Achieving superior performance in thermoelectric Bi0.4Sb1.6Te3.72 by enhancing texture and inducing high-density line defects

Abstract Due to its outstanding properties, SiC is a candidate material for use in special applications such as armor. In order to use SiC in these special applications, it is necessary to produce fully dense ceramics. The ability to produce high density materials with superior performance depends on a number of factors. One of these factors is the addition of carbon to aid sintering. In this study, the effect of different carbon sources and ratios on the elastic and mechanical properties of SiC was investigated. Two types of carbon (lamp black and phenolic resin) were added to SiC in different ratios (0-2% for 15 minutes under 50 MPa pressure. Samples made with lamp black were reached full density at 1.0 wt.%C, and the hardness and elastic modulus values were ~22GPa and 440GPa,respectively. While samples made with both carbon sources showed similar bulk mechanical properties, the samples made with lamp black showed more consistent microstructures. The carbon from the Phonelic resin source did not appear to be as well distributed as that from the lamp black source. The results also confirmed that addition of carbon into SiC was essential to improve the density and other mechanical properties associated with it.

Download Full-text

X-Ray Diffraction Topographic Observations of the Large-Angle Grain Boundary in Ice Under Deformation

Journal of Glaciology ◽

10.3189/s0022143000033748 ◽

1978 ◽

Vol 21 (85) ◽

pp. 629-638

Author(s):

T. Hondoh ◽

A. Higashi

Keyword(s):

Coincidence Site Lattice ◽

Large Angle ◽

Parallel Line ◽

High Density ◽

X Ray Diffraction ◽

X Ray ◽

Time Period ◽

Different Types ◽

Line Defects ◽

Misorientation Angles

AbstractLarge-angle tilt grain boundaries in artificially-grown ice bicrystals were observed by the method of X-ray diffraction topography. In bicrystals for which misorientation angles satisfy the conditions of a high-density coincidence site lattice (CSL) at the boundary, the images of fine parallel line defects appear on the topograph taken immediately after a light deformation. Since these images disappear in a time period between several hours and a few days and reappear again at the same sites when the specimen is deformed subsequently, it is concluded that these line defects are not stable like the boundary dislocations but may be steps generated on the boundary to form facets which coincide with the high-density CSL plane. X-ray topographic images of boundaries which do not satisfy the conditions of a high density CSL are complex and difficult to interpret, although some of the images indicate that there may be different types of structures on such boundaries.

Download Full-text

Spatial Distribution of Spray from a Solid Set Canopy Delivery System in a High-Density Apple Orchard Retrofitted with Modified Emitters

Applied Sciences ◽

10.3390/app11020709 ◽

2021 ◽

Vol 11 (2) ◽

pp. 709

Author(s):

Rakesh Ranjan ◽

Rajeev Sinha ◽

Lav R. Khot ◽

Gwen-Alyn Hoheisel ◽

Matthew Grieshop ◽

...

Keyword(s):

Spray Deposition ◽

Delivery Systems ◽

Apple Orchard ◽

High Density ◽

Superior Performance ◽

Hollow Cone ◽

Perennial Crop ◽

Laboratory Assessment ◽

Leaf Surfaces ◽

Tracer Solution

Solid Set Canopy Delivery Systems (SSCDS) are fixed agrochemical delivery systems composed of a network of micro-sprayers/nozzles distributed in perennial crop canopies. A previous SSCDS design composed of a 3-tier configuration using hollow cone sprayer nozzles has been shown to provide excellent coverage and deposition in high-density apple orchards. However, the hollow cone nozzles substantially increases the initial system installation costs. This study evaluated the effect of irrigation micro-emitters replacement on spray deposition, coverage and off-target drift. A micro-emitter used in greenhouse irrigation systems was duly modified to enhance its applicability with SSCDS. After laboratory assessment and optimization of the micro-emitters, a replicated field study was conducted to compare 3-tier SSCDS configured with either of modified irrigation micro-emitters or traditional hollow cone nozzles. Canopy deposition and off target drift were evaluated using a 500 ppm fluorescent tracer solution sprayed by the field installed systems and captured on mylar collectors. Spray coverage was evaluated using water sensitive papers. The overall canopy deposition and coverage for treatment configured with modified irrigation micro-emitters (955.5 ± 153.9 [mean ± standard error of mean] ng cm−2 and 22.7 ± 2.6%, respectively) were numerically higher than the hollow cone nozzles (746.2 ± 104.7 ng cm−2 and 19.0 ± 2.8%, respectively). Moreover, modified irrigation micro-emitter SSCDS had improved spray uniformity in the canopy foliage and on either side of leaf surfaces compared to a hollow cone nozzle. Ground and aerial spray losses, quantified as deposition, were numerically lower for the modified irrigation micro-emitter (121.8 ± 43.4 ng cm−2 and 0.7 ± 0.1 ng cm−2, respectively) compared to the traditional hollow cone nozzle (447.4 ± 190.9 ng cm−2 and 3.2 ± 0.4 ng cm−2, respectively). Overall, the modified irrigation micro-emitter provided similar or superior performance to the traditional hollow cone nozzle with an estimated 12 times reduction in system installation cost.

Download Full-text

Optimizing the use of reactive terpolymer, polyphosphoric acid and high-density polyethylene to achieve asphalt binders with superior performance

Construction and Building Materials ◽

10.1016/j.conbuildmat.2018.02.206 ◽

2018 ◽

Vol 169 ◽

pp. 522-529 ◽

Cited By ~ 11

Author(s):

Dennyele A. Gama ◽

Yu Yan ◽

John Kennedy G. Rodrigues ◽

Reynaldo Roque

Keyword(s):

High Density Polyethylene ◽

Polyphosphoric Acid ◽

High Density ◽

Superior Performance ◽

Asphalt Binders

Download Full-text

Logging Trail Segmentation via a Novel U-Net Convolutional Neural Network and High-Density Laser Scanning Data

Remote Sensing ◽

10.3390/rs14020349 ◽

2022 ◽

Vol 14 (2) ◽

pp. 349

Author(s):

Omid Abdi ◽

Jori Uusitalo ◽

Veli-Pekka Kivinen

Keyword(s):

Laser Scanning ◽

High Density ◽

Superior Performance ◽

Surface Model ◽

Digital Surface Model ◽

Commercial Thinning ◽

Digital Elevation ◽

Main Components ◽

Mature Stands ◽

Height Model

Logging trails are one of the main components of modern forestry. However, spotting the accurate locations of old logging trails through common approaches is challenging and time consuming. This study was established to develop an approach, using cutting-edge deep-learning convolutional neural networks and high-density laser scanning data, to detect logging trails in different stages of commercial thinning, in Southern Finland. We constructed a U-Net architecture, consisting of encoder and decoder paths with several convolutional layers, pooling and non-linear operations. The canopy height model (CHM), digital surface model (DSM), and digital elevation models (DEMs) were derived from the laser scanning data and were used as image datasets for training the model. The labeled dataset for the logging trails was generated from different references as well. Three forest areas were selected to test the efficiency of the algorithm that was developed for detecting logging trails. We designed 21 routes, including 390 samples of the logging trails and non-logging trails, covering all logging trails inside the stands. The results indicated that the trained U-Net using DSM (k = 0.846 and IoU = 0.867) shows superior performance over the trained model using CHM (k = 0.734 and IoU = 0.782), DEMavg (k = 0.542 and IoU = 0.667), and DEMmin (k = 0.136 and IoU = 0.155) in distinguishing logging trails from non-logging trails. Although the efficiency of the developed approach in young and mature stands that had undergone the commercial thinning is approximately perfect, it needs to be improved in old stands that have not received the second or third commercial thinning.

Download Full-text

X-Ray Diffraction Topographic Observations of the Large-Angle Grain Boundary in Ice Under Deformation

Journal of Glaciology ◽

10.1017/s0022143000033748 ◽

1978 ◽

Vol 21 (85) ◽

pp. 629-638 ◽

Cited By ~ 9

Author(s):

T. Hondoh ◽

A. Higashi

Keyword(s):

Coincidence Site Lattice ◽

Large Angle ◽

Parallel Line ◽

High Density ◽

X Ray Diffraction ◽

X Ray ◽

Time Period ◽

Different Types ◽

Line Defects ◽

Misorientation Angles

Abstract Large-angle tilt grain boundaries in artificially-grown ice bicrystals were observed by the method of X-ray diffraction topography. In bicrystals for which misorientation angles satisfy the conditions of a high-density coincidence site lattice (CSL) at the boundary, the images of fine parallel line defects appear on the topograph taken immediately after a light deformation. Since these images disappear in a time period between several hours and a few days and reappear again at the same sites when the specimen is deformed subsequently, it is concluded that these line defects are not stable like the boundary dislocations but may be steps generated on the boundary to form facets which coincide with the high-density CSL plane. X-ray topographic images of boundaries which do not satisfy the conditions of a high density CSL are complex and difficult to interpret, although some of the images indicate that there may be different types of structures on such boundaries.

Download Full-text

First Demonstration of Ultra-Thin Glass Panel Embedded (GPE) Package with Sheet Type Epoxy Molding Compound for 5G/mm-wave Applications

International Symposium on Microelectronics ◽

10.4071/2380-4505-2019.1.000202 ◽

2019 ◽

Vol 2019 (1) ◽

pp. 000202-7 ◽

Cited By ~ 1

Author(s):

Nobuo Ogura ◽

Siddharth Ravichandran ◽

Tailong Shi ◽

Atom Watanabe ◽

Shuhei Yamada ◽

...

Keyword(s):

Antenna Arrays ◽

High Density ◽

Superior Performance ◽

Glass Panel ◽

Low Loss ◽

Epoxy Molding Compound ◽

Thin Glass ◽

Packaging Technology ◽

Molding Compound ◽

Low Dissipation

Abstract With the number of connected-devices increasing tremendously, communication data rates are projected to be at least 10–100X in the 5G/mm-wave (MMW) technology - much higher than the existing 4G LTE connections.[1], [2] To catch up with the trend, novel packaging technology in the MMW frequency range is required, which will address fundamental MMW technical challenges such as high dielectric loss, degradation of quality factors in passives, increased parasitic, dramatically-enhanced electromagnetic interference, and the reduced radiation efficiency of antenna arrays. State-of-the-art approaches being pursued include organic-core substrates that have a low dielectric constant (Dk) and low dissipation factor (Df) such as fluorine based or liquid-crystal polymer (LCP) substrates in order to achieve enhanced antenna performance and low signal dissipations. These organic-based substrate technologies, however, can neither miniaturize packages nor handle precision signal routings that enable high density packages. To address these challenges, attention is focused on Fan-Out Wafer Level Package (FOWLP) technologies, like eWLB, InFO, and SWIFT, where integrated circuits (ICs) are embedded in epoxy molding compound. [3]–[6] Recently, glass-panel embedding (GPE) technology is emerging as an ideal packaging methodology that enables superior performance along with small form factor, ultra-low-loss, high density, ultra-short interconnects, and low cost. [7] These benefits stem from the advantages of using glass which has excellent properties such as ultra-smooth surface for precision redistribution layer (RDL), exceptional dimensional stability for panel-scalability and tailorability of CTE that allow direct board-attach for improved system performance. In addition, utilizing the epoxy molding compounds as encapsulation material allows the GPE package to be thinner and more robust package with small farm factor. Molding of glass cavity panels also helps with the handling of ultra-thin glass which is seen as a bottleneck towards glass based packaging solutions in production. These facilitates enhanced throughput by allowing more cavity cut outs (more coupons) per panel. This paper presents the first demonstration of ultra-thin GPE with sheet type epoxy molding compound (SMC) for 5G/mm-wave applications. First part of this paper discusses the process-flow used in glass-panel embedding with laminated SMC, including chip placement in glass cavities, lamination of SMC, and the reliability of the package architecture. This paper reports on such a demonstration in 60 μm glass substrates with 40 μm thickness SMC. The second part of this paper focuses on low-loss interconnects for 5G/mm-wave applications and presents the process development of signal routings such as transmission lines and microvias in RDLs as well as through-package vias (TPVs) with via-in-via process. The results suggest that the ultra-thin GPE architecture is a promising packaging technology solution for a variety of applications including high-frequency communications and high-performance computing.

Download Full-text

Planar defects in ordered (Ga,In)P

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106570 ◽

1988 ◽

Vol 46 ◽

pp. 902-903

Author(s):

S. McKernan ◽

C. B. Carter ◽

D. Bour ◽

J. R. Shealy

Keyword(s):

Electron Diffraction ◽

Vapor Phase ◽

Growth Direction ◽

High Density ◽

Ordered Structure ◽

Planar Defects ◽

Diffraction Patterns ◽

Ternary Semiconductors ◽

Anion Species ◽

Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

Download Full-text

Defects in Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100962 ◽

1968 ◽

Vol 26 ◽

pp. 244-245

Author(s):

Kenneth R. Lawless

Keyword(s):

Electron Microscope ◽

Point Defects ◽

Surface Defects ◽

Chemical Properties ◽

Material Point ◽

Crystal Defects ◽

Defects In Crystals ◽

Irradiation Effects ◽

Normal Lattice ◽

Line Defects

One of the most important applications of the electron microscope in recent years has been to the observation of defects in crystals. Replica techniques have been widely utilized for many years for the observation of surface defects, but more recently the most striking use of the electron microscope has been for the direct observation of internal defects in crystals, utilizing the transmission of electrons through thin samples.Defects in crystals may be classified basically as point defects, line defects, and planar defects, all of which play an important role in determining the physical or chemical properties of a material. Point defects are of two types, either vacancies where individual atoms are missing from lattice sites, or interstitials where an atom is situated in between normal lattice sites. The so-called point defects most commonly observed are actually aggregates of either vacancies or interstitials. Details of crystal defects of this type are considered in the special session on “Irradiation Effects in Materials” and will not be considered in detail in this session.

Download Full-text