scholarly journals Three-dimensional mortar models using real-shaped sand particles and uniform thickness interfacial transition zones: Artifacts seen in 2D slices

2020 ◽  
Vol 236 ◽  
pp. 117590 ◽  
Author(s):  
Yang Lu ◽  
Md Aminul Islam ◽  
Stephen Thomas ◽  
Edward J. Garboczi
Keyword(s):  
Three Dimensional ◽  
Uniform Thickness ◽  
Transition Zones ◽  
Sand Particles

scholarly journals Conformal Fabrication of an Electrospun Nanofiber Mat on a 3D Ear Cartilage-Shaped Hydrogel Collector Based on Hydrogel-Assisted Electrospinning

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jin Yeong Song ◽  
Hyun Il Ryu ◽  
Jeong Myeong Lee ◽  
Seong Hwan Bae ◽  
Jae Woo Lee ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Electrospun Nanofibers ◽  
Cell Delivery ◽  
Complex Geometries ◽  
Two Dimensional ◽  
Uniform Thickness ◽  
Electrospun Nanofiber ◽  
Electrospinning Technique ◽  
Ear Cartilage ◽  
Focused Electric Field

AbstractElectrospinning is a common and versatile process to produce nanofibers and deposit them on a collector as a two-dimensional nanofiber mat or a three-dimensional (3D) macroscopic arrangement. However, 3D electroconductive collectors with complex geometries, including protruded, curved, and recessed regions, generally caused hampering of a conformal deposition and incomplete covering of electrospun nanofibers. In this study, we suggested a conformal fabrication of an electrospun nanofiber mat on a 3D ear cartilage-shaped hydrogel collector based on hydrogel-assisted electrospinning. To relieve the influence of the complex geometries, we flattened the protruded parts of the 3D ear cartilage-shaped hydrogel collector by exploiting the flexibility of the hydrogel. We found that the suggested fabrication technique could significantly decrease an unevenly focused electric field, caused by the complex geometries of the 3D collector, by alleviating the standard deviation by more than 70% through numerical simulation. Furthermore, it was experimentally confirmed that an electrospun nanofiber mat conformally covered the flattened hydrogel collector with a uniform thickness, which was not achieved with the original hydrogel collector. Given that this study established the conformal electrospinning technique on 3D electroconductive collectors, it will contribute to various studies related to electrospinning, including tissue engineering, drug/cell delivery, environmental filter, and clothing.

scholarly journals Petiole-Lamina Transition Zone: A Functionally Crucial but Often Overlooked Leaf Trait

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 774
Author(s):  
Max Langer ◽  
Thomas Speck ◽  
Olga Speck
Keyword(s):  
Transition Zone ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Body Plan ◽  
The Body ◽  
Vascular Bundles ◽  
Cross Sectional ◽  
Thin Sections ◽  
Transition Zones ◽  
The Cross

Although both the petiole and lamina of foliage leaves have been thoroughly studied, the transition zone between them has often been overlooked. We aimed to identify objectively measurable morphological and anatomical criteria for a generally valid definition of the petiole–lamina transition zone by comparing foliage leaves with various body plans (monocotyledons vs. dicotyledons) and spatial arrangements of petiole and lamina (two-dimensional vs. three-dimensional configurations). Cross-sectional geometry and tissue arrangement of petioles and transition zones were investigated via serial thin-sections and µCT. The changes in the cross-sectional geometries from the petiole to the transition zone and the course of the vascular bundles in the transition zone apparently depend on the spatial arrangement, while the arrangement of the vascular bundles in the petioles depends on the body plan. We found an exponential acropetal increase in the cross-sectional area and axial and polar second moments of area to be the defining characteristic of all transition zones studied, regardless of body plan or spatial arrangement. In conclusion, a variety of terms is used in the literature for describing the region between petiole and lamina. We prefer the term “petiole–lamina transition zone” to underline its three-dimensional nature and the integration of multiple gradients of geometry, shape, and size.

Research on Transition Zones of Spherical Surface Parts in 3D Rolling Process

2014 ◽  
Vol 687-691 ◽  
pp. 3-6
Author(s):  
Da Ming Wang ◽  
Ming Zhe Li ◽  
Zhong Yi Cai
Keyword(s):  
Sheet Metal ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Rolling Process ◽  
Experimental Results ◽  
Transition Zones ◽  
Spherical Surfaces ◽  
Sheet Width ◽  
Forming Precision ◽  
Roll Gap

3D rolling is a novel technology for three-dimensional surface parts. In this process, by controlling the gap between the upper and lower forming rolls, the sheet metal is non-uniformly thinned in thickness direction, and the longitudinal elongation of the sheet metal is different along the transverse direction, which makes the sheet metal generate three-dimensional deformation. In this paper, the transition zones of spherical surface parts in 3D rolling process are investigated. Spherical surface parts with the same widths but different lengths are simulated in condition of the same roll gap, and their experimental results are presented. The forming precision of forming parts and the causes of transition zones in the head and tail regions are analyzed through simulated results. The simulated and experimental results show that the lengths of transition zones of spherical surfaces in the head and tail regions are fixed values in condition of the same sheet width and roll gap.

A three-dimensional gravity model of the southern contact of the Sebago pluton, Maine

1998 ◽  
Vol 35 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Mark D Behn ◽  
J Dykstra Eusden, Jr. ◽  
John A Notte III
Keyword(s):  
Three Dimensional ◽  
Average Thickness ◽  
Uniform Thickness ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Metasedimentary Rocks ◽  
The North ◽  
Dimensional Gravity ◽  
Relationship Of ◽  
The Relationship

The Sebago pluton is a two-mica granite that intruded the metasedimentary rocks of the Central Maine Terrane around 292 Ma. In recent years, geologists have raised an increasing number of questions related to the overall thickness of the Sebago pluton and the position of its subsurface contact with the underlying metasedimentary rocks. Past studies have shown the Sebago pluton to be a thin, 1-2 km thick, subhorizontal sheet dipping 3° to the northeast. This study examines anomalies in the Earth's gravitational field related to the southern portion of the Sebago pluton, specifically to determine the thickness of the pluton and to locate the subsurface contact between the pluton and the underlying metasedimentary rocks. A three-dimensional model shows the thickest portions of the pluton (~1.8 km) to occur at the bottom of a bowl hape along the southwestern contact. Moreover, the model shows the pluton to thin toward the northern and eastern regions of the study area, where the average thickness is less than 0.5 km. The pluton appears to extend southward below the cover of the metasedimentary rocks along the southwestern contact. Thus, contrary to previous models, the Sebago pluton is not a northeasterly dipping sheet of uniform thickness, but rather an arched sheet with an irregular thickness extending beneath the metasedimentary rocks along both its northern and southern contacts. Based on this new geometry, either the relationship of the pluton to the surrounding metamorphic zones must be modified, or the possibility must be considered that the Sebago pluton is actually a composite batholith, composed of a younger (Permian) granite to the north and an older (Carboniferous) granite to the south.

A Photoelastic Study of Stresses in Rotating Disks

1940 ◽  
Vol 7 (2) ◽  
pp. A57-A60
Author(s):  
R. E. Newton
Keyword(s):  
Stress Analysis ◽  
Fringe Pattern ◽  
Three Dimensional ◽  
New Technique ◽  
Uniform Thickness ◽  
Rotating Disks ◽  
Photoelastic Method ◽  
Freezing Method ◽  
Stress Freezing Method

Abstract The recent experiments of Hetényi and others in developing a technique for “freezing” stresses in bakelite and other photoelastic plastics have broadened tremendously the scope of the photoelastic method of stress analysis. In addition to making possible the solution of three-dimensional problems, the new technique offers itself as a powerful tool in solving problems in which it is inconvenient to study the fringe pattern while the model is actually under load. Problems of centrifugal stresses in constant-speed rotors fall in this class and are readily handled by the stress-freezing method. It is the purpose of this paper to discuss the application of the technique to the determination of the stresses in rotating disks of uniform thickness having symmetrically placed noncentral holes, as shown in Fig. 1 (1, 2).

Development of Bionic Auditory Membrane With Non-Uniform Thickness for Acoustic Sensor With Wide-Range Frequency Selectivity

2011 ◽  
Author(s):  
Hirofumi Shintaku ◽  
Satoyuki Kawano
Keyword(s):  
Acoustic Wave ◽  
Three Dimensional ◽  
Frequency Selectivity ◽  
Acoustic Sensor ◽  
Uniform Thickness ◽  
Negative Photoresist ◽  
Wide Range ◽  
Novel Method ◽  
Eigen Frequencies ◽  
Photolithography Process

In this study, we propose a bionic auditory membrane (BAM) which realizes the wide-range frequency selectivity by non-uniform thick structure. BAM developed here is an acoustic sensor consisting of flexible bridges that vibrate by applying acoustic wave. BAM works as frequency analyzer via resonance of vibration; the eigen frequencies of bridges are changed by varying the dimensions such as the length and the thickness. To overcome difficulties in fabricating three-dimensional structures by conventional microfabrication, a novel method was developed using a grayscale lithography and a negative photoresist. The thicknesses of bridges are varied by different tones of grayscale patterns in a photomask. BAM consisting of 64 bridges with various thicknesses from 6.6 μm to 49 μm is successfully fabricated and integrated in 2.0 mm × 30 mm area by single photolithography process. The eigen frequencies of the vibration were measured in air. The results revealed that the range of the frequency selectivity is from 16.7 kHz to 502 kHz, which is drastically widened by the non-uniform thick bridges compared with the uniform ones.

Producing Three-Dimensional Shapes by Laser Milling

1990 ◽  
Vol 112 (4) ◽  
pp. 375-379 ◽  
Author(s):  
R. K. C. Hsu ◽  
S. M. Copley
Keyword(s):  
Carbon Dioxide ◽  
Laser Beam ◽  
Carbon Dioxide Laser ◽  
Three Dimensional ◽  
Milling Process ◽  
Model Material ◽  
Layer Plane ◽  
Uniform Thickness ◽  
Laser Milling ◽  
Focused Beam

A laser milling process employing a pulsed, carbon dioxide laser has been investigated using graphite as a model material. Material is removed by scanning the focused beam across the surface of the workpiece leaving behind a series of narrow, parallel, overlapping grooves. These grooves, together, constitute the removal of a thin layer of uniform thickness lying parallel to a layer plane. In order to remove layers bounded at the edge by upright walls perpendicular to the layer plane, the laser beam must be tilted with respect to the layer plane. Using this approach, it is possible to produce perpendicular steps and cylindrical surfaces.

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