Artículos de revistas: "Enriched thermal instrumentation"

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Porosev, V. V. y G. A. Savinov. "Evaluation of boron-enriched plastic scintillator for thermal neutron detection". Journal of Instrumentation 14, n.º 06 (3 de junio de 2019): P06003. http://dx.doi.org/10.1088/1748-0221/14/06/p06003.

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Burak, Ya V., V. T. Adamiv, I. M. Teslyuk y V. M. Shevel. "Optical absorption of isotopically enriched Li2B4O7 single crystals irradiated by thermal neutrons". Radiation Measurements 38, n.º 4-6 (agosto de 2004): 681–84. http://dx.doi.org/10.1016/j.radmeas.2003.12.029.

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Mahl, Adam, Henok A. Yemam, Roshan Fernando, Joshua T. Koubek, Alan Sellinger y Uwe Greife. "10B enriched plastic scintillators for application in thermal neutron detection". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 880 (febrero de 2018): 1–5. http://dx.doi.org/10.1016/j.nima.2017.10.042.

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4

Chan, Wing-Tat, X. L. Mao y Richard E. Russo. "Differential Vaporization during Laser Ablation/Deposition of Bi-Sr-Ca-Cu-O Superconducting Materials". Applied Spectroscopy 46, n.º 6 (junio de 1992): 1025–31. http://dx.doi.org/10.1366/0003702924124510.

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Nanosecond and picosecond pulsed laser ablated materials from Bi-Sr-Ca-Cu-O superconducting targets are monitored by inductively coupled plasma-atomic emission spectrometry with a photodiode array detector. Differential vaporization was observed; elements of the lower-melting-point oxides (Bi2O3, and CuO) are enriched in the vapor phase, indicating a thermal vaporization mechanism. Melted droplets observed with SEM and enriched Ca and Sr content in the ablation crater measured with EDX support the hypothesis. A steady-state mass ablation composition after prolonged laser sampling is also observed; the ratios of intensity for Bi, Ca, and Sr to Cu are constant for power density 0.1 to 3.0 GW/cm2.

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Sahani, R. M., Arun Pandya y Ambesh Dixit. "ZnO-⁶LiF/polystyrene composite scintillator for thermal neutron radiation detection". Review of Scientific Instruments 94, n.º 2 (1 de febrero de 2023): 024101. http://dx.doi.org/10.1063/5.0126282.

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We report the preparation of the ZnO-6LiF composite with a polystyrene (PS) polymer as a host using the solution mixing process. 6LiF acts as a converter material that absorbs a thermal neutron and produces alpha particles, which excites ZnO micro-particles, resulting in UV–vis photons’ emission. The free-standing ZnO-6LiF/PS composite film is coupled to a photomultiplier tube (PMT). 241Am-Be (1Ci) is used as the neutron radiation source for measuring the response. We compared the response of the composite scintillator consisting of (i) natural LiF and (ii) 95% 6Li enriched LiF (6LiF). The increased pulse heights are recorded for 95% 6Li enriched, i.e., 6LiF converter. It confirms the generation of alpha particles after the absorption of a neutron in 6LiF. Furthermore, ZnO and 6LiF are considered in different weight proportions, 2:1, 1:1, and 1:2, keeping the total loading 50% (w/w) of polystyrene. The ZnO:6LiF (1:1)/PS composite showed higher scintillation pulse heights than the other two composites. Repetitive measurements are performed for the ZnO-6LiF(1:1)/PS composite, showing ±5% variation in respective responses. We also investigated the impact of different counting times and source-to-detector responses for the ZnO-6LiF(1:1)/PS composite. The response increases linearly with neutron dose, exhibiting a sensitivity of ∼203 counts/ μSv. Neutron measurement counts at different source-to-detector distances have a similar trend as that of neutron dose measured by using a neutron dosimeter. Thus, this work demonstrated the potential of the ZnO-6LiF/PS composite, coupled to PMT for detecting thermal neutron radiation.

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6

Burkhardt, Cindy A. y Joseph A. Gardella. "Comparison of Electron and Infrared Spectroscopy with Thermal Analysis to Study Molecular Weight Effects in PVC-PMMA Blends". Applied Spectroscopy 47, n.º 10 (octubre de 1993): 1636–42. http://dx.doi.org/10.1366/0003702934334543.

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The effects of homopolymer molecular weight on the miscibility of PVC/PMMA solvent cast blends were studied. Two significantly different molecular weights were chosen for each of the homopolymers, and a series of blends was prepared from the four possible homopolymer-homopolymer combinations. Angle-dependent ESCA results suggest that the surfaces of the blends are enriched with PMMA. The extent of this enrichment is dependent on molecular weight, with the most enrichment seen in blends containing the lower-molecular-weight PMMA homopolymer. Differential scanning calorimetry (DSC) results are also presented.

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Akula, Aparna, Ripul Ghosh, Satish Kumar y H. K. Sardana. "WignerMSER: Pseudo-Wigner Distribution Enriched MSER Feature Detector for Object Recognition in Thermal Infrared Images". IEEE Sensors Journal 19, n.º 11 (1 de junio de 2019): 4221–28. http://dx.doi.org/10.1109/jsen.2019.2900268.

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Tartaglione, A., F. Di Lorenzo y R. E. Mayer. "Detection of thermal-induced prompt fission neutrons of highly-enriched uranium: A position sensitive technique". Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 267, n.º 14 (julio de 2009): 2453–56. http://dx.doi.org/10.1016/j.nimb.2009.04.019.

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Borrmann, Thomas, James H. Johnston, Andrew J. McFarlane, Kenneth J. D. MacKenzie y Akihiko Nukui. "Structural elucidation of synthetic calcium silicates". Powder Diffraction 23, n.º 3 (septiembre de 2008): 204–12. http://dx.doi.org/10.1154/1.2957881.

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A series of synthetic calcium silicates has been produced comprising nano-sized plates. The starting calcium silicate referred to as nano-structured calcium silicate, NCS, appears itself X-ray amorphous but contains impurities of calcite. These impurities decompose during the dry thermal conversion of the material into wollastonite. NCS can be enriched with calcium or silicon, respectively. The silicon enriched NCS can be hydrothermally transformed into a sheet material related to Ca7Si16O38(OH)2. The X-ray pattern of this material was sufficient to allow the calculation of its unit cell with a comparatively high figure of merit. The calcium enriched NCS can form two very distinctly different ceramic materials upon hydrothermal treatment, one a band material (formed below 200 °C) and the other a rose petal shaped material (formed above 210 °C). The X-ray diffraction patterns could not be resolved. The fit between the observed and calculated patterns was less than 50% as expressed in comparatively low figures of merit (unusually <20), which is attributed to calcium carbonate impurities in the samples disrupting the long range order. The patterns of these calcium enriched samples could be best compared to those of tobermorite or truscotite.

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10

Ackerman, N., J. Albert, M. Auger, D. J. Auty, I. Badhrees, P. S. Barbeau, L. Bartoszek et al. "The EXO-200 detector, part II: auxiliary systems". Journal of Instrumentation 17, n.º 02 (1 de febrero de 2022): P02015. http://dx.doi.org/10.1088/1748-0221/17/02/p02015.

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Abstract The EXO-200 experiment searched for neutrinoless double-beta decay of 136Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. This paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector.

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11

Vinayak, A., S. R. Abhilash, M. M. Hosamani, G. B. Hiremath, G. R. Umapathy, D. Khandelwal, N. Madhavan, D. Kabiraj y N. M. Badiger. "Fabrication and Characterization of the self support enriched ^{107, 109}Ag thin targets for heavy ion induced transfer reaction". Journal of Instrumentation 17, n.º 02 (1 de febrero de 2022): T02006. http://dx.doi.org/10.1088/1748-0221/17/02/t02006.

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Abstract The enriched, self-supported, and thin isotopic targets of 107Ag and 109Ag were fabricated at the target development laboratory, IUAC New-Delhi, using a vacuum deposition facility. The targets were fabricated by the thermal evaporation technique with minimum material consumption. The simple and efficient method for the fabrication of thin targets with high quality without major impurities was discussed in detail. The prepared targets were characterised by using Rutherford Backscattering Spectrometry, X-Ray Diffraction, Total-Reflection X-Ray-Fluorescence and Scanning-Electron-Microscope techniques. From the characterizations, it was found that the fabricated targets were quite stable, had the same crystalline nature, the absence of any other elements, and were suitable for nuclear reaction experiments.

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Vreugdenhil, Andrew J. y Ian S. Butler. "Detection of the Engine Anti-Knock Additive Methylcyclopentadienyl Manganese Tricarbonyl (MMT) from Unleaded Gasoline in Soil by Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Mass Spectrometry". Applied Spectroscopy 49, n.º 4 (abril de 1995): 482–85. http://dx.doi.org/10.1366/0003702953964282.

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Soil samples were washed with dilute solutions of the toxic anti-knock fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) in hexanes and commercial unleaded gasoline. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was then used to detect the v(CO) modes of MMT, and subsequently 13CO-enriched MMT, in the soil samples. The presence of MMT in the soils was further confirmed by mass spectrometry. Concentrations corresponding to ∼10 ppm Mn in soil could be detected by DRIFTS of the dry samples, and, most interestingly, there was no evidence of significant MMT decomposition over a period of eight months. Apparently, MMT is stabilized by physisorption onto the soils. In the absence of such stabilization, however, MMT undergoes photolytic and thermal decomposition in a matter of minutes. These results suggest the possibility of longer-term environmental problems associated with gasoline spills containing MMT than was previously suspected.

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13

Aleksandrova, Mariya, Belgina Ustova, Tsvetozar Tsanev, Ioannis Raptis, Angeliki Tserepi, Evangelos Gogolides y Georgi Kolev. "Microheater Topology for Advanced Gas Sensor Applications with Carbyne-Enriched Nanomaterials". Applied Sciences 14, n.º 5 (21 de febrero de 2024): 1728. http://dx.doi.org/10.3390/app14051728.

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The response characteristics of carbyne-enriched surface-acoustic-wave (SAW)-based gas sensors utilizing meander and rectangular microheater topologies were investigated to assess their desorption and recovery properties. Comparative analysis of contact resistance and interface capacitance before and after heating revealed minimal deviation in contact resistance, signifying strong thermal stability in the carbyne-enriched layer. However, the interface capacitance varied with the microheater size. Our analysis reveals that a small meander microheater configuration (line width: 300 µm) facilitates efficient sensor recovery at ethanol concentration measurements in the range of 180–680 ppm, maintaining a low deviation in time delay across different concentrations (~2.3%), resulting in a narrow hysteresis and linear sensor response. Conversely, the large meander microheater (line width: 450 µm) and rectangular dense microheater induce irreversible changes in the sensing structure, leading to a widened hysteresis at higher concentrations and increased power consumption. Recovery patterns display substantial deviations from initial values at different concentration levels. Higher concentrations exhibit broader hysteresis, while lower concentrations show narrower hysteresis loops, compared to the small meander microheater. The study offers insights into desorption rates, power consumption variations, and recovery behaviors related to different microheater configurations. It demonstrates the importance of microheater topology selection in tailoring recovery properties and response characteristics, contributing to the advancement of carbyne-based sensor technology.

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14

Schischmanow, Adrian, Dennis Dahlke, Dirk Baumbach, Ines Ernst y Magdalena Linkiewicz. "Seamless Navigation, 3D Reconstruction, Thermographic and Semantic Mapping for Building Inspection". Sensors 22, n.º 13 (23 de junio de 2022): 4745. http://dx.doi.org/10.3390/s22134745.

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We present a workflow for seamless real-time navigation and 3D thermal mapping in combined indoor and outdoor environments in a global reference frame. The automated workflow and partly real-time capabilities are of special interest for inspection tasks and also for other time-critical applications. We use a hand-held integrated positioning system (IPS), which is a real-time capable visual-aided inertial navigation technology, and augment it with an additional passive thermal infrared camera and global referencing capabilities. The global reference is realized through surveyed optical markers (AprilTags). Due to the sensor data’s fusion of the stereo camera and the thermal images, the resulting georeferenced 3D point cloud is enriched with thermal intensity values. A challenging calibration approach is used to geometrically calibrate and pixel-co-register the trifocal camera system. By fusing the terrestrial dataset with additional geographic information from an unmanned aerial vehicle, we gain a complete building hull point cloud and automatically reconstruct a semantic 3D model. A single-family house with surroundings in the village of Morschenich near the city of Jülich (German federal state North Rhine-Westphalia) was used as a test site to demonstrate our workflow. The presented work is a step towards automated building information modeling.

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15

Greiter, Matthias B., Vera Höllriegl y Uwe Oeh. "Method development for thermal ionization mass spectrometry in the frame of a biokinetic tracer study with enriched stable isotopes of zirconium". International Journal of Mass Spectrometry 304, n.º 1 (junio de 2011): 1–8. http://dx.doi.org/10.1016/j.ijms.2011.02.013.

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Wei, Peng, Kaiming Fu, Juan Villacres, Thomas Ke, Kay Krachenfels, Curtis Ryan Stofer, Nima Bayati et al. "A Compact Handheld Sensor Package with Sensor Fusion for Comprehensive and Robust 3D Mapping". Sensors 24, n.º 8 (12 de abril de 2024): 2494. http://dx.doi.org/10.3390/s24082494.

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This paper introduces an innovative approach to 3D environmental mapping through the integration of a compact, handheld sensor package with a two-stage sensor fusion pipeline. The sensor package, incorporating LiDAR, IMU, RGB, and thermal cameras, enables comprehensive and robust 3D mapping of various environments. By leveraging Simultaneous Localization and Mapping (SLAM) and thermal imaging, our solution offers good performance in conditions where global positioning is unavailable and in visually degraded environments. The sensor package runs a real-time LiDAR-Inertial SLAM algorithm, generating a dense point cloud map that accurately reconstructs the geometric features of the environment. Following the acquisition of that point cloud, we post-process these data by fusing them with images from the RGB and thermal cameras and produce a detailed, color-enriched 3D map that is useful and adaptable to different mission requirements. We demonstrated our system in a variety of scenarios, from indoor to outdoor conditions, and the results showcased the effectiveness and applicability of our sensor package and fusion pipeline. This system can be applied in a wide range of applications, ranging from autonomous navigation to smart agriculture, and has the potential to make a substantial benefit across diverse fields.

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17

Provenzano, Chiara, Marcella Marra, Anna Paola Caricato, Paolo Finocchiaro, Simone Amaducci, Fabio Longhitano, Maurizio Martino, Gaetano Elio Poma y Gianluca Quarta. "Development of a High-Efficiency Device for Thermal Neutron Detection Using a Sandwich of Two High-Purity 10B Enriched Layers". Sensors 23, n.º 24 (14 de diciembre de 2023): 9831. http://dx.doi.org/10.3390/s23249831.

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The shortage of 3He, a crucial element widely used as a neutron converter in neutron detection applications, has sparked significant research efforts aimed at finding alternative materials, developing appropriate deposition methods, and exploring new detector architectures. This issue has required the exploration of novel approaches to address the challenges faced in neutron detection. Among the available conversion materials, 10B has emerged as one of the most promising choices due to its high neutron-capture cross-section and relatively high Q value. In our previous papers, we delved into the possibility of depositing neutron conversion layers based on 10B using Pulsed Laser Deposition (PLD). We investigated and evaluated the performance of these layers based on various factors, including deposition conditions, substrate properties, and film thickness. Moreover, we successfully developed and tested a device that employed a single conversion layer coupled with a silicon particle detector. In this current study, we present the development of a new device that showcases improved performance in terms of efficiency, sensitivity, and discrimination against γ background signals. The background signals can arise from the environment or be associated with the neutron field. To achieve these advancements, we considered a new detection geometry that incorporates the simultaneous use of two 10B conversion layers, each with a thickness of 1.5 μm, along with two solid-state silicon detectors. The primary objective of this design was to enhance the overall detection efficiency when compared to the single-layer geometry. By employing this novel setup, our results demonstrate a significant enhancement in the device’s performance when exposed to a neutron flux from an Am-Be neutron source, emitting a flux of approximately 2.2 × 106 neutrons per second. Furthermore, we established a noteworthy agreement between the experimental data obtained and the simulation results.

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Guo, Yuanxin, Chenyang Xu, Zhenwen Hu, Liang Wang, Gongbing Yue, Shidong Zheng, Qiuyi Li y Peihan Wang. "Study on the Performance of Foam Concrete Prepared from Decarburized Fly Ash". Applied Sciences 12, n.º 24 (11 de diciembre de 2022): 12708. http://dx.doi.org/10.3390/app122412708.

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Although the energy structure has been gradually enriched in recent years, China, as the world’s largest producer and consumer of coal, still accounts for more than 50% of resources. Therefore, in this paper, the high carbon fly ash raw ash (HCFARA) was mechanically activated, and the flotation was treated to obtain decarburized fly ash (DFA) with a loss on ignition of 1.18%, water demand ratio of 101% and strength activity coefficient of 74.5%. With the exception of for water demand ratio, the rest meet the national requirements for the use of Class I fly ash. The foam concrete was prepared by partially replacing cement with decarburized fly ash in different proportions and at different water-to-cement ratios (0.3, 0.4 and 0.5) in order to study its dry density, porosity, compressive strength and thermal conductivity. The results show that the porosity of foam concrete grows with the increase in water-to-cement ratio and fly ash replacement rate. In addition, the dry density and thermal conductivity of the prepared foam concrete can meet the requirements of A05 grade foam concrete (Density less than 500 kg/m3, thermal conductivity less than 0.12 W/(m·k)). The compressive strength can meet the requirements of C0.3 grade foam concrete (Minimum use standard).

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Milea, Ștefania Adelina, Oana Crăciunescu, Gabriela Râpeanu, Anca Oancea, Elena Enachi, Gabriela Elena Bahrim y Nicoleta Stănciuc. "Multifunctional Ingredient from Aqueous Flavonoidic Extract of Yellow Onion Skins with Cytocompatibility and Cell Proliferation Properties". Applied Sciences 11, n.º 16 (6 de agosto de 2021): 7243. http://dx.doi.org/10.3390/app11167243.

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Significant quantities of onion are cultivated annually, such that industrial processing leads to an appreciable amount of by-products, estimated at around 500,000 tons. Onion skins are considered an important source of naturally occurring antioxidant compounds, particularly flavonoid compounds. Our study follows the development of a sustainable solution in order to manage the by-products of yellow onion skins by designing ingredients with multifunctional activities. A green solvent aqueous extraction of flavonoids was applied to obtain a safe, flavonoid-enriched extract, yielding a total flavonoid content of 50.21 ± 0.09 mg quercetin equivalent (QE)/g dry weight (DW), and an antioxidant activity of 250.81 ± 6.76 mM Trolox/g DW. Complex biopolymeric matrices consisting of whey protein isolates, whey protein hydrolysates, maltodextrin, and pectin were further dissolved in the flavonoid-enriched aqueous extract, followed by freeze-drying. Two powders were obtained, both showing satisfactory phytochemical content and good stability during storage. The application of confocal microscopy revealed that the microscopic structure of the powders have a distribution of the bioactive compounds within the biopolymeric matrices. The in vitro digestion suggested remarkable stability in the gastric tract and a flavonoid-controlled release in the intestinal phase. A significant compatibility range of up to 1 mg/mL for both powders was found, whereas concentrations between 10 and 250 µg/mL stimulated cell proliferation after 24 h of cultivation. The powders showed satisfactory thermal and pH stability, which favors their addition to different food matrices.

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Nowak, Nikola, Wiktoria Grzebieniarz, Gohar Khachatryan, Karen Khachatryan, Anna Konieczna-Molenda, Marcel Krzan y Jacek Grzyb. "Synthesis of Silver and Gold Nanoparticles in Sodium Alginate Matrix Enriched with Graphene Oxide and Investigation of Properties of the Obtained Thin Films". Applied Sciences 11, n.º 9 (24 de abril de 2021): 3857. http://dx.doi.org/10.3390/app11093857.

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Polymer nanocomposites containing nanometals became a subject of interest due to their bactericidal properties. Different polysaccharides have been used as matrices for nanosilver and nanogold synthesis. In this study, we present a novel, environmentally friendly method for the preparation of sodium alginate/nanosilver/graphene oxide (GOX) and sodium alginate/nanogold/graphene oxide GOX nanocomposites and their characteristics. The formation of approximately 10–20 nm ball-shaped Ag and Au nanoparticles was confirmed by UV–vis spectroscopy, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectra. The incorporation of GOX sheets within the ALG matrix improved the thermal stability of the nanocomposites film, which was measured using the differential scanning calorimetry (DSC). We also estimated the molecular weights of polysaccharide chains of the matrix with the size exclusion chromatography coupled with multiangle laser light scattering and refractometric detectors (HPSEC-MALLS-RI). The composites were more prone to enzymatic hydrolysis. The strongest bacteriostatic activity was observed for the sample containing nanosilver.

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Gholamzadeh, Zohreh, Seyed Amir Hossein Feghhi, Leila Soltani, Marzieh Rezazadeh, Claudio Tenreiro y Mahdi Joharifard. "Burn-up calculation of different thorium-based fuel matrixes in a thermal research reactor using MCNPX 2.6 code". Nukleonika 59, n.º 4 (1 de diciembre de 2014): 129–36. http://dx.doi.org/10.2478/nuka-2014-0017.

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Abstract Decrease of the economically accessible uranium resources and the inherent proliferation resistance of thorium fuel motivate its application in nuclear power systems. Estimation of the nuclear reactor’s neutronic parameters during different operational situations is of key importance for the safe operation of nuclear reactors. In the present research, thorium oxide fuel burn-up calculations for a demonstrative model of a heavy water- -cooled reactor have been performed using MCNPX 2.6 code. Neutronic parameters for three different thorium fuel matrices loaded separately in the modelled thermal core have been investigated. 233U, 235U and 239Pu isotopes have been used as fissile element in the thorium oxide fuel, separately. Burn-up of three different fuels has been calculated at 1 MW constant power. 135X and 149Sm concentration variations have been studied in the modelled core during 165 days burn-up. Burn-up of thorium oxide enriched with 233U resulted in the least 149Sm and 135Xe productions and net fissile production of 233U after 165 days. The negative fuel, coolant and void reactivity of the used fuel assures safe operation of the modelled thermal core containing (233U-Th) O2 matrix. Furthermore, utilisation of thorium breeder fuel demonstrates several advantages, such as good neutronic economy, 233U production and less production of long-lived α emitter high radiotoxic wastes in biological internal exposure point of view

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Rosson, Egle, Acacio Rincón Romero, Denis Badocco, Federico Zorzi, Paolo Sgarbossa, Roberta Bertani, Paolo Pastore y Enrico Bernardo. "Production of Porous Ceramic Materials from Spent Fluorescent Lamps". Applied Sciences 11, n.º 13 (29 de junio de 2021): 6056. http://dx.doi.org/10.3390/app11136056.

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Spent fluorescent lamps (SFL) are classified as hazardous materials in the European Waste Catalogue, which includes residues from various hi-tech devices. The most common end-of-life treatment of SFL consists in the recovery of rare earth elements from the phosphor powders, with associated problems in the management of the glass residues, which are usually landfilled. This study involves the manufacturing of porous ceramics from both the coarse glass-rich fraction and the phosphor-enriched fraction of spent fluorescent lamps. These porous materials, realizing the immobilization of Rare Earth Elements (REEs) within a glass matrix, are suggested for application in buildings as thermal and acoustic insulators. The proposed process is characterized by: (i) alkaline activation (2.5 M or 1 M NaOH aqueous solution); (ii) pre-curing at 75 °C; (iii) the addition of a surfactant (Triton X-100) for foaming at high-speed stirring; (iv) curing at 45 °C; (v) viscous flow sintering at 700 °C. All the final porous ceramics present a limited metal leaching and, in particular, the coarse glass fraction activated with 2.5 M NaOH solution leads to materials comparable to commercial glass foams in terms of mechanical properties.

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Vamvuka, Despina y Konstantina Zacheila. "Gasification Performance of Barley Straw Waste Blended with Lignite for Syngas Production under Steam or Carbon Dioxide Atmosphere". Applied Sciences 14, n.º 2 (12 de enero de 2024): 665. http://dx.doi.org/10.3390/app14020665.

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The gasification performance of lignite/barley straw mixtures for syngas production was investigated. The experiments were carried out under a steam or carbon dioxide atmosphere, in fixed-bed and thermogravimetric–mass spectrometry systems. The thermal behavior, reactivity, conversion, product gas composition, liquid and gaseous by-products and interactions between fuels were determined and correlated with the structural characteristics and inherent minerals in ashes, which were analyzed via mineralogical, chemical and fusibility tests. Devolatilization of the materials up to 600 °C resulted in the carbon enrichment of chars and a 30–90-fold increase in the specific surface area. Gaseous and liquid by-products with higher heating values of 5–7 MJ/m3 and 20–28 MJ/kg could offer valuable energy. Upon steam gasification up to 1000 °C, product gas was enriched in hydrogen and carbon monoxide. The syngas yield and heating value of the gas mixture were higher for barley straw fuel (0.77 m3/kg, 11.4 MJ/m3), which, when blended with the lignite, produced upgraded products. Upon carbon dioxide gasification up to 1000 °C, barley straw char exhibited a 3-times higher rate than the lignite, as well as higher conversion (94.5% vs. 62.9%) and a higher syngas yield (0.84 m3/kg vs. 0.55 m3/kg). Lignite/barley straw blends showed synergistic effects and presented higher gasification reactivity and conversion in comparison to lignite. The overall performance of lignite was improved with the steam reagent, while that of barley straw was improved with the carbon dioxide reagent.

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Zorin, Ivan, Jakob Kilgus, Kristina Duswald, Bernhard Lendl, Bettina Heise y Markus Brandstetter. "Sensitivity-Enhanced Fourier Transform Mid-Infrared Spectroscopy Using a Supercontinuum Laser Source". Applied Spectroscopy 74, n.º 4 (25 de febrero de 2020): 485–93. http://dx.doi.org/10.1177/0003702819893364.

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Fourier transform infrared (FT-IR) spectrometers have been the dominant technology in the field of mid-infrared (mid-IR) spectroscopy for decades. Supercontinuum laser sources operating in the mid-IR spectral region now offer the potential to enrich the field of FT-IR spectroscopy due to their distinctive properties, such as high-brightness, broadband spectral coverage and enhanced stability. In our contribution, we introduce this advanced light source as a replacement for conventional thermal emitters. Furthermore, an approach to efficient coupling of pulsed mid-IR supercontinuum sources to FT-IR spectrometers is proposed and considered in detail. The experimental part is devoted to pulse-to-pulse energy fluctuations of the applied supercontinuum laser, performance of the system, as well as the noise and long-term stability. Comparative measurements performed with a conventional FT-IR instrument equipped with a thermal emitter illustrate that similar noise levels can be achieved with the supercontinuum-based system. The analytical performance of the supercontinuum-based FT-IR spectrometer was tested for a concentration series of aqueous formaldehyde solutions in a liquid flow cell (500 µm path length) and compared with the conventional FT-IR (130 µm path length). The results show a four-times-enhanced detection limit due to the extended path length enabled by the high brightness of the laser. In conclusion, FT-IR spectrometers equipped with novel broadband mid-IR supercontinuum lasers could outperform traditional systems providing superior performance, e.g., interaction path lengths formerly unattainable, while maintaining low noise levels known from highly stable thermal emitters.

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Richter, Veronika Elisabeth, Marc Syndicus, Jérôme Frisch y Christoph van Treeck. "Extending the IFC-Based bim2sim Framework to Improve the Accessibility of Thermal Comfort Analysis Considering Future Climate Scenarios". Applied Sciences 13, n.º 22 (18 de noviembre de 2023): 12478. http://dx.doi.org/10.3390/app132212478.

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Future weather scenarios significantly affect indoor thermal comfort, influencing people’s well-being and productivity at work. Thus, future weather scenarios should be considered in the design phase to improve a building’s climate change resilience for new constructions as well as renovations in building stock. As thermal comfort is highly influenced by internal and external thermal loads resulting from weather conditions and building usage, only a dynamic building performance simulation (BPS) can predict the boundary conditions for a thermal comfort analysis during the design stage. As the model setup for a BPS requires detailed information about building geometry, materials, and usage, recent research activities have tried to derive the required simulation models from the open BIM (Building Information Modeling) Standard IFC (Industry Foundation Classes). However, even if IFC data are available, they are often faulty or incomplete. We propose a template-based enrichment of the BPS models that assists with imputing missing data based on archetypal usage of thermal zones. These templates are available for standardized enrichment of BPS models but do not include the required parameters for thermal comfort analysis. This study presents an approach for IFC-based thermal comfort analysis and a set of zone-usage-based templates to enrich thermal comfort input parameters.

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26

Dong, Yunsheng, Baoping Xi, Shuixin He y Luhai Chen. "Experimental Study on the Effect of Thermal Shock on Physical and Mechanical Properties of Limestone". Applied Sciences 13, n.º 6 (13 de marzo de 2023): 3649. http://dx.doi.org/10.3390/app13063649.

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Thermal shock is the physical process of rapid cooling of a hot object. The physical and mechanical properties of rocks that have undergone thermal shock will change. This variation can be applied to the development of geothermal in limestone reservoirs and serve as an effective means of enhancing heat exchange capacity. The essence of this is rock thermal shock rupture. The reason for the change in rock properties due to thermal shock is distinguished from other factors and is a process of instantaneous impact thermal stress caused by non-constant heat transfer, resulting in rock damage from microscopic damage to macroscopic damage. In order to study the variation of physical and mechanical properties of limestone with heating and cooling temperatures under the effect of thermal shock, a self-developed thermal shock test device was used to test the physical and mechanical properties of limestone heated to 100 °C~600 °C after thermal shock. The results strongly suggest that the heating temperature under the effect of thermal shock is the main factor affecting the evolution of basic physical properties of limestone; with the increase in heating temperature, the color of the specimen changes from off-white to white, the mass decreases and the volume nonlinearly increases, with a maximum reduction of 1.39% in mass and a maximum expansion of 2.79% in volume at 600 °C. Indeed, 500 °C is the temperature of abrupt mass loss. The heating temperature and the cooling medium temperature act together to deteriorate the mechanical properties of limestone. With increasing heating temperature (decreasing cooling temperature), the uniaxial compressive strength of limestone decreased by 39.5% (19.3%), modulus of elasticity by 59.5% (22.9%), tensile strength by 42.9% (7.6%), and cohesion by 43.2% (22.5%). The peak strain increases by 74.2% and the angle of internal friction increases by 27% (25.9%). The above data are average values. The empirical equations of the compressive strength, modulus of elasticity, tensile strength of limestone under the action of thermal shock versus heating temperature were obtained. The differences in the physical and mechanical properties of limestone after two heat treatments (thermal shock and high-temperature heating) were compared and analyzed, and the results showed that the physical and mechanical properties of limestone deteriorated more severely after thermal shock compared to high-temperature heating. The research results can provide technical support for the drilling of geothermal development and wellbore stability assessment in limestone reservoirs, and enrich the theory of high-temperature rock mechanics.

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27

Li, Haobo, Liangjin Huang, Hanshuo Wu, Zhiyong Pan y Pu Zhou. "Influence of Gain Saturation Effect on Transverse Mode Instability Considering Four-Wave Mixing". Photonics 9, n.º 8 (17 de agosto de 2022): 577. http://dx.doi.org/10.3390/photonics9080577.

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Transverse mode instability (TMI) has been recognized as onse of the primary limiting factors for the average power scaling of high-brightness fiber lasers. In this work, a static model of the TMI effect based on stimulated thermal Rayleigh scattering (STRS) is established while considering the four-wave mixing (FWM) effect. The focus of the model is to theoretically investigate the TMI phenomenon and threshold power dominated by FWM. The gain saturation effect and fiber laser system parameters, such as seed power, pumping direction, and core numerical aperture, which have not been considered in the previous perturbation theory model, are also investigated. This work will enrich the perturbation theory model and extend its application scope in TMI mitigation strategies, providing guidance for understanding and suppressing TMI.

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28

Lin, Xing-Tao, Ge Sun, Jing-Qiang Zhao, Ling-Li Tang, Sheng-Hua Li y Ya-Bo Xie. "UiO-66 Selective Enrichment Integrated with Thermal Desorption GC-MS for Detection of Benzene Homologues in Ambient Air". Journal of Analytical Methods in Chemistry 2021 (14 de diciembre de 2021): 1–9. http://dx.doi.org/10.1155/2021/3138436.

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In this study, UiO-66 was selected as sorbent media packed in the tube to selectively enrich trace levels of benzene homologues such as benzene, toluene, and xylene (BTX) in ambient air prior to thermal desorption (TD)-GC-MS determination. A series of experiments were conducted to obtain the optimal TD conditions. The results indicated that the optimal TD parameters were as follows: desorption temperature of 180°C, desorption flow rate of 50 mL min−1, and desorption time of 30 min. Furthermore, the method based on UiO-66 enrichment integrated with TD-GC-MS for trace levels of BTX was successfully developed. It exhibited a good linearity (R2 > 0.99) in the range of 50–1000 ng, except for p, m-xylene in the range of 100–2000 ng, and achieved the recovery of 69.4–101.3%, and the relative standard deviation of 3.8–6.4%. The detection limits of BTX were 1.6–4.0 ng; according to 10 L of sampling volume, the method detection limits would be in the range of 0.16–0.40 µg m−3. Additionally, the method was successfully applied to determine BTX in indoor air and showed good selectivity and sensitivity. In summary, the findings in this work revealed that UiO-66 was an attractive adsorbent for selective enrichment trace levels of BTX compounds in ambient air, which was favorable for the subsequent detection by TD-GC-MS.

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29

Landi, Elena, Stefano Guizzardi, Elettra Papa y Carlo Galli. "Mg,Sr-Cosubstituted Hydroxyapatite with Improved Structural Properties". Applied Sciences 11, n.º 11 (27 de mayo de 2021): 4930. http://dx.doi.org/10.3390/app11114930.

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Bone substitute materials require specific properties to make them suitable for implantation, such as biocompatibility and resistance to mechanical loads. Mg,Sr-cosubstituted hydroxyapatite (MgSr-HA) is a promising bone scaffold candidate because its structure is similar to the native bone matrix. However, MgSr-HA materials do not typically withstand thermal treatments over 800 °C, because Mg promotes HA degradation to less stable tricalcium phosphate, a compound that, albeit biocompatible, is not found in bone. We, therefore, designed an ion-exchange process to enrich sintered Sr-HA with Mg and obtain MgSr-HA porous constructs. These materials contained a 0.04–0.08 Mg/Ca molar ratio and a 0.12–0.13 Sr/Ca molar ratio, and had up to 20 MPa of compressive strength, suitable for use as bone fillers or scaffolds. Unlike previous synthetic Mg,Sr-substituted apatite powders, the proposed process did not degrade HA and thus preserved its similarity to bone structure. The obtained material thus combines the presence of bioactive Mg and Sr ions in the HA lattice with a 3D morphological/structural organization that can be customized in pore size and distribution, as well as in mechanical strength, thus potentially covering a wide range of clinical applications.

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30

Liu, Gaoyang, Faguo Hou, Xindong Wang y Baizeng Fang. "Conductive Polymer and Nanoparticle-Promoted Polymer Hybrid Coatings for Metallic Bipolar Plates in Proton Membrane Exchange Water Electrolysis". Applied Sciences 13, n.º 3 (17 de enero de 2023): 1244. http://dx.doi.org/10.3390/app13031244.

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Proton exchange membrane water electrolysis (PEMWE) is a green hydrogen production technology with great development prospects. As an important part of PEMWE, bipolar plates (BPs) play an important role and put forward special requirements due to the harsh environments on both the anode and cathode. Recently, metal-based BPs, particularly stainless steel and titanium BPs have attracted much attention from researchers all over the world because of their advantages of high corrosion resistance, low resistivity, high thermal conductivity, and low permeability. However, these metallic BPs are still prone to being oxidized and are facing with hydrogen embrittlement problems in the PEMWE working environment, which would result in reduced output power and premature failure of the PEMWE stack. In order to reduce the corrosion rate and maintain low interfacial contact resistance, the surface modification of the metallic BPs with protective coatings, such as precious metals (e.g., Au, Pt, etc.) and metal nitrides/carbides, etc., have been extensively investigated. However, the above-mentioned coating materials are restricted by the high-cost materials, complex equipment, and the complicated operation process. In this review, the surface modification of metallic BPs based on silane treatment, conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPy) as well as some nanoparticles-promoted polymer hybrid coatings which have been investigated for PEMWE, are summarized and reviewed. As for the silane treatment, the dense silane can not only effectively enhance the corrosion resistance but also improve the adhesion between the substrate and the conductive polymers. As for PANI and PPy, the typical value of corrosion current density of a PANI coating is 5.9 μA cm−2, which is significantly lower than 25.68 μA cm−2 of the bare metal plate. The introduction of nanosized conductive particles in PANI can further reduce the corrosion current density to 0.15 μA cm−2. However, further improvement in the electrical conductivity is still desired to decrease the interface contact resistance (ICR) to be lower than 10 mΩ cm2. In addition, serious peeling off of the coating during long-term operation also needs to be solved. Typically, the conductive polymer reinforced by graphene, noble metals, and their compounds in the form of nanoparticle-promoted polymer hybrid coatings could be a good choice to obtain higher corrosion resistance, durability, and conductivity and to extend the service life of PEMWE. Especially, nanoparticle-promoted polymer hybrid coatings consisting of polymers and conductive noble metals or nitrides/carbides can be controlled to balance the conductivity and mechanical properties. Due to the advantages of a simple preparation process, low cost, and large-scale production, nanoparticle-promoted polymer hybrid coatings have gradually become a research hotspot. This review is believed to enrich the knowledge of the large-scale preparation process and applications of BPs for PEMWE.

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31

Ganguli, Anurup, Jongwon Lim, Ariana Mostafa, Carlos Saavedra, Archith Rayabharam, Narayana R. Aluru, Matthew Wester et al. "A culture-free biphasic approach for sensitive and rapid detection of pathogens in dried whole-blood matrix". Proceedings of the National Academy of Sciences 119, n.º 40 (26 de septiembre de 2022). http://dx.doi.org/10.1073/pnas.2209607119.

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Blood stream infections (BSIs) cause high mortality, and their rapid detection remains a significant diagnostic challenge. Timely and informed administration of antibiotics can significantly improve patient outcomes. However, blood culture, which takes up to 5 d for a negative result, followed by PCR remains the gold standard in diagnosing BSI. Here, we introduce a new approach to blood-based diagnostics where large blood volumes can be rapidly dried, resulting in inactivation of the inhibitory components in blood. Further thermal treatments then generate a physical microscale and nanoscale fluidic network inside the dried matrix to allow access to target nucleic acid. The amplification enzymes and primers initiate the reaction within the dried blood matrix through these networks, precluding any need for conventional nucleic acid purification. High heme background is confined to the solid phase, while amplicons are enriched in the clear supernatant (liquid phase), giving fluorescence change comparable to purified DNA reactions. We demonstrate single-molecule sensitivity using a loop-mediated isothermal amplification reaction in our platform and detect a broad spectrum of pathogens, including gram-positive methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria, gram-negative Escherichia coli bacteria, and Candida albicans (fungus) from whole blood with a limit of detection (LOD) of 1.2 colony-forming units (CFU)/mL from 0.8 to 1 mL of starting blood volume. We validated our assay using 63 clinical samples (100% sensitivity and specificity) and significantly reduced sample-to-result time from over 20 h to <2.5 h. The reduction in instrumentation complexity and costs compared to blood culture and alternate molecular diagnostic platforms can have broad applications in healthcare systems in developed world and resource-limited settings.

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32

Lindstrom, Jake K., Chad A. Peterson, Peter N. Ciesielski, John Ralph, Mingjie Chen, Joseph E. Jakes, Patrick A. Johnston, Sean A. Rollag y Robert C. Brown. "Structural and chemical changes in hardwood cell walls during early stages of flash pyrolysis". Frontiers in Energy Research 12 (6 de marzo de 2024). http://dx.doi.org/10.3389/fenrg.2024.1348464.

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Volatile products from thermal decomposition of lignocellulosic biomass have been well characterized, but the solid- and liquid-phase reactions during the early stages of decomposition are largely unknown. Here the initial solid-phase biomass thermal deconstruction reactions were analyzed in situ and with high particle heating rates, delineating how these processes occur. A variety of instrumentation was used to quantify the extent and relative rates of deconstruction, demonstrating that biopolymers resist the thermally energetic conditions to differing degrees, even when ensconced in biomass cell walls. Hemicellulose and the more frangible lignin components decompose and volatilize more readily than cellulose, which temporarily enriches biomass with cellulose. These chemical changes manifest in larger cell wall structural and mechanical property transformations. In all, this investigation concludes that these solid-phase reactions strongly influence the production rates of volatile species and will require additional study before these processes can be modeled precisely to improve yields of desired product.

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33

Sharma, Vaishali, vandana dhingra, snehlata shakya, Ashok Kumar y mayank goswami. "Thermal Imaging based pre-diagnostics tool for graves' disease". Measurement Science and Technology, 4 de diciembre de 2023. http://dx.doi.org/10.1088/1361-6501/ad123a.

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Abstract Infrared thermography Images of the facial region are taken from sixty persons. Scintigraphy and standard thyroid blood test are used to categorize these persons into thirty-three females and thirteen males suffering from Graves' disease. This study is approved by the All-India Institute of Medical Science Rishikesh Ethics Committee with reference number AIIMS/IEC/19/997. Eleven Females and three males are found to be in healthy conditions and used as control. A convolutional neural networks (CNN) model is developed to automatically segment and extract the histogram-associated information within the thyroid and cheek region from the collected images. The sub-surface temperature of the thyroid gland and control is extracted using these set of images. We have acquired moderately correlated imaging biomarker with respect to age and gender from this sparse data. An Artificial Intelligence-based app is developed and deployed in a clinical environment to enrich the prognosis model in real time. An affordable Thermal plug-and-play addon device is developed to connect with any smartphone for faster diagnosis at the patient end to carry out this test now. This smartphone and AI-based app combination is successfully deployed as a point-of-care device. It is expected that this IR based preliminary test will automatically categorize healthy cases from patients. This step may save the clinicians to unnecessarily recommending the radioactive contamination-prone Scintigraphy and/or expensive and relatively slower thyroid blood tests. Such preliminary tests may (a) save costs to the patients and (b) relieve the burden on pathology labs. These two points are impactful for the healthcare industry, particularly in densely populated countries having low per capita income.

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