Relevant bibliographies by topics / MoS2 characterization

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  4. Book chapters
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Academic literature on the topic 'MoS2 characterization'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "MoS2 characterization"

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Withanage, Sajeevi S., Mike Lopez, Wasee Sameen, Vanessa Charles, and Saiful I. Khondaker. "Elucidation of the growth mechanism of MoS2 during the CVD process." MRS Advances 4, no. 10 (December 26, 2018): 581–86. http://dx.doi.org/10.1557/adv.2018.660.

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ABSTRACTChemical vapor deposition (CVD) growth of two-dimensional molybdenum disulfide (MoS2) using molybdenum trioxide (MoO3) and sulfur (S) powder often results in intermediate molybdenum oxy-sulfide (MoOS2) species along with MoS2 due to a lack of control over the vapor pressure required for the clean growth. Much effort has been devoted in understanding and controlling of these intermediate MoOS2 specifies. Here, we show that with a second step sulfurization at moderate temperatures, these MoOS2 crystals can be transformed to monolayer MoS2 crystals. Scanning electron microscopy, Raman and photoluminescence spectroscopy and atomic force microscopy characterization carried out before and after re-sulfurization confirm the monolayer MoS2 growth via this route. This study shows that MoOS2 formed at the intermediate state can be successfully recycled to MoS2.
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Zhang, Xian. "Characterization of Layer Number of Two-Dimensional Transition Metal Diselenide Semiconducting Devices Using Si-Peak Analysis." Advances in Materials Science and Engineering 2019 (September 10, 2019): 1–7. http://dx.doi.org/10.1155/2019/7865698.

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Atomically thin materials such as semiconducting transition metal diselenide materials, like molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2), have received intensive interests in recent years due to their unique electronic structure, bandgap engineering, ambipolar behavior, and optical properties and have motivated investigations for the next-generation semiconducting electronic devices. In this work, we show a nondestructive method of characterizing the layer number of two-dimensional (2-D) MoSe2 and WSe2 including single- and few-layer materials by Raman spectroscopy. The related photoluminescence properties are also studied as a reference. Although Raman spectroscopy is a powerful tool for determining the layer number of 2-D materials such as graphene and molybdenum disulfide (MoS2), there have been difficulties in precisely characterizing the layer number for MoSe2 and WSe2 by Raman spectroscopy due to the uncertain shifts during the Raman measurement process and the lack of multiple separated Raman peaks in MoSe2 and WSe2 for referencing. We then compared the normalized Si peak with MoSe2 and WSe2 and successfully identified the layer number of MoSe2 and WSe2. Similar to graphene and MoS2, the sample layer number is found to modify their optical properties up to 4 layers.
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Niu, Yue, Sergio Gonzalez-Abad, Riccardo Frisenda, Philipp Marauhn, Matthias Drüppel, Patricia Gant, Robert Schmidt, et al. "Thickness-Dependent Differential Reflectance Spectra of Monolayer and Few-Layer MoS2, MoSe2, WS2 and WSe2." Nanomaterials 8, no. 9 (September 14, 2018): 725. http://dx.doi.org/10.3390/nano8090725.

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The research field of two dimensional (2D) materials strongly relies on optical microscopy characterization tools to identify atomically thin materials and to determine their number of layers. Moreover, optical microscopy-based techniques opened the door to study the optical properties of these nanomaterials. We presented a comprehensive study of the differential reflectance spectra of 2D semiconducting transition metal dichalcogenides (TMDCs), MoS2, MoSe2, WS2, and WSe2, with thickness ranging from one layer up to six layers. We analyzed the thickness-dependent energy of the different excitonic features, indicating the change in the band structure of the different TMDC materials with the number of layers. Our work provided a route to employ differential reflectance spectroscopy for determining the number of layers of MoS2, MoSe2, WS2, and WSe2.
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Chikukwa, Evernice, Edson Meyer, Johannes Mbese, and Nyengerai Zingwe. "Colloidal Synthesis and Characterization of Molybdenum Chalcogenide Quantum Dots Using a Two-Source Precursor Pathway for Photovoltaic Applications." Molecules 26, no. 14 (July 9, 2021): 4191. http://dx.doi.org/10.3390/molecules26144191.

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The drawbacks of utilizing nonrenewable energy have quickened innovative work on practical sustainable power sources (photovoltaics) because of their provision of a better-preserved decent environment which is free from natural contamination and commotion. Herein, the synthesis, characterization, and application of Mo chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of QDSSCs is discussed. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100), and (105) for the MoS2 nanoparticles; (002), (100), (103), and (110) for the MoSe2 nanoparticles; and (0002), (0004), (103), as well as (0006) for the MoTe2 nanoparticles. MoSe2 presented the smallest size of the nanoparticles, followed by MoTe2 and, lastly, by MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV–Vis and PL were used. The shift of the peaks from the red shift (600 nm) to the blue shift (270–275 nm and 287–289 nm (UV–Vis)) confirmed that the nanoparticles were quantum-confined. The application of the MoX2 NPs in QDSSCs was performed, with MoSe2 presenting the greatest PCE of 7.86%, followed by MoTe2 (6.93%) and, lastly, by MoS2, with the PCE of 6.05%.
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Hu, J. J., J. H. Sanders, and J. S. Zabinski. "Synthesis and microstructural characterization of inorganic fullerene-like MoS2 and graphite-MoS2 hybrid nanoparticles." Journal of Materials Research 21, no. 4 (April 1, 2006): 1033–40. http://dx.doi.org/10.1557/jmr.2006.0118.

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The structures of inorganic fullerene-like (IF) MoS2 nanoparticles produced by arc discharge in water are reported in this paper. To adjust the chemistry and structure of IF nanoparticles, 2H–MoS2, graphite and composite 2H–MoS2/graphite rods were used as electrodes in the arc synthesis. In comparison to using MoS2 as both anode and cathode, mixed electrodes (graphite and MoS2) significantly increased the discharge current. Various IF-MoS2 nanoparticles were successfully produced by the water-based arc method, and their microstructures were studied using a transmission electron microscope equipped with an x-ray energy dispersive spectrometer. The IF–MoS2 nanoparticles commonly had a solid core wrapped with a few MoS2 layers and exhibit some differences in size and geometry. The IF-MoS2 nanoparticles were typically 5–30 nm in diameter as observed by transmission electron microscopy. Tiny IF-MoS2 nanoparticles (<10 nm) along with fragments of lamellar MoS2 were produced from arc discharge in water using both graphite and MoS2 electrodes. Carbon nano-onions and hybrid nanoparticles consisting of carbon and MoS2 were synthesized by using mixed electrodes of graphite and 2H–MoS2. The hybrid nanoparticles were MoS2 cores covered by a graphite shell. Our results show that the water-based arc method provides a simple tool for producing a variety of nanoparticles including some familiar and some new hybrid structures.
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Politano, Grazia Giuseppina, Marco Castriota, Maria Penelope De Santo, Mario Michele Pipita, Giovanni Desiderio, Carlo Vena, and Carlo Versace. "Variable Angle Spectroscopic Ellipsometry Characterization of Spin-Coated MoS2 Films." Materials Proceedings 4, no. 1 (November 12, 2020): 86. http://dx.doi.org/10.3390/iocn2020-07978.

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In the field of Transition Metal Dichalcogenides (TMDCs), molybdenum disulfide (MoS2) has attracted an outstanding interest due to it having several applications. MoS2 has potentialities not yet fully realized in solution-based applications. However, the lack of knowledge of the optical properties of MoS2, especially in the infrared range, has significantly limited its use in many exciting photonic fields. In this work, the broadband optical properties of MoS2 films deposited by spin-coating onto Si/SiO2 substrates were studied by means of Variable Angle Spectroscopic Ellipsometry (VASE). The morphological and the structural properties of the samples were investigated by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Micro-Raman Spectroscopy. Micro-Raman spectroscopy measurements reveal the presence of 2H-MoS2 and 1T-MoS2 phases. The optical properties of the films show a mid-gap state at 0.6 eV, not reported in an ellipsometry work before, induced by defects in the MoS2 samples.
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Zhang, Huiying, Xiang Li, Wenjie Qian, Jianguo Zhu, Beibei Chen, Jin Yang, and Yu Xia. "Characterization of mechanical properties of epoxy/nanohybrid composites by nanoindentation." Nanotechnology Reviews 9, no. 1 (February 18, 2020): 28–40. http://dx.doi.org/10.1515/ntrev-2020-0003.

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AbstractThe carbon nanofibers and molybdenum disulfide (CNF-MoS2) nanohybrid material was fabricated and incorporated into epoxy resin to form the nanocomposite coating. Firstly, microstructure observation shows that each CNF was uniformly wrapped up with MoS2 nanosheets, and the nanohybrids were well dispersed in the coating. Then, nanoindentation experiments were carried out to explore the effect of the CNF-MoS2 nanohybrids on the mechanical properties of the epoxy resin coating. The results demonstrate that elastic modulus, hardness and creep deformation resistance of the CNF-MoS2 epoxy resin coating are greatly increased in comparison with both pure epoxy resin and MoS2 epoxy resin coatings. Finally, the underlying mechanism of high-performance tribological behavior of the nanocomposites is analyzed accordingly. It can be concluded that the wrapped structure with MoS2 sheets growing on the surface of CNF increases the contact area and reduces the friction coefficient of the composite coating, while the wear resistance of the nanocomposite coating is also greatly improved due to the superior high hardness of CNF.
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Venkateswarlu, Gundu, Devarapaga Madhu, and Jetti Vatsala Rani. "Electroanalytical characterization of F-doped MoS2 cathode material for rechargeable magnesium battery." Functional Materials Letters 12, no. 03 (May 16, 2019): 1950041. http://dx.doi.org/10.1142/s1793604719500413.

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Fluorine (F)-doped MoS2 was prepared by F-doping into layered MoS2 via chemical solution process with fluoroboric acid. X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were applied to conform the effect of F on the structure. The electrochemical performance was investigated by using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge studies. The F-doped MoS2 as cathode material for rechargeable Mg battery exhibited a good discharge capacity of 55[Formula: see text]mAhg[Formula: see text], with a good rate capability and good cycling stability when compared to pristine B-MoS2. The effective performance of F-doped MoS2 are attributed to the unique structure and synergetic effect between layered MoS2.
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Hu, Kun Hong, Xian Guo Hu, Xiao Jun Sun, He Feng Jing, and Song Zhan. "Synthesis and Characterization of Nanosize Molybdenum Disulfide Particles by Quick Homogeneous Precipitation Method." Key Engineering Materials 353-358 (September 2007): 2107–10. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.2107.

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Molybdenum sulfide nanoparticles were prepared via quick homogeneous precipitation method (QHPM) by the reaction between Na2MoO4 and CH3CSNH2 in the presence of sulfuric acid at 80 oC. The as-synthesized molybdenum sulfide particles were studied by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results showed that the as-synthesized molybdenum sulfide was amorphous MoS3 nanoparticles with an average size of 40 nm. The resultant amorphous MoS3 nanoparticles were then calcined under hydrogen gas flow at a selected temperature for 50 minutes. The results of XRD, TEM, and HRTEM confirmed that the MoS2 nanoparticles with about 40 nm were prepared from the amorphous MoS3 nanoparticles at 780 oC.
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Abid, Mohammad F., Mohammed A. Hamza, Shakir M. Ahmed, Salah M. Ali, and Sattar J. Hussein. "SYNTHESIS AND CHARACTERIZATION OF UNSUPPORTED CATALYST FOR GAS OIL DESULFURIZATION." Al-Qadisiyah Journal for Engineering Sciences 11, no. 3 (January 31, 2019): 357–71. http://dx.doi.org/10.30772/qjes.v11i3.566.

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Unsupported MoS2 catalysts were synthesized for the hydrodesulfurization (HDS) of real feed gas oil using different temperatures and pressures. Hydrothermal method was utilized to prepare by using molybdenum trioxide and sodium sulfide. The characterization of the catalyst was identified by XRD, SEM, and BET techniques. It was found that BET surface and pore volume were positively affected by pressure and temperature that could improve the activity of MoS2. Kinetic analysis showed that HDS reaction over MoS2 follow pseudo-first order kinetics. Experimental results revealed that the HDS activity of the unsupported MoS2 catalyst was better than supported CoMo/Al2O3 catalyst under the same operating conditions.
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Dissertations / Theses on the topic "MoS2 characterization"

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Ma, Lu. "Synthesis and Characterization of Large Area Few-layer MoS2 and WS2 Films." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1388149255.

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Huang, Zhida [Verfasser]. "Characterization and catalytic activity study of SBA-15-supported MoO3, MoS2, Ni or Co promoted MoS2 and Co promoted WS2 / Zhida Huang." Kiel : Universitätsbibliothek Kiel, 2010. http://d-nb.info/1019951621/34.

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Young, Justin R. "Synthesis and Characterization of Novel Two-Dimensional Materials." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468925594.

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Alrobei, Hussein. "Synthesis and Characterization of Alpha-Hematite Nanomaterials for Water-Splitting Applications." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7661.

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The recent momentum in energy research has simplified converting solar to electrical energy through photoelectrochemical (PEC) cells. There are numerous benefits to these PEC cells, such as the inexpensive fabrication of thin film, reduction in absorption loss (due to transparent electrolyte), and a substantial increase in the energy conversion efficiency. Alpha-hematite ([U+F061]-Fe2O3) has received considerable attention as a photoanode for water-splitting applications in photoelectrochemical (PEC) devices. The alpha-hematite ([U+F061]-Fe2O3) nanomaterial is attractive due to its bandgap of 2.1eV allowing it to absorb visible light. Other benefits of [U+F061]-Fe2O3 include low cost, chemical stability and availability in nature, and excellent photoelectrochemical (PEC) properties to split water into hydrogen and oxygen. However, [U+F061]-Fe2O3 suffers from low conductivity, slow surface kinetics, and low carrier diffusion that causes degradation of PEC device performance. The low carrier diffusion of [U+F061]-hematite is related to higher resistivity, slow surface kinetics, low electron mobility, and higher electro-hole combinations. All the drawbacks of [U+F061]-Fe2O3, such as low carrier mobility and electronic diffusion properties, can be enhanced by doping, which forms the nanocomposite and nanostructure films. In this study, all nanomaterials were synthesized utilizing the sol-gel technique and investigated using Scanning Electron Microscopy (SEM), X-ray Diffractometer (XRD), UV-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), Raman techniques, Particle Analyzer, Cyclic Voltammetry (CV), and Chronoamperometry, respectively. The surface morphology is studied by SEM. X-Ray diffractometer (XRD) is used to identify the crystalline phase and to estimate the crystalline size. FTIR is used to identify the chemical bonds as well as functional groups in the compound. A UV-Vis absorption spectral study may assist in understanding electronic structure of the optical band gap of the material. Cyclic voltammetry and chronoamperometry were used to estimate the diffusion coefficient and study electrochemical activities at the electrode/electrolyte interface. In this investigation, the [U+F061]-Fe2O3 was doped with various materials such as metal oxide (aluminum, Al), dichalcogenide (molybdenum disulfide, MoS2), and co-catalyst (titanium dioxide, TiO2). By doping or composite formation with different percentage ratios (0.5, 10, 20, 30) of aluminum (Al) containing [U+F061]-Fe2O3, the mobility and carrier diffusion properties of [U+F061]-hematite ([U+F061]-Fe2O3) can be enhanced. The new composite, Al-[U+F061]-Fe2O3, improved charge transport properties through strain introduction in the lattice structure, thus increasing light absorption. The increase of Al contents in [U+F061]-Fe2O3 shows clustering due to the denser formation of the Al-[U+F061]-Fe2O3 particle. The presence of aluminum causes the change in structural and optical and morphological properties of Al-[U+F061]-Fe2O3 more than the properties of the [U+F061]-Fe2O3 photocatalyst. There is a marked variation in the bandgap from 2.1 to 2.4 eV. The structure of the composite formation Al-[U+F061]-Fe2O3, due to a high percentage of Al, shows a rhombohedra structure. The photocurrent (35 A/cm2) clearly distinguishes the enhanced hydrogen production of the Al-[U+F061]-Fe2O3 based photocatalyst. This work has been conducted with several percentages (0.1, 0.2, 0.5, 1, 2, 5) of molybdenum disulfide (MoS2) that has shown enhanced photocatalytic activity due to its bonding, chemical composition, and nanoparticle growth on the graphene films. The MoS2 material has a bandgap of 1.8 eV that works in visible light, responding as a photocatalyst. The photocurrent and electrode/electrolyte interface of MoS2-[U+F061]-Fe2O3 nanocomposite films were investigated using electrochemical techniques. The MoS2 material could help to play a central role in charge transfer with its slow recombination of electron-hole pairs created due to photo-energy with the charge transfer rate between surface and electrons. The bandgap of the MoS2 doped [U+F061]-Fe2O3 nanocomposite has been estimated to be vary from 1.94 to 2.17 eV. The nanocomposite MoS2-[U+F061]-Fe2O3 films confirmed to be rhombohedral structure with a lower band gap than Al-[U+F061]-Fe2O3 nanomaterial. The nanocomposite MoS2-[U+F061]-Fe2O3 films revealed a more enhanced photocurrent (180 μA/cm2) than pristine [U+F061]-Fe2O3 and other transition metal doped Al-[U+F061]-Fe2O3 nanostructured films. The p-n configuration has been used because MoS2 can remove the holes from the n-type semiconductor by making a p-n configuration. The photoelectrochemical properties of the p-n configuration of MoS2-α-Fe2O3 as the n-type and ND-RRPHTh as the p-type deposited on both n-type silicon and FTO-coated glass plates. The p-n photoelectrochemical cell is stable and allows for eliminating the photo-corrosion process. Nanomaterial-based electrodes [U+F061]-Fe2O3-MoS2 and ND-RRPHTh have shown an improved hydrogen release compared to [U+F061]-Fe2O3, Al-[U+F061]-Fe2O3 and MoS2-[U+F061]-Fe2O3 nanostructured films in PEC cells. By using p-n configuration, the chronoamperometry results showed that 1% MoS2 in MoS2-[U+F061]-Fe2O3 nanocomposite can be a suitable structure to obtain a higher photocurrent density. The photoelectrochemical properties of the p-n configuration of MoS2-α-Fe2O3 as n-type and ND-RRPHTh as p-type showed 3-4 times higher (450 A/cm2) in current density and energy conversion efficiencies than parent electrode materials in an electrolyte of 1M of NaOH in PEC cells. Titanium dioxide (TiO2) is known as one of the most explored electrode materials due to its physical and chemical stability in aqueous materials and its non-toxicity. TiO2 has been investigated because of the low cost for the fabrication of photoelectrochemical stability and inexpensive material. Incorporation of various percentages (2.5, 5, 16, 25, 50) of TiO2 in Fe2O3 could achieve better efficiencies as the photoanode by enhancing the electron concentration and low combination rate, and both materials can have a wide range of wavelength which could absorb light in both UV and visible spectrum ranges. TiO2 doped with [U+F061]-Fe2O3 film was shown as increasing contacting area with the electrolyte, reducing e-h recombination and shift light absorption along with visible region. The [U+F061]-Fe2O3-TiO2 nanomaterial has shown a more enhanced photocurrent (800 μA/cm2) than metal doped [U+F061]-Fe2O3 photoelectrochemical devices.
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Singh, Harpal. "An Investigation of Material Properties and Tribological Performance of Magnetron Sputtered Thin Film Coatings." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1449850005.

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Gomes, Francis Oliver Vinay [Verfasser], Veit [Akademischer Betreuer] Wagner, Veit [Gutachter] Wagner, Thomas [Gutachter] Heine, and Ralf [Gutachter] Anselmann. "Film growth and characterization of solution processed MoS2 semiconductor films for thin film transistors / Francis Oliver Vinay Gomes ; Gutachter: Veit Wagner, Thomas Heine, Ralf Anselmann ; Betreuer: Veit Wagner." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2019. http://d-nb.info/1190888181/34.

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Swati, Swati, Richard Sante, and Aruna Kilaru. "Characterization of Arachidonylethanolamide Metabolic Pathway in Moss." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/4803.

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Arachidonylethanolamide (AEA) is a bioactive lipid ligand for mammalian cannabinoid receptors (CB). Thus far, AEA was reported to occur only in animals and was shown to regulate a wide range of physiological responses. Our recent fi nding of the occurrence of AEA in moss has led us hypothesize that AEA might mediate stress responses in plants, similar to that in animals. In mammals, AEA is generated from hydrolysis of N-acylphosphatidylethanolamine (NAPE) by a NAPE-specifi c phospholipase D (NAPE-PLD), and degraded by a fatty acid amide hydrolase (FAAH) and this metabolic pathway is highly conserved among eukaryotes. Here, using in silico approach, putative genes encoding for AEA pathway enzymes, were identifi ed in moss. Full-length coding sequences for putative NAPE-PLD and FAAH were isolated from Physcomitrella patens and were cloned and expressed into a heterologous expression vector. Biochemical characterization of AEA pathway enzymes is underway and is expected to lead to generation of AEA metabolite mutants in moss. Such mutants will allow for elucidation of the role of AEA in development of moss and mediating stress responses. Overall, this study will provide novel insights into functional and evolutionary role of lipid-mediated signaling in plants.
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Swati, Swati, Richard Sante, Brent Kinser, and Aruna Kilaru. "Characterization of Anandamide Metabolic Pathway in Moss." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/4853.

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N-Acylethanolamines (NAEs) including anandamide (NAE 20:4) are fatty acid ethanolamides generated by the hydrolysis of N-acylphoshotidylethanolamine (NAPE) by phospholipase D (PLD) and degraded by fatty acid amide hydrolase (FAAH). In mammals, ligands such as NAE 20:4 act through cannabinoid receptors and regulate several physiological processes like neuroprotection, pain perception, mental depression, and appetite suppression. In plants, NAE with chain length C12 to C18 are common and affect physiological processes such as cytoskeletal organization, endomembrane trafficking, cell wall and cell shape formation, seedling growth and response to stress. However, our recent identification of NAE 20:4 in moss, Physcomitrella patens prompted us to elucidate its metabolic pathway and physiological implications. We hypothesize that unique NAE metabolites such as anandamide in moss might play a role in rendering moss its ability to tolerate temperature, dehydration, salt and osmotic stress. To address the above hypothesis, three main objectives are being pursued using P patens. 1)Biochemical and molecular characterization of NAE metabolic pathway, 2) Generation and phenotypic characterization of NAE metabolite mutants, and 3) Elucidation of the physiological role of NAEs in abscisic acid-mediated dehydration tolerance. A NAPE-PLD, known to synthesize NAE 20:4 has been identified in mammals and FAAH in several eukaryotes, including plants. Here, identification and cloning of putative NAPE-PLD and FAAH genes that are likely involved in NAE synthesis and degradation, respectively, in P patens is discussed. Our long-term objective is to understand lipid-mediated stress responses in plants.
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Diouf, Cheikh. "Caractérisation électrique des transistors d’architecture innovante pour les longueurs de grilles décananométriques." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT082/document.

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La taille du transistor MOS ne cesse de diminuer pour des questions de performance et de rentabilité de fabrication. Les procédés de fabrication évoluent, l'architecture se complexifie et les méthodologies d'extraction de paramètres électriques doivent être adaptées. C'est ainsi que dans un premier temps, les effets d'un recuit haute pression sous atmosphère hydrogène (HPH2) ou deutérium (HPD2) sur le transistor MOS sont étudiés en détail dans cette thèse. La comparaison des performances apportées en termes de transport électronique et de dégradations engendrées en fiabilité a permis de montrer que le HPD2 présente un meilleur compromis. Une étude des effets d'un canal silicium-germanium (SiGe) sur les performances des transistors MOS est ensuite réalisée. L'incorporation du SiGe a permis d'atténuer l'impact négatif sur les performances des charges contenues dans l'empilement de grille. La présence de ces charges est d'ailleurs confirmée par l'analyse des effets néfastes d'un oxyde de grille à haute permittivité, utilisé entre autre pour faciliter la miniaturisation. Dans un deuxième temps, la « fonction Y » a été étendue en régime de saturation afin d'extraire la vitesse de saturation qui est un indicateur de performance obtenu dans les mêmes conditions que le courant ION. En outre, la problématique liée à l'extraction de la charge d'inversion sur des transistors courts et à forte tension de drain VD a été résolue grâce à des mesures à hautes fréquences réalisées sur une structure deux ports. Ceci a rendu possible l'obtention de la mobilité effective, de la vitesse moyenne et de la vitesse limitante sur des transistors déca-nanométriques
The MOS gate length is continuously downscaling because of the need of higher performance and cost-effectiveness. In addition to the fabrication process, the device architecture is being more and more complex and parameters extraction need to be adapted. First in this thesis, the effects of high pressure final anneal with hydrogen (HPH2) or deuterium (HPD2) on MOSFET properties is investigated. The transport performances and reliability degradation comparison allow to consider HPD2 as a good compromise. The effect of a silicon-germanium (SiGe) channel is also studied. It is demonstrated that SiGe channel decreases defects located in the high-κ gate stack. The presence of these defects is confirmed by the study of the negative effects of a high-k as a gate oxide. Secondly, the “Y function” method is extended to the saturation regime to reliably extract saturation velocity, obtained in the same conditions as ION current. The problematic due to inversion charge estimation in short devices is solved using high frequency measurements with a two ports structure. Then, effective mobility, average velocity and limiting velocity are obtained in ultra-scaled devices
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Persson, Stefan. "Modeling and characterization of novel MOS devices." Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3720.

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Challenges with integrating high-κ gate dielectric,retrograde Si1-xGexchannel and silicided contacts in future CMOStechnologies are investigated experimentally and theoreticallyin this thesis. ρMOSFETs with either Si or strained Si1-xGex surface-channel and different high-κgate dielectric are examined. Si1-xGex ρMOSFETs with an Al2O3/HfAlOx/Al2O3nano-laminate gate dielectric prepared by means ofAtomic Layer Deposition (ALD) exhibit a great-than-30% increasein current drive and peak transconductance compared toreference Si ρMOSFETs with the same gate dielectric. Apoor high-κ/Si interface leading to carrier mobilitydegradation has often been reported in the literature, but thisdoes not seem to be the case for our Si ρMOSFETs whoseeffective mobility coincides with the universal hole mobilitycurve for Si. For the Si1-xGexρMOSFETs, however, a high density ofinterface states giving riseto reduced carrier mobility isobserved. A method to extract the correct mobility in thepresence of high-density traps is presented. Coulomb scatteringfrom the charged traps or trapped charges at the interface isfound to play a dominant role in the observed mobilitydegradation in the Si1-xGexρMOSFETs.

Studying contacts with metal silicides constitutes a majorpart of this thesis. With the conventional device fabrication,the Si1-xGexincorporated for channel applications inevitablyextends to the source-drain areas. Measurement and modelingshow that the presence of Ge in the source/drain areaspositively affects the contact resistivity in such a way thatit is decreased by an order of magnitude for the contact of TiWto p-type Si1-xGex/Si when the Ge content is increased from 0 to 30at. %. Modeling and extraction of contact resistivity are firstcarried out for the traditional TiSi2-Si contact but with an emphasis on the influenceof a Nb interlayer for the silicide formation. Atwo-dimensional numerical model is employed to account foreffects due to current crowding. For more advanced contacts toultra-shallow junctions, Ni-based metallization scheme is used.NiSi1-xGex is found to form on selectively grown p-typeSi1-xGexused as low-resistivity source/drain. Since theformed NiSi1-xGex with a specific resistivity of 20 mWcmreplaces a significant fraction of the shallow junction, athree-dimensional numerical model is employed in order to takethe complex interface geometry and morphology into account. Thelowest contact resistivity obtained for our NiSi1-xGex/p-type Si1-xGexcontacts is 5´10-8Ωcm2, which satisfies the requirement for the 45-nmtechnology node in 2010.

When the Si1-xGexchannel is incorporated in a MOSFET, it usuallyforms a retrograde channel with an undoped surface region on amoderately doped substrate. Charge sheet models are used tostudy the effects of a Si retrograde channel on surfacepotential, drain current, intrinsic charges and intrinsiccapacitances. Closed-form solutions are found for an abruptretrograde channel and results implicative for circuitdesigners are obtained. The model can be extended to include aSi1-xGexretrograde channel. Although the analytical modeldeveloped in this thesis is one-dimensional for long-channeltransistors with the retrograde channel profile varying alongthe depth of the transistor, it should also be applicable forshort-channel transistors provided that the short channeleffects are perfectly controlled.

Key Words:MOSFET, SiGe, high-k dielectric, metal gate,mobility, charge sheet model, retrograde channel structure,intrinsic charge, intrinsic capacitance, contactresistivity.

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Books on the topic "MoS2 characterization"

1

Massachusetts. Bureau of Waste Site Cleanup. Top ten most common MCP risk characterization problems. [Boston, Mass.]: Massachusetts Dept. of Environmental Protection, Bureau of Waste Site Cleanup, 1996.

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Development and characterization of SiC/MoSi₂-Si₃N₄(p) hybrid composites. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, 1998.

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Supercapacitor Technology. Materials Research Forum LLC, 2019. http://dx.doi.org/10.21741/9781644900499.

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Supercapacitors are most interesting in the area of rechargeable battery based energy storage because they offer an unbeatable power density, quick charge/discharge rates and prolonged lifetimes in comparison to batteries. The book covers inorganic, organic and gel-polymer electrolytes, electrodes and separators used in different types of supercapacitors; with emphasis on material synthesis, characterization, fundamental electrochemical properties and most promising applications.
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Mahapatra, Souvik. Fundamentals of Bias Temperature Instability in MOS Transistors: Characterization Methods, Process and Materials Impact, DC and AC Modeling. Springer, 2016.

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North, Robert, and Ganesh Rao. Medulloblastoma. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190696696.003.0006.

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Medulloblastoma is the most common brain malignancy in children. This chapter details the current diagnostic criteria, pathological classification, and treatment paradigms. Recent molecular characterization of medulloblastoma has revealed significant variations in clinical behavior of different tumor types. While the treatments for medulloblastoma are generally quite successful, with 5 year survival rates approaching 80%, the responsiveness of each subtype to treatment varies. The authors cover common clinical scenarios along with management pearls and key references.
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Dietrich, Franz, and Christian List. Probabilistic Opinion Pooling. Edited by Alan Hájek and Christopher Hitchcock. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199607617.013.37.

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Suppose several individuals (e.g., experts on a panel) each assign probabilities to some events. How can these individual probability assignments be aggregated into a single collective probability assignment? This chapter is a review of several proposed solutions to this problem, focusing on three salient proposals: linear pooling (the weighted or unweighted linear averaging of probabilities), geometric pooling (the weighted or unweighted geometric averaging of probabilities), and multiplicative pooling (where probabilities are multiplied rather than averaged). Axiomatic characterizations of each class of pooling functions are presented (most characterizations are classic results, but one is new), with the argument that linear pooling can be justified “procedurally” but not “epistemically”, while the other two pooling methods can be justified “epistemically”. The choice between them, in turn, depends on whether the individuals' probability assignments are based on shared information or on private information. In conclusion a number of other pooling methods are mentioned.
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Lattman, Eaton E., Thomas D. Grant, and Edward H. Snell. Before the Beamtime. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199670871.003.0005.

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This chapter describes preparation before collecting solution scattering data. SAXS requires a sample concentration similar to that typically used for crystallization, and a volume on the order of tens of μ‎l. SANS can require an order of magnitude more than this. The sample should be well characterized, and free from impurities. Standard laboratory techniques are suitable for characterization. Buffer choice and accurate matching is a component of experimental success and after sample preparation is the next most critical step. The sample should be monodisperse, stable, and well characterized.
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Duggan, John. Candidate Objectives and Electoral Equilibrium. Edited by Donald A. Wittman and Barry R. Weingast. Oxford University Press, 2009. http://dx.doi.org/10.1093/oxfordhb/9780199548477.003.0004.

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This article looks at the known foundational results on spatial models of elections. The issues of equilibrium existence, the characterization of equilibria (in terms of their social welfare properties), and the distance between equilibrium policy and positions of the candidates are examined. It then discusses the results of the case where candidates are able to give precise predictions of voters' behaviour precisely; the article also introduces the ‘Downsian model’. The article looks at two models of probabilistic voting, before finally moving on to consider the most common objective functions that are used to model the electoral incentives of different types of candidates.
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Anthony, Cullen. Part IV The ICC and its Applicable Law, 30 The Characterization of Armed Conflict in the Jurisprudence of the ICC. Oxford University Press, 2015. http://dx.doi.org/10.1093/law/9780198705161.003.0030.

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The existence of armed conflict is the most fundamental prerequisite for the exercise of jurisdiction over war crimes. This chapter probes the characterization of armed conflict in the case-law of the ICC. It shows that the ICC has relied heavily on the jurisprudence of the ICTY concerning the conceptualization of non-international armed conflict (e.g. Tadić) and internationalization of prima facie internal armed conflict based on the overall control test. It argues that maintaining the integrity of armed conflict as a concept of international humanitarian law is one of the greatest longer-term challenges facing the Court.
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Walsh, Richard A. “It Has to Be Functional!”. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190607555.003.0026.

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The paroxysmal dyskinesias are a heterogeneous group of rare movement disorders, characterized by the abrupt onset of involuntary hyperkinetic movements with or without trigger factors and of variable duration. Interictal periods are marked by relative normality, although there is evidence for an association between some genotypes and migraine, episodic ataxia, and seizure disorders. Three genes have been identified that are associated with the three most common syndromes; however, these do not account for some cases with an otherwise typical history. The clinical phenotype continues to evolve with increasing characterization of genetically proven cases. Paroxysmal kinesigenic dyskinesia responds well to carbamazepine therapy.
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Book chapters on the topic "MoS2 characterization"

1

Sarode, K. M., S. G. Bachhav, U. D. Patil, and D. R. Patil. "Synthesis and Characterization of MoS2-Graphene Nanocomposite." In Techno-Societal 2016, 629–34. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-53556-2_64.

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Korn, T., G. Plechinger, S. Heydrich, F. X. Schrettenbrunner, J. Eroms, D. Weiss, and C. Schüller. "Optical Characterization, Low-Temperature Photoluminescence, and Photocarrier Dynamics in MoS2." In Lecture Notes in Nanoscale Science and Technology, 217–36. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-02850-7_8.

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Wang, Shengkai, and Xiaolei Wang. "MOS Characterizations." In MOS Interface Physics, Process and Characterization, 95–154. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003216285-4.

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Wang, Shengkai, and Xiaolei Wang. "MOS Processes." In MOS Interface Physics, Process and Characterization, 51–94. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003216285-3.

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Cristoloveanu, Sorin, and Sheng S. Li. "MOS Transistor Characteristics." In Electrical Characterization of Silicon-on-Insulator Materials and Devices, 209–73. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-2245-4_8.

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Wang, Shengkai, and Xiaolei Wang. "Introduction." In MOS Interface Physics, Process and Characterization, 1–6. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003216285-1.

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Wang, Shengkai, and Xiaolei Wang. "Physics of Interface." In MOS Interface Physics, Process and Characterization, 7–50. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003216285-2.

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Michael, Christopher, and Mohammed Ismail. "Experimental Process Characterization for MOS Statistical Model." In The Kluwer International Series in Engineering and Computer Science, 51–83. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-3150-0_4.

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Hirvonen, J.-P., H. Kattelus, I. Suni, J. Likonen, T. R. Jervis, and M. Nastasi. "Sputter Deposition and Characterization of MoSi2/SiC Composite Coatings." In Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures, 469–74. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1765-4_31.

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Tack, M., M. H. Gao, C. Claeys, and G. Declerck. "Characterization of Different SOI-MOS Technologies at Cryogenic Temperatures." In ESSDERC ’89, 767–70. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-52314-4_161.

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Conference papers on the topic "MoS2 characterization"

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Camellini, Andrea, Eugenio Cinquanta, Christian Martella, Carlo Mennucci, Alessio Lamperti, Giulio Cerullo, Giuseppe Della Valle, Alessandro Molle, Francesco Buatier de Mongeot, and Margherita Zavelani-Rossi. "Optical characterization of anisotropic MoS2 nanosheets." In 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE, 2017. http://dx.doi.org/10.1109/cleoe-eqec.2017.8087717.

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Imran, Mohammad, Nahid Chaudhary, Aurangzeb Khurram Hafiz, Bharti Singh, and Manika Khanuja. "CVD synthesis and characterization of ultrathin MoS2 film." In PROCEEDINGS OF INTERNATIONAL CONFERENCE ON RECENT TRENDS IN MECHANICAL AND MATERIALS ENGINEERING: ICRTMME 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0026128.

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Mootheri, Vivek, Albert Minj, Goutham Arutchelvan, Alessandra Leonhardt, Inge Asselberghs, Marc Heyns, Iuliana Radu, and Dennis Lin. "Contact Interface Characterization of Graphene contacted MoS2 FETs." In 2021 IEEE International Interconnect Technology Conference (IITC). IEEE, 2021. http://dx.doi.org/10.1109/iitc51362.2021.9537337.

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Li Bin, Yang Daheng, Chen Jiuju, Yang Xiaolei, and Meng Qinggang. "Sonochemical preparation and characterization of MoO3 and MoS2 nanoparticles." In 2011 International Conference on Management Science and Industrial Engineering (MSIE). IEEE, 2011. http://dx.doi.org/10.1109/msie.2011.5707604.

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Rashidifar, Mahsa, Sara Darbari, and Yaser Abdi. "Characterization of humidity sensor based on nickel-MoS2-nickel." In 2020 28th Iranian Conference on Electrical Engineering (ICEE). IEEE, 2020. http://dx.doi.org/10.1109/icee50131.2020.9260786.

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Jahangir, Ifat, Alina Wilson, A. K. Singh, N. Sbrockey, E. Coleman, G. S. Tompa, and Goutam Koley. "Graphene/InN and Graphene/MoS2 heterojunctions: Characterization and sensing applications." In 2014 IEEE 14th International Conference on Nanotechnology (IEEE-NANO). IEEE, 2014. http://dx.doi.org/10.1109/nano.2014.6968176.

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Tomar, Rupika Singh, Kajol Taiwade, Javid Ali, Samina Khan, and Fozia Z. Haque. "Synthesis of heterojunction layers of graphene/MoS2 and its characterization." In INTERNATIONAL CONFERENCE ON SUSTAINABLE ENGINEERING AND TECHNOLOGY (ICONSET 2018). Author(s), 2018. http://dx.doi.org/10.1063/1.5079036.

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Shahi, Simran, Maomao Liu, Hemendra Nath Jaiswal, Licheng Xiao, Sichen Wei, Hyun Kim, Seok Joon Yun, Young Hee Lee, Fei Yao, and Huamin Li. "Field Effect and Raman Characterization of Self-Assembled Mos2 Nanoscrolls." In 2019 Device Research Conference (DRC). IEEE, 2019. http://dx.doi.org/10.1109/drc46940.2019.9046427.

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Cheah, A. J., W. S. Chiu, P. S. Khiew, S. Radiman, and M. A. A. Hamid. "Synthesis and characterization of visible-active molybdenum disulfide (2H-MoS2) nanospheres." In PROCEEDINGS OF THE 23RD SCIENTIFIC CONFERENCE OF MICROSCOPY SOCIETY MALAYSIA (SCMSM 2014). AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4919168.

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Vianna, Pilar G., Syed Hamza Safeer, Alexandre S. M. V. Ore, Vanessa O. Gordo, Isabel C. S. Carvalho, Victor Carozo, and Christiano J. S. de Matos. "Synthesis and Characterization of MoS2/WS2 Heterostructures by Second Harmonic Generation." In 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC). IEEE, 2019. http://dx.doi.org/10.1109/sbfoton-iopc.2019.8910214.

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Reports on the topic "MoS2 characterization"

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Burghaus, U. Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study. Office of Scientific and Technical Information (OSTI), July 2012. http://dx.doi.org/10.2172/1045023.

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McPherson, Brian, and Vince Matthews. Characterization of Most Promising Sequestration Formations in the Rocky Mountain Region (RMCCS). Office of Scientific and Technical Information (OSTI), September 2013. http://dx.doi.org/10.2172/1163843.

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Kramer, K. Status Quo of PVT Characterization. Edited by Korbinian Kramer,. IEA SHC Task 60, September 2020. http://dx.doi.org/10.18777/ieashc-task60-2020-0004.

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Report B1: This report therefore aims at displaying the Status Quo of PVT Characterization in order to support PVT technology in its further development and applications. The report is hence of interest for researchers as well as public and private sector stakeholders. A key finding is that the reliability and durability of PVT modules are especially challenged at elevated temperatures and higher humidity loads. The test methods available from the IEC and ISO standards are covering the specifics of PV and ST module’s, most of which are similar for PVT modules, too.
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Gschwander, Stefan, Ana Lazaro, Monica Delgado, Christoph Rathgeber, Michael Brütting, Stephan Höhlein, Melissa Obermeyer, et al. Summary of Work On development and characterization of improved Materials. IEA SHC Task 58, June 2021. http://dx.doi.org/10.18777/ieashc-task58-2021-0003.

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As the material development is done at different institution the objective of the work was to collect the materials which are under research and development to get an overview on the most relevant properties of these materials and application which are addressed.
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Hart, Carl R., D. Keith Wilson, Chris L. Pettit, and Edward T. Nykaza. Machine-Learning of Long-Range Sound Propagation Through Simulated Atmospheric Turbulence. U.S. Army Engineer Research and Development Center, July 2021. http://dx.doi.org/10.21079/11681/41182.

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Conventional numerical methods can capture the inherent variability of long-range outdoor sound propagation. However, computational memory and time requirements are high. In contrast, machine-learning models provide very fast predictions. This comes by learning from experimental observations or surrogate data. Yet, it is unknown what type of surrogate data is most suitable for machine-learning. This study used a Crank-Nicholson parabolic equation (CNPE) for generating the surrogate data. The CNPE input data were sampled by the Latin hypercube technique. Two separate datasets comprised 5000 samples of model input. The first dataset consisted of transmission loss (TL) fields for single realizations of turbulence. The second dataset consisted of average TL fields for 64 realizations of turbulence. Three machine-learning algorithms were applied to each dataset, namely, ensemble decision trees, neural networks, and cluster-weighted models. Observational data come from a long-range (out to 8 km) sound propagation experiment. In comparison to the experimental observations, regression predictions have 5–7 dB in median absolute error. Surrogate data quality depends on an accurate characterization of refractive and scattering conditions. Predictions obtained through a single realization of turbulence agree better with the experimental observations.
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Qamhia, Issam, and Erol Tutumluer. Evaluation of Geosynthetics Use in Pavement Foundation Layers and Their Effects on Design Methods. Illinois Center for Transportation, August 2021. http://dx.doi.org/10.36501/0197-9191/21-025.

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This report presents findings of a research effort aimed at reviewing and updating existing Illinois Department of Transportation (IDOT) specifications and manuals regarding the use of geosynthetic materials in pavements. The project consisted of three tasks: evaluate current IDOT practice related to the use of geosynthetics; review research and state of the practice on geosynthetics applications, available products, design methods, and specifications; and propose recommendations for geosynthetic solutions in pavements to modernize IDOT’s practices and manuals. The review of IDOT specifications revealed that geotextiles are the most used geosynthetic product in Illinois, followed by geogrids. Several of IDOT’s manuals have comprehensive guidelines to properly design and construct pavements with geosynthetics, but several knowledge gaps and potential areas for modernization and adoption of new specifications still exist. Based on the review of the available design methods and the most relevant geosynthetic properties and characterization methods linked to field performance, several updates to IDOT’s practice were proposed. Areas of improvement are listed as follows. First, establish proper mechanisms for using geogrids, geocells, and geotextiles in subgrade restraint and base stabilization applications. This includes using shear wave transducers, i.e., bender elements, to quantify local stiffness enhancements and adopting the Giroud and Han design method for subgrade restraint applications. Second, update IDOT’s Subgrade Stability Manual to include property requirements for geogrids, geotextiles, and geocells suitable for subgrade restraint applications. Third, establish proper standards on stabilization, separation, and pumping resistance for geotextiles by incorporating recent research findings on geotextile clogging and permeability criteria. Fourth, promote the use of modern geosynthetic products, such as geotextiles with enhanced lateral drainage, and fifth, elaborate on proper methods for construction/quality control measures for pavements with geosynthetics.
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Sinclair, Samantha, and Sandra LeGrand. Reproducibility assessment and uncertainty quantification in subjective dust source mapping. Engineer Research and Development Center (U.S.), August 2021. http://dx.doi.org/10.21079/11681/41523.

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Accurate dust-source characterizations are critical for effectively modeling dust storms. A previous study developed an approach to manually map dust plume-head point sources in a geographic information system (GIS) framework using Moderate Resolution Imaging Spectroradiometer (MODIS) imagery processed through dust-enhancement algorithms. With this technique, the location of a dust source is digitized and recorded if an analyst observes an unobscured plume head in the imagery. Because airborne dust must be sufficiently elevated for overland dust-enhancement algorithms to work, this technique may include up to 10 km in digitized dust-source location error due to downwind advection. However, the potential for error in this method due to analyst subjectivity has never been formally quantified. In this study, we evaluate a version of the methodology adapted to better enable reproducibility assessments amongst multiple analysts to determine the role of analyst subjectivity on recorded dust source location error. Four analysts individually mapped dust plumes in Southwest Asia and Northwest Africa using five years of MODIS imagery collected from 15 May to 31 August. A plume-source location is considered reproducible if the maximum distance between the analyst point-source markers for a single plume is ≤10 km. Results suggest analyst marker placement is reproducible; however, additional analyst subjectivity-induced error (7 km determined in this study) should be considered to fully characterize locational uncertainty. Additionally, most of the identified plume heads (> 90%) were not marked by all participating analysts, which indicates dust source maps generated using this technique may differ substantially between users.
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Sinclair, Samantha, and Sandra LeGrand. Reproducibility assessment and uncertainty quantification in subjective dust source mapping. Engineer Research and Development Center (U.S.), August 2021. http://dx.doi.org/10.21079/11681/41542.

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Accurate dust-source characterizations are critical for effectively modeling dust storms. A previous study developed an approach to manually map dust plume-head point sources in a geographic information system (GIS) framework using Moderate Resolution Imaging Spectroradiometer (MODIS) imagery processed through dust-enhancement algorithms. With this technique, the location of a dust source is digitized and recorded if an analyst observes an unobscured plume head in the imagery. Because airborne dust must be sufficiently elevated for overland dust-enhancement algorithms to work, this technique may include up to 10 km in digitized dust-source location error due to downwind advection. However, the potential for error in this method due to analyst subjectivity has never been formally quantified. In this study, we evaluate a version of the methodology adapted to better enable reproducibility assessments amongst multiple analysts to determine the role of analyst subjectivity on recorded dust source location error. Four analysts individually mapped dust plumes in Southwest Asia and Northwest Africa using five years of MODIS imagery collected from 15 May to 31 August. A plume-source location is considered reproducible if the maximum distance between the analyst point-source markers for a single plume is ≤10 km. Results suggest analyst marker placement is reproducible; however, additional analyst subjectivity-induced error (7 km determined in this study) should be considered to fully characterize locational uncertainty. Additionally, most of the identified plume heads (> 90%) were not marked by all participating analysts, which indicates dust source maps generated using this technique may differ substantially between users.
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Baral, Aniruddha, Jeffery Roesler, and Junryu Fu. Early-age Properties of High-volume Fly Ash Concrete Mixes for Pavement: Volume 2. Illinois Center for Transportation, September 2021. http://dx.doi.org/10.36501/0197-9191/21-031.

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High-volume fly ash concrete (HVFAC) is more cost-efficient, sustainable, and durable than conventional concrete. This report presents a state-of-the-art review of HVFAC properties and different fly ash characterization methods. The main challenges identified for HVFAC for pavements are its early-age properties such as air entrainment, setting time, and strength gain, which are the focus of this research. Five fly ash sources in Illinois have been repeatedly characterized through x-ray diffraction, x-ray fluorescence, and laser diffraction over time. The fly ash oxide compositions from the same source but different quarterly samples were overall consistent with most variations observed in SO3 and MgO content. The minerals present in various fly ash sources were similar over multiple quarters, with the mineral content varying. The types of carbon present in the fly ash were also characterized through x-ray photoelectron spectroscopy, loss on ignition, and foam index tests. A new computer vision–based digital foam index test was developed to automatically capture and quantify a video of the foam layer for better operator and laboratory reliability. The heat of hydration and setting times of HVFAC mixes for different cement and fly ash sources as well as chemical admixtures were investigated using an isothermal calorimeter. Class C HVFAC mixes had a higher sulfate imbalance than Class F mixes. The addition of chemical admixtures (both PCE- and lignosulfonate-based) delayed the hydration, with the delay higher for the PCE-based admixture. Both micro- and nano-limestone replacement were successful in accelerating the setting times, with nano-limestone being more effective than micro-limestone. A field test section constructed of HVFAC showed the feasibility and importance of using the noncontact ultrasound device to measure the final setting time as well as determine the saw-cutting time. Moreover, field implementation of the maturity method based on wireless thermal sensors demonstrated its viability for early opening strength, and only a few sensors with pavement depth are needed to estimate the field maturity.
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