bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elemental composition of soybean seeds
Authors: Yaklich R. W. , Chaney N. , Vigil E. L. , Wergin W. P. 
Published: June 2020

The soybean (Glycine max L. Merr.) seed coat is the terminal maternal tissue that supplies the developing embryo with nutrients. Between the embryo and seed coat, where this transfer presumably occurs, we have found (1,2) a specialized convex area (antipit) on the inside surface of the soybean seed coat that is opposed by a concave area (pit) on the surface of the cotyledon. The cells of this pit-antipit complex are larger than those of the surrounding tissue. Furthermore, the aleurone and cone cells of the antipit have many characteristics of secretory cells. Previous data about these structures has been cytological; very limited biochemical information is knownabout the area. This paper presents preliminary data about the elemental content of these surfaces in the mature seeds of domesticated soybean, G. max and a close relative, G. soja.The seed was dissected into right and left cotyledons; the right cotyledon was used for all microscopy and X-ray analysis. The seed coat was then separated from the cotyledon and excess tissue was removed.
Ultrastructural changes in avian toxic heterophils
Authors: Latimer S. , Steffens W.L. , Goodwin Mark 
Published: June 2020

In mammals, morphologic changes in peripheral blood neutrophils are often reflections of bacterial infection and severe inflammation. These light microscopic changes as evidenced by Romanowsky staining may include appearance of D&#x00F6;hle bodies, toxic granules, vacuolation, and cytoplasmic basophilia. Cells exhibiting such changes are referred to as “toxic” neutrophils. Studies of ultrastructural alterations in toxic neutrophils are reported and well-documented in humans (1) and dogs (2). Detailed controlled investigations of leukocyte changes in response to inflammation in birds are lacking. It was the purpose of this study to document toxic changes induced by intramuscular turpentine injection in the equivalent avian cell, the heterophil.Young adult female White Leghorn chickens were obtained and divided into 2 groups, one receiving injection with 1 ml of filter-sterilized commercial grade turpentine in the right breast muscle, and the other (controls) receiving a similar volume of sterile saline.
Immunogold labeling of bluetongue virus in cryosections fromCulicoides variipennis(Coquillett) salivary gland
Authors: Nunamaker R. A. , Wick B. C. , Nunamaker C. E. 
Published: June 2020

When an arbovirus enters its arthropod host during a viremic blood meal it quickly reaches the midgut where virus penetration of the host parenchyma and infection of epithelial cells apparently occur. Subsequently, viral particles enter the arthropod's hemolymph and are transported to other tissues which may then become infected. Previous studies have demonstrated that when the arbovirus reaches the salivary glands it increases in titer and persists over long periods, often throughout the life of the vector.It is this persistent presence and associated continual shedding of virus into saliva which is one reason that certain arthropods are extremely efficient biological vectors.Culicoides variipennis(Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife. Although there have been numerous electron microscopic studies of many mosquito-borne viruses in their natural hosts, virtually nothing is known about the replicative cycle of BTV in the salivary glands of its primary vector.
Evaluation of erythrocyte membranes by immunocytochemical techniques following the transfusion of incompatible blood
Authors: Hathaway T. K. , Adams J. L. , Heckman C. 
Published: June 2020

The hemolytic transfusion reaction (HTR) is the most formidable complication in blood transfusion therapeutics. Immune clearance and destruction of red blood cells (RBC) following infusion of incompatible blood have generally been thought to involve opsonic proteins, i.e., immunoglobulins (IgG, IgM) and complement. Fibronectin (FN), a multifunctional plasma and tissue protein, participates in many significant biological and pathophysiological activities and has opsonic characteristics. Plasma fibronectin (PFN) has been associated with acute HTR and the use of dogs as effective models for HTR research has been established. By using immunocytochemical techniques, this study proposed to localize and identify opsonic proteins coating and contributing to lysis of RBC during an acute HTR.Three dogs were infused with heterologous RBC. Plasma hemoglobin (Hb), PFN, IgG, IgM, and complement (C3) were measured to assess the HTR. RBC collected at timed intervals before and after the infusion were viewed by fluorescent and electron microscopy using fluorescein isothiocyanate conjugate and immunogold staining.
Hyperglycogenic secondary center cells in rat femurs
Authors: Shepard Nora , Mitchell Nelson 
Published: June 2020

The cells forming the secondary center have been described and compared to the hypertrophic chondrocytes of the primary growth plate (ref.I,2). In an attempt to clarify the nature of the vacuolization and associated cell hypertrophy reported to also take place within the chondrocytes of the secondary center prior to the onset of ossification an attempt to improve chondrocyte morphology was made. Glutaraldehyde fixation followed by buffered osmium was compared to tissue fixed with potassium ferrocyanide reduced osmium.Cartilage slices from 5-7 day rats (distal femur) were fixed in 2% glutaraldehyde/0.1M Na phosphate pH 7.4 (2 hrs.); rinsed in 0.1M N phosphate buffer plus 0.1M sucrose (15. min.); post fixed in 1.5% potassium ferrocyanide in aqueous OSO4 or in 2% OSO4/0.1M Na phosphate (2 hrs.); rinsed in 0.1M Na acetate (pH 6.3); en bloc stained in .25% uranyl acetate/0.1M Na acetate; dehydrated in alcohol and Spurr embedded.
The quantitation of volume, surface, and length using classical stereological principles
Authors: Basqen John M. 
Published: June 2020

Biologists and material scientists are often confronted with the problem of quantitating the volume, surface, or length of certain components contained within a reference structure. For example, the biologists might be interested in knowing the volume of mitochondria within a liver cell. A mineralogist might be interested in knowing how much gold 1s contained within a certain rock sample. To obtain structural Information about the component (mitochondria, gold) within the reference space (liver cell, rock sample) sections are made through the 3-dimensional reference space and measurements are made on the 2-dimensional sections or micrographs of the sections.Stereology is the science of mathematical methods relating 3-dimensional parameters defining a structure to measurements obtained from 2-d1mens1onal samples of the structure, such as sections or micrographs.
Solid-state amorphization by electron irradiation
Authors: Luzzi D.E. 
Published: June 2020

When certain intermetallic compounds are irradiated with ballistic electrons at low temperatures, the crystal becomes unstable and transforms into an amorphous phase. This electron irradiation induced crystalline to amorphous (C-A) transition is one of a recently discovered class of amorphization processes which occur in the solid state [1]. The relative simplicity of electron-matter interactions, and the ability to follow the transition inside the microscope, make the electron induced C-A transition ideal for the study of these amorphization processes.A bright field image sequence which depicts several features of the C-A transition is shown in the figure. In this example, CuTim was irradiated with 2 MeV electrons at 191 K (9.2 x 1023 e/m2-s; 5.5 x 10-3 dpa/s). The arrows mark a fixed position. In the images, taken after different irradiation times (a:30s, b:60s c:300s), the transition is evident from the distortion of the bend contour around the irradiated area.
Alpha-decay damage and the aperiodic structure of pyrochlore
Authors: Lumpkin G. R. , Ewing R. C. 
Published: June 2020

Alpha-decay damage in minerals which contain U and Th involves two separate damage processes: a high energy (4-5 MeV) alpha particle with a range of 10,000 nm displaces several hundred atoms creating Frenkel defects near the end of die track; and a recoil atom (0.1 MeV) with a range of 10 nm produces several thousand atomic displacements creating “tracks” of disordered material. Pyrochlore group minerals are suitable for the study of alpha-decay damage because they contain variable amounts of U and Th such that the accumulated dose spans the transition from the crystalline to the fully aperiodic, “metamict” state.More than 50 natural pyrochlores were characterized by a number of experimental techniques. Electron microprobe analyses were obtained using a JEOL 733 Superprobe operated at 15 KV and 20 nA. X-ray diffraction studies were completed using an automated Scintag powder diffractometer.
Absolute determination of surface atomic concentration by reflection electron energy-loss spectroscopy
Authors: Wang Z. L. , Egerton R.F. 
Published: June 2020

Reflection electron energy-loss spectroscopy (REELS) has been demonstrated as a useful technique for analyzing the structure of crystal surfaces. It is a combination of EELS with reflection electron microscopy (REM) performed in a transmission electron microscope. Here, we suggest a basic theory and experiment which enable REELS to determine absolutely the atomic concentration (atoms per unit volume) at a crystal surface.In the RHEED case, not all the incident electrons will travel an equal distance within the sample (fig. 1A). Under the surface-resonance condition, the incident electrons are propagating parallel or nearly parallel to the crystal surface. Then a mean travelling distance (MTD) D can be defined, along which the excitation of atomic inner shells is equivalent to the total excitation of the atomic inner shells in the dynamical scattering (fig. IB). It can be found from the analysis of experimental data as:(1)
Tetragonal microdomains in partially reduced zirconia
Authors: Kim Y. M. 
Published: June 2020

Tweed structure often forms when ZrO2-Y2O3 alloy is cooled at a moderate rate through the cubic plus tetragonal two-pnase field. Hannink1 and Ishizawa et al. have explained that tweed character comes from the strain field around fine tetragonal precipitates in a cubic matrix. Sakuma et al. have reported similar structures after isothermal annealing at appropriate temperature and composition and explained in terms of spinodal decomposition. But, Lanteri et al. have suggested that the matrix have transformed displacively to t-symmetry once sample is cooled rapidly, observing antiphase boundaries(APB's) in DF with [112] type reflections. There is still uncertainty on the microstructure of tweed structures. This study presents the microstructures obtained from vacuum sintered ZrO2-5mol Y2O3, that show fine tetragonal microdomains with APB's in a cubic matrix.A 10mm dia. by 2mm thick pellet was cold-pressed from a ZrO2-5mol % Y2O3 powder, sintered at 2000°C for 2 h in vacuum, and fast-cooled (from 2000°C to 1100°C in 4 min.). Then, a 0.7mm thick disc was cut, sintered again at 2000°C for 4 h and fast cooled. The specimens were reduced and were black in color.
TEM examination of 2014-SiC metal matrix composite
Authors: Burke M. G. , Gungor M. N. , Liaw P. K. 
Published: June 2020

Aluminum-based metal matrix composites offer unique combinations of high specific strength and high stiffness. The improvement in strength and stiffness is related to the particulate reinforcement and the particular matrix alloy chosen. In this way, the metal matrix composite can be tailored for specific materials applications. The microstructural characterization of metal matrix composites is thus important in the development of these materials. In this study, the structure of a p/m 2014-SiC particulate metal matrix composite has been examined after extrusion and tensile deformation.Thin-foil specimens of the 2014-20 vol.% SiCp metal matrix composite were prepared by dimpling to approximately 35 μm prior to ion-milling using a Gatan Dual Ion Mill equipped with a cold stage. These samples were then examined in a Philips 400T TEM/STEM operated at 120 kV. Two material conditions were evaluated: after extrusion (80:1); and after tensile deformation at 250°C.
The influence of heat treatment on the fiber/matrix interface in a SiC-reinforced glassceramic
Authors: Bischoff E. , Sbaizero O. 
Published: June 2020

Fiber or whisker reinforced ceramics show improved toughness and strength. Bridging by intact fibers in the crack wake and fiber pull-out after failure contribute to the additional toughness. These processes are strongly influenced by the sliding and debonding resistance of the interfacial region. The present study examines the interface in a laminated 0/90 composite consisting of SiC (Nicalon) fibers in a lithium-aluminum-silicate (LAS) glass-ceramic matrix. The material shows systematic changes in sliding resistance upon heat treatment.As-processed samples were annealed in air at 800 °C for 2, 4, 8, 16 and 100 h, and for comparison, in helium at 800 °C for 4 h. TEM specimen preparation of as processed and annealed material was performed with special care by cutting along directions having the fibers normal and parallel to the section plane, ultrasonic drilling, dimpling to 100 pm and final ionthinning. The specimen were lightly coated with Carbon and examined in an analytical TEM operated at 200 kV.
Atomic growth mechanisms for lamellar structures
Authors: Fonda R.W. , Black L.R. , Shiflet G.J. 
Published: June 2020

The pearlite transformation product is composed of alternating plates resulting from a eutectoid transformation whereas the discontinuous or cellular transformation is also composed of alternating plates due to relief of supersaturation. This paper will describe the relationship between the growth interface and interlamellar structure that results from the pearlite and cellular structures. Some important similarities will be noted that relate to both types of phase transformations.The Cu—4w/o Ti alloy was made by induction melting high purity materials and homogenizing. Samples were then solutionized at 900 C and isothermally transformed at 740 C for 60 m. Details of the experimental procedure for the Fe—.8w/o C—12 w/o Mn alloy are given elsewhere.Cellular precipitation in Cu—Ti alloys consists of the synchronous growth of lamallae of less saturated fcc Cu and an ordered orthorhombic Cu4Ti β phase. The conjugate habit planes between the depleted matrix and β phase is (010)β//(111)α with [001]β//[110]α.
Hydride formation in pure titanium
Authors: Vanderwalker D. M. 
Published: June 2020

Hydrogen embrittlement of metals is a subject of importance because it is often the cause of catastrophic failure. The loss in ductility occurs when the hydrogen concentration exceeds a percent or few. In titanium, the embrittlement effect depends on the alloy composition. α-Ti, the low temperature hexagonal phase transforms to bcc β-Ti at 882°C in pure Ti. The transformation temperature is suppressed by β-stabilizing impurities such as Fe ie 4% Fe reduces the temperature to 400°C. This paper examines the hydride formation in iodide-Ti and 99% pure Ti.Thin foils of iodide Ti (.1Sn-.05 Si-.04Fe-.01Cu) and 99% pure Ti(Fe,Mo,Cu,Al) were encapsulated in vacuum tubes, annealed for 2 hours at 800°C, and quenched in ice water. The titanium was then charged in an H2SO4.H2O solution with an applied voltage of +4.5V for one hour. The samples were encapsulated in vacuum tubes and aged for 3 or 4 hours at 200°C.
Applications of image processing techniques to the structural characterization of small metallic particles
Authors: Pérez R. , Pérez-Ramírez J.G. 
Published: June 2020

Digital image processing techniques have become one of the main tools on image characterization in transmission electron microscopy. Applications of these techniques in the field of small metallic particles are widely known. The results presented in this communication explore some of the structural characteristics of decahedral gold particles. The work is based on HREM images of these type of particles obtained along five-fold axis.Small gold particles have been prepared by evaporation onto a vacuum cleaved NaCl surface. Lattice resolution images and microdiffraction patterns from individual particles have been obtained. Some of the images have been digitized with a scanning microdensitometer and computer processed.Fig. 1 shows a HREM image of a decahedral gold particle obtained under diffraction conditions close to a five-fold zone axis. This image has been digitized and a computed “microdiffraction” pattern has been obtained from each of the five segments.
Low temperature transformations and twinning in La2-xSrxCuO4-δ and La2CuO4
Authors: Roy T. , Mitchell T. E. 
Published: June 2020

Electron microscopists have played an important role in structure and microstructure determinations of ceramic superconductors ever since their discovery. Most of the work has been done on the 123 compounds. In the present investigation, we have used conventional TEM techniques at various temperatures to study the tetragonal to orthorhombic transformation in 214 compounds.Single crystal La2CuO4 and polycrystalline La2-xSrxCuO4-δ (x∼0.15) were used in this investigation. La2CuO4 crystals were grown from a PbO flux and polycrystalline La2-xSrxCuO4-δ was made from stoichiometric mixtures of La2O3, CuO and SrO in the usual way. The results reported here were obtained from bulk ion-milled samples. Microscopy was performed using a Philips EM400T operating at 120kV, sometimes using a Gatan specimen cooler.Both compounds have a triple perovskite structure. At room temperature, La2-xSrxCuO4-δ has a tetragonal unit cell (ao=3.775 A, co=13.223 A) while La2CuO4 has an orthorhombic unit cell (ao=5.363 A, bo=5.403 A, co=13.17 A).
Practical TEM cross section technique for ceramic superconducting thin films
Authors: Nazar L. R. 
Published: June 2020

Within the last eighteen months, great interest has developed in certain ceramic materials which superconduct above liquid nitrogen temperatures. Recently it has been shown that these materials can be deposited as thin films on various substrates without significant change in critical temperature. Cross-sectional TEM studies have provided key information regarding the structure of these films and their interaction with the various substrates. However, specimen preparation for such studies can be difficult, and only a few successful results have been reported. This paper describes a successful method adapted from routine semiconductor cross section technique.The following technique has been applied to specimens of superconducting ceramic films (Y-Ba-Cu-O) deposited by pulsed excimer laser or electron beam co-evaporation on sapphire and strontium titanate substrates.Wafers bearing the films must have their major crystallographic axes identified and marked on the back surface. The wafer is cemented face down to a microscope slide with Crystalbond.
In Situ Annealing Observations of Silicon Cross-Sectional TEM Specimens
Authors: Fiore E.M. , Herring R.A. 
Published: June 2020

With conventional transmission electron microscopy (TEM), dynamic events are pieced together with micrographs from a multitude of specimens annealed at different temperatures over the range of interest. Real-time imaging of dynamic events in the microscope provides the ability to view the entire anneal temperature span with one specimen. As reported by Parker, cross-sectional TEM can be used to observe real-time kinetic phenomena in silicon. Fiore and Herring later reported a new technique for preparing cross-sectional specimens that are annealable to temperatures as high as 1300°C. Both of these recently developed techniques have been used to observe the amorphous-to-crystalline phase transformation and defect network formation in high-energy ion implanted silicon.Cross-sectional specimens were annealed in a Philips CM 12 transmission electron microscope equipped with a heating holder. The specimens were prepared from [111 ]-oriented silicon wafers implanted with 5.5 Mev Ga ions at a dose of lO15 cm-2. Using a ramp-up temperature from ∽30°C to 1000°C over a 5-minute period, the dynamic events were recorded on 3/4-inch video tape from a TEM TV system.
D-spacing/formula index for compound identification using electron diffraction data
Authors: Mighell A. D. , Himes V. L. , Anderson R. , Carr M. J. 
Published: June 2020

NBS CRYSTAL DATA and the PDF-2 are large databases containing chemical, crystallographic and physical data on all classes of materials. From these databases, a derivative database has been prepared that is specifically designed for electron diffractionists. This database contains up to 60 calculated d-spacings for each of 70,000 inorganic compounds. An efficient computer program permits the identification of compounds by matching chemical and d-spacing data obtained from the unknown against the entire database.A Printed D-SPACING/FORMULA INDEX has been prepared that contains a critical subset of the chemical and crystallographic data contained in the electron diffraction computer database. This printed index is designed to be used independently or in conjunction with the computer database. The INDEX contains one line of data for each of approximately 70,000 inorganic compounds. Each line contains a number of data items including: element types present; the first ten low-angle d-spacings; chemical formula; mineral name; lattice type; chemical class indicator; and unique CD and PDF numbers.
Copper precipitate formation by internal reduction of (Ni,Cu)O
Authors: Shao Beiling , Merkle K. L. , Reddy J. F. , Wiley C. L. 
Published: June 2020

Studies of the structure and properties of metal-ceramic interfaces have recently become of considerable interest due to the need for a basic understanding of ceramic-metal bonds, which are increasingly used in ceramic technology. A convenient means to experimentally study such interfaces is by internal oxidation of metal alloys or by the internal reduction of oxide systems. In this manner low-energy interface structures are expected to be formed which provides a means for testing theoretical concepts regarding the energetics and structure of heterophase interfaces.NiO-10at% Cu-doped polycrystalline boules were grown by the Verneuil process in an arc-image furnace. The reagent-grade starting powder from which the boule was grown was produced by the amorphous citrate process. The polycrystalline boule was cut into slices which were annealed separately at 900, 950, 1000, 1100, 1300 and 1500°C under CO2/CO atmospheres for 3 to 6 days.
Gallium ZSM-5 type zeolites: A catalytical and structural electron microscopy study
Authors: Acosta Dwight R. , Schifter Isaac , Contreras José L. 
Published: June 2020

Synthesis of stereo selective zeolites using Gallium as partial or total substitute instead of aluminum, may lead to obtention of a novel class of zeo lites with modification of channel apertures, cage size and total acidity. Reaction velocity and selectivity for isomerization and cracking processes, for instance, are influenced by acid force of protonic sites, which may be selective or active for particular catalytic reactions.Zeolites Z-683 and Z-691 with a 50% and 100% of A1 atoms substituted respectively, were synthesized using a modified method for ZSM-5 zeolite crystallization as described in the literature. The samples obtained were studied using ammonia (NH3) thermodesorption techniques. X-ray diffraction, high resolution electron microscopy, selected area electron diffraction and optical diffractometry methods were used in order to determine structural characteristics of zeolites above mentioned.Figure 1 shows the results of NH3 thermodesortion studies for three zeolites: Z-601 (ZSM-5), Z-683 (50% A1 - 50% Ga) and Z-691 (100% Ga).