Fractionation of solid component of welding aerosol

The design of portable filtration device with electrostatic filter and description of its work, which provides the trapping efficiency about 99.5% and fractionation of the polydisperse aerosol to four fractions via particles’ electrical mobility, are presented. The samples of aerosol particles’ fractions are obtained under usual welding regimes by welding wire Св08Г2С in CO2 and their specific surface area, element and phase compositions, phase ratio and crystallite sizes are determined. The correlation between fraction’s element composition and its specific surface area is demonstrated – the iron content is decreased, and manganese and silicon contents are increased when specific surface area is increased. The polyphase content (Fe3O4, FeO, FeMn2O4 и a-Fe are determined) and presence of the monocrystal nanosized magnetite particles, wustite and iron-manganese spinel in the fraction samples are confirmed by the X-ray analysis. The silicon compounds in particles are in amorphous state. The possibility of utilization of the nanostructured aerosol particles are proposed as a result of experimental data analysis.

Determination of the Error in Transferring of Length Unit’s Size when Measuring the Nanoparticles’ Diameter Using an Analyzer of Particles’ Differential Electrical Mobility

The quality of nanomaterials and nanotechnologies is largely determined by the stability of the applied technologies, which, to a large extent, depend on the constancy of particle sizes. In this regard, metrological problems arise that are associated both with measuring the dimensions of the microstructure of aerosols, suspensions and powders, and with ensuring the uniformity of measurements when transferring a unit of a physical quantity from a standard to working measuring instruments. The purpose of this work was to determine and calculate the error in transferring the size of a unit of length when measuring the diameter of nanoparticles.An analyzer of differential electric mobility of particles was determined as a reference measuring instrument for which the calculation was made. It allows the separation of aerosol particles based on the dependence of their electrical mobility on the particle size. In combination with a condensation particle counter, it allows you to scan an aerosol and build a particle size distribution function. This measurement method is the most accurate in the field of measuring the diameters of particles in aerosols, therefore, the error in the transmission of particle size must be set as for a standard.The paper describes the physical principles of measurement by this method and presents an equation for determining the diameter of nanoparticles. Based on this equation, the sources of non-excluded systematic error were identified. Also, an experimental method was used to determine the random component of the measurement error of nanoparticles and to calculate the error in transferring the size of a unit of length when measuring the diameter of nanoparticles.The obtained results will be used for metrological support of standard samples of particle size, ensuring traceability of measurements of aerosol particle counters and for aerosol research.

Laser enabled ultra-high doping patterns in graphene for rewritable photodetectors

Chemical doping has been extensively studied for control of charge carrier polarity and concentration in two-dimensional (2D) van der Waals materials. However, conventional routes by substitutional doping or absorbed molecules suffer from degradation of the electrical mobility due to structural disorder, while the maximum doping density is set by the solubility limit of dopants. Here, we show that laser assisted chlorination can achieve high doping concentration (> 3×1013 cm− 2) in graphene monolayer with minimal mobility drop, while holding reversibility and spatial selectivity. Such superior doping scheme is enabled by two lasers with selected photon energies and geometric configurations, resulting to high Cl coverage ratio (C2Cl) and subsequent local Cl-removal without damaging graphene. Based on this method, we demonstrate rewritable graphene photodetector, manifesting high quality reversible doping patterns in graphene. We believe that the presented results offer a new route for chemical doping of 2D materials that may enable exotic optoelectronic applications.

Frame Designing and Architecture of Electric dirt bike

A bike frame is also a non-standard structural component of a motorcycle linking various components of the vehicle systems and providing the vehicle rigidity and strength while running on various road conditions. This study is geared toward designing the frame of a two-wheeler, two-seater motorcycle for an electrical mobility purpose, while considering strength, safety and optimum performance of the vehicle. The said study has been allotted with a two-step approach. the first step includes modelling of the frame as per structural and ergonomic considerations, the design constraints governed by the front and rear suspension, steering and transmission systems and assemblies further because the determination of loads functioning on the frame. The second step is that the strain analysis using finite element analysis software and magnificence modifications for weight reduction without affecting structural strength. The main aim was to cut back the burden, centralize the load and lower the burden of the frame. Thus, the metal tubes were divided into primary, secondary and tertiary members supported the tube diameters and thicknesses so on reduce the final weight of the frame without affecting its strength. The centre of gravity of the frame is below the rider way thus ensuring an occasional and centralized frame weight. The trusses not only provide strength and rigidity but also safety of the actuation and essential vehicle components against impacts. The chassis is additionally a skeleton upon which parts like battery and motor are mounted. The two-wheeler chassis consists of a frame, suspension, wheels and brakes. The chassis is what truly sets the sort of the twowheeler. Commonly used material for two- wheeler chassis is steel which is heavy in weight or more accurately in density. There are various alternate materials like aluminium alloys, titanium, carbon fibre, magnesium, etc. which are lesser in weight and provide high strength and thus are often used for chassis. Keywords: Frame, Chassis, Finite element analysis, Analysis, Frequency Analysis, Swing arm.

Forecast of the Demand for Electric Mobility for Rome–Fiumicino International Airport

Following electrification of automotive transport, studies on the penetration of electric vehicles (EVs) are widespread, especially in defined contexts. As major transport hubs, airports fall within contexts worthy of interest. In this work, a forecast of the demand for electric mobility in an Italian international airport (Rome–Fiumicino) is presented. The main goal of the research is to build up a methodology that allows evaluating the penetration index of EVs that will access the airport parks in 2025 and 2030, to be able to have a preliminary assessment of the number of charging points necessary for serving them. In the paper, first, a wide review of proposed scenarios on the penetration of EVs at international and national level and available data on local automotive transport are presented, as a preliminary study for the definition of reference scenarios for the local context. Then, the proposed methodology is presented and applied to the specific case study. Finally, a preliminary sizing of the required charging infrastructure is reported. The results show that a significant impact on the airport electricity network can be foreseen, and it requires proper planning of adaptation/upgrading actions. The proposed approach can be considered as a reference for similar studies on electrical mobility in other airport areas around the world.

The nano-scanning electrical mobility spectrometer (nSEMS) and its application to size distribution measurements of 1.5–25 nm particles

Particle size measurement in the low nanometer regime is of great importance to the study of cloud condensation nuclei formation and to better understand aerosol–cloud interactions. Here we present the design, modeling, and experimental characterization of the nano-scanning electrical mobility spectrometer (nSEMS), a recently developed instrument that probes particle physical properties in the 1.5–25 nm range. The nSEMS consists of a novel differential mobility analyzer and a two-stage condensation particle counter (CPC). The mobility analyzer, a radial opposed-migration ion and aerosol classifier (ROMIAC), can classify nanometer-sized particles with minimal degradation of its resolution and diffusional losses. The ROMIAC operates on a dual high-voltage supply with fast polarity-switching capability to minimize sensitivity to variations in the chemical nature of the ions used to charge the aerosol. Particles transmitted through the mobility analyzer are measured using a two-stage CPC. They are first activated in a fast-mixing diethylene glycol (DEG) stage before being counted by a second detection stage, an ADI MAGIC™ water-based CPC. The transfer function of the integrated instrument is derived from both finite-element modeling and experimental characterization. The nSEMS performance has been evaluated during measurement of transient nucleation and growth events in the CLOUD atmospheric chamber at CERN. We show that the nSEMS can provide high-time- and size-resolution measurement of nanoparticles and can capture the critical aerosol dynamics of newly formed atmospheric particles. Using a soft x-ray bipolar ion source in a compact housing designed to optimize both nanoparticle charging and transmission efficiency as a charge conditioner, the nSEMS has enabled measurement of the contributions of both neutral and ion-mediated nucleation to new particle formation.

The Effect of RF Sputtering Temperature Conditions on the Structural and Physical Properties of Grown SbGaN Thin Film

By using a single ceramic SbGaN target containing a 14% Sb dopant, Sb0.14GaN films were successfully grown on n-Si(100), SiO2/Si(100), and quartz substrates by an RF reactive sputtering technology at different growth temperatures, ranging from 100 to 400 °C. As a result, the structural characteristics, and optical and electrical properties of the deposited Sb0.14GaN films were affected by the various substrate temperature conditions. By heating the temperature deposition differently, the sputtered Sb0.14GaN films had a wurtzite crystal structure with a preferential (101¯0) plane, and these Sb0.14GaN films experienced a structural distortion and exhibited p-type layers. At the highest depositing temperature of 400 °C, the Sb0.14GaN film had the smallest bandgap energy of 2.78 eV, and the highest hole concentration of 8.97 × 1016 cm−3, a conductivity of 2.1 Scm−1, and a high electrical mobility of 146 cm2V−1s−1. The p-Sb0.14GaN/n-Si heterojunction diode was tested at different temperatures, ranging from 25 to 150 °C. The testing data showed that the change of testing temperature affected the electrical characteristics of the diode.

Sizing response of the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) and Laser Aerosol Spectrometer (LAS) to changes in submicron aerosol composition and refractive index

We evaluate the sensitivity of the size calibrations of two commercially available, high-resolution optical particle sizers to changes in aerosol composition and complex refractive index (RI). The Droplet Measurement Technologies Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) and the TSI, Inc. Laser Aerosol Spectrometer (LAS) are two commonly used instruments for measuring the portion of the aerosol size distribution with diameters larger than nominally 60–90 nm. Both instruments illuminate particles with a laser and relate the single-particle light scattering intensity and count rate measured over a wide range of angles to the size-dependent particle concentration. While the optical block geometry and flow system are similar for each instrument, a significant difference between the two models is the laser wavelength (1054 nm for the UHSAS and 633 nm for the LAS) and intensity (about 100 times higher for the UHSAS), which may affect the way each instrument sizes non-spherical or absorbing aerosols. Here, we challenge the UHSAS and LAS with laboratory-generated, mobility-size-classified aerosols of known chemical composition to quantify changes in the optical size response relative to that of ammonium sulfate (RI of 1.52+0i at 532 nm) and NIST-traceable polystyrene latex spheres (PSLs with RI of 1.59+0i at 589 nm). Aerosol inorganic salt species are chosen to cover the real refractive index range of 1.32 to 1.78, while chosen light-absorbing carbonaceous aerosols include fullerene soot, nigrosine dye, humic acid, and fulvic acid standards. The instrument response is generally in good agreement with the electrical mobility diameter. However, large undersizing deviations are observed for the low-refractive-index fluoride salts and the strongly absorbing nigrosine dye and fullerene soot particles. Polydisperse size distributions for both fresh and aged wildfire smoke aerosols from the recent Fire Influence on Regional to Global Environments Experiment and Air Quality (FIREX-AQ) and the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex) airborne campaigns show good agreement between both optical sizers and contemporaneous electrical mobility sizing and particle time-of-flight mass spectrometric measurements. We assess the instrument uncertainties by interpolating the laboratory response curves using previously reported RIs and size distributions for multiple aerosol type classifications. These results suggest that, while the optical sizers may underperform for strongly absorbing laboratory compounds and fresh tailpipe emissions measurements, sampling aerosols within the atmospherically relevant range of refractive indices are likely to be sized to better than ±10 %–20 % uncertainty over the submicron aerosol size range when using instruments calibrated with ammonium sulfate.