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Progress In Element Analysis On A High-Voltage Electron Microscope, W. F. Tivol, D. Barnard, T. Guha

Scanning Electron Microscopy

X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements.

XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled.

Oxidation Of Aluminum Studied By Ion Scattering Spectroscopy (I.S.S) In A Scanning Auger Microscope, M. Gautier, J. P. Duraud, J. P. Vigouroux, C. Le Gressus, R. Shimizu

Scanning Electron Microscopy

The set up of an ion gun, producing a focused beam in the analysis chamber of a Scanning Auger Microscope permits ion scattering experiments: surface studies performed by electron spectroscopies can then be enlarged by Ion Scattering Spectroscopy (I.S.S.) to get additional information.

I.S.S. appears to be very sensitive to the cleanliness of the surface: comparison between Electron Energy Loss Spectroscopy (E.E.L.S.) and I.S.S. studies on clean samples show that I.S.S. can still detect oxygen even when it is not detectable by E.E.L.S.

Preliminary results on oxidation of Al (111) and Al (100) give oxidation curves in good agreement with …

Cross-Sectional Analysis Of Silicon Metal Oxide Semiconductor Devices Using The Scanning Electron Microscope, Daniel S. Koellen, David I. Saxon, Kenneth E. Wendel

Scanning Electron Microscopy

A technique has been developed which enables one to cross-section specific devices or features for examination with the scanning electron microscope (SEM). This method is used for investigation of all facets of microelectronic circuit manufacture from research and development to failure analysis of the finished product.

Selective etching is used to provide contrast to each processed layer. Etch type and sequence, used for delineation, are important to understand since they may add artifacts to the cross-section, leading to erroneous analysis conclusions. The etchant and etch conditions used will be dictated by the information needed from a particular sample.

Etching systems …

Factors Influencing The Degree Of Saturation Of The Surface And Intermediate Waters Of The North Pacific Ocean With Respect To Aragonite, Richard A. Feely, Robert H. Byrne, Peter R. Betzer, James F. Gendron, James G. Acker

Marine Science Faculty Publications

New carbonate chemistry data obtained during a 1982 cruise have been combined with earlier GE‐OSECS and INDOPAC data to determine the degree of aragonite saturation of surface and intermediate waters of the North Pacific. Large gradients in saturation state occur in the region of the Subarctic Front in the north‐south direction and across the Subtropical Gyre in the east‐west direction. These gradients are primarily due to the extensive mixing that occurs in the intermediate waters of the western North Pacific. The major variations in saturation state were primarily related to the carbonate ion concentration, which, in turn, is primarily a …

Digital Processing Of Electron Energy Loss Spectra And Images, R. D. Leapman, K. E. Gorlen, C. R. Swyt

Scanning Electron Microscopy

Processing in electron energy loss spectroscopy involves both data acquisition and analysis. The interface of an analytical electron microscope to a laboratory computer with a satellite microcomputer dedicated to data acquisition results in a system with a high degree of flexibility. In spectrum acquisition, channels may be selected around specific core edges, or dwell times may be varied continuously as a function of energy loss to reduce the dynamic range of the signal. Data transfer to the host computer allows further analysis such as the removal of plural scattering by spectral deconvolution. Elemental maps and line-scans can be recorded with …

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m³. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m³. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …

Alterations Of The Intracellular Water And Ion Concentrations In Brain And Liver Cells During Aging As Revealed By Energy Dispersive X-Ray Microanalysis Of Bulk Specimens, Gy. Lustyik, I. Zs.-Nagy

Scanning Electron Microscopy

Age dependence of the intracellular concentrations of monovalent ions (Na+, K+ and Cl-) was examined in 1, 11 and 25-month-old rat brain and liver cells by using energy dispersive X-ray microanalysis. The in vivo concentrations of Na+, K+ and Cl- ions were calculated from two different measurements: The elemental concentrations were measured in freeze-dried tissue pieces, and the intracellular water content was determined by means of a recently developed X-ray microanalytic method, using frozen-hydrated and fractured bulk specimens as well as subsequent freeze-drying.

All the single monovalent ion concentrations and consequently, also the total monovalent ion content showed statistically significant …

Intracellular Localization Of Heavy Metals In Yeast By X-Ray Microanalysis, Ljerka Kunst, Godfried M. Roomans

Scanning Electron Microscopy

The intracellular localization of heavy metals in yeast cells was studied by means of energy-dispersive X-ray microanalysis. The yeast, Saccharomyces cerevisiae, was pretreated with phosphate and then loaded with different metal ions, by suspending the cells in salt solutions (Ni, Zn, Cd, Pb, Al and Cr). For the analysis, the cells were embedded in gelatin, rapidly frozen, and thin cryosections were cut on a dry knife.

A considerable uptake of divalent cations by the yeast cells was found to occur. The cations were bound to the polyphosphate granules localized in or close to the cell vacuoles. Immediately after phosphate …

Study By Scanning Electron Microscopy And Electron Spectroscopy Of The Cascade Of Electron Multiplication In An Insulator Submitted To An Electric Field, J. P. Vigouroux, J. P. Duraud, C. Le Gressus, G. Petite, P. Agostini, C. Boiziau

Scanning Electron Microscopy

An original method for revealing the dielectric heterogeneities on an insulating surface has been developed on creation of an electron multiplication cascade inside the insulator placed in an electric field. The steps of the physical process are: (i) excitation of electrons into the conduction band, (ii) electric field acceleration of the conduction electrons, (iii) ionization of the valence levels, (iv) creation of many more new defects in the vicinity of dielectric heterogeneities, (v) charge localization on defects and appearance of a local residual potential. The potential map is observable by scanning electron microscopy after propagation of the ionizing cascade, but …

High Accuracy And Automatic Measurement Of The Pattern Linewidth On Very Large Scale Integrated Circuits, H. Yamaji, M. Miyoshi, M. Kano, K. Okumura

Scanning Electron Microscopy

High accuracy measurement of pattern linewidth is particularly important in Very Large Scale Integrated Circuits (VLSI) manufacturing.

The measurement of pattern linewidth has been done by optical methods. However, the optical methods have several problems: as the measured value depends on slope angle at pattern edge, thickness and optical property of film and also substrate, there exists a large difference in size (0.3 μm) between the defined edge and the true edge in case of photoresist linewidth measurements. Especially, the optical methods have severe problems to measure bottom of pattern edge and are unsuitable to measure pattern linewidth in VLSI's …

A Wien Filter Energy Loss Spectrometer For The Dedicated Scanning Transmission Electron Microscope, P. E. Batson

Scanning Electron Microscopy

A Wien filter electron spectrometer has been added to a VG Microscopes, Ltd. HB501 STEM to improve the energy resolution and accuracy of energy loss analysis combined with a high spatial resolution. An energy resolution of 130meV is obtained with a 2mR collection angle at the specimen. The 0.28eV wide field emission energy profile therefore dominates the energy resolution for the device. The energy axis is automatically calibrated by the electrostatic method of scanning, yielding an accuracy and stability of 30meV. A preliminary energy resolution of 0.5eV is demonstrated for 20mR full collection angles at the specimen. Results of experiments …

Scanning Electron Microscopy Of The Lateral Ventricle Of The Pigeon Brain, P. Mestres, K. Rascher, J. D. Delius

Scanning Electron Microscopy

Adult pigeons of both sexes were used for this study. Depending upon the distribution of various surface profiles, for example cilia, microvilli and blebs, ependymal areas with differing surface patterns were distinguished in the lateral ventricle. The topographical locations of these areas with respect to the underlying forebrain nuclei were determined in accord with the atlas of Karten and Hodos (1967). The medial surface (A) of the ventricle was much more densely ciliated than the lateral surface (B). There did not appear to be any correlation between a given surface pattern and a specific type of underlying nervous tissue. Comparison …

Characterization Of Carbonaceous Materials By Correlated Electron And Optical Microscopy And Raman Microspectroscopy, C. Beny-Bassez, J. N. Rouzaud

Scanning Electron Microscopy

Carbonaceous materials differ according to their chemical composition (types of heteroatoms), their structure and their microtexture. So, it is interesting to find methods for characterizing them. We choose to correlate data from Raman microspectroscopy, optical microscopy and transmission electron microscopy. First, we use both graphitizable or non-graphitizable reference carbon series of simple chemical composition in order to follow the structural transformation of the carbonaceous materials according to the evolution of these data throughout heat-treatment of these samples. Then, the coals of different ranks are studied.

The Raman results are correlated with those from electron microscopy, particularly by plotting, for the …

Advances In Non-Contact Thermal-Wave Imaging With Infrared Detection, F. H. Dacol, H. Ermert, R. L. Melcher

Scanning Electron Microscopy

We are making further advances in non-destructive and non-contact thermal imaging with infrared detection. We employ a chopped and scanned electron beam as heat source, a cooled HgCdTe infrared detector as temperature sensor, and digital processing of the measured temperature pattern for display and storage. The results give a convincing, high contrast image of subsurface structures.

Kentucky Warbler (Vol. 60, No. 4), Kentucky Library Research Collections

The Kentucky Warbler

No abstract provided.

Life History Patterns And The Comparative Social Ecology Of Carnivores, Marc Bekoff, Thomas J. Daniels, John L. Gittleman

Ethology Collection

No abstract provided.

Agricultural Experiment Station News November 1984

Agricultural Research Division: News and Annual Reports

CONTENTS:
CAPITALIZING ON COMPREHENSIVE REVIEWS
NEW FACULTY APPOINTMENTS
PARTIAL RETIREMENTS
AGRICULTURAL EXPORTS
INDIRECT COST RATES
NEW OR REVISED PROJECTS
FEDERAL RESEARCH BUDGET APPROVED
SCHAEFER JOINS IANR
CAPITAL CONSTRUCTION PROGRESS ACCOMPLISHMENT REPORT
RESEARCH FUNDING ASSISTANCE
RESEARCH EXPENDITURES FOR 1983-84
RESEARCH GRANTS AND CONTRACTS RECEIVED OCTOBER 1984

University Of Richmond Herbarium, W. John Hayden

Biology Faculty Publications

The Department of Biology at the University of Richmond, Richmond, Virginia, maintains an herbarium of approximately 15,000 specimens. Although recently assigned the acronym URV, this collection has not yet been included in Index Herbariorum and, consequently, few botanists outside of Virginia are aware of its existence. This note provides a brief account of the history of URV, a summary of its contents, and a short bibliography of works pertaining to the collection.

Number 16 (November 1986), Southern Fishes Council

Southeastern Fishes Council Proceedings

Biology and Conservation of the Slackwater Darter, Etheostoma boschungi (Pisces: Percidae). By H.T. Boschung and D. Nieland, 4 pp.

Fishes of the North Fork Holston River System, Virginia and Tennessee. By J.C. Feeman, 7 pp.

Fishes of the North Fork Holston River System, Virginia and Tennessee. By J.C. Feeman, 7 pp.

Reintroduction of an Undescribed Species of Elassoma into Pryor Branch, Limestone County, Alabama. By M.F. Mettee and J.J. Pulliam, 2 pp., plus News Notes.

Biology And Conservation Of The Slackwater Darter, Etheostoma Boschungi (Pisces: Percidae), Herbert T. Boschung, David Nieland

Southeastern Fishes Council Proceedings

No abstract provided.

Reintroduction Of An Undescribed Species Of Elassoma Into Pryor Branch, Limestone County, Alabama, Maurice F. Mettee, John J. Pulliam Jr.

Southeastern Fishes Council Proceedings

No abstract provided.

Fishes Of The North Fork Holston River System, Virginia And Tennessee, Joe C. Feeman Jr.

Southeastern Fishes Council Proceedings

No abstract provided.

Fishes Of The Buttahatchee River System Of Alabama And Mississippi, J. Malcom Pierson, C. A. Schultz, Herbert T. Boschung

Southeastern Fishes Council Proceedings

No abstract provided.

Book Review: Mammals Of The Northern Great Plains By J. K. Jones, Jr., D. M. Armstrong, R. S. Hoffmann, And C. Jones, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Mammals of the Northern Great Plains is an attractive clothbound book that comes in a colored dust jacket showing a female pronghorn walking in the snow. The book is produced in a double-column format set in a 47½ by 32½ pica typebed (I personally do not like the unjustified right-hand margins on both columns). The book contains 206 figures most of which are set in a single column. Of the 206 figures, 80 are distribution maps, 104 are photographs mostly of living animals, 20 are drawings used to illustrate keys or points made in the text, and two are maps …

Crop Residue Removal And Soil Productivity With No-Till Corn, Sorghum, And Soybean, J. W. Doran, Wallace Wilhelm, J. F. Power

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crop residues have been considered during the past decade as alternate energy sources to supplement dwindling fossil fuel sources and enhance energy independence in the United States. Agricultural scientists have demonstrated the importance of crop residues in reducing soil erosion, enhancing the soil physical environment for plant growth, and as a reserve for major crop nutrients. In eastern Nebraska, we evaluated the effects of various amounts of surface crop residues (aboveground dry matter remaining after harvest) on dryland production of no-till corn (Zea mays L.), sorghum [Sorghum bicolor (L.) Moench], and soybean [Glycine max (L.) Merrill] over …

Genetics And Epidemiology Of Gallbladder Disease In New World Native Peoples, K M Weiss, R E Ferrell, C L Hanis, P N Styne

Faculty, Staff and Student Publications

Native peoples of the New World, including Amerindians and admixed Latin Americans such as Mexican-Americans, are highly susceptible to diseases of the gallbladder. These include cholesterol cholelithiasis (gallstones) and its complications, as well as cancer of the gallbladder. Although there is clearly some necessary dietary or other environmental risk factor involved, the pattern of disease prevalence is geographically associated with the distribution of genes of aboriginal Amerindian origin, and levels of risk generally correspond to the degree of Amerindian admixture. This pattern differs from that generally associated with Westernization, which suggests a gene-environment interaction, and that within an admixed population …

Influence Of Sample Treatment On Apparent Hydrocyanic Acid Potential Of Sorghum Leaf Tissue, Francis A. Haskins, Herman J. Gorz, R. M. Hill, J. Brakke Youngquist

Department of Agronomy and Horticulture: Faculty Publications

When dhurrin [p-hydroxy-(S)-mandelonitrile-β-D-glucoside], the cyanogenic glucoside of sorghum [Sorghum bicolor (L.) Moench], is hydrolyzed by autoclaving, p-hydroxybenzaldehyde (p-HB) is released. The spectrophotometric determination of p-HB concentration in autoclaved sorghum leaf extracts provides a measure of the hydrocyanic acid potential (HCN-p) of leaf tissue. Extracts of field-grown sorghum leaves contained substances that interfered with this procedure, but ether extraction effectively separated p-HB from these interfering materials. We observed that when flag leaf tissue from field-grown sorghum was dried at 75°C and then autoclaved, HCN-p values were about three times as high …

Scanning Electron Microscopy Methodology For Study Of The Pathophysiology Of Calcification In Bioprosthetic Heart Valves, Alan C. Nelson, Frederick J. Schoen, Robert J. Levy

Scanning Electron Microscopy

Scanning electron microscope (SEM) morphologic analysis combined with energy dispersive characteristic X-ray (EDX) microprobe analysis provides insight into the mechanisms associated with disease-related crystal formation in biological materials. SEM and EDX were employed in analyzing specimens which were embedded in standard fashion in glycolmethacrylate (JB-4). The specimen surfaces under electron microscope investigation resulted from microtomy used in the preparation of reference light microscope histological sections; thus histology served as a direct reference for the SEM and EDX analyses.

The particular application of these methods was in the study of bioprosthetic heart valve calcification, largely responsible for clinical failure of these …

Detection System For Scanning Electron Microscope, J. Hejna, Z. Radzimski, A. Buczkowski

Scanning Electron Microscopy

The kind of information and the quality of the backscattered electron (BSE) images depend upon numerous features of the detector. Therefore, various types of detectors should be used simultaneously to obtain as much of information as possible. The detection system presented here contains a large area semiconductor detector and a BSE to secondary electrons (SE) converter system. These two different kinds of detectors give different BSE images. After subtracting the signal of a semiconductor detector from that of a converter system, an image with good topography and reduced material contrast can be achieved.

Ultrasonic Microdissection Of Rat Cerebellum For Scanning Electron Microscopy, C. E. Arnett Iii, F. N. Low

Scanning Electron Microscopy

The cerebelli of rats were initially fixed with aldehydes (modified Karnovsky's fixative; 503 mOsM/L) by cardiac perfusion. Blocks of tissue were razor-cut, usually longitudinal to folia, and immersed in the same fluid for 2-4 hours. Three separate methods of treatment followed: (1) immersion in 1% aqueous boric acid, or (2) in 2% phosphate buffered OsO₄ followed by boric acid or (3) in an 8/2 mixture of boric acid and OsO₄. After 18-48 hours immersion the blocks were dehydrated in ascending grades of acetone. They were then exposed to ultrasound in 100% acetone at frequencies of 80 kHz …