Digital Commons Network^™

The Use Of Lanthanum Hexaboride Cathodes In Electron Beam Lithography, T. R. Groves, W. Stickel, H. C. Pfeiffer

Scanning Microscopy

Lanthanum Hexaboride (LaB₆) is best known as a thermionic electron emitter with high brightness and long lifetime. It is used in a variety of electron optical instruments, including systems for electron beam lithography of integrated circuits.

The major limitation in present-day electron beam lithography systems is throughput, or the ability to process a wafer or mask in a reasonable time. The design of the electron optics is, therefore, governed by a desire to make the writing time as short as possible, together with the other system overhead times. This places inevitable constraints on the electron source.

The simplest …

A Calculation Method For Quantitative X-Ray Microanalysis For Microparticle Specimens By Monte Carlo Simulation, Yen-Cai Ho, Jia-Guang Chen, Min Hu, Xin-Lei Wang

Scanning Microscopy

A calculation method for quantitative X-ray microanalysis (QXMA) for microparticle specimens of a compound with various shapes is proposed in this paper. On the basis of a simplified physical model, the scattering of electrons in particles is calculated by Monte Carlo simulation. We have derived a series of evaluation formulae of the absorption and fluorescence of characteristic X-rays for the particles with regular shapes. With the use of these theories, along with an iteration calculation, compositions of microparticle specimens can be obtained from the measured X-ray intensity ratios. In order to examine the reliability of the method, a large number …

Scanning Electron Microscopy Of Vascular Corrosion Casts In Comparative Studies On Renal Vascular Structure, H. Ditrich, H. Splechtna

Scanning Microscopy

In comparative microcorrosion casting studies on renal vascular systems the following demands should be met: The preparation procedure (anaesthesia, operation, flushing of the blood vascular system, ...) should be in accord with the specific physiological properties of the animal under investigation and the casting procedure (injection, curing, maceration, ...) should be kept constant as far as possible. If these points are considered, comparative data, even of quantitative nature, can be obtained from corrosion casts. Examples of results at the organ, single vessel and intercellular level as well as correlation of the results with physiological data are given.

Enamel Structure In Odontocete Whales, M. Ishiyama

Scanning Microscopy

With regard to the enamel structure of mammals, a large number of studies have been reported in the past. Of them, however, the enamel structure of odontocetes has not yet been sufficiently elucidated. The author therefore observed the enamel structure of 11 species in 7 families of living odontocetes.

A clear prism structure in the enamel is noted in delphinids and Pontoporia blainvillei. Neophocaena phocaenoides has a very simple-structured prism, but even this structure is obvious only in the deep layer of the enamel, disappearing gradually from the mid layer to surface layer.

The prism pattern of delphinids differs …

Utah Science Vol. 48 No. 1, Spring 1987

Utah Science

4 A SEEDBED FOR INNOVATION Doyle J. Matthews

5 A MIRACLE OCCURS ... Plant Science Department

25 AGGIE ICE CREAM V. T. Mendenhall A brief history.

41 THE SCIENCE OF LIVESTOCK PRODUCTION Animal, Dairy & Veterinary Sciences Department

55 GOOD FOOD AND SOLID NUTRITION Nutrition and Food Sciences Department

Mineralization Of Normal And Rachitic Chick Growth Cartilage: Vascular Canals, Cartilage Calcification And Osteogenesis, Irving M. Shapiro, Alan Boyde

Scanning Microscopy

This paper reviews recent work in the authors' laboratories that has led to new observations and thoughts concerning the mineralization of normal and rachitic chick growth cartilage. The proximal tibial growth cartilages of normal and rachitic chicks were rapidly frozen and prepared for SEM and biochemical studies. Using a scanning microfluorimetric technique we showed that at the mineralization front of normal and rachitic cartilage there is an abrupt change in chondrocyte metabolism. Thus cells in this region exhibited an increase in NADH and oxidative metabolism. In rickets, there was a decrease in the reduced pyridine nucleotide content of each of …

The Application Of An Improved Laser Microprobe In Art Analysis, Gary W. Carriveau, Lin Chang-Shan, David M. Coleman

Scanning Microscopy

The laser microprobe has many features which would seem to make it an ideal tool for analysis of art objects. These include high spatial resolution, extremely small sample requirements, a wide variety of possible elements for analysis over a large dynamic range of concentrations and capability of sampling a variety of sizes and shapes. Problems of surface damage, spectral insensitivity, and poor accuracy and precision had limited the applicability of this technique in the past. Following a systematic study of these limitations, improved performance has been achieved. In addition, a mathematical model of the sampling process has been developed in …

Mass Fractionation And Energy Distribution Of Sputtered Monatomic Positive Ions, U. Södervall, H. Odelius, A. Lodding, E. U. Engström

Scanning Microscopy

Secondary ion yields in sputtering depend significantly on the mass of the emitted species. Ionization as observed by secondary ion mass spectrometry is characterized by isotope fractionation; the yield of an isotope ion of mass M_i being proportional to M^-𝝰, where a varies with the emitted species, its kinetic energy E_k, and the matrix.

By means of SIMS, isotope ratios have been measured for ions at energies up to ca 120 eV in different metallic matrices. For singly charged positive monatomic ions, a has been found to range between O and ca 4. While a …

Distinguishing Adult Pectinophora Scutigera (Holdaway) According To Larval Diet By X-Ray Microanalysis, R. A. Lewis, P. W. Walker

Scanning Microscopy

In an exploratory study using scanning electron microscope (SEM) based energy dispersive spectroscopy (EDS) of X-rays, differences were detected in the elemental compositions of adult Pectinophora scutigera raised on contrasting diets - cotton, Hibiscus tiliaceus and laboratory medium.

X-ray spectra were collected from the thorax and abdomen of 13 male and 13 female moths. X-ray yields are optimised by ashing the insects for 1 h at 400-600°C, and by operating the SEM at 25 kV.

Spectrum matching, element matching, discriminant analysis and principal components analysis were used to classify the specimens on the basis of diet with 54-100% success. Spectra …

A Comparative Study On In Vitro Invasion Rates By Melanoma Cells In The Human Amniotic Basement Membrane Model Versus In Vivo Tumor Nodule Formation In C57bl6 Mice, B. Persky, G. W. Chmielewski

Scanning Microscopy

Invasion by murine B16-F10 melanoma cells was studied using the human amniotic basement membrane (HABM) assay. B16-F10 cells were collected after a single passage through the amnion and grown to near confluency. The cycle of plating, passaging, collecting, and culturing B16-F10 cells was repeated five times. The invasion rate for B16-F10 cells remained relatively unchanged after six passages through the amnion. Injection of first-passage B16-F10 cells into C57BL6 mice resulted in 29 lung tumors per animal whereas sixth-passage cells resulted in 300+ lung tumors. While there exists no correlation of the number of cells penetrating the amnion with colonization number, …

On-Line Analysis Of Electron Back Scatter Diffraction Patterns. I. Texture Analysis Of Zone Refined Polysilicon, D. J. Dingley, M. Longden, J. Weinbren, J. Alderman

Scanning Microscopy

A technique has been developed for determining crystal orientations on-line from bulk polycrystalline materials using wide angle back scatter electron diffraction patterns. The patterns were imaged on a phosphor screen and viewed using a low light level television camera. A computer generated cursor superimposed on the diffraction pattern, permitted the coordinates of zone axes to be determined. These were interpreted by the computer to yield the crystal orientation. The accuracy of the technique for absolute orientation was shown to be of the order 1° and the precision for relative orientation better than 0.5°. The technique was used to investigate texture …

Three Dimensional Secondary Ion Mass Spectrometry Imaging And Retrospective Depth Profiling, D. R. Kingham, A. R. Bayly, D. J. Fathers, P. Vohralik, J. M. Walls, A. R. Waugh

Scanning Microscopy

Secondary Ion Mass Spectrometry (SIMS) for three dimensional analysis of materials is an exciting and rapidly developing technique. We describe a framestore datasystem for ion microprobe instruments and present images and three dimensional SIMS data acquired and processed with this system. The concept of retrospective depth profiling is introduced, particularly as a means to optimise concentration detection limits. We examine the dependence of concentration detection limits on spatial resolution.

Morphological Criteria For Comparing Effects Of X-Rays And Neon Ions On Mouse Small Intestine, K. E. Carr, T. L. Hayes, M. Indran, S. J. Bastacky, G. Mcalinden, E. J. Ainsworth, S. Ellis

Scanning Microscopy

Several techniques have been used to assess changes in different parts of mouse small intestine three days after a single dose of either 16.5 Gy X-rays or 11 Gy neon beam. The doses were chosen to be approximately equivalent in terms of their effect on the number of microcolonies present.

In qualitative terms, villous damage was seen after both types of radiation exposure: collared crypts, similar to those seen in biopsies taken from patients suffering from coeliac disease, were conspicuous after neon irradiation.

In semi quantitative terms the doses used, although estimated from previous work to give biologically equivalent damage, …

Theory Of Electron Beam Induced Current And Cathodoluminescence Contrasts From Structural Defects Of Semiconductor Crystals; Steady-State And Time-Resolved Problems, A. Jakubowicz

Scanning Microscopy

Electron-beam-induced current and cathodoluminescence are powerful tools for revealing and characterizing point-like defects, dislocations, and grain boundaries in semiconductor crystals.

This paper reviews the theoretical studies of electron-beam-induced current and cathodoluminescence contrasts from local structure defects of semiconductor crystals (the geometrical aspects of both contrasts, the assessment of the defect properties from the contrast, the evaluation of bulk parameters in the presence of defects, and time-resolved characterization of defects), including recent developments in this area.

Electron Energy Loss Spectroscopy And Biology, C. Jeanguillaume

Scanning Microscopy

Although most of the recent work concerning EELS in electron microscopy is related to instrumental developments, there are a number of papers relating to biological applications. The aim of this paper is to attempt to present in a pedagogical manner the subject of EELS and biology. The biologist will be taught about EELS and the physicist about the possible biological applications of this technique. The paper thus consists of: 1) a presentation of a minimum background on EELS required for biologists to realize what its potential is; 2) a description of why EELS is a useful tool in biology; 3) …

Immuno-Scanning Electron Microscopy Of Normal And Leukemic Leukocytes Labeled With Colloidal Gold, D. Soligo, G. Lambertenghi-Deliliers, E. De Harven

Scanning Microscopy

The immunogold method, utilizing 40 nm colloidal gold particles which can be selectively visualized with the scanning electron microscope (SEM) in the backscattered electron imaging mode was used for the study of blood cells incubated with various monoclonal antibodies. Numerous antileukocyte monoclonal antibodies still recognize lightly glutaraldehyde prefixed antigens and can be used to identify various blood cell types and even to recognize their different maturation stages.

Clearcut differences in surface morphology exist among peripheral blood normal leukocytes and even among the principal lymphocyte subclasses. Marked heterogeneity in surface morphology is, on the other hand, evident when studying precursors or …

Exploring Folk Art, Michael Owen Jones

All USU Press Publications

Jones explores the human impulse to create, the necessity for having aesthetically satisfying experiences, and the craving for tradition. He also considers topics such as making chairs, remodeling houses, using and preserving soda-fountain slang, preparing and eating food, and sculpting lifelike figures out of cement.

Selecting An Innerspring Mattress, Leona K. Hawks

All Archived Publications

No abstract provided.

Selecting Ceramic Tile, Leona K. Hawks

All Archived Publications

No abstract provided.

Finding The Appropriate Forage Value For Analyzing The Feasibility Of Public Range Improvements, United States Department Of Agriculture, Forest Service

Forestry

To complete economic analysis of range improvements completed on the Oak Creek Management area of central Utah, we needed an estimate of the value of forage. A review of the literature revealed several methods of estimating forage values. These methods yielded eight estimates of public rangeland forage ranging from $1.23 to $30 per animal unit month (AUM). Six of the estimates were based on actual market transactions or current administered prices and were the most reflective of actual economic processes. The best estimates of value were those for leasing similar rangeland in the immediate area.

Western Spruce Budworm, M. H. Brooks, J. J. Colbert, R. G. Mitchell, R. W. Stark

The Bark Beetles, Fuels, and Fire Bibliography

No abstract provided.

Hemispherical Emissivity Of V, Nb, Ta, Mo, And W From 300 To 1000 K, S. X. Cheng, P. Cebe, L. M. Hanssen, D. Mark Riffe, A. J. Sievers

All Physics Faculty Publications

The hemispherical emissivities of five transition elements, V, Nb, Ta, Mo, and W, have been measured from 300 to 1000 K, complementing earlier higher-temperature results. These low-temperature data, which are similar, are fitted to a Drude model in which the room-temperature parameters have been obtained from optical measurements and the temperature dependence of the dc resistivity is used as input to calculate the temperature dependence of the emissivity. A frequency-dependent free-carrier relaxation rate is found to have a similar magnitude for all these elements. For temperatures larger than 1200 K the calculated emissivity is always greater than the measured value, …

Proceedings From The 24th Annual Marschall Italian Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.

Selecting A Carpet And Pad, Leona K. Hawks

All Archived Publications

No abstract provided.

Selecting Vinyl Flooring, Leona K. Hawks

All Archived Publications

No abstract provided.

Selecting A Comfortable Chair, Leona K. Hawks

All Archived Publications

No abstract provided.

Selecting A Comfortable Mattress, Leona K. Hawks

All Archived Publications

No abstract provided.

Selecting Plastic Laminates, Leona K. Hawks

All Archived Publications

No abstract provided.

San Juan Resource Management Plan, Proposed Resource Management Plan, Final Environmental Impact Statement, Volume 1, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The San Juan proposed RMP and final EIS is bound in two volumes. Volume 1 contains the proposed RMP and part of the final EIS; volume 2, the remainder of the final EIS.

San Juan Resource Management Plan, Proposed Resource Management Plan, Final Environmental Impact Statement, Volume 2, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

Volume 2 of the San Juan Proposed Resource Management Plan (RMP) and Final Environmental Impact Statement (EIS) contains copies of the public and agency comments received on the draft and the Bureau of Land Management's (BLM's) responses to those comments.