Digital Commons Network^™

Compton Scattering In Electron Energy Loss Spectrometry, P. Schattschneider, P. Pongratz, H. Hohenegger

Scanning Microscopy

It is well known that the distribution of electron momenta (electron density in momentum representation) of gases can be probed by Compton scattering of either photons (γ-rays or X-rays) or electrons. Recently it has been shown that Compton scattering of electrons is suited to the study of the electron momentum densities of solids on a microscopic scale. This technique, known as ECOSS, Electron Compton Scattering from Solids can be done in the electron microscope by electron energy loss spectrometry (EELS).

After a discussion of inherent approximations and the introduction of the reciprocal form factor a method is proposed in order …

Grasshoppers In Utah: General Biology, Edward W. Evans

All Archived Publications

No abstract provided.

Chemical And Biological Control Of Grasshoppers In Utah, Edward W. Evans

All Archived Publications

No abstract provided.

An Enzyme/Surfactant Treatment And Filtration Technique For The Retrieval Of Listeria Monocytogenes From Ice Cream Mix, Kelly-Ann Hale, Stephanie Doores, Rosemary A. Walsh

Food Structure

This study combines an enzyme/surfactant treatment with centrifugal ion and prefiltration to solubilize food constituents in a dairy product containing listeria monocytogenes, remove the constituents by a second filtration and examine the isolated bacteria under the scanning electron microscope. Treatment of an ice cream mix with a combined 2% (w/w} trypsin and 2% (w/w) Tween 80 so lution for 20 minutes at 35 °C resulted i n proteolysis of the dairy mix without lysing the bacteria. Centrifugation at 4300 x g for 20 minutes at 5°C concentrated the bacteria in the form of a pellet which was subsequently purified through …

Microstructure And Firmness Of Processed Cheese Manufactured From Cheddar Cheese And Skim Milk Powder Cheese Base, A. Y. Tamime, M. Kalab, G. Davies, M. F. Younis

Food Structure

Processed cheese (10 different types) was made from Cheddar cheese and a cheese base produced from reconstituted skim milk powder by blending and melting with commercial emulsifying salts at 9Q<>C. In one experiment, the cheese base was subjected 10 accelerated cheese ripening by added enzyme. The finished products had 50.1- 53.5% total solids, 18.2-19.3% protein, 47.4-49.7% fat in dry matter, and 2.7-3.0% salt in water; pH was 5.3-5.4 after three months of storage at 10 C and 30 C.

The experimental cheeses were markedly firmer than the control cheeses. All processed cheeses exhibited a similar pattern of firmness whereby …

Fat Polymorphism And Crystal Seeding Effects On Fat Bloom Stability Of Dark Chocolate, T. Koyano, I. Hachiya, K. Sato

Food Structure

The effects of seeding with fine crystal powders on the physical properties of dark chocolate are re viewed in terms of the polymorphism and crystallization behavior of cocoa butter (CBJ and of its major fat constituents. The polymorphic structure of four symmetric mixed acids saturated -oleic-saturated (Sat-0- Sat) triacylglycerols (TAGs I [POP (1 ,3-dipalmitoyl-2- oleoyl-glyceroll ;SOS I 1 ,3-distearoyl-2-oleoyl-glycerol); AOA (1 ,3-diarachidoyl-2-oleoyl-glycerol); and BOB 11 ,3-dibehenoyl-2-oleoyl-glyceroi)J. and of tristearoylglycerol (SSSI are briefly explained. An attempt is made at replacing the currently used tempering meth ~ ad in the chocolate solidification process, by a simple cooling technique using fat seed crystals. …

The Role Of The Interfacial Protein Film In Meat Batter Stabilization, A. Gordon, S. Barbut

Food Structure

The microstructure of meat batters made with equal ionic strengths of NaCl, MgC1 2 , CaCl2 and KCl (IS- 0.43) and a reduced-NaCl batter (IS- 0.43) were examined by scanning and transmission electron microscopy. Micrographs revealed that fat globules with smooth and rough protein coats were present in all treatments. The roughly-coated globules were prevalent in the unstable batters. Pores were observed in the interfacial protein film (IPF) surrounding the globul es and were more prevalent in the globules with rough protein coats. Fat was seen to exude from the pores in both types of globules, Fat globules were shown …

Applications Of Microscopy In The Paper Industry: Case Histories Of The Mead Corporation, A. J. Leonardi, B. A. Blakistone, S. W. Kyryk

Food Structure

Microscopial application in the Mead Corporation are herein discussed: 1) defining proper starch cook for maintaining paper quality, 2) microbial degradation of paperboard used for beverage cartons, and 3) examination of high oxygen barrier plastic cups for hermetic seal and barrier construction. Visualization of the cooked starch by iodine staining and polarized light (PL) microscopy is a quick diagnostic aid to Mead mills. Scanning electron microscopy (SEM) and particularly PL proved useful in examining fiber biodegration by fungi on Coated Natural Kraft beverage cartons. Nomarski differential interference contrast (DIC), PL, and SEM aided in qualifying lid materials for Mead's Crosscheck …

The Structure-Function Relationship Of Polymeric Sorbents For Colloid Stabilization Of Beer, Gabriela Basarova

Food Structure

This review considers the research relating to the formation of non-biological haze in beer. The basic information regarding mutual interactions of haze-causing substances with precipitating, enzymatic, and adsorptive stabilizers of beer is discu ssed. The main haze-causing compounds in beer are polypeptides and polyphenols. To reduce the levels of these compounds in beer, adsorptive stabilizing agents are usually used during filt ration. Electron microscopy and methods measuring the surface and dimensions of adsorbent particles and the volumes and diameters of their pores make it possible to assess morphological properties and suitability of the stabilizers for beer filtration. Determination of the …

A Method For The Examination Of The Microstructure Of Stabilized Peanut Butter, Clyde T. Young, William E. Schadel

Food Structure

A method for light and scanning electron microscopy of damaged resting peanut seed tissue was adapted as a research tool for evaluating the microstructural features of commercially available stabilized peanut butter. This method was used in the present study to evaluate the degree of homogenization of stabilized peanut butter by examining the spatial relationship which exists among the microstructural features. Light and scanning electron microscopy of three commercially available stabilized peanut butters revealed varying degrees of homogenization of broken cell and tissue fragments, protein bodies, and starch grains within a matrix of stabilized oil.

The Effect Of Tumbling, Sodium Chloride And Polyphosphates On The Microstructure And Appearance Of Whole-Muscle Processed Meats, P. D. Velinov, M. V. Zhikov, R. G. Cassens

Food Structure

The properties of a whole-muscle processed meat were determined. The complex action of socium chloride, polyphosphates and mechanical agitation caused extraction of myofibrillar protein, swelling of fibers and loss of cross-strations. A new functional ability was found for the extracted proteins to form a fine cover or membrane on the surface of the whole muscle during cooking. These changes produced a product with improved cooking yield and color appearance.

Preparation Of Cereals And Grain Products For Transmission Electron Microscopy, Donald B. Bechtel

Food Structure

This tutorial specifically addresses the techniques used in the processing of cereals and grain products for various aspects of transmission electron microscopy. Methods covered include sample treatment, chemical and physical fixation, dehydration, embedding, sectioning techniques, immunocytochemistry, enzymatic digestions, carbohydrate localization, and lectin binding. The primary goal is to provide information on the preparation of cereals and cereal-based products for microscopic analysis and to assist the reader in solving technical problems associated with studying cereals or other difficult-to-prepare samples.

Encapsulation Of Viscous High-Fat Foods In Calcium Alginate Gel Tubes At Ambient Temperature, Ivan A. Veliky, Miloslav Kalab

Food Structure

Viscous high-fat foods such as cream, egg yolk, or mayonnaise are co-extruded with a 3% sodium alginate solution from a syringe into a 50 mM calcium chloride solution. The food sample passes through the inner tube of a double needle assembly while the alginate solution is simultaneously extruded through a mantle surrounding the inner needle. As the sodium alginate solution forms a gel on contact with calcium ions, the food sample becomes encapsulated in the calcium alginate gel formed on the surface of the food sample. The encapsulation procedure may be carried out within a temperature range between 0 C …

Spatially Sensitive Electron Energy Loss Spectroscopy, Helmut Kohl

Scanning Microscopy

Over the last decade electron energy loss spectroscopy has been increasingly used as a microanalytical technique. Under favorable conditions a spatial resolution better than 1 nm has been achieved. It is therefore possible to obtain spectroscopic information at an atomic scale. Such a spectrum can be used for the investigation of

- the elemental composition

- defect levels

- surface excitations

- the fine structure.

The spatial sensitivity of such experiments implies, that the initial or the final state of the scattered electrons must have a spatial structure. The theory for the scattering of wave packets will be discussed, focussing …

Secondary Electron Emission From Solids. I. Secondary Electron Spectroscopy, Michel Cailler, Jean-Pierre Ganachaud

Scanning Microscopy

The secondary electron emission spectroscopy can provide useful information about the transitions in the electronic structure from solids and deals with the detection of fine structures superimposed on the true secondary peak, in the kinetic energy range of the true secondary electrons.

Several mechanisms have been proposed for the creation of these fine structures: diffraction phenomena, plasmon decay, interband transitions to unoccupied levels, Auger transitions and more recently, autoionization emission. Some features could not be explained as being due to any bulk effect and were considered as indicative of a need to include surface wave-matching arguments in the analysis of …

Monte Carlo Simulation Of Secondary Electrons In Solids And Its Application For Scanning Electron Microscopy, M. Kotera, T. Kishida, H. Suga

Scanning Microscopy

A new Monte Carlo calculation model is introduced to simulate not only the primary electron behavior but also the secondary electron cascade in a specimen bombarded with an electron beam. Either the primary or the generated electron in a specimen having energy greater than 0.1 keV is defined as a fast electron and the single scattering model is used in the simulation which employs the Mott elastic scattering cross section and the Rao Sahib-Wittry energy loss equation. The electron having energy smaller than 0.1 keV is defined as a slow electron and the cascade model is used which takes into …

Channelling And Related Effects In Electron Microscopy: The Current Status, Kannan M. Krishnan

Scanning Microscopy

The channelling or Borrmann effect in electron diffraction has been developed into a versatile, high spatial resolution, crystallographic technique with demonstrated applicability in solving a variety of materials problems. In general, either the characteristic x-ray emissions or the electron energy-loss intensities are monitored as a function of the orientation of the incident beam. The technique, as formulated in the planar geometry has found wide applications in specific site occupancy and valence measurements, determination of small atomic displacements and crystal polarity studies. For site occupancy studies, the appropriate orientations in most cases can be determined by inspection and the analysis carried …

Electron Beam Nano-Etching In Oxides, Fluorides, Metals And Semiconductors, C. J. Humphreys, T. J. Bullough, R. W. Devenish, D. M. Maher, P. S. Turner

Scanning Microscopy

Etching, lithography, hole formation, surface restructuring and external machining can all be performed on a nanometre scale using an intense electron beam. Results are presented for a range of different materials which demonstrate the variety of mechanisms by which electron beam nano-etching can occur. For example, in crystalline 13-alumina hole formation occurs by surface indentations growing inwards to join up and form a nanometre diameter hole. In amorphous alumina, on the other hand, hole formation is from the inside-out: oxygen gas bubbles form under the electron beam, coalesce, and burst to leave a well defined nanometre diameter hole. In MgO …

Impacts Of Recreation On Biodiversity In Wilderness, David N. Cole, Richard L. Knight

Natural Resources and Environmental Issues

We discuss seven recreational impacts on biodiversity in wilderness areas. These include: 1) construction of trails, 2) trampling of vegetation and soils on trails and campsites, 3) collection and burning of wood in campfires, 4) water pollution associated with camping activities, 5) unintentional harassment of animals, 6) hunting, fishing, and associated management programs, and 7) grazing by processes and functions of ecosystems. The activities which have caused the greatest impact on diversity at a regional scale are fishing, hunting and associated management practices. None of these perturbations, however, have been studied in insufficient detail to assess their long-term impact.

Natural Disturbances And Biodiversity In Wilderness Landscapes, William H. Romme

Natural Resources and Environmental Issues

No abstract provided.

Utah Science Vol. 51 No. 4, Winter 1990

Utah Science

130 USU Researcher Help Mink Producers

133 Parasite Target of USU Research

136 Unraveling the Origin of Animal Appetites

144 Riding in Balance

147 Grain-Rich Diet Can Cripple Young Horses

148 Tracking the Causes of Airborne Cancer

150 ‘Octopus’ May Carry Genome-Free Vaccines

151 New Faculty

152 Birth Defects and Retinoic Acid

153 Scrapie: Cause Unkown But Control Possible

156 Food Safety and Chemical Contamination: Facts vs. Fantasy

162 Food Safety Then and Now

165 Food Safety and the Consumer: Making Informed Decisions

169 Allan Adam Receives USU Land Grant Hall of Fame A ward

170 Recent Grant and Contract …

General Catalog 1990-1992, Utah State University

University Catalogs

Contains course descriptions, University college calendar, and college administration.

Hybrid Popular Productivity And Suitability For The Forest Tent Caterpillar: A Framework Of Evaluation, D.J. Robison, K.F. Raffa

Aspen Bibliography

Fifteen hybrid poplar, Populus spp., clones were evaluated for growth, tolerance to defoliation, and suitability for the forest tent caterpillar, Malacosoma disstria. Poplar clones were ranked according to their suitability for M. disstria, as indicated by behavioral and developmental bioassays. Patterns of poplar growth characteristics and M. disstria preference and performance among the 15 clones were used to construct a productivity - suitability matrix. This matrix provides a framework for evaluating insect pest resistance in selected poplar clones and for considering clonal contributions to poplar-M. disstria interactions. The matrix concept and design incorporates both biologically and …

Reconnaissance-Level Alternative Optimal Groundwater Use Strategies, Richard C. Peralta, Bithin Datta

Civil and Environmental Engineering Faculty Publications

This study develops regionally optimal ground-water extraction strategies. Alternative explicit planning objectives arc: (1) Maximize total pumping from the underlying aquifer while causing the evolution of a steady potentiometric: surface: and (2) maintain a prespecified target potentiometric surface. Implicit objectives involve controlling stream/aquifer interflow and water flow across a state boundary, and attempting to avoid poss disruption of current cropping patterns. Models, bounds, constraints, and data arc: formulated. Alternative optimal strategies and the rationale for preferring one strategy arc: presented for a region in Arkansas. The objective of maintaining the relatively unstressed target potentiometric: surl1ce yields politically and socially unacceptable …

Approach To Bioremediation Of Contaminated Surface Soils, J. L. Sims, Ronald C. Sims, J. E. Matthews

Biological Engineering Faculty Publications

Biological processes, including microbial degradation, have been identified as critical mechanisms for attenuating organic contaminants during transit through the vadose zone to the groundwater. On-site soil remedial measures using biological processes can reduce or eliminate groundwater contamination, thus reducing the need for extensive groundwater monitoring and treatment requirements. On-site remedial systems that utilize the soil as the treatment system accomplish treatment by using naturally occurring microorganisms to treat the contaminants. Treatment often may be enhanced by a variety of physical/chemical methods, such as fertilization, tilling, soil Ph adjustment, moisture control, etc. The development of a bioremediation program for a specific …

Microbial Production And Consumption Of Nitrate In An Annual Grassland, John M. Stark, E. A. Davidson, M. K. Firestone

Biology Faculty Publications

Gross nitrification rates (calculated by 15N pool dilution) ranged from 12 to 46% of gross mineralization rates during the growing season of annual grasses. Pools of NH4+ and NO3 (measured as N) remained below 7 and 4 ,ug/g soil, respectively, but turned over about once a day. Microbial assimilation of NO3- occurred at rates similar to previous estimates of plant uptake. Hence two common assumptions, that nitrifying bac-teria are poor competitors for NH4+ and that microbial immobilization of NO3- is insig-nificant, are not correct for this grassland system. Soil heterogeneity probably results in NH4+ availability to NH4+ oxidizers at some …

Exeis, Expert Screening And Optimal Extraction/Injection Pumping Systems For Short-Term Plume Immobilization, R. L. Ward, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This report presents the EXEIS family of micro-computer based programs for achieving short-term contaminant plume containment. EXEIS is applicable if contaminated water cannot be extracted and water cannot be imported to or exported from the site. There are two main purposes and types of users. For persons relatively unfamiliar with groundwater remedial actions, an expert screening system gives guidance concerning whether extraction/injection (Eli) pumping, slurry wall or sheet piling are most appropriate. For personal more experienced in remedial actions, management models compute optimal E/I strategies for short-term containment. Via deterministic and stochastic multiobjective optimization models, uncertainty in both planning horizon …

Regrowth And Palatability Of Acacia Shoots Following Pruning By African Savanna Browsers, Johan T. Du Toit, J. P. Bryant, K. Frisby

Wildland Resources Faculty Publications

Stands of two species of African Acacia were monitored for 1 yr in a natural savanna ecosystem, to compare shoot regrowth and leaf chemistry in lightly browsed and heavily browsed trees. Where ungulates concentrated at a seasonal waterhole, A. nigrescens was more severely browsed than the thornier and finer leafed A. tortilis. Shoot regrowth in heavily browsed A. nigrescens more than compensated for herbivory, as net annual shoot extension was not significantly different from that in light browsed trees. Foliage of heavily browsed A. nigrescens was higher in nutrients and lower in condensed tannins than foliage of light browsed trees. …

Quantitative Evaluation Of Scanning Electron Microscopy-Examined Ciliary Morphological Changes In Control And Noise Exposed Guinea Pig Cochleas, S. Rydmarker, P. Nilsson, D. E. Dunn, C. Lindqvist

Scanning Microscopy

Many investigations of noise-induced hearing loss have demonstrated a poor correlation between hearing threshold and hair cell loss. One reason for this is that more subtle changes in the hair cell, such as detailed morphological changes of stereocilia, have not been evaluated. However, examining such changes increases the problem of distinguishing experimental pathological changes from artefacts. Preparation of the specimen for scanning electron microscopy (SEM) may result in too many artefacts for an adequate quantification of defects due to noise exposure.

One problem with some earlier studies seems to be lack of controls and/or statistical analysis for the purpose of …

Calcium Pyrophosphate Crystal Deposition: A Kinetic Study Using A Type I Collagen Gel Model, Gretchen S. Mandel, Paul B. Halverson, Melisa Rathburn, Neil S. Mandel

Scanning Microscopy

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease is characterized by deposits of triclinic (t) and monoclinic (m) CPPD crystals in articular and fibrocartilage. Many investigators have attempted to model CPPD crystal growth using both solution and a variety of gel systems. We have investigated the effect of type I collagen fibrils on CPPD crystal nucleation and growth using an ionic diffusion model. Collagen was isolated from porcine menisci using a pepsin solubilization procedure and gelled in three layers, with one containing 10 mM pyrophosphate (PPi) plus physiologic ions, the middle containing only the ions, while the third contained 25 mM …