Snow particle motion in process of cornice formation

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While gas aggregation cluster sources can tailor the chemistry, size, and shape of nanoparticles (NPs), low NP yield and instability over time still limit the fabrication of nanoparticle-based coatings or nanocomposite films. In this work, we propose controlled addition of ambient air as a nucleation source to enhance the efficiency and stability of the process. Additionally, the type of power source is varied, juxtaposing direct current and high-power impulse magnetron sputtering. Quadruple mass spectromet

In this work, we propose a polarization enhanced GaN vertical Schottky barrier diode (PE-SBD) with p-NiO/LiNiO junction termination extensions (JTEs). A thin, fully depleted p-InGaN layer is implemented at the metal/semiconductor interface to induce an opposite polarization field to reduce reverse leakage current. Furthermore, a junction termination structure is included based on high-quality conductive p-NiO/LiNiO, grown via low-temperature deposition processes, to decrease the electric field crowding at a

Abstract. A comprehensive study of aerosol exchange surface fluxes was conducted at a suburban site in Fairbanks (Alaska) during the Arctic winter as part of the ALPACA experiment. Aerosol fluxes were measured by an eddy covariance system on a snow-covered field located at the University of Alaska Fairbanks (UAF) Farm site from January 26th to February 17th, 2022. In general, bidirectional (emission and deposition) fluxes were measured at the site. Median deposition velocities were 0.61, 0.04, and 8.73 mm s

NiOx is widely used as a hole transport material in perovskite solar cells (PSCs). This wide band gap p-type material is conveniently deposited via high throughput RF-sputtering, making it suitable for the industrialization of PSCs. Nonetheless, for the cells to pass accelerated degradation tests such as the IEC 61215 damp heat (DH) test, the chemistry of the NiOx film should remain constant at elevated temperaturs to preserve its optoelectronic properties. This study emphasizes that structural defects resu

We present the equation of state for two classes of new ultralight particles, a scalar field coupling to electrons and a light

\mathbb {Z}_\mathcal {N}

QCD axion field coupling to nucleons. Both are potential candidates for dark matter. Using the scalar modified equations of state, we calculate models for white dwarf stars and compare their radii and masses with observed mass-radius data. The comparison results in stringent constraints on the masses of the particles and the coupling parameters. For a wide

This thesis explores the deposition of aluminium scandium nitride (AlScN) thin films on quartz substrates for tuning forks. The study is motivated by the superior piezoelectric properties of AlScN compared to tradition quartz tuning forks. Specifically, this research aims to take advantage of the high electromechanical coupling that AlScN demonstrates to improve the power efficiency of quartz tuning forks. The research methodology involves both analytical modeling and finite element simulations to compare

Imparting electrical functionalities onto curved surfaces is an area of research which has been gaining momentum recently as such structures can provide multi-purpose parts enabling their use as cuff electrodes in tissue engineering for electrical stimulation and recording or as printed circuit AM parts for 3D antennas. Transfer printing using an advanced stamp design and a laser assisted metal deposition approach have previously been used for metallic deposition on curved substrates. However, both techniqu

We discuss recent advances in developing a fundamental, mechanistic, understanding of the evolution of surface roughness of solids during dry sliding. The time evolution of surface roughness is little understood although it crucially impacts friction and wear. Engineering wear models are for the most part empirical, and the development of physics-based predictive models will require intensive experimental, theoretical and numerical research at various scales. This presentation focuses on atomistic and mesos

In the leading edge of a bidisperse gravity-driven granular flow, two opposing mechanisms coexist: size-segregation and mixing. As a result of shear-induced particle segregation, large particles are displaced to upper layers of the flow where they move faster towards the tip. Rapidly, they are dragged back, sticked to the bottom where they mix with small particles and are driven again to the upper layers, hence repeating the process. This recirculation phenomenon called breaking size-segregation wave is wel

We have successfully demonstrated the fabrication of self-actuating multilayer NEMS resonators including cantilevers and double clamped beams. Resonant sensors are widely used as precision mass sensors for the detection and quantification of small concentration of analyte molecules in a gaseous solution or bacteria from biological sample which requires extremely high mass sensitivity and responsivity of the resonant sensor. Nanofabrication techniques have enabled the use of ultrathin layers for the fabricat

We evaluate the performance of thin-film silicon micromorph tandem solar cells deposited on transparent superstrates with embossed micrometer-scale 2-D gratings. Once coated with a thin conductive layer of hydrogenated indium oxide, the textured superstrates can be used as 2-D periodic single-texture front electrodes. Combining these almost loss-free front electrodes with a highly transparent, random self-textured zinc oxide layer (with a thickness 1 um) deposited by low-pressure chemical vapor deposition (

This paper presents a novel probabilistic framework for localizing multiple speakers with a microphone array. In this framework, the generalized cross correlation function (GCC) of each microphone pair is interpreted as a probability distribution of the time difference of arrival (TDOA) and subsequently approximated as a Gaussian mixture. The distribution parameters are estimated with a weighted expectation maximization algorithm. Then, the joint distribution of the TDOA Gaussian mixtures is mapped to a mul

Microsimulation of urban transportation and land use evolution require base year, individual characteristics and disaggregate locations of the households and persons living in the study area. On the other hand, mainly due to privacy reasons, at best the census and travel survey, which are the primary sources of the data, provide only cross tabulations at various level of spatial aggregations (sector, commune, region, and country) and a small sample of the individual level information (microdata) that usuall

A systematic study of niobium oxide deposition using niobium tetraethoxy-dimethyl-amino-ethoxide (Nb(OEt)(4)(dmae)) precursor is presented. The deposition process was conducted in a high-vacuum chemical vapor deposition machine with precursor flux gradient capability. An efficient optimization of the deposition process was achieved and both mass-transport- and chemical-reaction-limited regimes were identified.

The role of secondary gas-phase reactions during plasma-enhanced chemical vapor deposition of microcrystalline silicon is a controversial subject. In this paper, we show that the enhancement of such reactions is associated with the improvement of material properties of absorber layers deposited at high constant rate. We detect powder, a product of secondary gas-phase reactions, via infrared laser absorption spectroscopy, laser light scattering, and optical emission spectroscopy. As the powder formation is i

Vertically aligned carbon nanotubes and nanofibers are grown on metallic Ta and Pd underlayers at temperatures below 500°C. Controlling the size of the grains of the underlayer film is critical because this leads to a more uniform distribution of catalyst dots, which in turn results in vertical alignment of the carbon nanostructures. Rapid and limited heating and appropriate materials selection can also be used to limit catalyst/underlayer reactions that hinder or suppress carbon nanostructure growth or tha

We investigated Si nanowires (SiNWs) fabricated by wet etching and chemical vapor deposition (CVD), and core-shell structures, formed by depositing silicon layers around the SiNWs, with respect to their crystallinity, the doping level, and the influence of surface passivation on carrier lifetime. The effects expected to be critical to improve the performance of nanowire-based solar cells are discussed. ©2010 IEEE.

In the first results of electron Bernstein wave heating (EBWH) via O-X-B double mode conversion in a medium aspect ratio tokamak performed in TCV, the total power absorption efficiency was typically 60% and the deposition was made off-axis to avoid the central sawteeth perturbation that would prevent a clear detection of the deposition location. Central power deposition is however needed to maximize the global EBWH effects. Therefore, initial experiments have been started to optimize central deposition usin

The growth dynamics of oxygen assisted focused electron beam induced deposition of Si-containing materials (from SiOxCy to SiO2) were investigated as a function of relevant process parameters. The results obtained from organosilanes of different families (alkoxy, alkyl, and isocyanatosilanes) are compared. Residual water molecules in the SEM chamber were found to be responsible for side reactions leading to carbon etching and oxygen incorporation in focused electron beam induced deposition (FEBID) materials

Thick film deposition of conductive, dielectric and resistive pastes on ceramic membranes is a cost effective technique to manufacture piezoresistive pressure sensors. Thick-film resistors consist of a percolating network of conductive oxide nanoparticles dispersed in an insulating glassy matrix, the electrical properties of which depend on firing conditions and composition. Ceramic membranes are appropriate to withstand the firing temperatures of thick-film materials, which are about 850°C. However brittle

Snow particle motion in process of cornice formation

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Morphology and yield of W nanoparticles in gas aggregation: Pathways towards functional nanocomposite films

Polarization Enhanced GaN SBDs with p-NiO/LiNiO Junction Termination Extensions Achieving 1 kV Breakdown Voltage

Aerosol dry deposition fluxes on snow during the ALPACA campaign in Fairbanks, Alaska

Stabilizing the Chemistry of NiOx in Perovskite Solar Cells to Pass the Damp Heat Test

New ultralight scalar particles and the mass-radius relation of white dwarfs - the important role of Sirius B

AlScN Thin Film Deposition on Quartz for Power Efficient Tuning Forks

Resist-free metal patterning inside 3D printed concave tubular structures using a flexible stencil

A mechanistic understanding of adhesive wear

Breaking size segregation waves in experimental bidisperse granular flows.

Design and Fabrication of Multilayer Piezoelectric NEMS Resonators

2-D Periodic and Random-on-Periodic Front Textures for Tandem Thin-Film Silicon Solar Cells

A Probabilistic Framework for Multiple Speaker Localization

Simulation based Approach for Agents Synthesis in Large-Scale Urban Systems Modelling

Efficient optimization of high vacuum chemical vapor deposition of niobium oxide on full wafer scale

Impact of secondary gas-phase reactions on microcrystalline silicon solar cells deposited at high rate

The critical role of the underlayer material and thickness in growing vertically aligned carbon nanotubes and nanofibers on metallic substrates by chemical vapor deposition

Structural, optical, and electrical properties of silicon nanowires for solar cells

Electron Bernstein Wave Core Deposition via O-X-B Double Mode Conversion in TCV

Oxygen assisted focused electron beam induced deposition of Si-containing materials: Growth dynamics

Development of pressure sensors by powder technology