290 research outputs found

    Altar to Uncertainty

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    ABSTRACT I have always been in awe of great storytellers. Like an alchemist, the masterful storyteller can take the most mundane of tales and transmute it into an enrapturing experience. The best of these, however, are the stories which seem very otherworldly but, in the end, can reveal deep and relatable truths to the listener. For this exhibition, “Altar to Uncertainty,” I have undertaken the creation of a single book and story which surrounds and visually extends itself through printed etchings upon the walls to tell a transformative tale of redemption through trauma, hopelessness and loss. My intention with this work is to create an empowering, immersive experience where the viewer can contemplate their own personal hardships and find comfort and strength in the shared struggle to overcome these more difficult times in life

    Biolabeling Through the Use of Water-Soluble Colloidal Quantum Dots

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    Nanomaterials continues to be a growing field of study due to their wide range of potential applications. Quantum dots are artificially synthesized crystalline clusters of atoms able to confine electron motion as a result of their incredibly small size. Recently, medical applications of nanomaterials have expanded greatly. Quantum dots are ideal for biolabeling due to their rather narrow photoluminescence emission peaks. By synthesizing quantum dots of a specific diameter, it is possible to predetermine the peak photoluminescence wavelength of a sample. Through ligand exchange and immunoconjugation of the quantum dots with proteins, it is possible to use the quantum dots as biolabels to study the inner machinations of the cellular world. These processes have a predictable effect on the properties of the quantum dots: most importantly, their photoluminescence peak wavelength. By understanding the ways in which these processes effect the quantum dots, it is possible to choose the correct quantum dots for a specific final emission wavelength. Further research is being conducted to perform bio-imaging using these processes and resolve some current limitations found therein

    Racial Identity Attitudes Among African-American Workers

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    In this paper I compared racial identity attitudes of professional and non-professional African-American workers. Comparisons were made using means for each of the stages of the Racial Identity Attitude Scale. The Racial Identity Attitude Scale was developed by Janet Helms and was based on an identity model developed by Cross. Means for each stage are compared among men and women, professionals and non-professionals, salary, and educational levels. However, responses to the scale proved to be more interesting than the actual results. So, due to the overwhelming opposition to the use of this scale, I also discuss implications of the subjects responses to the RIAS

    Technology to Improve Sprayer Accuracy

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    A number of new technologies have been introduced over the last several years aimed at improving the accuracy of spray application, but do they really work? The purpose of this document is to highlight the most common causes of application errors then discuss the array of new sprayer technologies that are becoming available, how they might affect application accuracy, and pitfalls involved in using them

    Performance Evaluation of a Tracking Total Station as a Position Reference forDynamic GNSS Accuracy Testing

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    The dynamic accuracy of a tracking total station (TTS) was evaluated using a rotary test fixture to determine the viability of using a TTS as a position reference for dynamic global navigation satellite-based system (GNSS) accuracy testing. Tests were performed at angular velocities ranging from 0 to 3.72 rad/s at a radius of 0.635 m. A technique was developed to determine the average latency of the TTS measurement serial data output. TTS measurements were interpolated at a GNSS sampling interval to provide a method for direct comparison between TTS and GNSS position measurements. The estimated latency from the TTS serial data output was shown to be consistently near 0.25 s for all angular velocities and less variable when using a reflector-based machine target versus a prism-based target. Average positional error in the TTS position measurement increased with angular velocity from 3 to 90 mm, partly due to internal filtering which caused the magnitude of the TTS position measurement to decrease under stead-state sinusoidal motion. The standard deviation of error ranged from less than 1 to 20 mm as angular velocity increased. Sight distance from the TTS to the target was shown to have very little effect on accuracy between 4 and 30 m. The TTS was determined to be an adequate benchmark for most dynamic GNSS and vehicle auto-guidance testing but is limited by relatively large position measurement errors at high angular velocities

    Development of a Biologically Based Aerobic Composting Simulation Model

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    A relatively simple dynamic model based on microbial process kinetics has been developed for aerobic composting. Differential equations describing microbial, substrate, and oxygen concentrations, as well as moisture and temperature profiles have been derived as a function of vessel size and aeration rate. Microbial biomass growth was described using Monod growth kinetics as a function of degradable substrate concentration, oxygen concentration, moisture content, and compost temperature. Facility and fan operating costs have been included to permit economic optimization of the process. Predicted results demonstrated the ability of the model to quantify and describe the influence of multiple interacting factors (temperature, oxygen, moisture, and substrate availability) on the process driving the composting: microbial growth kinetics. Future development of the approach should be undertaken to provide a robust engineering model that can be used to evaluate and design environmentally sound composting facilities. An example application is presented along with data from a laboratory scale composter

    Frequency and Isostericity of RNA Base Pairs

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    Most of the hairpin, internal and junction loops that appear single-stranded in standard RNA secondary structures form recurrent 3D motifs, where non-WatsonCrick base pairs play a central role. Non-WatsonCrick base pairs also play crucial roles in tertiary contacts in structured RNA molecules. We previously classified RNA base pairs geometrically so as to group together those base pairs that are structurally similar (isosteric) and therefore able to substitute for each other by mutation without disrupting the 3D structure. Here, we introduce a quantitative measure of base pair isostericity, the IsoDiscrepancy Index (IDI), to more accurately determine which base pair substitutions can potentially occur in conserved motifs. We extract and classify base pairs from a reduced-redundancy set of RNA 3D structures from the Protein Data Bank (PDB) and calculate centroids (exemplars) for each base combination and geometric base pair type (family). We use the exemplars and IDI values to update our online Basepair Catalog and the Isostericity Matrices (IM) for each base pair family. From the database of base pairs observed in 3D structures we derive base pair occurrence frequencies for each of the 12 geometric base pair families. In order to improve the statistics from the 3D structures, we also derive base pair occurrence frequencies from rRNA sequence alignments

    Nozzle Sensor for In-System Chemical Concentration Monitoring

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    Chemical concentration is a vital parameter for determining appropriate chemical application. This study describes the design and testing of a sensor that attempted to monitor concentration of chemicals upstream from each nozzle body. The sensor is based on an LED and photodiode pair. Its ability to detect chemical concentration within the main carrier was tested with a 2,4-D formulation, a glyphosate formulation, and a powdered Acid Blue 9 dye. The liquid herbicide formulations of glyphosate and 2,4-D were tested across common application concentrations of 0% to 12.5% by volume. The powdered dye produced a much stronger effect on the sensor and was only tested at the much lower concentrations of 0 to 50 mg L-1. Further tests were conducted in which the dye was mixed with the herbicide formulation before the combined solution was added to the carrier. While this enabled establishment of pre-determined sensor outputs based on given concentrations of the pre-mixed solution, the sensor may have been responding to the predominance of a dye mixed with a herbicide formulation and not directly to the concentration of the herbicide. While the sensor did not appreciably respond to the concentration of the glyphosate formulation, it did respond in a consistent manner to the 2,4-D formulation and the dye. The sensor‘s response to the concentration of these chemicals was a rational (1/x type) relationship, and the R2 values for the rational models describing these relationships were greater than 0.99. With the mixed dye and herbicide formulation, the effects of the dye and the 2,4-D formulation combined independently, and the total sensor output was a multiplication of the percent effect of each alone. The test with the pre-mixed dye and 2,4-D formulation produced the expected 1 V output at a 12.5% by volume concentration of the 2,4-D formulation, proving that dye can be added to a herbicide to produce a desired response from the sensor. Overall, the sensor‘s response was remarkably stable, with a maximum standard deviation of 42.2 mg L-1 of 2,4-D active ingredient for samples taken at a constant chemical concentration. These tests confirmed that the sensor could respond to chemical formulations and dye in a consistent and predictable manner. However, use of the sensor for herbicide monitoring will require sensor calibration for each combination of herbicide and dye mixture, as the light transmittance properties of the tested mixtures were not quantified and the light transmittance properties of formulations and dyes can be arbitrarily changed by manufacturers

    Methods for Calculating Relative Cross-Track Error for ASABE/ISO Standard 12188-2 from Discrete Measurements

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    ASABE/ISO Standard 12188-2 provides test procedures for positioning and guidance systems in agricultural vehicles during straight and level travel. While the standard provides excellent descriptions of test procedures, it does not provide detail on methods to carry out the calculations necessary to calculate relative cross-track error (XTE), which is the primary error statistic used to judge accuracy. Given the travel speed and sampling constraints provided by the standard, the difference between a method based on nearest points or one based on path interpolation could hypothetically be as large as 25 cm. In this project, the standard was used to estimate the guidance accuracy of a relatively low-accuracy vehicle at 1.25 and 0.5 m s-1. At 1.25 m s-1, a basic nearest point calculation overestimated mean XTE by 0.8 cm, or 8.2%. The location sampling density was much higher with a 0.5 m s-1 travel speed, and mean XTE was only overestimated by 0.1 cm with the nearest point method. There are clearly situations where the calculation method will affect results, and the use of the more complicated methods explained in this article are suggested when using this standard

    Biodiesel Basics

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    Biodiesel is a renewable fuel for diesel engines. Biodiesel, defined by ASTM International (D6751), consists of longchain fatty acid alkyl esters and is made from renewable vegetable oils, recycled cooking oils, or animal fats. It can be used at full strength, but it is typically blended with petroleum diesel. A blend of 2 percent biodiesel and 98 percent diesel is referred to as B2. Other typical blends include B5, B10, and B20; pure biodiesel is sometimes referred to as B100. Biodiesel is safer for the environment and produces significantly less air pollution compared to petroleum diesel. Biodiesel can be produced locally and can be integrated into the existing petroleum infrastructure
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