The relevance of shape and size of Au55 clusters

2008 ◽  
Vol 37 (9) ◽  
pp. 1909 ◽  
Author(s):  
Günter Schmid
Keyword(s):  
Au55 Clusters ◽  
Shape And Size

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

ULTRA-FORM 80

Alloy Digest ◽  
1973 ◽  
Vol 22 (7) ◽  
Keyword(s):  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Low Alloy Steel ◽  
Bethlehem Steel Corporation ◽  
Temperature Performance ◽  
Inclusion Shape ◽  
Ferrite Grain Size ◽  
Minimum Yield ◽  
Shape And Size

Abstract Ultra-Form 80 is a low-alloy steel developed for its combination of high strength, good formability, fatigue resistance, toughness and weldability. It has a minimum yield strength of 80,000 psi and is characterized by its low carbon and alloy content, very fine ferrite grain size, and controlled inclusion shape and size. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: SA-291. Producer or source: Bethlehem Steel Corporation.

Morphological peculiarities of seeds of some species of the genus Epipactis Zinn. (Orchidaceae Juss.) of Ukrainian flora

2019 ◽  
Vol 11 (1) ◽  
pp. 93-100
Author(s):  
T Ljubka ◽  
O Tsarenko ◽  
I Tymchenko
Keyword(s):  
Seed Coat ◽  
Cell Walls ◽  
Morphological Study ◽  
Population Level ◽  
Intercellular Spaces ◽  
Different Populations ◽  
Periclinal Walls ◽  
High Degree ◽  
Shape And Size ◽  
Generative Organs

The investigation of macro- and micromorphological peculiarities of seeds of four species of genus Epipactis (Orchidaceae) of Ukrainian flora were carried out. The genus Epipactis is difficult in the in in taxonomic terms and for its representatives are characterized by polymorphism of morphological features of vegetative and generative organs of plants and ability of species to hybridize. The aim of the research was to perform a comparative morphological study of seeds of E. helleborine, E. albensis, E. palustris, E. purpurata and to determine carpological features that could more accurately identify species at the stage of fruiting. A high degree of variation in the shape of the seeds in different populations within the species and overlap of most quantitative carpological characteristics of studied species are noted. There were no significant differences in micromorphological features of the structure of the testa at species or population level. The reticulate surface of the testa is characteristic of all species, the cells of testa are mostly elongated, penta-hexagonal, individual cells almost isodiametric-pentagonal. From the micropillary to the chalasal end, a noticeable change in the shape and size of the seed coat cells is not observed. There are no intercellular spaces, the anticlinal walls of adjacent cells are intergrown and the boundaries between them become invisible. The outer periclinal walls have a single, mainly longitudinal thin ribbed thickenings. Anticlinal cell walls are thick, dense, smooth. The longitudinal Anticlinal walls are almost straight, transverse - straight or sometimes curved in some cells. Epicuticular deposits on the periclinal walls are absent. It is concluded that the use of macro and micromorphological characteristics of seeds of these species for clearer diagnosis at the stage of fruiting is low informative.

An Obstacle-resistant Relay Node Placement in Constrained Environment

2019 ◽  
Author(s):  
Abhishek Verma ◽  
Virender Ranga
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Mobile Robots ◽  
Relay Node ◽  
Wireless Sensor ◽  
Relay Node Placement ◽  
Node Placement ◽  
Simulation Results ◽  
Additional Hardware ◽  
Shape And Size

Relay node placement in wireless sensor networks for constrained environment is a critical task due to various unavoidable constraints. One of the most important constraints is unpredictable obstacles. Handling obstacles during relay node placement is complicated because of complexity involved to estimate the shape and size of obstacles. This paper presents an Obstacle-resistant relay node placement strategy (ORRNP). The proposed solution not only handles the obstacles but also estimates best locations for relay node placement in the network. It also does not involve any additional hardware (mobile robots) to estimate node locations thus can significantly reduce the deployment costs. Simulation results show the effectiveness of our proposed approach.

Surfactant involved in Copper Sulfide Nanocrystallites Synthesis

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Claudia Maria Simonescu ◽  
Valentin Serban Teodorescu ◽  
Camelia Capatina
Keyword(s):  
Copper Sulfide ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Shape Of Nanoparticles ◽  
Tem Transmission Electron Microscopy ◽  
Shape And Size

This paper presents the obtaining of copper sulfide CuS (covelite) from Cu(CH3COO)2.H2O and thioacetamide (TAA) system. The reaction was conducted in presence or absence of sodium-bis(2-ethylhexyl) sulfosuccinate (Na-AOT). The effects of various reaction parameters on the size and on the shape of nanoparticles have been examined. CuS obtained was characterized by X ray diffraction, IR spectroscopy, TEM � transmission electron microscopy and SAED selected area electron diffraction. The influence of surfactant to the shape and size of CuS (covellite) nanocrystals was established. The size of the nanocrystals varied from 10-60 nm depending on the reaction conditions such as quantity of surfactant.

A New Study of Shape and Size-dependent Properties of Nanocrystals Utilizing the Fractional Fourier Transform

2020 ◽  
Vol 5 (2) ◽  
pp. 165-174
Author(s):  
Aeshah Salem
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Surface Area ◽  
Fractional Fourier Transform ◽  
Fourier Transform Infrared ◽  
Chemical Dynamics ◽  
Znse Nanoparticles ◽  
Size Dependent ◽  
Shape And Size

Background: Possessions of components, described by their shape and size (S&S), are certainly attractive and has formed the foundation of the developing field of nanoscience. Methods: Here, we study the S&S reliant on electronic construction and possession of nanocrystals by semiconductors and metals to explain this feature. We formerly considered the chemical dynamics of mineral nanocrystals that are arranged according to the S&S not only for the big surface area, but also as a consequence of the considerably diverse electronic construction of the nanocrystals. Results: The S&S of models, approved by using the Fractional Fourier Transform Infrared Spectroscopy (FFTIR), indicate the construction of CdSe and ZnSe nanoparticles. Conclusion: In order to study the historical behavior of the nanomaterial in terms of S&S and estimate further results, the FFTIR was used to solve this project.

scholarly journals Impact of Deuteration and Temperature on Furan Ring Dynamics

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2889
Author(s):  
Przemyslaw Dopieralski ◽  
Iryna V. Omelchenko ◽  
Zdzislaw Latajka
Keyword(s):  
Conformational Changes ◽  
Furan Ring ◽  
Computational Studies ◽  
Significant Progress ◽  
Dynamic Simulations ◽  
Cyclic Molecules ◽  
Ring Dynamics ◽  
Different Temperatures ◽  
Long Time ◽  
Shape And Size

Despite significant progress in conformational analysis of cyclic molecules, the number of computational studies is still limited while most of that available in the literature data have been obtained long time ago with outdated methods. In present research, we have studied temperature driven conformational changes of the furan ring at three different temperatures. Additionally, the effect of deuteration on the ring dynamics is discussed; in addition, the aromaticity indices following the Bird and HOMA schemes are computed along all trajectories. Our ab initio molecular dynamic simulations revealed that deuteration has changed the furan ring dynamics and the obvious consequences; in addition, the shape and size of molecule are expected to be different.

scholarly journals Engineering large, anatomically shaped osteochondral constructs with robust interfacial shear properties

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wendy E. Brown ◽  
Brian J. Huang ◽  
Jerry C. Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Mechanical Properties ◽  
Interfacial Shear Strength ◽  
Femoral Condyle ◽  
Interfacial Shear ◽  
Cartilage Defects ◽  
Porous Hydroxyapatite ◽  
Cartilage Lesions ◽  
Large Cartilage Lesions ◽  
Articular Cartilage Defects ◽  
Shape And Size

AbstractDespite the prevalence of large (>5 cm2) articular cartilage defects involving underlying bone, current tissue-engineered therapies only address small defects. Tissue-engineered, anatomically shaped, native-like implants may address the need for off-the-shelf, tissue-repairing therapies for large cartilage lesions. This study fabricated an osteochondral construct of translationally relevant geometry with robust functional properties. Scaffold-free, self-assembled neocartilage served as the chondral phase, and porous hydroxyapatite served as the osseous phase of the osteochondral constructs. Constructs in the shape and size of an ovine femoral condyle (31 × 14 mm) were assembled at day 4 (early) or day 10 (late) of neocartilage maturation. Early osteochondral assembly increased the interfacial interdigitation depth by 244%, interdigitation frequency by 438%, interfacial shear modulus by 243-fold, and ultimate interfacial shear strength by 4.9-fold, compared to late assembly. Toward the development of a bioprosthesis for the repair of cartilage lesions encompassing up to an entire condylar surface, this study generated a large, anatomically shaped osteochondral construct with robust interfacial mechanical properties and native-like neocartilage interdigitation.

Fracture Toughness of Large Forgings for Power Producing Industry

2013 ◽  
Vol 577-578 ◽  
pp. 593-596 ◽  
Author(s):  
Václav Mentl
Keyword(s):  
Fracture Toughness ◽  
Chemical Composition ◽  
Steam Turbine ◽  
Mechanical Treatment ◽  
Material Degradation ◽  
The Real ◽  
Operational Safety ◽  
Local Properties ◽  
Thermo Mechanical Treatment ◽  
Shape And Size

The steam turbine rotors represent large components both in radial and axial directions. Their local properties generally differ from one forging to another, or if we compare head and bottom parts of the original ingot, or central and circumferential localities of one rotor body respectively, or if we compare the properties of separate discs e.g. in the case of welded rotors. These differences stem from both even slight changes in the chemical composition (of separate heats or even within one ingot) and thermo-mechanical treatment and in the differences in technology with respect to the real shape and size of the forgings in question. In the paper, the consequences of the differences in fracture toughness characteristics in various rotor localities are discussed with respect to the rotors operational safety taking into account the existence of cracks and material degradation.

scholarly journals A Spatiotemporal Statistical Method of Ship Domain in the Inland Waters Driven by Trajectory Data

2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  
Keyword(s):  
Statistical Method ◽  
Yangtze River ◽  
Domain Size ◽  
Inland Waters ◽  
The Yangtze River ◽  
Trajectory Data ◽  
Different Types ◽  
Dry Seasons ◽  
Ship Collision ◽  
Shape And Size

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.

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