61 research outputs found

    Measurement Techniques for Steady Shear Viscosity of Mozzarella-Type Cheeses at High Shear Rates and High Temperature

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    While measuring steady shear viscosity of Mozzarella-type cheeses in a rotational rheometer at 70 Ā°C, three main difficulties were encountered; wall slip, structural failure during measurement and viscoelastic time dependent effects. Serrated plates were the most successful surface modification at eliminating wall slip. However, even with serrated plates shear banding occurred at higher shear rates. Because of the viscoelastic nature of the cheeses, a time dependent viscous response occurred at shear rates \u3c1 \u3esāˆ’1, requiring longer times to attain steady shear conditions. Prolonged continuous shearing altered the structure of the molten cheeses. The effects of structural change were greatly reduced by minimising the total accumulated strain exerted on the sample during flow curve determination. These techniques enabled successful measurement of steady shear viscosity of molten Mozzarella-type cheeses at 70 Ā°C at shear rates up to 250 sāˆ’1

    Sets in Order: the official magazine of square dancing.

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    Published monthly for and by Square Dancers and for the general enjoyment of all

    ON THE RUN, November 2, 1978

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    Issue No. 9 The California Canadian by Roger RapoportFor Canadian Brian Maxwell, the ideal place to train is Califomia, the ideal cooking to eat is his own and the ideal marathon to win will be in Moscow. Indians Running by John KosterLong before the white man and long before the wheel, Indians were running on the paths of the Western World. New York, New York by William DunnettFor out-of-towners, the Big Apple can be a big bust if they don\u27t know where to go and what to do. To eliminate that problem, we have provided a marathoner\u27s guide to New York City. A Gathering of Eagles by Ray HoslerTwenty four elite runners swooped into Eugene, Ore., compliments of Nike, for that company\u27s marathon. When the gathering of eagles ended, a women\u27s record fell.https://openprairie.sdstate.edu/on_the_run/1007/thumbnail.jp

    PROBING NEUROCHEMISTRY WITH FAST-SCAN CYCLIC VOLTAMMETRY

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    Fast-scan cyclic voltammetry (FSCV) with carbon-fiber microelectrodes is a prominent analytical technique for rapid and sensitive detection of electrochemically active analytes in mammalian brain. In recent years this technique became very popular among neuroscientists. However, many improvements for FSCV are possible. Chapter 1 introduces the technique and provides brief description of recent improvements in fast-scan cyclic voltammetry. During voltammetric experiments, potential applied to electrodes changes carbon surface. Chapter 2 describes investigation of the changes induced by waveforms with anodic potential limits of 1.0 V, 1.3 V and 1.4 V. Instrumental methods of analysis such as XPS, AFM and SEM together with electrochemical studies were used. It was observed, that for waveforms with high anodic potential (1.3 V and 1.4 V) carbon electrode surface continuously oxidizes and etches away. Thus, the electrode surface which has surface groups that promote adsorption of catechols is constantly renewed. A benefit of surface renewal is sustainability to chemical fouling. Carbon electrode surface has electrochemically active chemical groups which are oxidized and reduced during voltammetric potential ramps. Electrochemical reactions for these groups involve protons, thus changes in pH of solution generate characteristic cyclic voltammograms. Hence, FSCV can be used to sample rapid pH fluctuations in the brain that are associated with metabolism and changes in the cerebral blood flow. However, cyclic voltammograms for pH changes recorded in brain in vivo and in the flow cell have different shapes, which compromises the identity of pH signal. Chapter 3 describes investigation of the peaks in cyclic voltammogram for pH which led to the conclusion that adsorption of electrochemically inert species to electrode surface is responsible for the interference and the mismatch. Identity of pH signal in brain in vivo was confirmed by inducing acidosis by increasing concentration of carbon dioxide in breathing mixture (hypercapnia). Acidic pH shift with characteristic cyclic voltammogram was recorded with FSCV in hypercapnia. Traditionally, FSCV experiments are done with a single carbon-fiber microelectrode. These electrodes are produced manually and they are very fragile. Chapter 4 describes alternative microfabricated microelectrode arrays (MEAs) which are more robust than glass-encased carbon fibers and can be produced using batch fabrication methods. Microelectrodes in MEAs are distant from each other, thus heterogeneity in analyte concentration such as difference in dopamine release in the brain can be studied. Also, microelectrodes in the array are independently addressable which means that multiplexed detection of different analytes in brain can be performed simultaneously. Instrumentation for FSCV experiments in freely moving animals is custom made which limits the dissemination of this technique. Chapter 5 describes instrumentation for FSCV experiments for combined electrochemical and electrophysiological measurements in details. All electronic components are documented and layouts of electronic circuits are provided in this chapter. Recording of brain functions with multiple electrodes is beneficial in providing information about interconnections of different brain regions as well as synchronization of their activity. This approach was limited to electrophysiological recordings. Chapter 6 describes recordings of endogenous and pharmacologically induced activity of dopaminergic neurons in separate brain hemispheres of anesthetized rat. Synchronization of activity of dopaminergic neurons between two separate and symmetrical systems is observed. Possible link to slow wave oscillations that occur in brain cortex during sleep is discussed.Doctor of Philosoph

    Sets in Order: the official magazine of square dancing.

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    Published monthly for and by Square Dancers and for the general enjoyment of all

    Community Building After Emancipation: An Anthropological Study of Charles\u27 Corner, Virginia, 1862-1922

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    The half-century marked by the end of the Civil War and the beginning of World War I was a critical period of cultural, social, and economic transition for African Americans in the southern United States. During the late nineteenth century, while African Americans were rebuilding communities and networks disrupted by enslavement and the ensuing Civil War, several settlements developed between Williamsburg and Yorktown on Virginia\u27s lower peninsula. One of the settlements, Charles\u27 Corner, is an optimal case study for understanding the gradual process of community building during a particularly challenging period of African American history dominated by systemic racism and legal persecution.;A majority of Charles\u27 Corner residents made their living as self-employed farmers and oysterers, work which provided them with a significant level of economic stability and autonomy. The neighborhood continued to flourish until the United States government commandeered the property in 1918 in order to create a naval facility fronting on the York River. Residents were forced to relocate and abandon the property where they had invested decades of physical labor and built substantial social and economic networks. Fortunately, their farmsteads were preserved as archaeological sites which may be eligible for nomination to the National Register of Historic Places as an archaeological district, due to their integrity and historical significance.;Archaeological assessments at four sites located at Charles\u27 Corner provided an opportunity to address research questions and themes critical to the archaeology of African American life in the South after Emancipation. Questions focus on the establishment of socioeconomic networks after the Civil War, episodic displacement, and their role in the community building process. Addressing these questions through the application of an anthropological model for community building emphasizes the role of a diversified economy and construction of networks on a path of self-determination.;This dissertation is a response to critiques about the need to understand transformative periods in African American history. A study of Charles\u27 Corner demonstrates the process of community building for one neighborhood during the late nineteenth and early twentieth centuries through the application of data from the archaeological record, historical documents, and oral histories. Furthermore, the residents\u27 compelling narrative demonstrates the ways that rural African Americans contributed to the black freedom movement

    Test-driven development of embedded control systems: application in an automotive collision prevention system

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    With test-driven development (TDD) new code is not written until an automated test has failed, and duplications of functions, tests, or simply code fragments are always removed. TDD can lead to a better design and a higher quality of the developed system, but to date it has mainly been applied to the development of traditional software systems such as payroll applications. This thesis describes the novel application of TDD to the development of embedded control systems using an automotive safety system for preventing collisions as an example. The basic prerequisite for test-driven development is the availability of an automated testing framework as tests are executed very often. Such testing frameworks have been developed for nearly all programming languages, but not for the graphical, signal driven language Simulink. Simulink is commonly used in the automotive industry and can be considered as state-of-the-art for the design and development of embedded control systems in the automotive, aerospace and other industries. The thesis therefore introduces a novel automated testing framework for Simulink. This framework forms the basis for the test-driven development process by integrating the analysis, design and testing of embedded control systems into this process. The thesis then shows the application of TDD to a collision prevention system. The system architecture is derived from the requirements of the system and four software components are identiļ¬ed, which represent problems of particular areas for the realisation of control systems, i.e. logical combinations, experimental problems, mathematical algorithms, and control theory. For each of these problems, a concept to systematically derive test cases from the requirements is presented. Moreover two conventional approaches to design the controller are introduced and compared in terms of their stability and performance. The eļ¬€ectiveness of the collision prevention system is assessed in trials on a driving simulator. These trials show that the system leads to a signiļ¬cant reduction of the accident rate for rear-end collisions. In addition, experiments with prototype vehicles on test tracks and ļ¬eld tests are presented to verify the systemā€™s functional requirements within a system testing approach. Finally, the new test-driven development process for embedded control systems is evaluated in comparison to traditional development processes

    Miniaturized Transistors, Volume II

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    In this book, we aim to address the ever-advancing progress in microelectronic device scaling. Complementary Metal-Oxide-Semiconductor (CMOS) devices continue to endure miniaturization, irrespective of the seeming physical limitations, helped by advancing fabrication techniques. We observe that miniaturization does not always refer to the latest technology node for digital transistors. Rather, by applying novel materials and device geometries, a significant reduction in the size of microelectronic devices for a broad set of applications can be achieved. The achievements made in the scaling of devices for applications beyond digital logic (e.g., high power, optoelectronics, and sensors) are taking the forefront in microelectronic miniaturization. Furthermore, all these achievements are assisted by improvements in the simulation and modeling of the involved materials and device structures. In particular, process and device technology computer-aided design (TCAD) has become indispensable in the design cycle of novel devices and technologies. It is our sincere hope that the results provided in this Special Issue prove useful to scientists and engineers who find themselves at the forefront of this rapidly evolving and broadening field. Now, more than ever, it is essential to look for solutions to find the next disrupting technologies which will allow for transistor miniaturization well beyond siliconā€™s physical limits and the current state-of-the-art. This requires a broad attack, including studies of novel and innovative designs as well as emerging materials which are becoming more application-specific than ever before
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