Surface Texture Characterization of Metal Selective Laser Melted Part With Varying Surface Inclinations

Abstract Additive manufacturing offers the advantage of infinite freedom to design and fabricate complex parts at reduced lead-time. However, the surface quality of additively manufactured parts remains well behind the conventionally processed counterparts. This paper aims to systematically investigate the impact of varying surface inclination angles with respect to the build direction on the resultant surface textures. A bespoke metal truncheon artifact with inclination angles varying from 0 deg to 180 deg was built by selective laser melting. Focus variation microscopy was used to measure the topography of inclined surfaces with a tilt angle of up to 132 deg. The measurement data were then analyzed to characterize the staircase effect and the particles adherent to the artifact surface. Areal surface texture parameters, including height parameters, spatial parameters, functional parameters, and feature parameters, were explored to quantify the general surface topography, the staircase effect, and the particle features. The areal surface texture characterization and particle analysis reveal the resulted surface topographies are strongly correlated with the surface inclination angles.

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Effect of Cut-Off, Evaluation Length, and Measurement Area in Profile and Areal Surface Texture Characterization of As-Built Metal Additive Manufactured Components

Applied Sciences ◽

10.3390/app11115089 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5089

Author(s):

Arun Prasanth Nagalingam ◽

Moiz Sabbir Vohra ◽

Pulkit Kapur ◽

Swee Hock Yeo

Keyword(s):

Surface Texture ◽

Maximum Diameter ◽

Random Roughness ◽

Standard Values ◽

Texture Characterization ◽

Areal Surface ◽

Measurement Area ◽

Metal Additive ◽

Sem Analyses

Surface texture characterization of components built using additive manufacturing (AM) remains a challenge. The presence of various asperities and random roughness distributions across a surface poses several challenges to users in selecting an appropriate cut-off wavelength (λc), evaluation length (ln), and measurement area. This paper investigates a modified framework for surface texture characterization of AM components. First, the surface asperities in an AM component were identified through scanning electron microscope (SEM) analyses. The maximum diameter (φm) of the surface asperities were determined through image processing and were used as cut-off for surface texture evaluation. Second, another set of surface texture results were extracted using standard measurement procedures per ISO 4287, 4288, 25178-1, -2, and -3. Third, the investigative measurement framework’s effectiveness and suitability were explored by comparing the results with ISO standard results. Last, the effects of using non-standard cut-off wavelength, evaluation length, and measurement area during surface texture characterization were studied, and their percentage deviations from the standard values were discussed. The key findings prove that (a) the evaluation length could be compromised instead of cut-off, (b) measurement area must be 2.5 times the maximum asperity size present in the surface, and (c) it is possible to identify, distinguish, and evaluate specific features from the AM surface by selecting appropriate filters, thereby characterizing them specifically. The investigations and the obtained results serve as valuable data for users to select appropriate measurement settings for surface texture evaluation of AM components.

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Quantification of Non-Exhaust Particulate Matter Traffic Emissions and the Impact of COVID-19 Lockdown at London Marylebone Road

Atmosphere ◽

10.3390/atmos12020190 ◽

2021 ◽

Vol 12 (2) ◽

pp. 190

Author(s):

William Hicks ◽

Sean Beevers ◽

Anja H. Tremper ◽

Gregor Stewart ◽

Max Priestman ◽

...

Keyword(s):

Particulate Matter ◽

Measurement Data ◽

Emission Factors ◽

Meteorological Conditions ◽

Traffic Emissions ◽

Atmospheric Particulate Matter ◽

Exhaust Emission ◽

Brake Wear ◽

The Impact ◽

Exhaust Particulate

This research quantifies current sources of non-exhaust particulate matter traffic emissions in London using simultaneous, highly time-resolved, atmospheric particulate matter mass and chemical composition measurements. The measurement campaign ran at Marylebone Road (roadside) and Honor Oak Park (background) urban monitoring sites over a 12-month period between 1 September 2019 and 31 August 2020. The measurement data were used to determine the traffic increment (roadside–background) and covered a range of meteorological conditions, seasons, and driving styles, as well as the influence of the COVID-19 “lockdown” on non-exhaust concentrations. Non-exhaust particulate matter (PM)10 concentrations were calculated using chemical tracer scaling factors for brake wear (barium), tyre wear (zinc), and resuspension (silicon) and as average vehicle fleet non-exhaust emission factors, using a CO2 “dilution approach”. The effect of lockdown, which saw a 32% reduction in traffic volume and a 15% increase in average speed on Marylebone Road, resulted in lower PM10 and PM2.5 traffic increments and brake wear concentrations but similar tyre and resuspension concentrations, confirming that factors that determine non-exhaust emissions are complex. Brake wear was found to be the highest average non-exhaust emission source. In addition, results indicate that non-exhaust emission factors were dependent upon speed and road surface wetness conditions. Further statistical analysis incorporating a wider variability in vehicle mix, speeds, and meteorological conditions, as well as advanced source apportionment of the PM measurement data, were undertaken to enhance our understanding of these important vehicle sources.

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Analysis of High-Friction Surface Texture with Respect to Friction and Wear

Coatings ◽

10.3390/coatings11070758 ◽

2021 ◽

Vol 11 (7) ◽

pp. 758

Author(s):

Cibi Pranav ◽

Minh-Tan Do ◽

Yi-Chang Tsai

Keyword(s):

Friction Coefficient ◽

Surface Texture ◽

Safety Concern ◽

Future Research ◽

Scanning System ◽

Novel Approach ◽

Texture Parameters ◽

Aggregate Loss ◽

Friction Surfaces ◽

The Impact

High Friction Surfaces (HFS) are applied to increase friction capacity on critical roadway sections, such as horizontal curves. HFS friction deterioration on these sections is a safety concern. This study deals with characterization of the aggregate loss, one of the main failure mechanisms of HFS, using texture parameters to study its relationship with friction. Tests are conducted on selected HFS spots with different aggregate loss severity levels at the National Center for Asphalt Technology (NCAT) Test Track. Friction tests are performed using a Dynamic Friction Tester (DFT). The surface texture is measured by means of a high-resolution 3D pavement scanning system (0.025 mm vertical resolution). Texture data are processed and analyzed by means of the MountainsMap software. The correlations between the DFT friction coefficient and the texture parameters confirm the impact of change in aggregates’ characteristics (including height, shape, and material volume) on friction. A novel approach to detect the HFS friction coefficient transition based on aggregate loss, inspired by previous works on the tribology of coatings, is proposed. Using the proposed approach, preliminary outcomes show it is possible to observe the rapid friction coefficient transition, similar to observations at NCAT. Perspectives for future research are presented and discussed.

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A Statistical Modeling Methodology for Long-Term Wind Generation and Power Ramp Simulations in New Generation Locations

Energies ◽

10.3390/en11092442 ◽

2018 ◽

Vol 11 (9) ◽

pp. 2442 ◽

Cited By ~ 3

Author(s):

Jussi Ekström ◽

Matti Koivisto ◽

Ilkka Mellin ◽

Robert Millar ◽

Matti Lehtonen

Keyword(s):

Power Generation ◽

Wind Power ◽

Statistical Modeling ◽

Renewable Energy Sources ◽

Measurement Data ◽

Wind Power Generation ◽

System Level ◽

Wind Generation ◽

The Impact

In future power systems, a large share of the energy will be generated with wind power plants (WPPs) and other renewable energy sources. With the increasing wind power penetration, the variability of the net generation in the system increases. Consequently, it is imperative to be able to assess and model the behavior of the WPP generation in detail. This paper presents an improved methodology for the detailed statistical modeling of wind power generation from multiple new WPPs without measurement data. A vector autoregressive based methodology, which can be applied to long-term Monte Carlo simulations of existing and new WPPs, is proposed. The proposed model improves the performance of the existing methodology and can more accurately analyze the temporal correlation structure of aggregated wind generation at the system level. This enables the model to assess the impact of new WPPs on the wind power ramp rates in a power system. To evaluate the performance of the proposed methodology, it is verified against hourly wind speed measurements from six locations in Finland and the aggregated wind power generation from Finland in 2015. Furthermore, a case study analyzing the impact of the geographical distribution of WPPs on wind power ramps is included.

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Impacts of Large-Scale Circulation on Urban Ambient Concentrations of Gaseous Elemental Mercury in New York, USA

10.5194/acp-2017-176 ◽

2017 ◽

Cited By ~ 1

Author(s):

Huiting Mao ◽

Dolly Hall ◽

Zhuyun Ye ◽

Ying Zhou ◽

Dirk Felton ◽

...

Keyword(s):

New York ◽

North American ◽

Large Scale ◽

Measurement Data ◽

Elemental Mercury ◽

Urban Site ◽

Large Scale Circulation ◽

Gaseous Elemental Mercury ◽

The North ◽

The Impact

Abstract. The impact of large-scale circulation on urban gaseous elemental mercury (GEM) was investigated through analysis of 2008–2015 measurement data from an urban site in New York City (NYC), New York, USA. Distinct annual cycles were observed in 2009–2010 with mixing ratios in warm seasons (i.e. spring–summer) 10–20 ppqv (~ 10 %–25 %) higher than in cool seasons (i.e. fall–winter). This annual cycle was disrupted in 2011 by an anomalously strong influence of the North American trough in that warm season and was reproduced in 2014 with annual amplitude enhanced up to ~ 70 ppqv associated with a particularly strong Bermuda High. North American trough axis index (TAI) and intensity index (TII) were used to characterize the effect of the North American trough on NYC GEM especially in winter and summer. The intensity and position of the Bermuda High had a significant impact on GEM in warm seasons supported by a strong correlation (r reaching 0.96, p

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Probabilistic assessment of pile capacity based on CPTu probing including random pile foundation depth

MATEC Web of Conferences ◽

10.1051/matecconf/201819601058 ◽

2018 ◽

Vol 196 ◽

pp. 01058 ◽

Cited By ~ 5

Author(s):

Marek Wyjadłowski ◽

Irena Bagińska ◽

Jakub Reiner

Keyword(s):

Bearing Capacity ◽

Objective Assessment ◽

Probabilistic Approach ◽

Measurement Data ◽

Direct Methods ◽

Side Surface ◽

Design Stage ◽

Direct Data ◽

Design Calculations ◽

The Impact

The modern recognition of subsoil with the use of CPTu static probes allows to obtain detailed information necessary for the designing. Registered basic two quantities, i.e. cone resistance qc and friction on the sleeve fs, often become direct data, which allow to estimate bearing capacity of the base and the side surface of the pile. Direct methods use similarity of the pile work and piezo-cone work during the examination. An important design stage is the appropriate development of measurement data prior to the commencement of the procedure of determining the pile bearing capacity. Algorithms generated on the basis of empirical experiments are often applied with the simultaneous use of test loads. The probabilistic approach is also significant, because it enables objective assessment of the reliability level of performed design calculations. This work contains an analysis of the impact on the estimated bearing capacity and reliability of a pile of variable random depth of the pile base. It also includes the determination of probabilities of obtaining the assumed safety index for the designed solution at random foundation depth.

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Measurement experiences with FluxSet digital D/I station

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-6-279-2017 ◽

2017 ◽

Vol 6 (2) ◽

pp. 279-284 ◽

Cited By ~ 2

Author(s):

László Hegymegi ◽

János Szöllősy ◽

Csaba Hegymegi ◽

Ádám Domján

Keyword(s):

Measurement Method ◽

Measurement Data ◽

Digital Form ◽

New Instrument ◽

Measurement Results ◽

Inclination Angles ◽

Flux Gate

Abstract. Geomagnetic observatories use classical theodolites equipped with single-axis flux-gate magnetometers known as declination–inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method are very reliable but need a lot of handwork and experience. The authors developed and built a non-magnetic theodolite which gives all measurement data in digital form. Use of this instrument significantly decreases the possibility of observation errors and minimises handwork. The new instrument is presented in this paper together with first measurement results in comparison to the classical DIM.

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Sensitivity of modeled atmospheric nitrogen species to variations in sea salt emissions in the North and Baltic Sea regions

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-29705-2015 ◽

2015 ◽

Vol 15 (20) ◽

pp. 29705-29745

Author(s):

D. Neumann ◽

V. Matthias ◽

J. Bieser ◽

A. Aulinger ◽

M. Quante

Keyword(s):

Baltic Sea ◽

Atmospheric Chemistry ◽

Surf Zone ◽

Fine Particles ◽

Measurement Data ◽

Monitoring And Evaluation ◽

Sea Salt ◽

The North ◽

A Minor ◽

The Impact

Abstract. Coarse sea salt particles are emitted ubiquitously from the oceans' surfaces by wave breaking and bubble bursting processes. These particles impact atmospheric chemistry by affecting condensation of gas-phase species and nucleation of new fine particles, particularly in regions with high air pollution. In this study, atmospheric particle concentrations are modeled for the North and Baltic Sea regions, Northwestern Europe, using the Community Multiscale Air Quality (CMAQ) modeling system and evaluated against European Monitoring and Evaluation Programme (EMEP) measurement data. As model extension, sea salt emissions are scaled by water salinity because of low salinity in large parts of the Baltic Sea and in certain river estuaries. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is separately considered. Additionally, the impact of sea salt particles on atmospheric nitrate, ammonium and sulfate concentrations is evaluated. The comparisons show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated when going inland. The introduced salinity scaling improves predicted Baltic Sea sea salt concentrations considerably. Dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to a minor increase of NH4+ and NO3- and a minor decrease of SO42- concentrations. However, the overall effect is very low and lower than the deviation from measurements. Size resolved measurements of Na+, NH4+, NO3-, and SO42- are needed for a more detailed analysis on the impact of sea salt particles.

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Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

10.21203/rs.3.rs-92597/v1 ◽

2020 ◽

Author(s):

Xiaoyu Wang ◽

Peng Liu ◽

Gongwen Xu

Keyword(s):

Cfd Simulation ◽

Simulation Analysis ◽

Thermal Environment ◽

Measurement Data ◽

Ground Temperature ◽

Rapid Urbanization ◽

Actual Measurement ◽

Heritage Sites ◽

Human Thermal Comfort ◽

The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

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THE EFFECTS OF ENVIRONMENTAL ISSUES ON RESIDENTIAL HOUSE PRICE (IN THE CASE OF ULAANBAATAR CITY)

Proceedings of the Mongolian Academy of Sciences ◽

10.5564/pmas.v58i2.1011 ◽

2018 ◽

pp. 117-130

Author(s):

Oyunjargal D ◽

Byambatseren Ch

Keyword(s):

Air Quality ◽

Quality Index ◽

House Price ◽

Measurement Data ◽

Quality Measurement ◽

Air Quality Index ◽

Quality Level ◽

Average Price ◽

Residential House ◽

The Impact

The purpose of this research is to determine the impact of the environment, especially the quality of air on house price. In addition, it also includes the research of the linkage between the index of air quality and average price of residential house which located in the most crowded districts of Ulaanbaatar such as Bayangol, Bayanzurkh, Chingeltei, Sukhbaatar, Songinokhairkhan and Khan-Uul. The statistical analysis and statistics determination methods were applied to identify the relationship utilizing the air quality index, determined from the air quality measurement data recorded in 2015-2017, and the average price per square meter of newly built apartment houses in the selected districts. The research findings suggest that there is little direct link between the house prices and air quality level, and the air quality levels of Ulaanbaatar districts do not have a significant impact on the price per square meter. Therefore, the air quality index should not considered as a house price determinant.

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