Biology Commons^™

Optimization Of Stroboscopic Electron Deflection Systems, H. Rose, J. Zach

Scanning Electron Microscopy

Highly corrected electron-beam blanking systems (EBBS) are required for analyzing fast periodic processes at submicron spatial resolutions by stroboscopic methods. The deleterious degradation of the probe during the blanking operation can be avoided by a new straight-vision deflection system. Chopping of the beam is performed within this system by deflecting it across a knife edge. Calculations demonstrate that this system should be able to generate almost rectangular beam pulses with rise times of a few picoseconds and spot sizes smaller than 0.5 µm. The proposed EBBS consists of two wedge-shaped plate capacitors located symmetrically about the midplane of a rotationally …

Electron Image Simulation: A Complementary Processing Technique, Michael A. O'Keefe

Scanning Electron Microscopy

At present it is difficult to use direct image processing techniques to determine the specimen structure from electron micrographs obtained under non-linear imaging conditions, and impossible when the effects of dynamical scattering are strong (as in the case of thicker specimens). However, computing techniques are available to simulate high-resolution transmission electron microscope (HRTEM) images of postulated model structures. With these techniques it is possible to confirm the validity of interpretation of recorded micrographs, to help analyze crystal defects, to characterize microscope parameters, and to determine the ranges of validity of commonly used interpretive approximations. Because processed micrographs can lead to …

A Computer Controlled Scanning Transmission Electron Microscope Equipped With An Energy Analyzer For Special Investigations On Electron Diffraction- And Channeling Patterns, W. Hylla, H.-J. Kohl, H. Niedrig, D. Wendtland

Scanning Electron Microscopy

A scanning electron microscope was equipped with a double tilting stage, driven by stepping motors, to investigate electron channeling patterns (ECPs) and large angle convergent beam patterns (LACBPs) of single crystals. Transmitted electrons may be energy-selected by a magnetic sector-field energy analyzer. The recording of experimental data and the experimental arrangement are controlled by a microprocessor system, including a picture storage unit of 512 x 512 pixels of 16 bit. Recorded patterns can be stored on 1 Megabyte floppies.

A set of useful programs allows one to perform calculations with stored patter ns, e.g., contrast enhancement or -inversion, noise reduction, …

Displays: Market And Technologies, Steve Blazo

Scanning Electron Microscopy

Displays provide the essential human interface to virtually all electronics instrumentation. The market is large with new applications appearing every year; sometimes with profound impact. Digital watches with liquid crystal displays appeared in the early 1970s and have virtually wiped out the mechanical timepiece industry. Personal computers with cathode ray tube (CRT) displays are proliferating with diverse applications in the industry and in the home. Work stations with high-resolution color displays are changing the way architects, draftsmen, and IC designers perform their job. The CRT is the dominant technology in today's market, and will, no doubt, continue to be for …

Field Emission Source Optics, L. W. Swanson

Scanning Electron Microscopy

The use of field emission processes as a means of generating high brightness sources of both electrons and ions is becoming of increasing practical use in electron/ion optical systems. A review is given of the source optics and emission characteristics of a zirconium oxide coated, <100> oriented, tungsten (Zr0/W(l00)), thermal field emitter electron (TFE) source and a liquid metal ion source (LMIS). The primary interest at present is the use of these high field sources in microprobe focusing columns where beam sizes of < 0.5 µm and target current densities of ~ 1 to 10 A/cm² (in the case of a LMIS) and 10² to 10⁴ A/cm² (in the case …

Synthesis Of Electron Lenses, M. Szilagyi

Scanning Electron Microscopy

This paper is a review of different approaches to one of the most ambitious goals of Electron and Ion Optics: to produce elements and systems with prescribed first-order properties and minimal aberrations. Synthesis of such elements is usually done in two steps: the first is a search for a field distribution with the given properties and the second is the reconstruction of electrodes (pole pieces) that would produce this field distribution. The first problem can be solved by the use of different techniques: Calculus of Variations, Dynamic Programming or Function Minimization. The second one is more complicated and requires a …

Electron Beam Deflection Without Off-Axis Aberrations, H. C. Pfeiffer, M. A. Sturans

Scanning Electron Microscopy

A novel focusing/deflection system for high accuracy, high throughput E-beam lithography, denoted as Variable Axis Immersion Lens (VAIL), has been successfully demonstrated. The main attributes of this system include: l) Perpendicular landing at all points of a deflection field > (10 x 10 mm), 2) Elimination of transverse chromatic aberration, 3) High resolution ( < 0.2μm edge slope) over the entire deflection field, 4) Elimination of eddy current effects in the target area, and 5) Total magnetic shielding of the target from external fields.

Rhizosphere N2 Fixation In A Forest Ecosystem In Situ Assays And Evaluation Of The Acetylene Reduction Technique, Inger Börjesson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In situ assays of N₂ fixation activity, using the acetylene reduction technique, were performed in four successional stages of a Northern Wasatch Mountain subalpine forest ecosystem, elevation 2,800 m. Emphasis was made on rhizosphere fixation in association with Antennaria microphylla and Achillea millefolium. The vegetation period was approximately 100 days.

Assays were performed in Saran bags. A defined amount of propane was injected at initiation of the assay and acetylene was generated from CaC₂. Samples were analyzed for ethylene and propane. Data were evaluated assuming that the ethylene production was directly proportional to the increase in …

Plant Responses To Clinostating And Mechanical Stress: Growth And Flowering Responses, Chauncy Steed Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants rotated about a horizontal axis show certain growth responses. This research was designed to clarify which of the responses of clinostating are caused by gravity compensation and which are caused by mechanical stresses. Plants used were Xanthium strumarium L. (cocklebur) Chicago strain and Lycopersicon esculentum Mill. (tomato) cv. Rutgers. Six automated treatments that ran for five days were used to separate out the effects. Treatments were: 1) controls, 2) horizontal clinostat, 3) intermittent clinostat, 4) inversion (every 10 min), 5) invert and return, and 6) vertical rotation. Plant height and diameter changes were measured at ink dots with a …

Effects Of Physical And Emotional Stress, Catecholamines And Naloxone On Hdl And Ldl Cholesterol Levels In Rats And Man, Andrew G. Goliszek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of investigations were undertaken to determine whether physical or emotional stress, catecholamines or naloxone (B-endorphon blocker) would increase serum total cholesterol and LDL and HDL levels. Physical stress given daily over a period of time caused a steady increase in serum total cholesterol and LDL without a significantly altering high density lipoproteins (HDL) or serum triglycerides. Daily injections of epinerphrine in oil caused an increase in both serum total cholesterol and LDL levels while daily injections of norepinephrine did not. Reversal of the treatments caused a reversed response in both groups of rats. Similar increases in both total …

Natural Killer Activity In Gardner's Syndrome, Ann Marie Stembridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gardner's syndrome is an autosomal dominant disease presenting multiple colonic polyps with a predisposition for malignant change. In addition to colonic polyp formation by early adolescence, extracolonic lesions appear often prior to polyp formation. One theoretical mechanism for the origin of polyps and malignancies in Gardner's syndrome is a genetic defect in the natural killer cell activity of patients with this disease. Natural killer cells are a subpopulation of lymphocytes that spontaneously lyse tumor cells and virally transformed cells. A study was undertaken to determine the natural killer activity of patients with Gardner's syndrome.

A technique termed chromium release was …

Alteration In Serum Enzyme Levels, Activity Of Hepatic Monooxygenases, And Hepatocyte Morphology Due To Liver Enzyme Inducers In Microtus Montanus, Jeffrey Robert Hincks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microtus sp. have been used in microcosm simulations of polluted environments. In this study, female Microtus montanus (mountain vole), 8 - 12 weeks of age, were pretreated with phenobarbital (PB), ß-naphthoflavone (BNF), or Aroclor 1254 (PCB) for 3 consecutive days. Doses ranged from 5 to 80 mg/kg for each pretreatment, while control animals received saline or corn oil only. The voles were sacrificed 1 day after the last dose of PB and 2 days after BNF and PCB. Hepatic microsomal enzyme activity of aniline hydroxylase (AH), p-nitroanisole-O-demethylase (PNA) and cytochrome C reductase (CCR) were measured in relation …

Defensive Adaptations And Natural Enemies Of A Case-Bearing Beetle, Exema Canadensis (Coleoptera: Chrysomelidae), R. B. Root, Frank J. Messina

Biology Faculty Publications

The larval habit of constructing and carrying a portable case has evolved many times in the Holometabola. It is a widespread trait of the Trichoptera and Lepidoptera (e.g. the Coleophoridae and Psychidae). Among the Coleoptera, casebearing is found in four related subfamilies of the Chrysomelidae, the so-called camptosomates: Clytrinae, Cryptocephalinae, Chlamisinae, and Lamprosomatinae (B6ving and Craighead 1931). The larval case of many insects is thought to function primarily in defense by providing armor or camouflage (Otto and Svensson 1980). Here we describe the uses of the case and other defenses in a chlamisine beetle, Exerna canadensis Pierce, and speculate briefly …

The Pathogenicity Of Blue-Stain Fungi On Lodgepole Pines Attacked By Mountain Pine Beetle, Richard Grant Ballard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western regions of North America, mountain pine beetle, Dendroctonus ponderosae Hopk., infestations take a tremendous toll of pines , especially lodgepole pine, Pinus contorta Dougl. var. latifolia Engelm.. Mass attack by the beetles is a devastating event for the trees. As well as girdling the tree, a massive inoculation of blue stain fungus "complex" (composed of several species of Ceratocystis, numerous yeasts and other mycelial fungi) is made beneath the bark. These fungi colonize and destroy the parenchyma tissue system of the host sapwood, primarily the ray parenchyma and resin duct epithelium.

A blue stain is produced …

Plant Spacing: A Size Sensitive Model With Implications For Competition, Robert L. Bayn Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An algorithm is presented which partitions space among mapped plants according to their relative sizes and positions using one of eight rules for locating boundaries between individuals. The performance of those rules is examined using several natural and artificial data sets with diverse measures of individual size. The relative performance of the rules was the same for all natural data sets examined. The best rule, as measured by a high correlation between individual size and assigned space, placed the boundary at a distance between neighbors proportional to the relative sizes of neighbors as long as a maximum distance (also a …

The Characterization Of Carbamate Resistance In The Colorado Potato Beetle, Leptinotarsa Decemlineata (Say), In Comparison With The House Fly, Musca Domestica (L), Randy L. Rose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Resistant and susceptible populations of the Colorado potato beetle, Leptinotarsa decemlineata (Say), and the house fly, Musca domestica (L), were compared with respect to carbofuran and carbaryl toxicity in the presence and absence of the synergist, piperonyl butoxide. Resistance levels of the New Jersey population when compared with the susceptible Logan population by topical application of carbaryl and carbofuran were > 833 and 820, respectively. A resistance level of 583 was determined from carbofuran bioassays of Rutgers and NAIDM house flies. Similar levels of resistance development between these species suggests the possibility that similar resistance mechanisms may be involved.

Utilization of …

A Revision Of The North American Species In The Genus Euodynerus (Hymenoptera: Eumenidae), Ali Shallan Moalif

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty-eight species of Euodynerus Dalla Torre are recognized from the Nearctic Region, of which one is Holarctic. Literature on the biology of fourteen species is reviewed and new biological information discussed for four species. The phylogenetic relationships of the genus Euodynerus to other genera and the classification and relationships of the species of Euodynerus are discussed. Seven subgenera are recognized of which four are new: Euodynerus, Pareuodynerus Bluethgen, Leucodynerus Bohart, Annodynerus new subgenus, Gonodynerus n. subgenus, Holodynerus n. subgenus and Plecodynerus n. subgenus. Their comparative morphology, phylogeny, and distrubution are discussed. Larval instars of E. hidalgo (Saussure), E. scutellaris …

Reproductive Behavioral And Physiological Traits In Domestic, Wild, And Hybrid Ovis, Kara-Lynn Crocker-Bedford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was part of a program to develop new genotypes of sheep (Ovis spp.) and goats (Capra spp.) which are more useful for food and fiber production. The study examined the influence of domestication on behavioral and physiological traits of ewes and lambs, the influence of a single or twin offspring on ewe and lamb behaviors, and general relationships between ewes and lambs during the lambs' first month of life.

Domestication has caused the intensities of observed traits to diverge greatly from the tendencies shown by wild populations. Domestication has produced increases in measurements associated with maternal …

Integrated Pest Management In Rice Culture, Che Salmah Md Rawi

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Rice, the staple diet of over half of the world population, is grown on about 124 million hectares and occupies almost one fifth of the total world cereal acreage. It is essentially tropical but has also been classified as a subtropical crop. Rich has been cultivated as far nother as 49° latitude and as far south as 35° and is grown from sea level to an altitude of 3,000 meters.

Estimating Esterase And Monooxygenase Detoxication By Bioassay, Electrophoresis And Metabolic Studies In Pea Aphid, Acrythosiphon Pisum (Harris) Populations (Homoptera: Aphididae), Deifalla H. Al-Rajhi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The role of esterases and monooxygenase in the detoxication vii processes of field populations of pea aphids was studied in relation to seasonal changes, developmental stage, and treatment with DEF and piperonyl butoxide. LCSO values for 12 hour exposure periods in glass vials ra nged from 0.04-2.3 micrograms / vial and 820-4871 J.Jg/vial for paraoxon and carbaryl, respectively. Topical bioassays showed the adults to be more tolerant to paraoxon (LDSO of 1. 4-12.3 ng/aphid) toxicity than nymphs (LDSO of 0.13-4. 7 ng/aphid).

Treatment with DEF® (S,S.S-tributylphosphorotrithioate) enhanced paraoxon toxicity against the pea aphid whereas piperonyl butoxide had little …

Western White Pine: The Effect Of Clone And Cone Color On Attacks By The Mountain Pine Cone Beetle, Michael J. Jenkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationship between clone and cone color in western white pine, Pinus monticola Douglas, to attack by the mountain pine cone beetle, Conophthorus monticolae Hopkins, was studied in the Sandpoint Seed Orchard, Idaho. A positive relationship was shown to exist during a 5 year field evaluation. Cone beetles were found to prefer dark colored cones and to attack certain clones at a higher rate than others.

Laboratory dissections did not indicate that cone color affected oviposition, brood development or brood mortality.

Olfactometer experiments demonstrated that olfactory stimuli are involved in the cone beetle attack sequence. Visual cues relating to cone …

Analytical Scanning Electron Microscopy For Surface Science, Olive Lee-Deacon, Claude Le Gressus, Daniel Massignon

Scanning Electron Microscopy

To correlate an electron image with surface properties requires thorough understanding of electron-solid interaction, secondary electron emission mechanism and operation functions of image detectors. We emphasize the importance and usefulness of combining electron spectroscopy with scanning electron microscope in interpreting electron image contrast. Linear relationships among secondary electron image (SEI) brightness, total emission current and the integration of electron energy distribution were measured. We propose that channeling effect, instead of primary electron diffraction, is the crystallographic cause of SEI contrast. Secondary electrons contribute most to SEI brightness because of their high constituent in total yield, not because of high efficiency …

A Transport Equation Theory Of Electron Scattering, D. J. Fathers, P. Rez

Scanning Electron Microscopy

The use of the Boltzmann transport equation to describe electron scattering in electron microscopy and electron probe microanalysis is discussed. A method of solution is given in which the transport equation is divided into angle and energy intervals. This gives rise to a number of coupled first order differential equations. Separation into forward and backward travelling components of the electron flux distribution enables the correct boundary conditions to be imposed. Solutions are derived which take the form of matrix operators analytic in both depth and target thickness. These matrices allow derivation of other physical quantities such as X-ray or Auger …

Monte Carlo Calculations On The Spatial And Angular Distributions Of High Energy Electron Beams In Amorphous And Polycrystalline Films, J. L. Balladore, J. P. Martinez, J. Trinquier, B. Jouffrey

Scanning Electron Microscopy

We study the plural scattering of electrons in amorphous and polycrystalline films. The incident electron energy ranges from 0.1 to 3 MeV. The cross sections are obtained by measuring the transmission coefficient for targets of gold, silver, aluminium and carbon. The partial elastic cross section is calculated from Lenz's theory using a Wentzel-Yukawa model for the atomic potential of the scattering atom. In the case of inelastic interactions, we take into account either scattering by a free atom (Morse's approximation) or scattering by plasmon creation (relativistic theory of Ashley Ritchie). From these results, we solve the problem of electron transport …

The Role Of The Background In Auger Electron Spectroscopy, H. E. Bishop

Scanning Electron Microscopy

In Auger Electron Spectroscopy (AES) the characteristic Auger peaks are superimposed on a relatively high continuum of back-scattered electrons. In the commonly used differential mode of recording Auger spectra, the influence of the background appears through its contribution to the noise and the enhancement of the Auger signal that makes a backscattering correction necessary in quantitative AES. With the increased use of low incident beam currents to achieve high spatial resolution, the direct spectrum is increasingly used, so that a better understanding of the background is desirable. In this paper the variations of the background with atomic number, incident beam …

Monte Carlo Simulation Of Electron Scattering In Resist Film/Substrate Targets, Kenji Murata

Scanning Electron Microscopy

First the fundamentals of resist modelling required to implement an analysis of developed resist patterns were studied, which represents the relationship between the energy deposited by incident electrons and the solubility characteristics of a positive or negative resist. Next, two models of single elastic scattering and fast secondary (knock-on) electron production were studied for Monte Carlo simulation of electron scattering in resist film/substrate targets, and the statistical errors of Monte Carlo results were evaluated. Finally, problems in electron beam lithography were investigated with the simulation. The exposure intensity distribution was studied with the two models. A comparison between Monte Carlo …

Modeling Of Depth Distribution Of X-Ray Production, J. D. Brown

Scanning Electron Microscopy

Knowledge of X-ray production as a function of depth by electrons (𝜙(𝜚z) curves) is important in quantitative electron probe microanalysis and other electron beam technologies. Extensive measurements of such curves have been made for electron energies between 6 and 30 keV and for many X-ray lines and matrix elements. Two experimental techniques based on measurements on sandwich or wedge shaped specimens have been used.

A number of expressions have been used to model 𝜙(𝜚z) curves from a square function through complicated polynomial expressions. Recently, a Gaussian model has been proposed which accurately reflects the shape of the 𝜙(𝜚z) curves and …

Some Applications Of The Electron Backscattering Diffusion Model, W. Czarczyński, Z. Radzimski

Scanning Electron Microscopy

Starting from a simple diffusion theory extended to oblique angles of incidence some empirical correction coefficients for electron backscattering have been found. These empirical coefficients have been used in calculations of backscattered electron surface density distribution, and good agreement with experimental data has been obtained.

Backscattering Of Electrons From Complex Structures, M. Kisza, Z. Maternia, Zbigniew Radzimski

Scanning Electron Microscopy

The backscattering of electrons from complex targets (for example, metal layer on a semi-infinite substrate with a polymer resist film above) has been studied both theoretically and experimentally. The experimental structures were exposed with an electron beam in a "spot mode". The experimental observations of developed disc radius vs. exposure time and metal layer thickness support the simple theory of scattering in such structures. The theory assumes that the backscattering causes enlarging of the exposed area by a constant value. This value is derived from the proposed scattering model based on the Archard's and Kanaya and Okayama's diffusion theories. The …

Monte Carlo Calculations For Electron Microscopy, Microanalysis, And Microlithography, David F. Kyser

Scanning Electron Microscopy

The methodology of Monte Carlo simulation for electron scattering and energy dissipation in solid targets is reviewed. The basic concepts of single and multiple elastic scattering models are compared, and the continuous energy loss model for inelastic scattering is discussed. Some new developments in Monte Carlo simulation are reviewed, including improvements in the elastic scattering model and discrete models for inelastic scattering. A variety of practical applications of Monte Carlo calculations in the fields of electron microscopy, electron probe microanalysis, and electron beam lithography are reviewed. The Monte Carlo computer program listings available in the literature are also described.