Citizen Science to Assess the Fine-Grain Distribution and Habitat Use of the Middle Spotted Woodpecker Dendrocoptes medius

2021 ◽  
Vol 55 (2) ◽  
Author(s):  
José María Fernández-García ◽  
Hugo Robles
Keyword(s):  
Habitat Use ◽  
Citizen Science ◽  
Fine Grain ◽  
Grain Distribution ◽  
Middle Spotted Woodpecker

Using long-term citizen science data to understand distribution and habitat use of an irruptive species

2021 ◽  
pp. 101377
Author(s):  
Anant Deshwal ◽  
Pooja Panwar ◽  
Joseph C. Neal ◽  
Matthew A. Young
Keyword(s):  
Habitat Use ◽  
Citizen Science ◽  
Science Data

EFFECT OF COARSE-TO-FINE WC GRAIN RATIO ON MECHANICAL PROPERTIES AND ABRASIVE WEAR OF WC-8Co CEMENTED CARBIDES

Tribologia ◽  
2016 ◽  
Vol 265 (1) ◽  
pp. 103-115
Author(s):  
Der-Liang YUNG ◽  
Maksim ANTONOV ◽  
Irina HUSSAINOVA ◽  
Renno VEINTHAL ◽  
Sture HOGMARK
Keyword(s):  
Abrasive Wear ◽  
Rupture Strength ◽  
Ultrafine Grain ◽  
Cemented Carbides ◽  
Wear Properties ◽  
Fine Grain ◽  
Material Hardness ◽  
Fine Tungsten ◽  
Grain Distribution ◽  
Coarse To Fine

This study performs a comprehensive analysis concerning the amount of fine tungsten carbide (WC) grains needed for the appropriate reinforcement of the cobalt (Co) metallic binder in WC-8Co cemented carbides. The goal is to investigate the balance of coarse-to-fine grain distribution to achieve overall improvement of the material’s mechanical and wear properties. All samples possessed the same WC-8Co binder content, therefore, allowing the role of grain size distribution to be tested. It was found that a ratio of 8:1 wt% of coarse to ultrafine grain WC yielded an appropriate balance between material hardness, fracture toughness, and rupture strength. Upon adding grain growth inhibitors vanadium carbide (VC) and chromium carbide (Cr3C2), the overall wear resistance is further improved compared to undoped composites when samples are tested under abrasive wear conditions.

The Effect of Ag Addition on the Corrosion of Zn-22wt%Al Alloys

2003 ◽  
Vol 781 ◽  
Author(s):  
Flores M. ◽  
Huerta L. ◽  
Casolco S. R. ◽  
Muhl S. ◽  
Torres-Villaseñor G. ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Sample Surface ◽  
Corrosion Products ◽  
Surface Cracks ◽  
Superplastic Behavior ◽  
Fine Grain ◽  
Grain Distribution ◽  
Superplastic Properties

AbstractA new Zn–Al-Ag alloy (ZINAG) with mechanical superplastic properties has been developed. In this work four of the Zn–22wt%Al eutectoid alloy doped with between 0.5 to 4.24 wt% Ag have been studied. The superplastic behavior can be explained as a consequence of the fine grain distribution induced during the deformation process. Here the corrosion resistance of these alloys was studied by means of potentiodynamic polarization and measurements of the temporal evolution of the corrosion potential, in a 0.5 M NaCl solution. The corrosion products in the sample surface were analyzed by Rutherford Backscattering Spectrometry (RBS), X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). It was found that the corroded surface had lost more Zn than Al. The surface was examined by SEM and it was seen that the corrosion products adhered to the surface cracks. It was found that the alloy with 2.12 wt% concentration of Ag had the best corrosion resistance in the electrolyte used, but no clear tendency with the Ag concentration was found.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

Superior 2X2 Slides

1975 ◽  
Vol 33 ◽  
pp. 158-159
Author(s):  
Harry Schaefer ◽  
Bruce Wetzel
Keyword(s):  
New York ◽  
High Resolution ◽  
Black And White ◽  
Fine Grain ◽  
White Film

High resolution 24mm X 36mm positive transparencies can be made from original black and white negatives produced by SEM, TEM, and photomicrography with ease, convenience, and little expense. The resulting 2in X 2in slides are superior to 3¼in X 4in lantern slides for storage, transport, and sturdiness, and projection equipment is more readily available. By mating a 35mm camera directly to an enlarger lens board (Fig. 1), one combines many advantages of both. The negative is positioned and illuminated with the enlarger and then focussed and photographed with the camera on a fine grain black and white film.Specifically, a Durst Laborator 138 S 5in by 7in enlarger with 240/200 condensers and a 500 watt Opale bulb (Ehrenreich Photo-Optical Industries, Inc., New York, NY) is rotated to the horizontal and adjusted for comfortable eye level viewing.

Microstructure Development in a High Current Density NbTi Superconducting Composite

1985 ◽  
Vol 43 ◽  
pp. 186-189
Author(s):  
P. J. Lee ◽  
D. C. Larbalestier
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Cold Drawing ◽  
Heat Treatments ◽  
Grain Structure ◽  
Fine Grain ◽  
Boundary Film ◽  
Quantitative Basis ◽  
Cold Worked ◽  
Very High

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.

High-resolution observation of sintered alumina (Al2O3) using the specimen-heated and electron-beam-induced conductivity method in a UHR-SEM

1994 ◽  
Vol 52 ◽  
pp. 1046-1047
Author(s):  
K. Ogura ◽  
T. Suzuki ◽  
C. Nielsen
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Specimen Preparation ◽  
Conductivity Method ◽  
Fine Grain ◽  
Grain Structures ◽  
Resolution Observation ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Charging Effect

In spite of the complicated specimen preparation, Transmission Electron Microscopes (TEM) have traditionally been used for the investigation of the fine grain structures of sintered ceramics. Scanning Electron Microscopes (SEM) have not been used much for the same purpose as TEM because of poor results caused by the specimen charging effect, and also the lack of sufficient resolution. Here, we are presenting a successful result of high resolution imaging of sintered alumina (pure Al2O3) using the Specimen Heated and Electron Beam Induced Conductivity (SHEBIC) method, which we recently reported, in an ultrahigh resolution SEM (UHR-SEM). The JSM-6000F, equipped with a Field Emission Gun (FEG) and an in-lens specimen position, was used for this application.After sintered Al2O3 was sliced into a piece approximately 0.5 mm in thickness, one side was mechanically polished to get a shiny plane for the observation. When the observation was started at 20 kV, an enormous charging effect occured, and it was impossible to obtain a clear Secondary Electron (SE) image (Fig.1).

High-resolution SEM and STEM of adrenocortical endothelium: Molecular resolution of membrane complexes

1993 ◽  
Vol 51 ◽  
pp. 610-611
Author(s):  
Robert P. Apkarian
Keyword(s):  
Fine Structure ◽  
Low Voltage ◽  
Uranyl Acetate ◽  
Correlative Microscopy ◽  
Coated Pits ◽  
Fine Grain ◽  
Structural Identity ◽  
Cellular Pathways ◽  
Steroidogenic Cells ◽  
Cr Film

A multitude of complex ultrastructural features are involved in endothelial cell (EC) gating and sorting of lipid through capillaries and into steroidogenic cells of the adrenal cortex. Correlative microscopy is necessary to distinguish the structural identity of features involved in specific cellular pathways. In addition to diaphragmed fenestrae that frequently appear in clusters, other 60-80 nm openings; plasmalemma vesicles (PV), channels and pockets fitted with diaphragms of the same dimension, coexist on the thin EC surface. Non-diaphragmed coated pits (CP) (100-120 nm) involved in receptor mediated endocytosis were also present on the EC membrane. The present study employed HRSEM of cryofractured and chromium coated specimens and low voltage HRSTEM of 80 nm thick LX-112 embedded sections stained with 2.0% uranyl acetate. Both preparations were imaged at 25 kV with a Topcon DS-130 FESEM equipped with in-lens stage and STEM detector.HRSEM images of the capillary lumen coated with a lnm continuous fine grain Cr film, provided the ability to scan many openings and resolve (SE-I contrast) the fine structure of diaphragm spokes and central densities (Fig. 1).

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