scholarly journals Rock Sample Surface Preparation Influences Thermal Infrared Spectra

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 475 ◽  
Author(s):  
Evelien Rost ◽  
Christoph Hecker ◽  
Martin Schodlok ◽  
Freek van der Meer
Keyword(s):  
Surface Roughness ◽  
Rock Sample ◽  
Surface Preparation ◽  
Thermal Infrared ◽  
Sample Surface ◽  
Spectral Shape ◽  
Spectral Signature ◽  
Rock Surface ◽  
Spectral Signatures ◽  
Spectral Contrast

High-resolution laboratory-based thermal infrared spectroscopy is an up-and-coming tool in the field of geological remote sensing. Its spatial resolution allows for detailed analyses at centimeter to sub-millimeter scales. However, this increase in resolution creates challenges with sample characteristics, such as grain size, surface roughness, and porosity, which can influence the spectral signature. This research explores the effect of rock sample surface preparation on the thermal infrared spectral signatures. We applied three surface preparation methods (split, saw, and polish) to determine how the resulting differences in surface roughness affects both the spectral shape as well as the spectral contrast. The selected samples are a pure quartz sandstone, a quartz sandstone containing a small percentage of kaolinite, and an intermediate-grained gabbro. To avoid instrument or measurement type biases we conducted measurements on three TIR instruments, resulting in directional hemispherical reflectance spectra, emissivity spectra and bi-directional reflectance images. Surface imaging and analyses were performed with scanning electron microscopy and profilometer measurements. We demonstrate that surface preparation affects the TIR spectral signatures influencing both the spectral contrast, as well as the spectral shape. The results show that polished surfaces predominantly display a high spectral contrast while the sawed and split surfaces display up to 25% lower reflectance values. Furthermore, the sawed and split surfaces display spectral signature shape differences at specific wavelengths, which we link to mineral transmission features, surface orientation effects, and multiple reflections in fine-grained minerals. Hence, the influence of rock surface preparation should be taken in consideration to avoid an inaccurate geological interpretation.

scholarly journals Rock Sample Surface Preparation Influences Thermal Infrared Spectra

2018 ◽  
Author(s):  
Evelien Rost ◽  
Christoph Hecker ◽  
Martin C. Schodlok ◽  
Freek D. van der Meer
Keyword(s):  
Surface Roughness ◽  
Rock Sample ◽  
Surface Preparation ◽  
Thermal Infrared ◽  
Sample Surface ◽  
Spectral Shape ◽  
Spectral Signature ◽  
Rock Surface ◽  
Spectral Signatures ◽  
Spectral Contrast

High-resolution laboratory-based thermal infrared spectroscopy is an up-and-coming tool in the field of geological remote sensing. Its spatial resolution allows for detailed analyses at centimeter to sub-millimeter scale. However, this increase in resolution creates challenges with sample characteristics such as grain size, surface roughness and porosity that can influence the spectral signature. This research explores the effect of rock sample surface preparation on the TIR spectral signatures. We applied three surface preparation methods (split, saw and polish) to determine how the resulting differences in surface roughness affects both the spectral shape as well as the spectral contrast. The selected samples are a pure quartz sandstone, a quartz sandstone containing a small percentage of kaolinite, and an intermediate-grained gabbro. To avoid instrument or measurement type biases we conducted measurements on three TIR instruments, resulting in directional hemispherical reflectance spectra, emissivity spectra and bi-directional reflectance images. Surface imaging and analyses were performed with scanning electron microscopy and profilometer measurements. We demonstrate that surface preparation affects the TIR spectral signatures influencing both the spectral contrast as well as the spectral shape. The results show that polished surfaces predominantly display a high spectral contrast while the sawed and split surfaces display up to 25% lower reflectance values. Furthermore, the sawed and split surfaces display spectral signature shape differences at specific wavelengths, which we link to mineral transmission features, surface orientation effects and multiple reflections in fine-grained minerals. Hence, the influence of rock surface preparation should be taken in consideration to avoid an inaccurate geological interpretation.

Machining of a Rock Surface Shaver with a Piezoelectric Actuator forIn situAnalysis in Lunar and Planetary Exploration

2016 ◽  
Vol 10 (4) ◽  
pp. 533-539 ◽  
Author(s):  
Katsushi Furutani ◽  
◽  
Eiji Kagami ◽  
Keyword(s):  
Surface Roughness ◽  
Piezoelectric Actuator ◽  
Thrust Force ◽  
Sample Surface ◽  
Rock Surface ◽  
Composition Analysis ◽  
Machining Performance ◽  
Asteroid Exploration ◽  
Offset Voltage

Future lunar, planetary, and asteroid exploration will strongly demandin situanalysis of rock samples to obtain data related to various aspects. For precise composition analysis, a sample surface should be smoothed. In this paper, a surface shaver with a piezoelectric actuator is proposed and its machining performance in air is investigated. Shaving teeth are mounted at the ends of a pair of lever mechanisms. The device is pressed through four springs onto the workpiece with a linear actuator. When a sinusoidal voltage of 50 Vp-pand an offset voltage of 25 V were applied, the resonance frequency was 556 Hz and the unloaded amplitude of the shaving teeth was 0.77 mmp-p. Basalt workpieces were machined for 10 min in air. Increasing the thrust force reduced the surface roughness, although the amount removed diminished with a further increase in the thrust force. The surface roughness varied widely not only due to the amount removed but also due to containing the pores.

scholarly journals Percussive Rock Surface Remover Driven by Solenoid with Planer Motion for Lunar Exploration

2017 ◽  
Vol 29 (5) ◽  
pp. 911-918
Author(s):  
Katsushi Furutani ◽  
◽  
Hisashi Kamiishi
Keyword(s):  
Vibration Amplitude ◽  
Rock Sample ◽  
Sample Surface ◽  
Frequency Component ◽  
Rock Surface ◽  
Lunar Exploration ◽  
X Ray ◽  
Sample Paths ◽  
Laser Induced Breakdown ◽  
Large Vibration Amplitude

This paper deals with a percussive rock surface crusher driven with a solenoid to smoothen the sample surface by a 2-axis planar motion. The weathered rock surface should be removed and smoothened before analyzing its structure and composition precisely. The solenoid, which generates a large vibration amplitude and a large impulsive force, was used to vibrate a tool bit with engineered 1-mm pyramids made of tungsten carbide. The tool bit was fixed parallel to the feed direction or with a skew. A rock sample was moved by a stage with movable ranges for the machining of 10 mm and 20 mm in the x- and y-directions, respectively. The sample paths were randomly generated in 1 or 2 directions. In the comparisons of the surface roughness, the 2-axis motion and tool skew not only allowed isotropic and small roughness but also the removal of more amount due to the removed debris. The roughness reached several tens of micrometers without a certain special frequency component. This level allows for component analysis by X-ray fluorescence or laser-induced breakdown spectrometer.

scholarly journals Geometric correction for thermographic images of asteroid 162173 Ryugu by TIR (thermal infrared imager) onboard Hayabusa2

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Takehiko Arai ◽  
Tatsuaki Okada ◽  
Satoshi Tanaka ◽  
Tetsuya Fukuhara ◽  
Hirohide Demura ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Surface ◽  
Thermal Inertia ◽  
Thermal Infrared ◽  
Shape Model ◽  
Infrared Imager ◽  
Least Squares Fit ◽  
Temperature Maps ◽  
Pixel Scale ◽  
Thermal Infrared Imager

AbstractThe thermal infrared imager (TIR) onboard the Hayabusa2 spacecraft performed thermographic observations of the asteroid 162173 Ryugu (1999 JU$$_3$$ 3 ) from June 2018 to November 2019. Our previous reports revealed that the surface of Ryugu was globally filled with porous materials and had high surface roughness. These results were derived from making the observed temperature maps of TIR using a projection method onto the shape model of Ryugu as geometric corrections. The pointing directions of TIR were calculated using an interpolation of data from the SPICE kernels (NASA/NAIF) during the periods when the optical navigation camera (ONC) and the light detection and ranging (LIDAR) observations were performed. However, the mapping accuracy of the observed TIR images was degraded when the ONC and LIDAR were not performed with TIR. Also, the orbital and attitudinal fluctuations of Hayabusa2 increased the error of the temperature maps. In this paper, to solve the temperature image mapping problems, we improved the correction method by fitting all of the observed TIR images with the surface coordinate addressed on the high-definition shape model of Ryugu (SFM 800k v20180804). This correction adjusted the pointing direction of TIR by rotating the TIR frame relative to the Hayabusa2 frame using a least squares fit. As a result, the temperature maps spatially spreading areas were converged within high-resolved $$0.5^\circ$$ 0 . 5 ∘ by $$0.5^\circ$$ 0 . 5 ∘ maps. The estimated thermal inertia, for instance, was approximately 300$$\sim$$ ∼ 350 Jm$$^{-2}$$ - 2 s$$^{-0.5}$$ - 0.5 K$$^{-1}$$ - 1 at the hot area of the Ejima Saxum. This estimation was succeeded in case that the surface topographic features were larger than the pixel scale of TIR. However, the thermal inertia estimation of smooth terrains, such as the Urashima crater, was difficult because of surface roughness effects, where roughness was probably much smaller than the pixel scale of TIR.

scholarly journals Investigation of Two-Dimensional Ultrasonic Surface Burnishing Process on 7075-T6 Aluminum

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Zhenyu Zhou ◽  
Qiuyang Zheng ◽  
Cong Ding ◽  
Guanglei Yu ◽  
Guangjian Peng ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Parameter Optimization ◽  
Wear Mechanism ◽  
Feed Rate ◽  
Sample Surface ◽  
Original Sample ◽  
Two Dimensional ◽  
Delamination Wear ◽  
Treated Sample ◽  
Burnishing Process

AbstractA novel two-dimensional ultrasonic surface burnishing process (2D-USBP) is proposed. 7075-T6 aluminum samples are processed by a custom-designed 2D-USBP setup. Parameter optimization of 2D-USBP is conducted to determine the best processing strategy of 7075-T6 aluminum. A uniform design method is utilized to optimize the 2D-USBP process. U13(133) and U7(72) tables are established to conduct parameter optimization. Burnishing depth, spindle speed, and feed rate are taken as the control parameters. The surface roughness and Vickers hardness are taken as the evaluation indicators. It establishes the active control models for surface quality. Dry wear tests are conducted to compare the wear-resistance of the 2D-USBP treated sample and the original sample. Results show that the machining quality of 2D-USBP is best under 0.24 mm burnishing depth, 5000 r/min spindle speed, and 25 mm/min feed rate. The surface roughness Sa of the sample is reduced from 2517.758 to 50.878 nm, and the hardness of the sample surface is improved from 167 to 252 HV. Under the lower load, the wear mechanism of the 2D-USBP treated sample is mainly abrasive wear accompanied by delamination wear, while the wear mechanism of the original sample is mainly delamination wear. Under the higher load, the accumulation of frictional heat on the sample surface transforms the wear mechanisms of the original and the 2D-USBP treated samples into thermal wear.

scholarly journals Bondability of Beech Wood with One-component Polyurethane Structural Adhesive

2016 ◽  
Vol 12 (2) ◽  
pp. 135-144
Author(s):  
Norbert Horvath ◽  
Csilla Csiha
Keyword(s):  
Surface Roughness ◽  
Preliminary Investigation ◽  
Beech Wood ◽  
Surface Preparation ◽  
Dry Density ◽  
Pressing Time ◽  
Glued Laminated Timber ◽  
Adhesive Application ◽  
The University ◽  
Structural Adhesive

Abstract The bondability of beech (Fagus sylvatica L.) wood with a one-component polyurethane (1K PUR) structural (load-bearing) adhesive has been investigated at the Simonyi Károly Faculty at the University of West Hungary. Our trial is considered a preliminary investigation in order to set the convenient parameters of bonding for the structural gluing of beech wood. Wood samples were characterized by their oven dry density, and the surfaces to be bonded were characterized by their surface roughness and surface tension after machining. Based on our measurements, we have made a suggestion on the value of the ensemble of open time, applied quantity and pressure, pressing time, and surface preparation/surface roughness parameters which result in good bonding and a shear strength higher than 10 N/mm2. Furthermore, we investigated the penetration of the adhesive into the surface and state that one-sided adhesive application results in differing levels of penetration. In order to check the suitability of beech wood for glued laminated timber production, further investigations according to EN standards are necessary. Based upon the considerations noted above, delamination tests are already under evaluation.

scholarly journals Mobile Application Development for Spectral Signature of Weed Species in Rice Farming

2021 ◽  
Vol 29 (4) ◽  
Author(s):  
Nor Athirah Roslin ◽  
Nik Norasma Che’Ya ◽  
Nursyazyla Sulaiman ◽  
Lutfi Amir Nor Alahyadi ◽  
Mohd Razi Ismail
Keyword(s):  
Mobile Application ◽  
Near Infrared ◽  
Spectral Signature ◽  
Weed Species ◽  
Application Development ◽  
Spectral Signatures ◽  
Weed Infestation ◽  
Access Information ◽  
Master Builder ◽  
And Control

Weed infestation happens when there is intense competition between rice and weeds for light, nutrients and water. These conditions need to be monitored and controlled to lower the growth of weeds as they affected crops production. The characteristics of weeds and rice are challenging to differentiate macroscopically. However, information can be acquired using a spectral signature graph. Hence, this study emphasises using the spectral signature of weed species and rice in a rice field. The study aims to generate a spectral signature graph of weeds in rice fields and develop a mobile application for the spectral signature of weeds. Six weeds were identified in Ladang Merdeka using Fieldspec HandHeld 2 Spectroradiometer. All the spectral signatures were stored in a spectral database using Apps Master Builder, viewed using smartphones. The results from the spectral signature graph show that the jungle rice (Echinochloa spp.) has the highest near-infrared (NIR) reflectance. In contrast, the saromacca grass (Ischaemum rugosum) shows the lowest NIR reflectance. Then, the first derivative (FD) analysis was run to visualise the separation of each species, and the 710 nm to 750 nm region shows the highest separation. It shows that the weed species can be identified using spectral signature by FD analysis with accurate separation. The mobile application was developed to provide information about the weeds and control methods to the users. Users can access information regarding weeds and take action based on the recommendations of the mobile application.

Lubricated Wear of Machinable Lithium Disilicate Glass Ceramic

2017 ◽  
Vol 739 ◽  
pp. 18-22
Author(s):  
Laura Elbourne-Binns ◽  
Juan Carlos Baena ◽  
Ling Yin ◽  
Zhong Xiao Peng
Keyword(s):  
Surface Roughness ◽  
Glass Ceramic ◽  
Sliding Friction ◽  
Surface Preparation ◽  
Lithium Disilicate ◽  
Wear Volume ◽  
Oral Environment ◽  
Dry Conditions ◽  
Applied Forces ◽  
Lubrication Conditions

An experimental investigation was performed to study the wear of a promising dental ceramic, i.e., machinable lithium disilicate glass ceramic, under lubrication conditions, in particular, to examine effects of the surface finish and applied load on wear. Our previous work has shown that a fine finish in a dry condition did not necessarily translate to the lowest wear volume due to changes in the dominant wear mechanisms. This study tested the ceramic specimens with four average surface roughness values of Sa = 143 nm, 217 nm, 353 nm, and 692 nm on a reciprocating sliding friction rig against alumina balls with two applied forces of 5 N and 25 N in a bath of distilled water. Comparing with the results obtained in the dry conditions, this study shows that surface roughness of approximately 200 nm may be suitable for surface preparation of crowns made from the material in the wet and dry wear conditions in the oral environment.

scholarly journals Effects of micrometer-scale surface roughness on thermal infrared emittance spectra of silica glass

Icarus ◽  
2020 ◽  
Vol 350 ◽  
pp. 113868 ◽  
Author(s):  
Jeff A. Berger ◽  
Sherry L. Cady ◽  
Victoria E. Hamilton
Keyword(s):  
Surface Roughness ◽  
Silica Glass ◽  
Thermal Infrared ◽  
Micrometer Scale ◽  
Scale Surface

scholarly journals Morphological and Chemical Characterization of Titanium and Zirconia Dental Implants with Different Macro- and Micro-Structure

2020 ◽  
Vol 10 (21) ◽  
pp. 7520
Author(s):  
Maria Menini ◽  
Francesco Pera ◽  
Francesco Bagnasco ◽  
Francesca Delucchi ◽  
Elisa Morganti ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Dental Implants ◽  
Chemical Characterization ◽  
Sample Surface ◽  
Titanium Implants ◽  
Good Care ◽  
Micro Structure ◽  
Chemical Residues ◽  
Micro Structures

Background: The aim of this study was to evaluate the macro- and micro-structure and the chemical composition of the surface of 5 different commercially available dental implants. Roughness values were also calculated. Materials and Methods: 1 zirconia implant (NobelPearl of Nobel Biocare) and 4 titanium implants, Syra (Sweden&Martina), Prama (Sweden&Martina), T3 (Biomet 3i), and Shard (Mech&Human), were analyzed through SEM-EDX analysis and quantitative evaluation of surface roughness (1 sample), and XPS chemical analysis (1 sample). Surface roughness was quantitatively assessed using the stereo-SEM method (SSEM). The following area roughness parameters were calculated, according to ISO25178: Sa, Sz, and Sdr. Results: From the SEM observations, all the implants analyzed presented modern well-developed micro-structures as the result of the specific process of double acid etching alone or combined with other additional treatments. Roughness values were generally greater at the level of the implant body and lower at the collar. The chemical characterization of the implant surfaces exhibited excellent results for all of the implants and indicated good care in the production processes. Conclusions: All the samples were well-conceived in terms of topography and surface roughness, and clean in terms of chemical residues.

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