Articles de revues : « Modeling of AR-XPS intensity »

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Amina et Norio Tanaka. « Numerical Investigation of 3D Flow Properties around Finite Emergent Vegetation by Using the Two-Phase Volume of Fluid (VOF) Modeling Technique ». Fluids 7, n^o 5 (18 mai 2022) : 175. http://dx.doi.org/10.3390/fluids7050175.

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This study predicts how the Free Surface Level (FSL) variations around finite length vegetation affect flow structure by using a numerical simulation. The volume of fluid (VOF) technique with the Reynolds stress model (RSM) was used for the simulation. Multizone Hexahedral meshing was adopted to accurately track the free surface level with minimum numerical diffusion at the water–air interface. After the validation, finite length emergent vegetation patches were selected based on the aspect ratio (AR = vegetation width-length ratio) under constant subcritical flow conditions for an inland tsunami flow. The results showed that the generation of large vortices was predominated in wider vegetation patches (AR > 1) due to the increase and decrease in the FSL at the front and back of the vegetation compared to longer vegetation patches (AR ≤ 1), as this offered more resistance against the approaching flow. The wider vegetation patches (AR > 1) are favorable in terms of generating a large area of low velocity compared to the longer vegetation patch (AR < 1) directly downstream of the vegetation patch. On the other hand, it has a negative impact on the adjacent downstream gap region, where a 14.3–34.9% increase in velocity was observed. The longer vegetation patches (AR < 1) generate optimal conditions within the vegetation region due to great velocity reduction. Moreover, in all the AR vegetation cases, the water turbulent intensity was maximum in the vegetation region compared to the adjacent gap region and air turbulent intensity above the FSL, suggesting strong air entrainment over this region. The results of this study are important in constructing vegetation layouts based on the AR of the vegetation for tsunami mitigation.

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Pishdast, M., A. Eslami Majd et M. Kavosh Tehrani. « The influence of plasma shielding effect on laser-ablated copper samples : a focus on signal-to-background ratio and plasma expansion ». Laser and Particle Beams 34, n^o 3 (13 juillet 2016) : 493–505. http://dx.doi.org/10.1017/s0263034616000355.

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AbstractThe influence of plasma shielding effect induced by ambient gas pressure and laser intensity on the laser-produced Cu plasma parameters, signal-to-background ratio (S/B) and expansion are experimentally and numerically investigated. A Q-switched Nd:YAG laser at 1064 nm at various intensities ranging from 2 to 7.1 GW/cm2 intensity (40–150 mJ) is used to produce Cu plasma in air, argon (Ar), helium (He), and neon (Ne) ambient gas at various pressures ranging from 5 to 1000 mbar. Laser-induced breakdown spectroscopy reveals that spectral radiation, S/B, electron temperature, number density, and front edge velocity of the plasma have an increasing trend up to a certain value of laser intensity and gas pressure. Afterwards, a saturation trend is achieved, which is attributed to the shielding and self-regulation effect. The numerical modeling of the laser-produced Cu plasma in the presence of air at atmospheric pressure is carried out using the MULTI radiation hydrodynamics code. We have shown that the feature of plasma shielding effect observed in the experiments can be reproduced using a continuum hydrodynamics model. Laser intensity at about 3.5 GW/cm2 is found to produce the highest S/B at 1000 mbar air. He, Ne, air, and Ar show the best S/B, respectively and the best S/B is found for air, Ar, He, and Ne at 10, 5, 10, and 20 mbar, respectively. The expansion of plasma plume is studied using a simple and effective technique based on probe laser absorption and scattering method. The plasma plume expansion through He, Ne, air, and Ar at 1000 mbar pressure has the highest velocity, respectively. The simulated results of strong shock wave model and Rankine–Hugoniot jump condition are fitted to the experimental data, which are then used to estimate the values of the ablation parameters.

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Shih, Naai-Jung, Yun-Ting Tasi, Yi-Ting Qiu et Ting-Wei Hsu. « Inspecting Pond Fabric Using Unmanned Aerial Vehicle-Assisted Modeling, Smartphone Augmented Reality, and a Gaming Engine ». Remote Sensing 16, n^o 6 (7 mars 2024) : 943. http://dx.doi.org/10.3390/rs16060943.

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Historical farm ponds have been designed, maintained, and established as heritage sites or cultural landscapes. Has their gradually evolving function resulted in changes to the landscape influenced by their degenerated nature and the new urban fabric? This study aimed to assess the interaction between urban fabrics and eight farm ponds in Taoyuan by determining the demolition ratio of ponds subject to the transit-oriented development (TOD) of infrastructure and to evaluate land cover using historical maps, unmanned aerial vehicle (UAV)-assisted 3D modeling, smartphone augmented reality (AR), and a gaming engine to inspect and compare well-developed or reactivated ponds and peripheries. A 46% reduction in pond area around Daxi Interchange was an important indicator of degeneration in the opposite direction to TOD-based instrumentation. Three-dimensional skyline analysis enabled us to create an urban context matrix to be used in the simulations. Nearly 55 paired AR comparisons were made with 100 AR cloud-accessed models from the Augment® platform, and we produced a customized interface to align ponds with landmark construction or other ponds using Unreal Engine®. Smartphone AR is a valuable tool for situated comparisons and was used to conduct analyses across nine categories, from buildings and infrastructure to the intensity and stage of development. The gaming engine handled large point models with high detail and was supported by a customized blueprint. We found that 3D virtual dynamics highlighted the evolving interstitial space and role substitution of the agricultural fabric. This combination of heterogeneous platforms provides a practical method of preserving heritage and enables conflict resolution through policy and TOD instrumentation.

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Ashirov, Atabek S., Uchkun O. Kutliev, Soyibjon Xakimov et Shavkat K. Ismailov. « Low Energy Ar<sup>+</sup> ; Ions Scattering from SiO<sub>2 </sub>(001)<Ῑ10&gt ; Surface under Grazing Incidence ». Materials Science Forum 1049 (11 janvier 2022) : 152–57. http://dx.doi.org/10.4028/www.scientific.net/msf.1049.152.

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This article presents the results of computer modeling of small-angle scattering of Ar+ ions from the surface of the SiO2 thin film under bombardment by low-energy. The study of the trajectory of the scattered ions showed that the trajectories with two focuses are observed not only near the center of the semichannel but also nearby the surface of the atomic chain. An increase in the value of the initial energy of incident particles leads to a narrowing of the trajectory of the scattered ions, which leads to the appearance of low-intensity peaks in the energy spectrum of the scattered ions.

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Cevc, Gregor. « Differential Diagnosis and Proper Treatment of Acute Rhinosinusitis : Guidance Based on Historical Data Analysis ». Allergy & ; Rhinology 8, n^o 2 (janvier 2017) : ar.2017.8.0206. http://dx.doi.org/10.2500/ar.2017.8.0206.

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Background The time course of rhinovirus positive and negative rhinosinusitis has not been quantified yet, which aggravates proper selection and justification of the optimum treatment for this illness. Such quantitative information would facilitate an early and proper identification of the disease and its differentiation from acute bacterial rhinosinusitis, and could diminish harmful overuse of antibiotics, arguably driven by patients’ want for attention and the treating physicians’ inability to offer an adequate verbal comfort in its stead. Objective Extraction of the quantitative information needed to identify rhinovirus positive or negative rhinosinusitis and to allow selection of the most appropriate treatment from the published time dependence of individual clinical symptoms of the disease. Methods Scrutiny (and modeling) of temporal evolution of all noteworthy symptoms of rhinosinusitis with a simple mathematical expression that relies on two adjustable parameters per symptom (and potentially a general time offset as an extra adjustable parameter). Results Adverse effects of rhinosinusitis can be grouped according to the sequence of their exponential appearance and ~2.6 times slower exponential disappearance, rhinovirus negative rhinosinusitis generally improving ~25% faster and being ~40% less severe. The major early local symptoms (throat soreness and scratchiness, headache) vanish with a half-life of ~1.8 days, whereas further local symptoms take ~1.6 times longer to disappear. At least 50–60% improvement of two prominent early symptoms, sore throat and sneezing (but not of nasal discharge, cough, and hoarseness) by day 5 of the disease implies a nonbacterial origin of rhinitis and should exclude use of antibiotics. Conclusion Temporal evolution of all rhinosinusitis symptoms is qualitatively similar, which makes the early symptom decay a good proxy for, and predictor of, the disease perspective. Knowing a symptom intensity at just three to four time points suffices for reconstructing its entire time course and total intensity or gravity. This permits an easy and early identification of rhinosinusitis, and its plausible differentiation from acute bacterial rhinosinusitis, disease treatment optimization, and corresponding clinical trials simplification and/or shortening.

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Naidoo, Michelle K., et Paraskevi Giannakakou. « Abstract 6271 : Novel insights into androgen receptor-variant 7 subnuclear localization and function in castration resistant prostate cancer ». Cancer Research 84, n^o 6_Supplement (22 mars 2024) : 6271. http://dx.doi.org/10.1158/1538-7445.am2024-6271.

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Abstract Prostate cancer (PC) stands as the most frequently diagnosed and second leading cause of cancer death among American men. PC mortality is predominantly attributed to castration-resistant prostate cancer (CRPC), often emerging within 2-3 years following the initiation of androgen deprivation therapy. This resistance primarily arises from sustained androgen receptor (AR) signaling, ultimately resulting in a compromised response to AR-directed therapies. AR splice variant expression is a key contributor to the persistent AR signaling in CRPC. AR-variant 7 (AR-V7) is the most clinically prevalent variant, expressed in about 75% of patients with CRPC and confers resistance to standard of care (SoC) treatments. AR-V7 differs from the full-length AR (AR-fl) because it lacks the ligand binding and hinge domains, rendering it resistant to SoC treatments. Currently, there are no selective inhibitors for AR-V7. Therefore, we sought to identify unique biological features of AR-V7, distinct from AR-fl, to exploit therapeutic options for targeting AR-V7. Previous studies have demonstrated high sequence homology, largely overlapping cistromes, and gene transactivation profiles between AR-V7 and AR-FL. Our published mechanistic studies revealed that AR-V7 utilizes a unique nuclear import pathway, not shared by AR-fl, allowing for constitutive import and activation of target genes in the nucleus. Herein, we report an additional novel subnuclear phenotype of AR-V7 in LNCAP95 and 22RV1 cells modeling CRPC. Staining with AR-V7- and AR-fl- specific antibodies revealed that unlike AR-fl, AR-V7 exhibited prominent nucleolar localization. To validate AR-V7 nucleolar localization, CRPC cells stained with fibrillarin (nucleolar marker), and subsequent fluorescence intensity analysis revealed that AR-V7 was predominantly localized in fibrillarin positive nucleoli, whereas AR-fl protein was solely localized in the nucleoplasm. This suggests a novel functional role of AR-V7 in the nucleus. To further confirm AR-V7 nucleolar localization, Actinomycin D (ActD) was used as a tool compound to disrupt nucleolar integrity. Treatment with ActD for 4 hours in CRPC cells significantly reduced the area of fibrillarin positive nucleoli and prompted AR-V7 re-distribution out of the nucleoli and into the nucleoplasm. Ongoing efforts to further investigate AR-V7 nucleolar function in CRPC cells include mutating the predicted nucleolar localization signal located in AR-V7 and identifying nucleolar-interacting proteins through proximity-labeling assays. In conclusion, we unveiled a novel nuclear compartmentalization of AR-V7 within the nucleolus, the primary hub for ribosomal biogenesis. These observations suggest that AR-V7 could regulate the high levels of protein synthesis occurring in CRPC cells, creating a window of a potential therapeutic opportunity for selective inhibition. Citation Format: Michelle K. Naidoo, Paraskevi Giannakakou. Novel insights into androgen receptor-variant 7 subnuclear localization and function in castration resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6271.

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Efremov, A. M., V. B. Betelin et K. H. Kwon. « Plasma Parameters and Kinetics of Reactive Ion Etching of SiO2 and Si3N4 in an HBr/Cl2/Ar Mixture ». Микроэлектроника 52, n^o 2 (1 mars 2023) : 152–59. http://dx.doi.org/10.31857/s0544126923700217.

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The parameters of the gas phase and the kinetics of reactive ion etching of SiO2 and Si3N4 under conditions of an induction RF (13.56 MHz) discharge with a varying HBr/Cl2 ratio is studied. The study includes plasma diagnostics using Langmuir probes, plasma modeling to find stationary concentrations of active particles, measuring velocities, and analyzing etching mechanisms in the effective interaction prob-ability approximation. It is found that the substitution of HBr by Cl2 at a constant argon content (a) is accompanied by a noticeable change in the electrical parameters of the plasma; (b) leads to a weak increase in the intensity of ion bombardment of the treated surface; and (c) causes a significant increase in the total concentration and flux density of reactive particles. It is shown that the etching rates of SiO2 and Si3N4 increase monotonically as the proportion of Cl2 increases in a mixture, while the main etching mechanism is an ion-stimulated chemical reaction. The model description of the kinetics of such a reaction in the first approximation assumes (a) the additive contribution of bromine and chlorine atoms and (b) the direct pro-portional dependence of their effective interaction probabilities on the intensity of ion bombardment. The existence of an additional channel of heterogeneous interaction with the participation of HCl molecules is proposed.

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Sheen, Sowon, Jeonghoon Lee et Chang Gyu Woo. « Application of coflow premixed flame for generating aggregate silica particles and its limitation ». AIP Advances 12, n^o 9 (1 septembre 2022) : 095007. http://dx.doi.org/10.1063/5.0082172.

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This paper reports the geometrical characteristics and the growth of aggregate silica particles generated in a premixed flame using thermophoretic sampling, a light scattering technique, and aggregate dynamics modeling only for a premixed flat flame condition. The area equivalent size and the morphology of thermophoretically collected silica aggregate particles were analyzed through images taken from a transmission electron microscope. The particle stream in flames was visualized through a planar light scattering technique. Light scattering intensity at 90° using an Ar-ion laser (wavelength, 514 nm) was monitored for various flame conditions. The results of aggregate dynamics modeling under a one-dimensional assumption indicated that the silica particles grew as the height above the burner increased. Aggregate particles produced at various equivalence ratios showed different levels of OH-species. The OH-related species increased as the equivalence ratio decreased, which implies that a high equivalence ratio is recommended to produce pure silica particles. In this study, the purest silica aggregate particles were produced at the equivalence ratio of 11.4, among others. Our study helps to determine which flame condition is best in terms of the quality and/or quantity of silica aggregate particles generated by a coflow burner.

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Shore, Josh, Emily Nalder, Michael Hutchison, Nick Reed et Anne Hunt. « Tele-Active Rehabilitation for Youth With Concussion : Evidence-Based and Theory-Informed Intervention Development ». JMIR Pediatrics and Parenting 5, n^o 2 (4 avril 2022) : e34822. http://dx.doi.org/10.2196/34822.

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Background Active rehabilitation involving subsymptom threshold exercise combined with education and support promotes recovery in youth with concussion but is typically delivered in person, which may limit accessibility for families because of a lack of services in their communities or logistical challenges to attending in-person sessions. Objective This paper describes the evidence-based and theory-informed development of the Tele-Active Rehabilitation (Tele-AR) intervention for pediatric concussion, which was specifically designed for remote service delivery. Methods The intervention was designed by clinician-researchers with experience in pediatric concussion rehabilitation following the Medical Research Council guidance for developing complex interventions. Development involved a critical review of the literature to identify existing evidence, the expansion of the theoretical basis for active rehabilitation, and the modeling of the intervention process and outcomes. Results Tele-AR is a 6-week home exercise and education and support program facilitated through weekly videoconferencing appointments with a clinician. Exercise consists of low- to moderate-intensity subsymptom threshold aerobic activity and coordination drills that are individualized to participant needs and interests (prescribed for 3 days per week). Education includes the evidence-supported Concussion & You self-management program, which covers topics related to energy management, nutrition, hydration, sleep hygiene, and return to activity. Elements of self-determination theory are incorporated to support motivation and engagement. We present a logic model describing predicted intervention effects using a biopsychosocial conceptualization of outcomes after concussion. Conclusions The Tele-AR intervention may help to increase access to care that improves recovery and promotes a timely return to activity in youth with concussion. Future research is needed to evaluate the feasibility and efficacy of this approach.

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Zhang, Q. M., et R. S. Zheng. « Remote coronal dimmings related to a circular-ribbon flare ». Astronomy & ; Astrophysics 633 (janvier 2020) : A142. http://dx.doi.org/10.1051/0004-6361/201937126.

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Aims. In this paper, we report multiwavelength observations of remote coronal dimmings related to an M1.1 circular-ribbon flare in active region (AR) 12434. Methods. The confined flare without a coronal mass ejection was observed by the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory on 2015 October 16. We obtained global three-dimensional (3D) magnetic fields before the flare using the potential field source surface modeling. Results. A few minutes before the flare hard X-ray peak time (06:13:48 UT), small-scale, weak dimming appeared ∼240″ away from the flare site, which can be observed by AIA only in 131 and 171 Å. Afterward, long and narrow dimmings became evident in all AIA extreme-ultraviolet passbands except 304 Å, while localized core dimming was not clearly observed near the flare site. The large-area dimmings extended southeastward and the areas increased gradually. The total area of dimmings reaches (1.2 ± 0.4) × 104 Mm2 in 193 Å. The maximal relative intensity decreases in 171 and 193 Å reach 90% and 80%, respectively. Subsequently, the dimmings began to replenish and the area decreased slowly, lasting for ≥3 h. The remote dimmings and AR 12434 are connected by large-scale coronal loops. The remote dimmings are associated with the southwest footpoints of coronal loops with weak negative polarities. Possible origins of remote dimmings are discussed.

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Ambroise, Laure, Isabelle Prim-Allaz, Christine Teyssier et Sophie Peillon. « The environment-strategy-structure fit and performance of industrial servitized SMEs ». Journal of Service Management 29, n^o 2 (12 mars 2018) : 301–28. http://dx.doi.org/10.1108/josm-10-2016-0276.

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Purpose The purpose of this paper is to examine the environment-strategy-structure fit in the context of industrial servitization and its impact on the profitability of manufacturing SMEs. Design/methodology/approach Data were collected from face-to-face interviews with the CEOs of 184 French manufacturing SMEs. These primary data were complemented by the indicators extracted from a financial database to ensure objective measures of financial performance. Analyses were conducted by means of partial least squares structural equation modeling. Findings The research tests the impact of the organizational design (customer interface, service delivery system and service culture (SC)) on financial performance. It also tests the moderating effect on this relationship of servitization strategies adopted by the firm (added services (AS), activities reconfiguration (AR) and business model reconfiguration (BMR)) and the environment in which the firm is situated (industry dynamism, competitive intensity and industry munificence). Research limitations/implications This study considers the coalescence of the environment-strategy-structure to be a driver of firm performance in the context of industrial firms’ servitization. Three specific servitization strategies (AS, AR and BMR) are suggested based on the service offering’s impact on the customer’s activity chain or business model. Practical implications The research proposes some optimal organizational design depending on servitization strategy and environmental factors; for example, SC has a strong impact on financial performance when BMR is adopted. Originality/value This empirical study is based on an extended sample of 184 SMEs and provides quantitative support for the claim that good alignment between strategy and organizational design based on environmental factors increases profitability.

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Mueller, Michael J., Kelly M. Mahoney et Mimi Hughes. « High-Resolution Model-Based Investigation of Moisture Transport into the Pacific Northwest during a Strong Atmospheric River Event ». Monthly Weather Review 145, n^o 9 (septembre 2017) : 3861–79. http://dx.doi.org/10.1175/mwr-d-16-0466.1.

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A series of precipitation events impacted the Pacific Northwest during the first two weeks of November 2006. This sequence was punctuated by a particularly potent inland-penetrating atmospheric river (AR) that produced record-breaking precipitation across the region during 5–7 November. The precipitation caused destructive flooding as far inland as Montana’s Glacier National Park, 800 km from the Pacific Ocean. This study investigates the inland penetration of moisture during the event using a 4–1.33-km grid spacing configuration of the Weather Research and Forecasting (WRF) modeling system. A high-resolution simulation allowed an analysis of interactions between the strong AR and terrain features such as the Cascade Mountains and the Columbia River Gorge (CR Gorge). Moisture transport in the vicinity of the Cascades is assessed using various metrics. The most efficient pathway for moisture penetration was through the gap (i.e., CR Gap) between Mt. Adams and Mt. Hood, which includes the CR Gorge. While the CR Gap is a path of least resistance through the Cascades, most of the total moisture transport that survived transit past the Cascades overtopped the mountain barrier itself. This is due to the disparity between the length of the ridge (~800 km) and relatively narrow width of the CR Gap (~93 km). Moisture transport reductions were larger across the Washington Cascades and the southern-central Oregon Cascades than through the CR Gap. During the simulation, drying ratios through the CR Gap (9.3%) were notably less than over adjacent terrain (19.6%–30.6%). Drying ratios decreased as moisture transport intensity increased.

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Ryoo, Ju-Mee, Sen Chiao, J. Ryan Spackman, Laura T. Iraci, F. Martin Ralph, Andrew Martin, Randall M. Dole et al. « Terrain Trapped Airflows and Precipitation Variability during an Atmospheric River Event ». Journal of Hydrometeorology 21, n^o 2 (février 2020) : 355–75. http://dx.doi.org/10.1175/jhm-d-19-0040.1.

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AbstractWe examine thermodynamic and kinematic structures of terrain trapped airflows (TTAs) during an atmospheric river (AR) event impacting Northern California 10–11 March 2016 using Alpha Jet Atmospheric eXperiment (AJAX) aircraft data, in situ observations, and Weather and Research Forecasting (WRF) Model simulations. TTAs are identified by locally intensified low-level winds flowing parallel to the coastal ranges and having maxima over the near-coastal waters. Multiple mechanisms can produce TTAs, including terrain blocking and gap flows. The changes in winds can significantly alter the distribution, timing, and intensity of precipitation. We show here how different mechanisms producing TTAs evolve during this event and influence local precipitation variations. Three different periods are identified from the time-varying wind fields. During period 1 (P1), a TTA develops during synoptic-scale onshore flow that backs to southerly flow near the coast. This TTA occurs when the Froude number (Fr) is less than 1, suggesting low-level terrain blocking is the primary mechanism. During period 2 (P2), a Petaluma offshore gap flow develops, with flows turning parallel to the coast offshore and with Fr > 1. Periods P1 and P2 are associated with slightly more coastal than mountain precipitation. In period 3 (P3), the gap flow initiated during P2 merges with a pre-cold-frontal low-level jet (LLJ) and enhanced precipitation shifts to higher mountain regions. Dynamical mixing also becomes more important as the TTA becomes confluent with the approaching LLJ. The different mechanisms producing TTAs and their effects on precipitation pose challenges to observational and modeling systems needed to improve forecasts and early warnings of AR events.

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Eisenfeld, Tsion, et Avi Karsenty. « Design and Modeling of Light Emitting Nano-Pixel Structure (LENS) for High Resolution Display (HRD) in a Visible Range ». Nanomaterials 10, n^o 2 (27 janvier 2020) : 214. http://dx.doi.org/10.3390/nano10020214.

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LENS (Light Emitting Nano-pixel Structure), a new nano-metric device, was designed, simulated, and modeled for feasibility analysis, with the challenge of combining high resolution and high brightness for display, essentially adapted for Augmented Reality (AR) and Virtual Reality. The device is made of two parts: The first one is a reflective nano-cone Light Emitting Device (LED) structure to reduce the Total Internal Reflection effects (TIR), and to enable improved light extraction efficiency. The second part is a Compound Parabolic Concentrator (CPC) above the nano-LED to narrow the outgoing light angular distribution so most of the light would be “accepted” by an imaging system. Such a way is drastically limiting any unnecessary light loss. Our simulations show that the total light intensity gain generated by each part of the pixel is at least 3800% when compared to a typical flat LED. It means that, for the same electrical power consumption, the battery life duration is increased by 38. Furthermore, this improvement significantly decreases the display thermal radiation by at least 300%. Since pixel resolution is critical to offer advanced applications, an extensive feasibility study was performed, using the LightTools software package for ray tracing optimization. In addition to the simulation results, an analytical model was developed. This new device holds the potential to change the efficiency for military, professional and consumer applications, and can serve as a game changer.

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Papinigis, Vytautas, Edgaras Geda et Kęstutis Lukošius. « DESIGN OF PEOPLE EVACUATION FROM ROOMS AND BUILDINGS ». JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 16, n^o 1 (31 mars 2010) : 131–39. http://dx.doi.org/10.3846/jcem.2010.12.

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There is a fire hazard in many civil buildings or engineering structures. Analysis of people evacuation time from the room or building is an important part of the designing process. Nevertheless, analysis of human behaviour in fire conditions is very complicated. Various factors should be evaluated, physical and even psychical, influencing safe evacuation of people from buildings. The analytical and calculating methods created are intended for analysis of people evacuation in fire conditions. Unfortunately, use of complicated calculations for determination of people evacuation requires too many resources; therefore, their application is limited. The calculation method for people evacuation presented in this paper is based on dependencies of the physical characteristics of people stream (density, intensity, movement speed) on people movement manner. The time required to evacuate people from people gathering room and building is determined in the numerical illustration of the method application. The article presents the comparison of simple calculation method and modeling with FDS+Evac software results of time for safe evacuation of people from rooms and buildings. Santrauka Daugelyje civiliniu pastatu ar inžineriniu statiniu kyla gaisro rizikos pavojus. Žmoniu evakuacijos laiko iš patalpos ar statinio analize yra svarbi projektavimo dalis. Tačiau žmoniu elgsenos gaisro salygomis analize yra labai sudetinga. Ivairūs fizikiniai ir netgi psichologiniai veiksniai, darantys itaka saugiai žmoniu evakuacijai iš statiniu, turi būti ivertinti. Išrasti analitiniai ir skaičiuojamieji metodai, skirti žmoniu evakuacijai gaisro salygomis analizuoti. Deja, sudetingu skaičiavimu metodu taikymas žmoniu evakuacijai nustatyti reikalauja pernelyg daug ištekliu, todel ju taikymas yra ribotas. Šiame straipsnyje pateikiamas žmoniu evakuacijos skaičiavimo metodas, paremtas fizikinemis žmoniu srauto charakteristikomis (tankiu, intensyvumu, judejimo greičiu), priklausomai nuo žmoniu judejimo būdo. Palyginti aprašyto ir sudetingojo žmoniu evakuacijos skaičiavimo metodu, naudojant FDS+Evac programine iranga, rezultatai.

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Fujii, J., K. Tamura, S. Ishizuka, T. Sato et T. Mizoguchi. « Band Bending and Surface States of Cs/GaAs Studied by XPS ». Surface Review and Letters 05, n^o 01 (février 1998) : 305–7. http://dx.doi.org/10.1142/s0218625x98000566.

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Photocurrent and work function of Cs/GaAs and band denging at the interface are measured at room temperature for p-type GaAs clean surfaces with different surface treatments [cleaved GaAs(110); sulfur-passivated GaAs(001); GaAs(001) cleaned by Ar + ion bombardment and annealing]. The photoemission intensity depends on the initial surface treatments of GaAs. Both work function and band bending which influence the photoemission intensity also depend on the surface treatments and the behavior of photoemission intensity is qualitatively explained by them.

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Manakhov, Anton, Philip Kiryukhantsev-Korneev, Miroslav Michlíček, Elizaveta Permyakova, Eva Dvořáková, Josef Polčák, Zakhar Popov, Maxim Visotin et Dmitry V. Shtansky. « Grafting of carboxyl groups using CO2/C2H4/Ar pulsed plasma : Theoretical modeling and XPS derivatization ». Applied Surface Science 435 (mars 2018) : 1220–27. http://dx.doi.org/10.1016/j.apsusc.2017.11.174.

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Romanyuk, O., J. Brault, I. Gordeev, E. Ukraintsev, J. Houdková et P. Jiříček. « Depth profiling of AlN and Al_xGa_1−xN crystals by XPS using Al Kα and Ag Lα line excitation and Ar ion gas cluster ion source ». Journal of Applied Physics 133, n^o 3 (21 janvier 2023) : 035301. http://dx.doi.org/10.1063/5.0125938.

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AlGaN-based heterostructures are promising candidates for the fabrication of ultraviolet light-emitting diodes. The analysis of the atomic composition of the grown epitaxial films is important from a technological point of view, allowing precise control over the wavelength and intensity of the emitted light. In this work, the depth profiling of AlN(0001), AlGaN(0001), and AlGaN quantum dot surfaces grown by molecular beam epitaxy was carried out by using angle-resolved x-ray photoelectron spectroscopy (XPS) combined with Ar gas cluster ion source (GCIS) sputtering. Core level shifts in XPS spectra measured by Al Kα and Ag Lα photon sources were determined. We found that sputtering by Ar1000+ ion clusters with an energy of 10 keV creates disorder on the surface and induces changes in surface atomic composition. As a result, depth profiling with a typical surface-sensitive Al Kα photon source is affected by the damaged layer. The application of a less surface-sensitive Ag Lα photon source with high photon energy could suppress the contribution from the damaged surface layer. Combining GCIS sputtering with Ag Lα line XPS measurements is, therefore, very promising for the quantification of atomic composition in the buried epitaxial layers or heterostructures with thicknesses of several tens of nm.

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HENG, C. L., Y. J. LI, J. MAYANDI, T. G. FINSTAD, S. JØRGENSEN, A. E. GUNNÆS, A. OLSEN et P. STORÅS. « A STUDY ON THE PRECIPITATION OF Ge-RICH NANOPARTICLES IN A LUMINESCENT (Er, Ge) CO-DOPED SiO2 FILM SPUTTERED WITH Ar + O2 PLASMA ». International Journal of Nanoscience 05, n^o 04n05 (août 2006) : 493–98. http://dx.doi.org/10.1142/s0219581x06004681.

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We report the photoluminescence (PL) from an ( Er , Ge ) co-doped SiO 2 film deposited by rf-magnetron sputtering in an Ar + O 2 ambience. The sample film was annealed in N 2 for 30 min at different temperatures. The PL intensity increases as the annealing temperature increases from 700 to 1000°C, and drops to very weak after 1100°C annealing. High-resolution transmission electron microscopy (TEM) observation shows that there are some Ge -rich nanoparticles precipitated after 700°C annealing, and more clusters precipitated after 1000°C annealing. However, no Ge nanocrystals were found in these films, the diffraction patterns are always halo which indicates that the precipitated clusters are in amorphous states. X-ray photoelectron spectroscopy (XPS) analysis indicates the Ge in the nanoclusters is mostly in an oxidized state and the oxidation state of Er increases with increasing annealing temperature.

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Achour, Amine, Mohammad Islam, Sorin Vizireanu, Iftikhar Ahmad, Muhammad Aftab Akram, Khalid Saeed, Gheorghe Dinescu et Jean-Jacques Pireaux. « Orange/Red Photoluminescence Enhancement Upon SF6 Plasma Treatment of Vertically Aligned ZnO Nanorods ». Nanomaterials 9, n^o 5 (23 mai 2019) : 794. http://dx.doi.org/10.3390/nano9050794.

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Although the origin and possible mechanisms for green and yellow emission from different zinc oxide (ZnO) forms have been extensively investigated, the same for red/orange PL emission from ZnO nanorods (nR) remains largely unaddressed. In this work, vertically aligned zinc oxide nanorods arrays (ZnO nR) were produced using hydrothermal process followed by plasma treatment in argon/sulfur hexafluoride (Ar/SF6) gas mixture for different time. The annealed samples were highly crystalline with ~45 nm crystallite size, (002) preferred orientation, and a relatively low strain value of 1.45 × 10−3, as determined from X-ray diffraction pattern. As compared to as-deposited ZnO nR, the plasma treatment under certain conditions demonstrated enhancement in the room temperature photoluminescence (PL) emission intensity, in the visible orange/red spectral regime, by a factor of 2. The PL intensity enhancement induced by SF6 plasma treatment may be attributed to surface chemistry modification as confirmed by X-ray photoelectron spectroscopy (XPS) studies. Several factors including presence of hydroxyl group on the ZnO surface, increased oxygen level in the ZnO lattice (OL), generation of F–OH and F–Zn bonds and passivation of surface states and bulk defects are considered to be active towards red/orange emission in the PL spectrum. The PL spectra were deconvoluted into component Gaussian sub-peaks representing transitions from conduction-band minimum (CBM) to oxygen interstitials (Oi) and CBM to oxygen vacancies (VO) with corresponding photon energies of 2.21 and 1.90 eV, respectively. The optimum plasma treatment route for ZnO nanostructures with resulting enhancement in the PL emission offers strong potential for photonic applications such as visible wavelength phosphors.

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Dumitrache, Florian, Iuliana P. Morjan, Elena Dutu, Ion Morjan, Claudiu Teodor Fleaca, Monica Scarisoreanu, Alina Ilie et al. « Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis : structural and optical properties ». Beilstein Journal of Nanotechnology 10 (2 janvier 2019) : 9–21. http://dx.doi.org/10.3762/bjnano.10.2.

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Zn/F co-doped SnO2 nanoparticles with a mean diameter of less than 15 nm and a narrow size distribution were synthesized by a one-step laser pyrolysis technique using a reactive mixture containing tetramethyltin (SnMe4) and diethylzinc (ZnEt2) vapors, diluted Ar, O2 and SF6. Their structural, morphological, optical and electrical properties are reported in this work. The X-ray diffraction (XRD) analysis shows that the nanoparticles possess a tetragonal SnO2 crystalline structure. The main diffraction patterns of stannous fluoride (SnF2) were also identified and a reduction in intensity with increasing Zn percentage was evidenced. For the elemental composition estimation, energy dispersion X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) measurements were performed. In general, both analyses showed that the Zn percentage increases with increasing ZnEt2 flow, accompanied at the same time by a decrease in the amount of F in the nanopowders when the same SF6 flow was employed. The Raman spectra of the nanoparticles show the influence of both Zn and F content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn dopant concentration).

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Juniawan, Fransiskus Panca, Dwi Yuny Sylfania, Harrizki Arie Pradana et Laurentinus Laurentinus. « Pengenalan alat musik tradisional Bangka dengan Marker-Based Augmented Reality ». Register : Jurnal Ilmiah Teknologi Sistem Informasi 5, n^o 2 (1 juin 2019) : 89. http://dx.doi.org/10.26594/register.v5i2.1498.

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Dengan berkembangnya teknologi, kesadaran akan pentingnya alat musik tradisional menjadi berkurang. Demikian juga dengan alat musik tradisional Bangka yang mulai kehilangan popularitasnya. Kondisi saat ini, para remaja di Bangka kebanyakan tidak dapat memainkan alat musik tradisionalnya. Begitu juga dengan anak-anak yang belum mengetahui dan bahkan tidak mengenal alat musik tradisional daerah mereka. Jika kondisi ini dibiarkan, dikhawatirkan keberadaan alat musik tradisional Bangka akan hilang, begitu juga dengan sumber daya manusia yang dapat memainkannya. Untuk menghindari hal tersebut, dibuatlah aplikasi pengenalan alat musik tradisional Bangka menggunakan Augmented Reality (AR). AR dipilih karena dapat memberikan gambaran alat musik secara real time dalam bentuk 3D sesuai dengan pergerakan kamera smartphone yang dinamis. Empat objek 3D alat musik yakni dambus, rebab, rebanatamborin, dan gong yang dibuat menggunakan Autodesk Maya. AR yang dibangun menggunakan metode berbasis marker. Metode ini dipilih agar lebih mudah digunakan oleh pengguna yang mayoritasnya adalah anak-anak. Selain itu, kelebihan metode ini memiliki tingkat akurasi posisi yang sangat tinggi. Unity sebagai engine untuk penerapan AR 3D modelling pada sistem Android dan Vuforia SDK sebagai engine pembentuk marker augmented reality. Pengujian fungsional memiliki hasil 100% dengan sistem yang berjalan baik. Hasil pengujian kinerja deteksi objek AR berdasarkan intensitas cahaya diketahui bahwa smartphone yang memiliki dua kamera di bagian belakang dapat mendeteksi objek dengan intensitas cahaya 0 Lux pada malam hari dengan kondisi gelap, sedangkan yang hanya memiliki satu kamera tidak dapat mendeteksi objek. Pengujian warna marker mendapatkan hasil modifikasi warna marker pink, kuning, dan hitam yang masih memungkinkan untuk pendeteksian objek, walaupun objek yang tampil tidak stabil. Dari pengujian kertas marker diketahui bahwa jenis kertas tidak berpengaruh terhadap pendeteksian objek. Pengujian beta dilakukan dengan cara membagikan kuesioner terkait pengalaman pengguna dalam penggunaan sistem. Hasil survei diketahui pengguna merasa sangat setuju dengan nilai sebesar 80%, bahwa penggunaan sistem dapat membantu mereka dalam mengenal alat musik tradisional Bangka. With the incessant development of technology, awareness on the importance of traditional musical instruments has declined. Similarly, teenagers living in Bangka no longer play their traditional musical instruments, and children are not exposed to their cultural heritage. However, if this continues, it is feared that the existence of traditional Bangka musical instruments will soon go extinct. To avoid this, researchers have proposed an application to identify this media using Augmented Reality (AR). This technique was chosen due to its ability to provide visuals of musical instruments in real time using 3D models in accordance with the dynamic movement of smartphone cameras. This comprises of four 3D objects namely dambus, rebab, rebanatamborin, and gong, which were designed and developed using Autodesk Maya. AR is built using marker-based methods, which was chosen for easy use because majority of its users are children, and its high level of accuracy. Unity was utilized as an engine for its implementation in the Android system, and Vuforia SDK as augmented reality marker-builder engine. Functional testing showed 100% results which means that the system is running well. From the results of the AR object detection performance test based on light intensity it is known that a smartphone with two cameras in the backside has the ability to detect objects with a light intensity of 0 Lux in dark rooms, while the other smartphone with one camera failed to detect the objects. Color testing obtained a modification of marker colors comprising of pink, yellow, and black which are still able to detect objects, although not stable. The paper test marker has no effect on object detection. Beta testing questionnaires were used to obtain information related to user experience. From the survey results, it is known that users strongly agree (80%) that the use of the system helps them to recognize traditional Bangka musical instruments.

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Ishag-Osman, Amira, David Hosfield, Rosemary Huggins et Geoffrey Greene. « Abstract 3439 : Evaluating nuclear receptor heterodimerization using live cell proximity assays : Implications for novel therapeutic approaches for hormone driven cancers ». Cancer Research 83, n^o 7_Supplement (4 avril 2023) : 3439. http://dx.doi.org/10.1158/1538-7445.am2023-3439.

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Abstract Breast and prostate cancer are the leading cancer diagnoses for women and men, respectively, second only to cutaneous cancers. Breast and prostate cancer arise from aberrant estrogen/estrogen receptor (ER) and testosterone/androgen receptor signaling (AR), respectively. These sex hormone receptors are members of the steroid hormone receptor family, which also includes the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and progesterone receptor (PR). Although these receptors canonically function through homodimerization, recent evidence has suggested that receptor crosstalk can amplify or dampen the actions of heterologous receptors. However, these interactions have not been extensively studied in all possible combinations of steroid hormone receptor crosstalk. In this project, we hypothesize that heterodimerization may amplify or repress the transcriptional response(s) elicited by the various receptor complexes depending upon conditions such as concentration of ligands, type of ligand, physiological states, and the types/functions of promoter regions. To test this hypothesis, we investigated the significance of ligand-induced interactions between different homo- and heterodimer combinations of AR, ARV7, GR, MR, PR, and ERα in HEK293 cells using IncuCyte live-cell imaging and NanoBRET technology. Ultimately, the combination of transfection experiments, live-cell imaging, and NanoBRET assays provided insight into which combination of steroid receptors successfully interact to amplify (or dampen) the HaloTag expression, luminescence intensity at 450nM (i.e., NanoLuc expression), and NanoBRET ratio (i.e., acceptor emission luminescence at 610nM divided by donor emission luminescence at 450nM) in HEK293 cells. Our studies revealed that heterodimerization of ERα-PR, ERα-MR, AR-GR, AR-PR, ARV7-MR, ARV7-PR, and GR-MR produced significant ligand-induced changes in signaling intensity compared to no ligand conditions for each fusion protein construct. Additionally, to demonstrate the value of the NanoBRET method for modelling clinically relevant disease conditions, we assessed the physical interaction of ERα and PR in the context of the ERα Y537S mutation - a mutation associated with endocrine therapy resistance in breast cancer that results in a constitutively active ERα. The results showed that ERα-Y537S mutation increases ERα/PR physical interaction upon PR-B stimulation in a NanoBRET proximity-based assay. Future directions include testing these interactions in breast and prostate cancer cell lines and identifying the receptors’ localization within the cell, the results of which may be of clinical importance. Citation Format: Amira Ishag-Osman, David Hosfield, Rosemary Huggins, Geoffrey Greene. Evaluating nuclear receptor heterodimerization using live cell proximity assays: Implications for novel therapeutic approaches for hormone driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3439.

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Reardon, D. J., W. A. Coles, G. Hobbs, S. Ord, M. Kerr, M. Bailes, N. D. R. Bhat et V. Venkatraman Krishnan. « Modelling annual and orbital variations in the scintillation of the relativistic binary PSR J1141−6545 ». Monthly Notices of the Royal Astronomical Society 485, n^o 3 (8 mars 2019) : 4389–403. http://dx.doi.org/10.1093/mnras/stz643.

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ABSTRACT We have observed the relativistic binary pulsar PSR J1141−6545 over a period of ∼6 yr using the Parkes 64 m radio telescope, with a focus on modelling the diffractive intensity scintillations to improve the accuracy of the astrometric timing model. The long-term scintillation, which shows orbital and annual variations, allows us to measure parameters that are difficult to measure with pulsar timing alone. These include: the orbital inclination i, the longitude of the ascending node Ω, and the pulsar system transverse velocity. We use the annual variations to resolve the previous ambiguity in the sense of the inclination angle. Using the correct sense, and a prior probability distribution given by a constraint from pulsar timing (i = 73 ± 3°), we find Ω = 24.8 ± 1.8° and we estimate the pulsar distance to be $D=10^{+4}_{-3}$ kpc. This then gives us an estimate of this pulsar’s proper motion of μαcos δ = 2.9 ± 1.0 mas yr−1 in right ascension and μδ = 1.8 ± 0.6 mas yr−1 in declination. Finally, we obtain measurements of the spatial structure of the interstellar electron-density fluctuations, including: the spatial scale and anisotropy of the diffraction pattern, the distribution of scattering material along the line of sight, and spatial variation in the strength of turbulence from epoch to epoch. We find that the scattering is dominated by a thin screen at a distance of (0.724 ± 0.008)D, with an anisotropy axial ratio Ar = 2.14 ± 0.11.

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Faria, Bruno Lopes, et Flavio Barbosa Justino. « Modelagem do Impacto da Topografia Boreal no Clima Global (Modelling the Impact of Topography on Global Climate Boreal) ». Revista Brasileira de Geografia Física 4, n^o 2 (20 septembre 2011) : 229. http://dx.doi.org/10.26848/rbgf.v4i2.232682.

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Foram realizadas simulações climáticas a partir de 2 experimentos de sensibilidade numérica conduzidos com um modelo acoplado de complexidade intermediária, LOVECLIM, estendendo-se para um período de 300 anos. Sendo que, neste experimento foi realizada a redução em 50% da topografia geral do hemisfério norte, um com modelo acoplado (oceano-atmosfera) e outro desacoplado (somente atmosfera). Nos resultados obtidos, foram observadas alterações no padrão de clima global e local, em especial a região da Ásia, relacionadas com aumento de temperatura do ar à superfície e intensidade do vento. Maiores alterações foram observados em regiões continentais no hemisfério norte. Isto mostra o maior impacto local causado pela forçante topográfica com o a redução da pela metade da topografia boreal. Palavras-chave: Topografia, Mudanças Climáticas, Modelos Climáticos, Forçante Climática Modelling the Impact of Topography on Global Climate Boreal ABSTRACTSimulations were conducted from two numerical sensitivity experiments conducted with a coupled model with intermediate complexity, LOVECLIM, extending for a period of 300 years. Since this experiment was carried out 50% reduction in the general topography of the northern hemisphere, with a coupled model (ocean-atmosphere) and the other uncoupled (atmosphere only). Their results have been observed changes in the pattern of global and local climate, particularly in Asia, linked to increase of air temperature and wind intensity. The biggest impacts were observed in continental regions in the north hemisphere. This shows the greater local impact caused by topographic forcing Keywords: Topography, Climate Change, Climate Models, Topographic Forcing

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HEIJLEN, Wouter, et Philippe MUCHEZ. « The individual analysis of fluid inclusions in minerals using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) : an evaluation ». Geologica Belgica 3, n^o 3-4 (1 octobre 2001) : 215–30. http://dx.doi.org/10.20341/gb.2014.030.

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During the last decade, the possible application of laser ablation inductively coupled plasma - mass spectrometry (LA-ICP-MS) as a quantitative technique for the analysis of individual fluid inclusions has been intensely studied. The quantitative ability of this technique is, however, complicated by several fractionation processes that operate during ablation, transport and analysis in the ICP-MS. In the present study, a number of these fractionation effects were studied and the quantitative ability of LA-ICP-MS analysis of fluid inclusions in natural quartz is evaluated. Using NIST SRM 612 and 614 as reference materials, it is shown that the fractionation during transport is minimised when the sample cell is flushed with He, in contrast with the set-up where Ar is used. Calcium has been successfully applied as an internal standard to calibrate the REE in NIST-glasses. The use of Ca to calibrate other lithophile and chalcophile elements, such as K, Zn, Cu and Pb, can however be questioned. It is shown that the technique is capable of semi-quantitatively characterising different fluid inclusion populations in natural quartz, which demonstrates its importance as a tool for palaeofluidflow modelling. However, during LA-ICP-MS analysis of fluid inclusions in natural quartz, elements are reprecipitated in a glassy phase, as shown by SEM-EDX analysis of the sample surface after ablation. This process could result in a fractionation and may account for the poor precision of the analysis.

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Zlatanova, S., S. Dragicevic et G. Sithole. « PREFACE : TECHNICAL COMMISSION IV ON SPATIAL INFORMATION SCIENCE ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B4-2020 (24 août 2020) : 7–9. http://dx.doi.org/10.5194/isprs-archives-xliii-b4-2020-7-2020.

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Abstract. The unusual circumstances created by the coronavirus pandemic has impacted recent activities of Commission IV. The situation also provides an excellent opportunity to connect the work of the Commission to addressing an important global problem. Managing the social and economic challenges brought by increased complexity and interconnectivity of activities in human society requires new dimensions of analysing information and specifically spatial information. The increased pressure on the usage of geographic space, maintaining sustainable development and creating liveable community environments increases the requirements for spatial decision-making tools. Commission IV Spatial Information Science (2016–2020) is dedicated to advance research activities in spatial information sciences for modelling, structuring, management, analysis, visualization and simulation of (big) data with focus on the third spatial dimension and taking into consideration dynamic changes. Special attention is given to linking information about real-world physical phenomena with societal, organizational and legal information in order to address the complexity of issues in their entirety. The Commission has contributed to advancements in data modelling, data fusion and management, visualization (web-based, VR and AR), simulation and city analytics, and 3D applications. The work had largely been implemented in cooperation with international organizations such as FIG, UDMS, 3DGeoinfo, ICA, OGC, ISO and Web3D.The Commission consists of 10 scientific areas of research that is coordinated by 10 working groups (WG) as follows - WG1: Strengthen the work on multidimensional spatial model and representations towards seamless data fusion; WG2: Advance the semantic modelling, development and linking of ontologies; WG3: Intensify research into data interpretation, quality and uncertainty modelling; WG4: Strengthen research on crowdsourced data and public participation, towards community-driven and participatory applications, collaborative mapping and use/usability of maps; WG5: Strengthen research on seamless indoor/outdoor location-based services, navigation and tracking, and analysis of human movement; WG6: Advance interoperable Internet of Things, Sensor web, SDI and linked data; WG7: Advance research on spatial data types, indexing methods and analysis to further contribute to development of spatial DBMS for management and analysis of multi-dimensional data; WG8: Encourage the use of functional programming and streaming algorithms in development of demos and applications as well as parallel and distributed processing paradigms; WG9: Advance visual analytics, online multi-dimensional visualization on mobile and desktop devices, considering human-centred applications, privacy and security issues; WG10: Advance knowledge on the use of spatial information (BIM/GIS) for urban modelling; ICWG IV/III: Global Mapping: Updating, Verification and Interoperability with the mission to promote the development of advanced methodologies and applications for the update, verification and interoperability of geospatial databases.The papers received for the ISPRS congress reflect the above-mentioned scientific research areas. The reported research ranges from advancements in new and emerging theories, through experiments and analysis to demonstration of technologies in different applications. The research was captured through papers and abstracts published in the collection of ISPRS Annals and ISPRS Archives. The papers and abstracts were selected for inclusion through a rigorous peer-review process. The ISPRS Annals contain 29 papers and the ISPRS Archives contain 114 papers. The diversity of the research topics presented in the published papers clearly indicate the wide range of topics within the field of Spatial Information Science. A rigorous peer-review process by the ISPRS TC IV Scientific Committee Working Group Chairs ensured hight quality and scientific innovation.

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Zlatanova, S., S. Dragicevic et G. Sithole. « Preface : Technical Commission IV on Spatial Information Science ». ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences V-4-2020 (3 août 2020) : 7–9. http://dx.doi.org/10.5194/isprs-annals-v-4-2020-7-2020.

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Abstract. The unusual circumstances created by the coronavirus pandemic has impacted recent activities of Commission IV. The situation also provides an excellent opportunity to connect the work of the Commission to addressing an important global problem. Managing the social and economic challenges brought by increased complexity and interconnectivity of activities in human society requires new dimensions of analysing information and specifically spatial information. The increased pressure on the usage of geographic space, maintaining sustainable development and creating liveable community environments increases the requirements for spatial decision-making tools. Commission IV Spatial Information Science (2016–2020) is dedicated to advance research activities in spatial information sciences for modelling, structuring, management, analysis, visualization and simulation of (big) data with focus on the third spatial dimension and taking into consideration dynamic changes. Special attention is given to linking information about real-world physical phenomena with societal, organizational and legal information in order to address the complexity of issues in their entirety. The Commission has contributed to advancements in data modelling, data fusion and management, visualization (web-based, VR and AR), simulation and city analytics, and 3D applications. The work had largely been implemented in cooperation with international organizations such as FIG, UDMS, 3DGeoinfo, ICA, OGC, ISO and Web3D.The Commission consists of 10 scientific areas of research that is coordinated by 10 working groups (WG) as follows - WG1: Strengthen the work on multidimensional spatial model and representations towards seamless data fusion; WG2: Advance the semantic modelling, development and linking of ontologies; WG3: Intensify research into data interpretation, quality and uncertainty modelling; WG4: Strengthen research on crowdsourced data and public participation, towards community-driven and participatory applications, collaborative mapping and use/usability of maps; WG5: Strengthen research on seamless indoor/outdoor location-based services, navigation and tracking, and analysis of human movement; WG6: Advance interoperable Internet of Things, Sensor web, SDI and linked data; WG7: Advance research on spatial data types, indexing methods and analysis to further contribute to development of spatial DBMS for management and analysis of multi-dimensional data; WG8: Encourage the use of functional programming and streaming algorithms in development of demos and applications as well as parallel and distributed processing paradigms; WG9: Advance visual analytics, online multi-dimensional visualization on mobile and desktop devices, considering human-centred applications, privacy and security issues; WG10: Advance knowledge on the use of spatial information (BIM/GIS) for urban modelling; ICWG IV/III: Global Mapping: Updating, Verification and Interoperability with the mission to promote the development of advanced methodologies and applications for the update, verification and interoperability of geospatial databases.The papers received for the ISPRS congress reflect the above-mentioned scientific research areas. The reported research ranges from advancements in new and emerging theories, through experiments and analysis to demonstration of technologies in different applications. The research was captured through papers and abstracts published in the collection of ISPRS Annals and ISPRS Archives. The papers and abstracts were selected for inclusion through a rigorous peer-review process. The ISPRS Annals contain 29 papers and the ISPRS Archives contain 114 papers. The diversity of the research topics presented in the published papers clearly indicate the wide range of topics within the field of Spatial Information Science. A rigorous peer-review process by the ISPRS TC IV Scientific Committee Working Group Chairs ensured hight quality and scientific innovation.

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Hayashi, Kenta, Hikaru Kamikawa, Naoto Todoroki et Toshimasa Wadayama. « WO _x /Pt(111) Prepared As PEFC Model Anode Catalyst : Surface Structure and Suppressed Hydrogen Peroxide Generation ». ECS Meeting Abstracts MA2022-02, n^o 42 (9 octobre 2022) : 1539. http://dx.doi.org/10.1149/ma2022-02421539mtgabs.

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Introduction To achieve prolonged lifetime of polymer electrolyte fuel cell (PEFC), hydrogen-peroxide (H2O2)-induced chemical degradation of polymer electrolyte membrane (PEM) is a crucial problem. In general, oxygen (O2) crossover from cathode to anode through the PEM yields H2O2 generation on Pt/C anode catalyst surface through 2-electron pathway of O2 reduction reaction. Thus, mitigation of H2O2 generation on Pt/C surface is a key to suppress the PEM degradation. Trogadas and Ramani reported tungsten trioxide (WO3) addition to Pt/C suppressed H2O2 generation.1 The results suggest that the cooperation of Pt nanoparticles and WO3 located near-by should be effective for suppression of H2O2 generation. However, influence of the oxidation states of tungsten oxide (WO x ) on H2O2 generation at the Pt surface is not fully resolved. Furthermore, it was reported that, although fully oxidized WO3 is stable in acid solution (pH < 2),2 sub-oxides of tungsten (WO x ) could dissolve in Pt-WO x electrochemical system.3 Thus, electrochemical dissolution behaviors of WO x located on Pt substrate surface should be investigated in detail. In this study, we prepare Pt(111) surface that modified by WO x having different oxidation states, and investigated the electrochemical H2O2 generations. Experimental Pt(111) single crystal substrate surface was cleaned by repeated cycles of Ar+ sputtering and annealing in an ultrahigh vacuum (UHV; ~10-8Pa). Subsequently, WO x was deposited on the cleaned Pt(111) via an arc-plasma deposition (APD) method using a W target under partial pressures of O2 (p(O2) = 1×10-1 or 1×10-3 Pa) at ca. 298 K. Deposition amounts of the WO x was estimated to be ca. 1.5 µg/(cm2 of substrate) by using a quartz crystal microbalance installed in the UHV chamber. Then, WO x -modified Pt(111) were annealed at 703 K for 10 min. in UHV. Hereafter, the fabricated samples are referred to as p(O2)-WO x /Pt(111). X-ray photoelectron spectroscopy (XPS) was conducted for the as-fabricated samples in situ in UHV. H2O2 generation amounts were evaluated by the tip generation/substrate collection mode of scanning electrochemical microscope (SECM)4 in O2-saturated 0.1 M HClO4. Generated H2O2 was detected by a Pt tip micro-electrode (diameter: ca. 20 µm, tip potential: 1.26 V vs. RHE) positioned ca. 50 µm at surface normal of the sample electrodes, with sweeping sample electrode potential (E S) at sweep rate of 2 mV/s in negative going direction. Thereafter, potential cycles (PCs: 0.05–1.0 V vs. RHE, sweep rate: 100 mV/s, 100 cycles) were applied to the sample surfaces; then, H2O2 generation was re-evaluated. Finally, the PCs-applied sample surfaces were re-introduced to the UHV chamber to perform XPS measurements. Results and Discussion XP spectra of W4f bands for the as-fabricated and PCs-applied sample surfaces are summarized in Figure. 1 (A). Considering peak areas of deconvoluted components (solid lines), the oxidation states of WO x as-fabricated can be judged mainly to be W6+ and Wx+ (x < 4) for 10-1 Pa-WO x /Pt(111) (a) and 10-3 Pa-WO x /Pt(111) (c), respectively. Figure. 1 (B) shows SECM-estimated H2O2 generations of the WO x /Pt(111) surfaces before (as-fabricated) and after the 100 PCs. As for the as-fabricated surfaces (solid lines), H2O2 detection current (i T) of the Pt tip micro-electrode normalized by respective sample electrode current (i S) is lower for 10-1 Pa-WO x /Pt(111) than 10-3 Pa-WO x /Pt(111), yet normalized i T/|i S|-values for both surfaces are smaller than that of clean Pt(111). The results show that surface modification of Pt(111) by the small amount of WO x , particularly with higher oxidation states, effectively suppressed H2O2 generations. However, the suppression effect degraded by the 100 PCs application for both the electrode surfaces (dotted lines). Compared of W4f bands for the PCs-applied surfaces (Figure. 1 (A) (b, d)) with corresponding as-fabricated ones (a, c), the bands shifted to negative- and positive-binding-energies for 10-1 Pa-WO x /Pt(111) and 10-3 Pa-WO x /Pt(111), respectively, indicating respective reduction and oxidation of the surface WO x by the PCs. In addition, W4f bands for both surfaces decreased in intensity by the PCs application, suggesting decrease in surface amount of the WO x , probably through electrochemical dissolution during the PCs. The PCs-induced changes in oxidation states and amounts of surface WO x should correlate to the degraded H2O2 generation suppressions. Acknowledgement This study was supported by the new energy and industrial technology development organization (NEDO) of Japan, JSPS KAKENHI Grant Number JP21H01645, and JST SPRING Grant Number JPMJSP2114. References P. Trogadas and V. Ramani, J. Electrochem. Soc., 155, B696–B703 (2008). M. Anik and K. Osseo-Asare, J. Electrochem. Soc., 149, B224 (2002). A. J. Martín, A. M. Chaparro, and L. Daza, J. Power Sources, 196, 4187–4192 (2011). C. M. Sánchez-Sánchez and A. J. Bard, Anal. Chem., 81, 8094–8100 (2009). Figure 1

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Kirilyuk, S. D. « Method of measuring antenna axis ratio close to unit ». Achievements of Modern Radioelectronics, 2021. http://dx.doi.org/10.18127/j20700784-202104-11.

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On purpose to increase efficiency of an orbital-frequency resource the usage of polarization-division multiplexing (PDM) is extended in satellite communication systems. For this aim the axis ratio (AR) of polarization ellipses on satellite radio lines with circular (rotating) polarization must be not less 0,94. Nowadays widespread techniques of experimental defining AR, are based on measurements of orthogonal components intensity of electromagnetic fields created by aerials. But, at high, more than 0,85 axis ratios, the information about a difference in components intensity loses on errors of the measurements realizing these techniques. The method of defining AR, close to extremely achievable value (nearly equal to unit) is presented in the article. The basic idea of this method consists in inclusion to the measurement scheme of two identical devices (DUT), working one towards to another. Also the scheme of counter inclusion of two identical DUT, similar used for measurements, may be applied for designing antenna elements with high AR. Good coincidence of results of modeling, laboratory measurements and field tests have confirmed suitability of the offered method for the designing and testing of aerials with high axis ratio.

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Kadia, Subhojit, Nils Rüther, Ismail Albayrak et Elena Pummer. « Reynolds Stress Modeling of Supercritical Narrow Channel Flows using OpenFOAM : Secondary Currents and Turbulent Flow Characteristics ». Physics of Fluids, 5 novembre 2022. http://dx.doi.org/10.1063/5.0124076.

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In this study, the full Launder, Reece and Rodi pressure-strain model and nonlinear boundary damping functions were incorporated in OpenFOAM® to simulate the turbulence-driven secondary currents in supercritical narrow channel flows such as in sediment bypass tunnels (SBTs). Five simulations were performed under uniform flow conditions covering Froude numbers from 1.69 - 2.56 and aspect ratios (channel width to flow depth) ar from 0.9 - 1.91 to investigate the formation of secondary currents and their impacts on longitudinal velocity, turbulence characteristics, and bed shear stress distribution. The numerical results of the maximum longitudinal velocity and the average shear velocity show marginal deviations, of less than 2.6%, from two-dimensional experimental results acquired under decelerating flow conditions. However, some differences are observed for the secondary currents and for the vertical turbulence intensity and Reynolds shear stress in the outer flow region, especially for cases with higher flow nonuniformity (that can influence the surface perturbation) whose influence is missing in the numerical model. No intermediate vortex is observed for ar = 1.91. However, it develops for lower ar, and detaches from the free surface vortex when ar {less than or equal to} 1.05. Such vortex bulges the longitudinal velocity contour lines inward and the zone of higher longitudinal velocity narrows and deepens with a decrease in ar. The decrement reduces the magnitude of the normalized maximum secondary velocity. It also affects the bottom vortex which alters the bed shear stress distribution.

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« ON THE COMPARISON OF REACTIVE-ION ETCHING MECHANISMS FOR SiO2 AND Si3N4 IN HBr + Ar PLASMA ». ChemChemTech 66, n^o 6 (15 mai 2023) : 37–45. http://dx.doi.org/10.6060/ivkkt.20236606.6786.

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This work investigated the influence of component ratio in the HBr + Ar gas mixture on electro-physical plasma parameters, steady-state densities of active species and reactive-ion etching (RIE) kinetics for SiO2 and Si3N4 under conditions of inductive RF (13.56 MHz) discharge. The combination of plasma diagnostics by Langmuir probes and plasma modeling indicated that an increase in Ar content at constant gas pressure and input power a) caused an increase in electron temperature and densities of charged species; b) results in increasing ion bombardment intensity; and c) leads to the nearly proportional decrease in Br atoms density and flux. It was found that variations of SiO2 and Si3N4 etching rates vs. mixture composition are qualitatively similar while the maximum difference in corresponding absolute values takes place in pure HBr plasma. The analysis of RIE mechanisms was carried out using model-predicted data on fluxes of ions and bromine atoms. It was found that the dominant SiO2 etching mechanism is the ion-assisted chemical reaction which is characterized by the nearly-constant rate in the range of 0–80% Ar due to an increase in the effective reaction probability. That is why the noticeable intensification of physical sputtering with increasing Ar fraction in a feed gas causes the only weak growth of obtained SiO2 RIE rate. Oppositely, the Si3N4 etching process is mainly contributed by the physical sputtering while the efficiency of ion-stimulated chemical reaction is limited by the low reaction probability. This provides both slower etching process (especially in Ar-poor plasmas) and stronger sensitivity of etching rate to the change in mixture composition. For citation: Efremov A.M., Betelin V.B., Kwon K.-H. On the comparison of reactive-ion etching mechanisms for SiO2 and Si3N4 in HBr + Ar plasma. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 6. P. 37-45. DOI: 10.6060/ivkkt.20236606.6786.

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Zou, Xun, Jason M. Cordeira, Samuel M. Bartlett, Brian Kawzenuk, Shawn Roj, Christopher Castellano, Chad Hecht et F. Martin Ralph. « Mesoscale and Synoptic Scale Analysis of Narrow Cold Frontal Rainband During a Landfalling Atmospheric River in California During January 2021 ». Journal of Geophysical Research : Atmospheres 128, n^o 20 (21 octobre 2023). http://dx.doi.org/10.1029/2023jd039426.

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AbstractNarrow cold‐frontal rain bands (NCFR) often produce short‐duration and high‐intensity precipitation that can lead to flooding and debris flow in California (CA). On 27 January 2021, an atmospheric river (AR) associated with an intense surface cyclone made landfall over coastal northern CA, which featured a prominent NCFR. This study uses high‐resolution West Weather Research and Forecasting simulations to accurately resolve the gap and core structure of the NCFR and provide reliable precipitation estimations, compensating for limitations of radar and satellite observations. This NCFR was supported by robust synoptic‐scale quasi‐geostrophic (QG) forcing for ascent and frontogenesis. It propagated southward from Cape Mendocino to Big Sur in 12 hr before stalling and rotating counter‐clockwise in central/southern CA due to upstream Rossby wave breaking and an amplifying upper‐tropospheric trough. With the lower to middle tropospheric flow backed considerably to the south‐southwest over the NCFR, the increase of the vertical wind shear caused the transition from parallel to trailing stratiform precipitation. The stall and pivot of the AR and NCFR led to intense rainfall with a 2‐day precipitation accumulation greater than 300 mm over central CA. In addition, under the potential instability and frontogenesis, a moist absolutely unstable layer between 850 and 700 hPa was captured at the leading edge of the NCFR, which indicated slantwise deep layer lifting and high precipitation efficiency. This study reveals synoptic‐scale and mesoscale drivers of rainfall outside orographic lifting and reaffirms the importance of high‐resolution numerical modeling for the prediction of extreme precipitation and related natural hazards.

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Gallardo-Diaz, E., R. C. Mancini, K. R. Carpenter, P. Adrian, J. Frenje et R. Florido. « Temperature and density dependence of Kr L-shell spectrum in hot dense plasmas ». Physics of Plasmas 31, n^o 3 (1 mars 2024). http://dx.doi.org/10.1063/5.0190238.

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Kr L-shell spectroscopy modeling results are discussed in this paper, focusing on the n = 4 to n = 2 line transitions of Be- and Li-like Kr ions. Collisional radiative atomic kinetic and Stark-broadened spectral line shape calculations show electron temperature Te and density ne sensitivity in the spectrum. The combination of the Te dependence due to the relative intensity of Be-like to Li-like line emissions in the range from 1.5 to 3 keV and the ne sensitivity from the Stark broadening effect on the line shapes in the range from 5×1023 to 2×1024/ cc results in a spectrum that can be employed to diagnose Te and ne. Two different collisional radiative atomic kinetic models i.e., Prismspect [J. J. MacFarlane, et al., Int. Fusion Sci. Appl. Conf. Proc. 457 (2003)] and ABAKO [Florido, et al., PRE, 80, 056402 (2009)] produce similar results in level populations and spectra. In x-ray spectroscopy of implosion cores, this Kr L-shell spectrum may prove useful in an intermediate Te range in which Ar is too ionized for its K-shell to be of diagnostic value and Kr is not ionized enough for its K-shell emission to be useful.

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Dimova-Malinovska, D., M. Tzolov et N. Malinowski. « Visible Luminescence from Laser-Induced Stain- and Dry Etched Silicon ». MRS Proceedings 397 (1995). http://dx.doi.org/10.1557/proc-397-503.

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ABSTRACTLight emitting silicon has been prepared by Ar laser (514.5 nm) induced stain etching and Nd:YAG impulse (532 nm) laser irradiation in air. Photoluminescence (PL), IR and XPS spectra have been studied. The intensity and position of the PL depend on the power or the energy and the duration of laser beam treatment during the etching. Correlation between the PL and chemical bonding is discussed.

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Wang, Jin, Mengting Wang, Yongqiang Wang, Dayan Ma et Hao Li. « EFFECT OF THE N2/Ar FLOW RATIO ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF TiSiCN COATINGS ». Materiali in tehnologije 55, n^o 6 (10 décembre 2021). http://dx.doi.org/10.17222/mit.2021.213.

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TiSiCN coatings were prepared with the multi-arc ion plating and magnetron sputtering technique. The effect of the N2/Ar flow ratio on the properties of TiSiCN coatings was studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and a friction and wear tester (UMT-3). With an increase in the N2/Ar flow ratio, the number of large particles on the surface first increases and then decreases. The intensity of the TiN (200) diffraction peak increases gradually, while the grain size first decreases and then increases. A TiSiCN coating consists of Ti (N, C) nanocrystallites, amorphous SiC, Si3N4 and carbon. When the N2/Ar flow ratio is 5 : 1, the coating exhibits the highest hardness and excellent wear resistance.

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Uekusa, Shin-ichiro, et Atsuhiko Kushida. « Optical Properties of Si and Ge/Si Nanocrystals in Silicon Oxide Matrix ». MRS Proceedings 958 (2006). http://dx.doi.org/10.1557/proc-0958-l10-28.

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ABSTRACTThe contribution of oxide-related emission in Photoluminescence (PL) spectra from Ge and Si nanocrystals mixture embedded in silicon oxide (Ge/Si-SiO2) and Si nanocrystals embedded in silicon oxide (Si-SiO2) thin film prepared by RF-magnetron co-sputtering method is investigated. All as-deposited thin films were annealed for 1 hour in the temperature range from 300 to 1100 °C in an Ar atmosphere. The samples were evaluated by using PL, Energy dispersive spectroscopy (EDX), Raman scattering and X-ray photoelectron spectroscopy (XPS) measurements. All the measurements were performed at room temperature. The maximum PL intensity of Ge+Si-SiO2 mixture thin film has increased more than the Si-SiO2 thin film by approximately 10 times. From the results of Raman scattering and XPS measurements, it is consider that the oxygen defect centers in the host material SiO2 increased by the diffusion of Ge. An increase in the PL intensity of Ge+Si-SiO2 mixture thin film is systematically discussed.

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Suda, Jun, Hiroyasu Yamashita, Robert Armitage, Tsunenobu Kimoto et Hiroyuki Matsunami. « Surface Control of ZrB2 (0001) Substrate for Molecular-Beam Epitaxy of GaN ». MRS Proceedings 798 (2003). http://dx.doi.org/10.1557/proc-798-y10.65.

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ABSTRACTZirconium diboride (ZrB2) is a promising lattice-matched substrate for GaN-based materials. A key issue to realize high-quality heteroepitaxial growth is preparation of the substrate surface. The ZrB2 surface was studied by x-ray photoemission spectroscopy (XPS) and reflection high-energy electron diffraction (RHEED). XPS results indicated the presence of both ZrO2 and ZrB2 on the as-received substrate surface. Thermal cleaning at 1000°C in ultra-high vacuum, Ar+ ion sputtering, and wet chemical treatments were examined as surface preparation methods. After treatment with HF acid, the O peak intensity was much reduced. The combination of HF treatment and thermal cleaning resulted in sharp and intense RHEED from the ZrB2 surface. GaN grown on the surface by molecular-beam epitaxy exhibited intense photoluminescence, suggesting that this treatment is effective to obtain high-quality GaN on ZrB2 substrates.

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Smiley, R. J., et W. N. Delgass. « Plasma Polymerization of Allylamine onto Pan-Based Carbon Fibers ». MRS Proceedings 305 (1993). http://dx.doi.org/10.1557/proc-305-129.

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AbstractThe plasma polymerization of allylamine onto PAN-based carbon fibers has been investigated by XPS and SEM. Fiber surfaces were cleaned and oxidized by treating in an O2 plasma for 5 minutes. XPS characterization of pretreated samples showed surfaces functionalized with COH, C=O, and COOH species. Fibers were coated with poly(allylamine) by introducing a monomer-saturated stream of Ar gas into the plasma chamber and reacting for 2–30 minutes. Some samples were further treated in an O2 plasma to determine the stability of the polymer coating. N(1s) spectra from the fiber surfaces showed two nitrogen peaks at 399.9 eV and 400.7 eV, which may be assigned to amine and amide groups, respectively. C(1s) spectra showed a decrease with treatment in the amine carbon peak at 287.2 eV and a corresponding increase in the peak at 288.7 eV, assigned to carboxyl and/or amide carbon. The increase in higher binding energy carbon corresponded with an increase in the 400.7 eV N(1s) peak and gave evidence for the conversion of amines to amides. Total O(1s) intensity initially decreased following 2 minutes of allylamine treatment but increased with further treatment. In addition to the carbon fiber samples, a silica wafer was coated and analyzed by XPS. Quantitative XPS results revealed that all the nitrogen present on the surface was in the form of amine and not amide species. Oxygen in the form of carboxyl species was also present on coated silica surfaces. Most likely, oxygen dissolved in the allylamine monomer was carried into the plasma chamber by the Ar gas. Comparing the silica wafer with the fiber samples revealed treatments were strongly sample dependent. Even after only 2 minutes of treatment, fiber samples showed the presence of amide and substituted amide species. SEM revealed coatings filled in the fiber grooves and left clumps of material on the surface. Micrographs of fibers treated for longer times revealed surfaces covered with particles < 0.25 μm in diameter. Finally, the XPS N(1s)/C(1s) and O(1s)/C(1s) intensity ratios indicated that some polymer remained on the fiber surface even after 15 minute post O2 plasma treatment. These experiments illustrate that plasma polymerization can be effective for functionalizing carbon fiber surfaces, but that optimization of conditions is necessary to improve wetting and control amine/amide functionality.

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Cumston, Quintin, Matthew Patrick, Ahmed R. Hegazy, Amirali Zangiabadi, Maximillian Daughtry, Kevin R. Coffey, Katayun Barmak et William E. Kaden. « Wafer-scale development, characterization, and high temperature stabilization of epitaxial Cr2O3 films grown on Ru(0001) ». Journal of Chemical Physics 160, n^o 14 (9 avril 2024). http://dx.doi.org/10.1063/5.0201818.

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This work outlines conditions suitable for the heteroepitaxial growth of Cr2O3(0001) films (1.5–20 nm thick) on a Ru(0001)-terminated substrate. Optimized growth is achieved by sputter deposition of Cr within a 4 mTorr Ar/O2 20% ambient at Ru temperatures ranging from 450 to 600 °C. The Cr2O3 film adopts a 30° rotated honeycomb configuration with respect to the underlying Ru(0001) substrate and exhibits a hexagonal lattice parameter consistent with that for bulk Cr2O3(0001). Heating to 700 °C within the same environment during film preparation leads to Ru oxidation. Exposure to temperatures at or above 400 °C in a vacuum, Ar, or Ar/H2 3% leads to chromia film degradation characterized by increased Ru 3d XPS intensity coupled with concomitant Cr 2p and O 1s peak attenuations when compared to data collected from unannealed films. An ill-defined but hexagonally well-ordered RuxCryOz surface structure is noted after heating the film in this manner. Heating within a wet Ar/H2 3% environment preserves the Cr2O3(0001)/Ru(0001) heterolayer structure to temperatures of at least 950 °C. Heating an Ru–Cr2O3–Ru heterostacked film to 950 °C within this environment is shown by cross-sectional scanning/transmission electron microscopy (S/TEM) to provide clear evidence of retained epitaxial bicrystalline oxide interlayer structure, interlayer immiscibility, and epitaxial registry between the top and bottom Ru layers. Subtle effects marked by O enrichment and O 1s and Cr 2p shifts to increased binding energies are noted by XPS in the near-Ru regions of Cr2O3(0001)/Ru(0001) and Ru(0001)/Cr2O3(0001)/Ru(0001) films after annealing to different temperatures in different sets of environmental conditions.

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Robert, Raphaël, Nader Sadeghi, Gerjan J. M. Hagelaar, Luc Stafford et Francoise Massines. « Influence of the RF voltage amplitude on the space- and time-resolved properties of RF-LF dielectric barrier discharges in α-γ mode ». Plasma Sources Science and Technology, 23 avril 2024. http://dx.doi.org/10.1088/1361-6595/ad4236.

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Abstract This work reports the results of an experimental and modelling study on dual-frequency Ar-NH3 dielectric barrier discharges (DBD) exhibiting the α – γ transition. A combination of space- and time-resolved optical absorption and emission spectroscopy is used to record spatio-temporal mappings of the Ar metastable number density, Ar 750.4 nm line emission intensity, and electron-Ar Bremsstrahlung continuum emission intensity. With the increase of the RF voltage amplitude in a 50 kHz-5 MHz DBD, maximum populations of Ar excited species (1s and 2p states, linked to the population of high-energy electrons) observed in the γ mode decrease and appear earlier in the low-frequency cycle. On the other hand, the density of the bulk electrons, monitored from the continuum emission intensity, increases, with a more prominent rise in the RF-α mode than in the γ regime. Such behaviors are consistent with the predictions of 1D fluid model and results from a decrease of the gas voltage required for self-maintenance of the cathode sheath in the γ breakdown.

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Salman, Baher I. « An Innovative Selective Fluorescence Sensor for Quantification of Hazardous Food Colorant Allura Red in Beverages Using Nitrogen-Doped Carbon Quantum Dots ». Journal of Fluorescence, 17 juin 2023. http://dx.doi.org/10.1007/s10895-023-03303-2.

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AbstractAn innovative simple, sensitive, and selective method has been developed and validated for quantification of hazardous Allura red (AR, E129) dye in beverages. Allura red (AR) is a synthetic dye that is commonly used in the food industry to give foods a bright and appealing color. The method is based on microwave-assistant nitrogen-doped carbon quantum dots (N@CQDs) from a very cheap source with a high quantum yield equal to (36.60%). The mechanism of the reaction is based on an ion-pair association complex between AR and nitrogen-doped carbon quantum dots (N@CQDs) at pH 3.2. The reaction between AR and N@CQDs led to a quenching effect of the fluorescence intensity of N@CQDs at 445 nm after excitation at 350 nm. Moreover, the quantum method’s linearity covered the range between 0.07 and 10.0 µg mL− 1 with a regression coefficient is 0.9992. The presented work has been validated by ICH criteria. High-resolution transmission electron microscopy (HR-TEM), X-ray photon spectroscopy (XPS), Zeta potential measurements, fluorescence, UV-VIS, and FTIR spectroscopy have all been used to fully characterize of the N@CQDs. The N@CQDs were successfully utilized in different applications (beverages) with high accuracy.

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Javed, Ahmed, Michael Jones, Stephen Campbell, Selcuk Yerci, Vincent Barrioz et Yongtao Qu. « In‐Depth Compositional Analysis of the Carbon‐Rich Fine‐Grain Layer in Solution‐Processed CZTSSe Films Accessed by a Photonic Lift‐Off Process ». Advanced Materials Interfaces, 4 décembre 2023. http://dx.doi.org/10.1002/admi.202300715.

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AbstractThe existence of a fine‐grain (FG) sub‐layer between the top large‐grain (LG) layer and the back contact is widely observed in kesterite absorbers prepared with organic solvents. In this paper, the distinguishing features of the lifted‐off carbon‐rich FG layer are investigated through direct analysis with a series of characterization techniques, including X‐ray photoelectron spectroscopy (XPS), attenuated total reflectance, X‐ray diffraction, and scanning electron microscopy. To access the FG layer for direct probing, a scalable and repeatable photonic lift‐off method is developed for carrying out the separation of the kesterite absorber layer from the Mo‐coated glass substrate. A very high light intensity of 4 kW cm−2 for a short interval of 1 ms is optimized by COMSOL simulations, and successful implementation is demonstrated. The XPS analysis has revealed significant carbon content at the exposed FG surface, which explains the hindrance of grain growth due to carbon abundance. The variations in cations and anions concentrations from FG layer leading into LG region are explored through argon ions (Ar+) assisted XPS depth profiling. The observed significant differences between the composition of FG and LG regions are speculated to negatively impact the performance of solar cells.

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Takeuchi, Masaya, Satoru Suzuki, Masaki Nakamura, Takashi Hata, Yusuke Nishiuchi, Kaori Tada et Noriaki Toyoda. « Highly sensitive electron-beam-induced X-ray detection from liquid using SiNx membrane ultrathinned by gas cluster ion beams ». Japanese Journal of Applied Physics, 7 juin 2024. http://dx.doi.org/10.35848/1347-4065/ad555f.

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Abstract We would like to improve detection sensitivity by making photoelectron transmission window (SiNx membrane) of liquid cell ultra-thin for liquid measurement using XPS or X-ray PEEM at UHV. In this study, thinning of the membrane using gas cluster ion beams (GCIB) was demonstrated and the burst pressure was compared with those thinned with atomic 400 eV Ar+ ions. It was shown that SiNx membranes thinned by GCIB was 2.5 times higher burst pressure than the Ar+ ions. In addition, improvement of sensitivity of characteristic X-ray from liquid-water induced by low-energy electrons was investigated. By using 4.5 nm thick SiNx membrane etched by GCIB, the X-ray intensity became 1.6 times higher than those from 11 nm thick pristine membrane at electron beam energy of 1.5 keV. This result showed good agreement with Monte Carlo simulation results of the electron-beam-induced X-ray emission from liquid-water beneath SiNx membrane.

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Koh, Seok-Keun, Sung-Chul Park, Chang-Kyu Choi, Seok-Kyun Song, Hyung-Jin Jung et Kook D. Pae. « Improving Adhesion of Polytetrafluoroethylene to Aluminum, Copper, and an Adhesive by Ar+ Irradiation with and without Oxygen Environment ». MRS Proceedings 396 (1995). http://dx.doi.org/10.1557/proc-396-335.

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AbstractA surface of thin square PTFE samples (1×1×0.2 cm3) was irradiated with Ar+ ion at 1 keV with varying ion dose from 5 x 1014 to 1 x 1017 ions/cm2 with and without oxygen environment. The chemical structure of the surface was examined by XPS. The high resolution XPS spectra showed decreased intensity of the Fls peak and formation of the Ol s peak when irradiated with O2 environment. The Ols peak reached the maximum height at the ion dose of 1 x l015 ions/cm2. The increase of the Ols peak may be attributed to the reaction of oxygen atoms and the free radicals created by Ar+ bombardment. Adhesion tests were conducted on 2000 Å thick Al or Cu film which was evaporated on the irradiated and unirradiated PTFE samples with and without O2 environment. Full detachment of the metal films was observed when PTFE samples were not modified. With regard to the Al film, partial detachment of the film occurred when PTFE was irradiated without O2 environment, regardless of ion dose. No detachment of the film occurred when PTFE was irradiated with O2 environment with the ion dose exceeding 1 x 1016 ions/cm2. As to the Cu film, partial detachment was observed with or without O2 environment when the ion dose was 5 x 1014 ions/cm2. No detachment occurred with or without O2 environment when the ion dose was 1 x 1015 ions/cm2 or greater. The adhesion of an adhesive (Crystal Bond) to the irradiated PTFE samples was found to increase significantly with increasing ion dose up to 1 x 1016 ions/cm2 in tensile tests. It appears that three separate mechanisms are at work in improving adhesion of Cu/PTFE and Al/PTFE system. The first is the surface roughness of PTFE caused by Ar+ bombardment, the second is the chemical changes on the PTFE surface, and the third is a change of the interface between the metal and PTFE. The wettability of the PTFE surface was also determined by dropping water droplets on the modified surfaces. The contact angle between water droplets and the irradiated surface of PTFE samples decreased with ion dose up to 1 x 1015ions/cm2, increased at higher dose, and finally increased to the extent that no wetting was possible at 1 x 1017 ions/cm2. The PTFE samples irradiated with Ar+ without O2 gas environment had lower contact angle than those with O2, even though the samples with O2 developed hydrophilic groups on the irradiated surface. This result on wettability is not consistent with our earlier results on PMMA and PC and is due to the unusually high level of surface roughness of PTFE caused by Ar+ bombardment.

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Rajeev, Anupoju, Lavish Pamwani, Shivam Ojha et Amit Shelke. « Adaptive Autoregressive Modelling Based Structural Health Monitoring of RC Beam-Column Joint Subjected to Shock Loading ». Structural Health Monitoring, 30 mai 2022, 147592172211013. http://dx.doi.org/10.1177/14759217221101325.

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In the present work, a novel technique based on the combination of singular spectral analysis (SSA) and recursive estimate of coefficients of adaptive autoregressive (AR) modelling is employed to identify the damage in the reinforced (RC) beam-column joints. The damage is induced by imparting shock load at the tip of the beam-column joints. The damage is identified with the help of the acceleration response of the healthy and damaged specimens excited by high intensity white noise. The proposed approach has two major components, first, filtering and removing the noise from the dynamic response using the singular spectral analysis and second, modelling the filtered response using adaptive AR process to get the recursive estimate of coefficient matrix for baseline and damage states. The coefficients evaluated for each time instant are presented in a multi-dimensional subspace to form distinct clusters corresponding to a healthy and damaged state. In order to identify and quantify the damage, the geometrical and statistical measures are evaluated that quantifies the segregation of clusters. In total, three distinct measures are used to quantify the damage, namely, Euclidean distance (ED), Mahalanobis distance (MD) and Bhattacharyya distance (BD). The BD accounts the variation in the distribution of both the clusters, thereby shows superior results comparatively than ED and MD. The results of DSFs also manifest the superiority of BD over the other two DSFs. These geometrical and statistical distances are the damage sensitive feature (DSF) to identify and quantify the damage in the specimen due to the shock load. The obtained results of all the DSFs show good consistency with the maximum deformation of the specimen due to shock loading highlighting the accuracy of the proposed algorithm.

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Yhdego, Haben, Nahom Kidane, Frederick Mckenzie et Michel Audette. « Development of deep-learning models for a hybrid simulation of auscultation training on standard patients using an ECG-based virtual pathology stethoscope ». SIMULATION, 29 mars 2023, 003754972311650. http://dx.doi.org/10.1177/00375497231165049.

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Cardiac auscultation (CA), the act of listening to the heart’s sound, is a critical skill that provides valuable information for identifying serious heart diseases. Proficiency in cardiac auscultation requires repeated stethoscope practice and experience in identifying abnormal or irregular cardiac rhythms. However, nowadays, most hospital admissions are short and intensely focused, with fewer opportunities for medical trainees to learn and practice bedside examination skills. It is common practice in many institutions to incorporate standardized patients (SPs) into CA training because these actors are able to represent the patient and convey the symptoms. However, SPs are typically healthy individuals, limiting the kinds of abnormalities that students can hear. In this work, we develop a novel real-time simulation-based method for virtual pathology stethoscope (VPS) detection. The VPS system uses augmented reality (AR) to teach medical students how to perform cardiac examinations by listening to abnormal heart sounds in SPs who are otherwise healthy. A digital stethoscope with two electrodes on the chest piece collects electrocardiogram (ECG) signal data sets from SPs at the four primary auscultation sites. Next, different deep-learning methods are evaluated for classifying the location of the stethoscope by taking advantage of subtle differences in the ECG signals. This study would significantly extend the simulation capabilities of SPs by allowing medical students and trainees to perform realistic CA and hear CA in a clinical environment.

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