208 research outputs found
An Historical Analysis of the Fay B. Kaigler Children’s Book Festival
This study focuses on investigating the origins of the Fay B. Kaigler Children’s Book Festival, an internationally renowned annual conference hosted at The University of Southern Mississippi. This research is based on archival collections available at the McCain Archives and Special Collections
By the Pricking of My Thumbs, State Restriction This Way Comes: Immunizing Vaccination Laws from Constitutional Review
The article argues how states should not allow philosophical exemptions and should either retain or create religious exemptions that meet certain requirements under the Free Exercise Clause, the Due Process Clause, and the Establishment Clause. It reports the U.S. Supreme Court\u27s jurisprudence regarding parental rights in cases \u27Jacobson v. Massachusetts\u27 and \u27Zucht v. King.\u2
Characterizing Wood Components as Network Polymers by Dynamic Mechanical Analysis
The characterization of structure-property relationships in wood components, such as lignin, is a critical aspect of utilization. This point has been emphasized recently with concerns directed toward the application of natural products as wood bonding agents. Dynamic mechanical analysis is a valuable technique for the study of these relations because of its sensitivity to variations in polymer structure
The Properties of The Wood-Polystyrene Interphase Determined by Inverse Gas Chromatography
The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inorganic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass transition temperatures, thermodynamic parameters, and the London component of the surface free energy (YsL) were deter mined. Values for YsL became constant at higher coverages, allowing the thickness of the interphase to be estimated
Defining the opportunities, challenges, and research needs for nanobiomaterials derived from lignocellulosics
Issued as final reportNational Science Foundation (U.S
The Application of Near Infrared (Nir) Spectroscopy to Inorganic Preservative-Treated Wood
There is a growing need to find a rapid, inexpensive, and reliable method to distinguish between treated and untreated waste wood. This paper evaluates the ability of near infrared (NIR) spectroscopy with multivariate analysis (MVA) to distinguish preservative types and retentions. It is demonstrated that principal component analysis (PCA) can differentiate lumber treated with CCA, ACZA, or ACQ preservatives. Furthermore, separation according to wood species and assay zone was also observed. Within the range of preservative concentrations available, partial least squares (PLS) regression was also performed on the NIR data, from which retention levels were predicted. The results highlight the potential for this technique to predict the concentration, as well as identify the type, of inorganic preservatives present
ANALYSIS OF SWITCHGRASS CHARACTERISTICS USING NEAR INFRARED SPECTROSCOPY
Switchgrass varieties grown under various environments were investi-gated by dispersive and Fourier Transform Near-Infrared (NIR) spectro-meters. The collected NIR spectra were analyzed using multivariate approaches. More specifically, principal component analysis (PCA) and projection to latent structures (PLS) regression techniques were employed to classify and predict characteristics of the switchgrass samples. The multivariate results were compared to reflectance indices that are commonly used to study the physiological performance of plants. From near infrared spectra, discrimination between the two growth locations was successfully achieved by PCA. Separation based on the ecotype and the rate of fertilizer applied to the field was also possible by the multivariable analysis of the spectral data. For the classification/ discrimination of the switchgrass samples, the near infrared spectra collected by the dispersive and the Fourier Transform spectrometers provided similar results. From the two near infrared data sets robust models were developed to predict non-structural carbohydrates content and the rate of nitrogen applied to the field. However, the spectra collected by the dispersive spectrometer resulted in more accurate models for these samples
Redesign Of Large Steam Turbines For Increased Reliability.
LecturePg. 123-132Two similar large steam turbines in an ethylene plant are profiled. One drives the cracked gas compressor train and the other
drives the propylene refrigeration compressor. The two machines are similar and this paper concentrates on the turbine driving the cracked gas compressors. Both turbines had a history of high vibration, short bearing life, and unusual sensitivity to thermal changes and imbalance due to operation near the second critical speed. In addition, numerous blade failures had occurred. When additional turbine performance was required, a complete review of the entire turbine including the blade designs, rotordynarnics, and governor operation was commissioned. The performance upgrade included new blading, disks, seals, and other changes to the steam
path. A turning gear was added for slow-roll operation to relieve thermal effects and rotor bow. A technique was developed for mounting the turbine disks on the rotor to minimize axial disk runout and local couple imbalances. The high bearing temperatures and high vibration issues were addressed with changes in shaft and bearing designs. A submerged arc welding process increased the governor end journal diameter from 51/4 inches to 7 inches. A rotordynamic optimization analysis resulted in replacing the tilting pad bearing on the governor end with an offset-half lobed journal bearing. The tilting pad bearings on the exhaust end of the turbines were retained but redesigned for optimum performance. Interchangeability of bearings between the
two machines was maintained. These shaft and bearing changes resulted in a significant
reduction in babbitt temperature, shaft vibration, and imbalance sensitivity as well as control of the second critical speed. The
interaction of the rotor with the foundation substructure was found to be significant, and its inclusion in the analysis was required to properly design the optimized bearings. The blade design changes and steam path changes produced a more reliable design and greater than the required extra power. The addition of a turning gear drive has eliminated the thermal bow problems. A new electronic governor system has eliminated the wear
associated with the original hydraulic governor. Both turbines are now operating very smoothly at the capacity of the production facility
Diagnosis And Solution Of High Noise And Vibration Issues After A Propylene Refrigeration Compressor Rerate.
Case Stud
Estudo da viabilidade de utilização de fibras naturais curtas em matrizes de resina epóxi
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