I flux increased by one or two orders of magnitude during the peak water discharge phases. These results underline the importance of particulate 129I dynamics during high-flow events for quantitative evaluation of the 129I cycle.

Design of Novel Membranes for the Efficient Separation of Bee Alarm Pheromones in Portable Membrane Inlet Mass Spectrometric Systems.

Bee alarm pheromones are essential molecules that are present in beehives when some threats occur in the bee population. In this work, we have applied multilevel modeling techniques to understand molecular interactions between representative bee alarm pheromones and polymers such as polymethyl siloxane (PDMS), polyethylene glycol (PEG), and their blend. This study aimed to check how these interactions can be manipulated to enable efficient separation of bee alarm pheromones in portable membrane inlet mass spectrometric (MIMS) systems using new membranes. The study involved the application of powerful computational atomistic methods based on a combination of modern semiempirical (GFN2-xTB), first principles (DFT), and force-field calculations. As a fundamental work material for the separation of molecules, we considered the PDMS polymer, a well-known sorbent material known to be applicable for light polar molecules. To improve its applicability as a sorbent material for heavier polar molecules, we considered two main factors-temperature and the addition of PEG polymer. Additional insights into molecular interactions were obtained by studying intrinsic reactive properties and noncovalent interactions between bee alarm pheromones and PDMS and PEG polymer chains.

Low-cost multispectral sensor reveals cold chain breaks, meat type, and storage time in chicken meat samples

A portable and low-cost spectrometric system has been proposed to discriminate cold chain (frozen) interruption during the supply chain, as well as, the sample type among four different tested chicken meat and products (nugget, wing, thigh and drumstick) and the storage time elapsed after the cold chain break. To achieve this, an AS7265x sensor chipset was used and controlled by a custom programmed microcontroller through a Qwiic I2C interface. Communication between the user and the sensor setup was made using a custom programmed interface developed using the Python. Frozen chicken samples were thawed under various temperature-time combinations (4, 8, 16, and 24 h at 4 and 24 °C) and then refrozen at -18 °C. The refrozen samples were stored for up to 60 days. Spectral measurements (410–940 nm) were taken before thawing and at 1, 10, 30 and 60 days of storage after refreezing. The spectra obtained were analysed using Principal Component Analysis and outliers were eliminated using Mahalobobis distance. Several classification models (including Decision Tree, Random Forest, AdaBoost, Support Vector Machine, k-Nearest Neighbors, Gaussian-Naïve Bayes, Multilayer Perceptron, Gaussian Process, Linear and Quadratic Discriminant Analysis and Partial Least Squares Discriminant Analysis) were trained where appropriate. The top models with the highest predictive ability were selected and merged to build Soft Voting Classifiers (SVC) for each feature to be predicted. The SVC models correctly classified the samples with 93%, 92% and 83% accuracy for cold chain interruption, chicken meat/product type and storage time after thaw-refreeze cycle, respectively. In addition, a graphical interface was also developed so that it can be used by end users for food safety concerns. The results showed the potential of the developed low-cost sensor to rapidly detect the potential food safety risks due to cold chain breakage and to trace back the problem by predicting the storage time after refreezing.

Study on the fourof Pfaffia glomerata based on the metabolomics technology and comparison of Dangshen () in the equivalent substitution prescription.

To explore the four Qiof Pfaffia glomerata (PG) and endow this foreign folk herb with the properties of Chinese medicine, make it Chinese medicinal and localized, and could be used as a Chinese medicine. The normal group, six cold herb groups, six hot herb groups, six cool herb groups, PG prescription group (PGPG), and Dangshen (Radix Codonopsis) prescription group (CPPG) were prepared with corresponding concentrations of water extracts, these herb extracts were administered by gavage to Sprague-Dawley rats, and the 12 h urine at night on the 29th day of the SD rats in each group were collected, Liquid Chromatograph Mass Spectrometer system was used to analyze them, the best discriminant models for the medicinal properties of cold-hot and cold-cool were set up, so as to the medicinal properties of PGPG, CPPG and PG were predicted. Based on the Progenesis QI, Human Metabolome Database, Kyoto Encyclopedia of Genes and Genomes, MetaboAnalyst 5.0 database, we enriched metabolic pathway and classification mechanism of medicinal properties of cold-cool Chinese herbs and the molecular mechanism of PG prescription. We established a best model of cold-hot herbal discrimination in the positive ion mode, then the probability that PGPG was predicted cold property was 88.9%. Furthermore, a model of cold-cool herbal discrimination was established, then the probability of PGPG containing the cool property was 77.8%. In addition, typical cold and cool herbs mainly affected nine biomarkers such as tyrosine-proline, (R)-3',7-Dihydroxy-2',4'-dimethoxyisoflavane in rats. The regulation trend of PGPG on markers was basically as same as the cool herbs and mainly involved in regulating the two pathways of cytochrome P450 and purine metabolism. The results showed PGPG had a cool medicinal property as same as CPPG, and the regulation trend of PGPG on markers was consistent with cool herbs. Therefore, the medicine properties PG and CP should be consistent, and the Traditional Chinese Medicine property of PG was predicted to be neutral.

Design and Optimization of the Irregular Shaped Permanent Magnet With High Homogeneity in the Magnetic Recoil Spectrometer System

Design and Optimization of the Irregular Shaped Permanent Magnet With High Homogeneity in the Magnetic Recoil Spectrometer System

Nanostructural characterization of surfaces and interfaces of Portland cement mortars using high resolution microscopy

In Portland cement mortars it is of paramount importance to investigate the bond strength between mortar and masonry by means of the study of interfaces and surfaces that make up the system mortar/ceramic block. In this work the aim was to characterize the chemical compositions, microstructures, surfaces and interfaces of mortars applied on ceramic blocks. Therefore, two important characterization tools were used: field-effect gun (FEG) scanning electron microscope (SEM) - FEI Quanta 200 with energy-dispersive (X-ray) spectrometer (EDS) and SEM system with EGF Nanofabrication FIB - FEI Quanta 3D FEG also with an EDS coupled. To date the results obtained from the research show that the characterization of cementitious materials with high resolution SEM is an important tool in the detection and differentiation of hydrated calcium silicates (CSH), calcium hydroxide (Ca(OH)2), ettringite and calcium carbonate by means of morphological, topographical and chemical data, thus providing extremely reliable as well as qualitative data from the structure of cementitious materials.

Retrieval of upper stratospheric ozone profiles from SCIAMACHY Hartley-Huggins limb scatter spectra using WMART

ABSTRACT The hyperspectral SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument, launched by Envisat in March 2002, measures atmospheric scattered radiance within the ultraviolet (UV) to near infrared range and has three geometric observation modes: nadir, occultation, and limb. This study describes a retrieval scheme to obtain middle and upper stratospheric ozone profiles from SCIAMACHY limb-scattered solar radiance. Owing to the low ozone concentration at high altitudes and rapid changes in ozone absorption cross-sections in the Hartley – Huggins band, a fundamental objective of this study was to establish a simple and effective retrieval scheme to derive reliable ozone profiles at high altitudes from UV spectral bands. In this study, short UV wavelengths of 302, 312, and 322 nm and a long wavelength of 331 nm were used for wavelength pairing to simplify the retrieval algorithm. Moreover, we employed the weighted multiplicative algebraic reconstruction technique (WMART), which is straightforward to understand, and easy to implement, combined with a radiative transfer model (i.e. SCIATRAN), and produced stable results. The retrieval error estimates for the upper stratosphere were provided, and the total retrieval error of the ozone profile was usually < 18% in the altitude range of 30–53 km. The results were compared with the SCIAMACHY v3.5 product and validated against profiles derived from Optical Spectrometer and InfraRed Imaging System (OSIRIS) v7.1, and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) v4.0 for 30–53 km altitude. The retrieved ozone profiles agreed with data from SCIAMACHY v3.5 within − 10%–5%, except at an altitude of 45 km, where the bias became larger (approximately −15%). The comparison of retrieved profiles with OSIRIS v7.1 showed differences within ± 10% for 30–53 km altitude. The errors were mostly less than − 5% below 43 km compared with ACE-FTS v4.0, but there was a large negative deviation in the upper stratosphere.

A Region-Monitoring-Type Slitless Imaging Spectrometer.

In modern scientific practice, it is necessary to consistently observe predetermined zones, with the expectation of detecting and identifying emerging targets or events inside such areas. This research presents an innovative imaging spectrometer system for the continuous monitoring of specific areas. This study begins by providing detailed information on the features and optical structure of the constructed instrument. This is then followed by simulations using optical design tools. The device has an F-number of 5, a focal length of 100 mm, a field of view of 3 × 7, and a wavelength range spanning from 400 nm to 600 nm. The optical path diagram demonstrates that the system's dispersion and imaging pictures can be distinguished, hence fulfilling the system's specifications. Furthermore, the utilization of a Modulation Transfer Function (MTF) graph has substantiated that the image quality indeed satisfies the specified criteria. To evaluate the instrument's performance in the spectrum observation of fixed regions, a region-monitoring-type slitless imaging spectrometer was built. The equipment has the capability to identify a specific region and rapidly capture the spectra of objects or events that are present inside that region. The spectral data were collected effectively by the implementation of image processing techniques on the captured photos. The correlation coefficient between these data and the reference data was 0.9226, showing that the device successfully measured the target's spectrum. Therefore, the instrument that was created successfully demonstrated its ability to capture images of the observed areas and collect spectral data from the targets located within those regions.

Numerical and experimental approach for dust dispersion and deposition behavior for safe decommissioning activities

ABSTRACT The use of high-fidelity modeling is a promising technique for studying the mechanisms of dust dispersion and deposition in safe decommissioning operations. Detailed multiphysics models for poly-dispersed turbulent flow, particle-laden flow, and particle surface interaction were coupled with a Reynolds Averaged Navier Stokes method for numerical simulation of dust dispersion and deposition. A model that considered the critical viscosity was utilized to estimate the interaction between particles and substrate. The deposition behavior of particles was a result of the competition between adhesion and rebound probabilities during the impact process, and only when the critical viscosity exceeded that of the impacting particles could they attach to the surfaces. To validate the accuracy of the simulation results, deposition experiments using zirconia particles were conducted. The experimental setup included a 3.2 m polycarbonate pipe, a fan regulated by an inverter to control the flow, an ultra-low penetration air filter capable of capturing particles with a minimum diameter of 120 nanometers. An air pump connected to a particle tank and a mixing tank was used for homogenizing the injection of particles. Particle concentration was measured during the experiments using a light scattering spectrometer system, WELASⓇ 2000, from the manufacturer PalasⓇ. This optical measurement technique functioned with a white light source and scattered light detection. The scattered light was collected via optical fibers, which led to the control and evaluation point, and results were displayed through special software. The numerical simulation results were compared with the experimental data and used to validate the numerical approach for flow with zirconia particles deposited on various material surfaces, including iron, titanium, stainless steel 304, and stainless steel 316, for airflow rates ranging from 54 L/min to 124 L/min.