scholarly journals 3D‐Printed Strong Dental Crown with Multi‐Scale Ordered Architecture, High‐Precision, and Bioactivity

2021 ◽  
pp. 2104001
Author(s):  
Menglu Zhao ◽  
Danlei Yang ◽  
Suna Fan ◽  
Xiang Yao ◽  
Jiexin Wang ◽  
...  
Keyword(s):  
High Precision ◽  
Multi Scale ◽  
3D Printed ◽  
Dental Crown

Study on 3D printed graphene/carbon fiber multi-scale reinforced PLA Composites

2021 ◽  
pp. 130173
Author(s):  
Li Liang ◽  
Tao Huang ◽  
Songxiang Yu ◽  
Weiwei Cao ◽  
Tingting Xu
Keyword(s):  
Carbon Fiber ◽  
Multi Scale ◽  
3D Printed

scholarly journals Multi-Scale Studies of 3D Printed Mn–Na–W/SiO2 Catalyst for Oxidative Coupling of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 290
Author(s):  
Tim Karsten ◽  
Vesna Middelkoop ◽  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Stephen Poulston ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Oxidative Coupling Of Methane ◽  
Operating Conditions ◽  
Homogeneous Distribution ◽  
Silica Support ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Multi Scale ◽  
3D Printed

This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO2 catalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support.

scholarly journals Characterization of surface topography of 3D printed parts by multi-scale analysis

2017 ◽  
Vol 12 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
Yann Quinsat ◽  
Claire Lartigue ◽  
Christopher A. Brown ◽  
Lamine Hattali
Keyword(s):  
Surface Topography ◽  
Scale Analysis ◽  
Multi Scale ◽  
3D Printed ◽  
Multi Scale Analysis

Imaging damage zones and fault growth processes with high-precision relocations of earthquake sequences.

2021 ◽  
Author(s):  
Pierre Henry ◽  
Anthony Lomax ◽  
Sophie VIseur
Keyword(s):  
High Precision ◽  
Slip Surface ◽  
Shear Crack ◽  
Damage Zone ◽  
Normal Faulting ◽  
Multi Scale ◽  
Crack System ◽  
Stress Changes ◽  
Background Seismicity ◽  
Earthquake Sequences

<p>The architecture of fault damage zones combines various elements. Halos of intense fracturing forms around principal slip planes, possibly resulting from the shearing of slip surface rugosity or from dynamic stresses caused by earthquake ruptures. Splays forming off the tips and off the edges of a growing fault result in larger scale fracture networks and damage zones. Faults also grow by coalescence of en-echelon segments, such as Riedel fractures in a shear zone, and stress concentration at the steps results in linking damage zones. We show that these various elements of a shear-crack system can be recognized at seismogenic depth in earthquake sequences. Here we examine high-precision, absolute earthquake relocations for the Mw5.7 Magna UT, Mw6.4 Monte Cristo CA and Mw 5.8 Lone Pine CA earthquake sequences in 2020. We use iterative, source-specific, station corrections to loosely couple and improve event locations, and then waveform similarity between events as a measure for strongly coupling probabilistic event locations between multiplet events to greatly improve precision (see presentation EGU21-14608, and Lomax, 2020). The relocated seismicity shows mainly sparse clusters of seismicity, from which we infer multi-scale fault geometries. The uncertainty on earthquake locations (a few hundred meters) is typically larger than the width of halo damage zones observed in the field so that it is not possible to distinguish small aftershocks that could occur on a fracture within the halo or on a principal slip plane.</p><p>The relocated Magna seismicity shows a west-dipping, normal-faulting mainshock surface with an isolated, mainshock hypocenter at its base, surrounded up-dip in the hanging wall by a chevron of complex, clustered seismicity, likely related to secondary fault planes. This seismicity and a shallower up-dip cluster of aftershock seismicity correspond to clusters of background seismicity. The Lone Pine seismicity defines a main, east-dipping normal-faulting surface whose bottom edge connects to a steeper dipping splay, surrounded by a few clusters of background and reactivated seismicity. The space-time relation between background seismicity and multi-scale, foreshock-mainshock sequences are clearly imaged. The Monte Cristo Range seismicity (Lomax 2020) illuminates two, en-echelon primary faulting surfaces and surrounding, characteristic shear-crack features such as edge, wall, tip, and linking damage zones, showing that this sequence ruptured a complete shear crack system. In this example the width of the damage zone increases toward the earth surface.  Shallow damage zones align with areas of dense surface fracturing, subsidence and after-slip, showing the importance of damage zones for shaking intensity and earthquake hazard.</p><p>For all three sequences, some of the seismicity clusters delineate planar surfaces and concentrate along the edges of the suspected main slip patches. Other clusters of seismicity may result from larger scale damage associated with splay faults, en-echelon systems and linking zones, or with zones of background seismicity reactivated by stress changes from mainshock rupture. These types of seismicity and faulting structures may be more developed in the case of a complex rupture on an immature fault</p><p>__<br>Lomax (2020) The 2020 Mw6.5 Monte Cristo Range, Nevada earthquake: relocated seismicity shows rupture of a complete shear-crack system. https://eartharxiv.org/repository/view/1904</p>

scholarly journals Wearable Augmented Reality Platform for Aiding Complex 3D Trajectory Tracing

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1612 ◽  
Author(s):  
Sara Condino ◽  
Benish Fida ◽  
Marina Carbone ◽  
Laura Cercenelli ◽  
Giovanni Badiali ◽  
...  
Keyword(s):  
Augmented Reality ◽  
High Precision ◽  
Ad Hoc ◽  
User Study ◽  
Peripersonal Space ◽  
Planar Structures ◽  
3D Printed ◽  
Quantitative Results ◽  
Manual Tasks ◽  
Wearable Augmented Reality

Augmented reality (AR) Head-Mounted Displays (HMDs) are emerging as the most efficient output medium to support manual tasks performed under direct vision. Despite that, technological and human-factor limitations still hinder their routine use for aiding high-precision manual tasks in the peripersonal space. To overcome such limitations, in this work, we show the results of a user study aimed to validate qualitatively and quantitatively a recently developed AR platform specifically conceived for guiding complex 3D trajectory tracing tasks. The AR platform comprises a new-concept AR video see-through (VST) HMD and a dedicated software framework for the effective deployment of the AR application. In the experiments, the subjects were asked to perform 3D trajectory tracing tasks on 3D-printed replica of planar structures or more elaborated bony anatomies. The accuracy of the trajectories traced by the subjects was evaluated by using templates designed ad hoc to match the surface of the phantoms. The quantitative results suggest that the AR platform could be used to guide high-precision tasks: on average more than 94% of the traced trajectories stayed within an error margin lower than 1 mm. The results confirm that the proposed AR platform will boost the profitable adoption of AR HMDs to guide high precision manual tasks in the peripersonal space.

On Scale Correction Model of Coastline and its Application for Coastline Remote Sensing Monitoring

2013 ◽  
Vol 303-306 ◽  
pp. 734-739
Author(s):  
Hua Guo Zhang ◽  
Dong Ling Li ◽  
Ai Qin Shi
Keyword(s):  
Remote Sensing ◽  
High Precision ◽  
Coastal Zone ◽  
Absolute Error ◽  
Correction Method ◽  
Remote Sensing Images ◽  
Correction Model ◽  
Remote Sensing Monitoring ◽  
Multi Scale ◽  
Map Scale

This paper focuses on the scale correction of coastline extracted from remote sensing images. Measurement of coastline is one of the basic and core work of coastal zone remote sensing monitoring projects. Based on analysis of coastline scale effect and multi-scale simulation of coastline, a scale correction method is presented for remote sensing coastline. This method can be used to correct remote sensing coastline to specified map scale, in order to obtain high-precision remote sensing monitoring results of coastline. The results of application example showed that the absolute error of coastline length is reduced to about one third of the original error after correction using the presented method. So the presented method can increase the accuracy of remote sensing coastline for specified scale substantially.

scholarly journals Mapping snow depth within a tundra ecosystem using multiscale observations and Bayesian methods

2016 ◽  
Author(s):  
Haruko M. Wainwright ◽  
Anna K. Liljedahl ◽  
Baptiste Dafflon ◽  
Craig Ulrich ◽  
John E. Peterson ◽  
...  
Keyword(s):  
High Precision ◽  
Snow Depth ◽  
Spatial Sampling ◽  
Multi Scale ◽  
Arctic Alaska ◽  
Winter Snow ◽  
Digital Elevation ◽  
Tundra Ecosystem ◽  
Ice Wedge ◽  
Ground Penetrating

Abstract. This paper compares and integrates different strategies to characterize the variability of end-of-winter snow depth and its relationship to topography in ice-wedge polygon tundra of Arctic Alaska. Snow depth was measured using in situ snow depth probes, and estimated using ground penetrating radar (GPR) surveys and the Photogrammetric Detection and Ranging (PhoDAR) technique with an unmanned aerial system (UAS). We found that GPR data provided high-precision estimates of snow depth (RMSE = 2.9 cm), with a spatial sampling of 10 cm along transects. UAS-based approaches provided snow depth estimates in a less laborious manner compared to GPR and probing while yielding a high precision (RMSE = 6.0 cm) and a fine spatial sampling (4 cm by 4 cm). We then investigated the spatial variability of snow depth and its correlation to micro- and macrotopography using the snow-free LiDAR digital elevation map (DEM) and the wavelet approach. We found that the end-of-winter snow depth was highly variable over short (several meter) distances, and the variability was correlated with microtopography. Microtopographic lows (i.e., troughs and centers of low-centered polygons) were filled in with snow, which resulted in a smooth and even snow surface following macrotopography. We developed and implemented a Bayesian approach to integrate the snow-free LiDAR DEM and multi-scale measurements (probe and GPR) as well as the topographic correlation for estimating snow depth over the landscape. Our approach led to high precision estimates of snow depth (RMSE = 6.0 cm), at 0.5-meter resolution and over the LiDAR domain (750 m by 700 m).

Advanced 3D-printed EAP actuator applied to high precision large optical-quality surface fabrication: first results

2020 ◽  
Author(s):  
Kritsadi Thetpraphi ◽  
Gil Moretto ◽  
Jeffrey R. Kuhn ◽  
Pierre-Jean Cottinet ◽  
Minh-Quyen Le ◽  
...  
Keyword(s):  
High Precision ◽  
Optical Quality ◽  
First Results ◽  
3D Printed ◽  
Surface Fabrication ◽  
Quality Surface
Sign in / Sign up

Export Citation Format

Share Document