2,907 research outputs found
Evaluation of a strain-gage load calibration on a low-aspect-ratio wing structure at elevated temperature
The environmental aspect of elevated temperature and its relationship to the science of strain gage calibrations of aircraft structures are addressed. A section of a wing designed for a high-speed aircraft structure was used to study this problem. This structure was instrumented with strain gages calibrated at both elevated and room temperatures. Load equations derived from a high-temperature load calibration were compared with equations derived from an identical load calibration at room temperature. The implications of the high temperature load calibration were studied from the viewpoint of applicability and necessity. Load equations derived from the room temperature load calibration resulted in generally lower equation standard errors than equations derived from the elevated temperature load calibration. A distributed load was applied to the structure at elevated temperature and strain gage outputs were measured. This applied load was then calculated using equations derived from both the room temperature and elevated temperature calibration data. It was found that no significant differences between the two equation systems existed in terms of computing this applied distributed load, as long as the thermal shifts resulting from thermal stresses could be identified. This identification requires a heating of the structure. Therefore, it is concluded that for this structure, a high temperature load calibration is not required. However, a heating of the structure is required to determine thermal shifts
Inequality Matters
This is one of a series of five papers outlining the particular domains and dimensions of inequality where new research may yield a better understanding of responses to this growing issue.The aim of this paper is to describe, in very broad brushstrokes, the state of academic scholarship regarding social inequality, with an eye toward identifying important gaps. The focus is on four key interacting social domains: 1) socioeconomic (financial and human capital)2) health (including physical and psychological) 3) political (access to power and political representation)4) sociocultural (identity, cultural freedoms, and human rights
Effects of the California High School Exit Exam on Student Persistence, Achievement, and Graduation
Analyzes the impact of the exit exam requirement on student persistence, achievement, and graduation by race/ethnicity and gender and the factors behind the differential effects. Considers implications for the fairness and effectiveness of the exams
New technique to measure the cavity defects of Fabry-Perot interferometers
(Abridged):
We define and test a new technique to accurately measure the cavity defects
of air-spaced FPIs, including distortions due to the spectral tuning process
typical of astronomical observations. We further develop a correction technique
to maintain the shape of the cavity as constant as possible during the spectral
scan. These are necessary steps to optimize the spectral transmission profile
of a two-dimensional spectrograph using one or more FPIs.
We devise a generalization of the techniques developed for the so-called
phase-shifting interferometry to the case of FPIs. The technique is applicable
to any FPI that can be tuned via changing the cavity spacing (-axis), and
can be used for any etalon regardless of the coating' reflectivity. The major
strength of our method is the ability to fully characterize the cavity during a
spectral scan, allowing for the determination of scan-dependent modifications
of the plates. As a test, we have applied this technique to three 50 mm
diameter interferometers, with cavity gaps ranging between 600 micron and 3 mm,
coated for use in the visible range.
We obtain accurate and reliable measures of the cavity defects of air-spaced
FPIs, and of their evolution during the entire spectral scan. Our main, and
unexpected, result is that the relative tilt between the two FPI plates varies
significantly during the spectral scan, and can dominate the cavity defects; in
particular, we observe that the tilt component at the extremes of the scan is
sensibly larger than at the center of the scan. Exploiting the capability of
the electronic controllers to set the reference plane at any given spectral
step, we develop a correction technique that allows the minimization of the
tilt during a complete spectral scan. The correction remains highly stable over
long periods, well beyond the typical duration of astronomical observations.Comment: 15 pages, 20+ figures, accepted for publication in A&A. Two
additional movies are available in the online version of the pape
Proceedings of the Twenty-First Annual Biochemical Engineering Symposium
The 21st Annual Biochemical Engineering Symposium was held at Colorado State University on April 20, 1991. The primary goals of this symposium series are to provide an opportunity for students to present and publish their research work and to promote informal discussions on biochemical engineering research.
Contents High Density Fed-Batch Cultivation and Energy Metabolism of Bacillus thuringtensis; W.-M. Liu, V. Bihari, M. Starzak, and R.K. Bajpai
Influences of Medium Composition and Cultivation Conditions on Recombinant Protein Production by Bacillus subtilis; K. Park, P.M. Linzmaier, and K.F. Reardon
Characterization of a Foreign Gene Expression in a Recombinant T7 Expression System Infected with λ Phages; F. Miao and D.S. Kompala
Simulation of an Enzymatic Membrane System with Forced Periodic Supply of Substrate; N. Nakaiwa, M. Yashima, L.T. Fan, and T. Ohmori
Batch Extraction of Dilut Acids in a Hollow Fiber Module; D.G. O\u27Brien and C.E. Glatz
Evaluation of a New Electrophoretic Device for Protein Purification; M.-J. Juang and R.G. Harrison
Crossflow Microfiltration and Membrane Fouling for Yeast Cell Suspension; S. Redkar and R. Davis
Interaction of MBP-β-Galactosidase Fusion Protein with Starch; L. Taladriz and Z. Nikolov
Predicting the Solubility of Recombinant Proteins in Escherichia coli; D.L. Wilkinson and R.G. Harrison
Evolution of a Phase-Separated, Gravity-Independent Bioractor; P.E. Villeneuve and E.H. Dunlop
A Strategy for the Decontamination of Soils Containing Elevated Levels of PCP; S. Ghoshal, S. K. Banelji, and RK. Bajpai
Practical Considerations for Implementation of a Field Scale In-Situ Bioremediation Project; J.P. McDonald, CA Baldwin, and L.E. Erickson
Parametric Sensitivity Studies of Rhizopus oligosporus Solid Substrate Fermentation; J. Sargantanis, M.N. Karim, and V.G. Murphy, and RP. Tengerdy
Production of Acetyl-Xylan Esterase from Aspergillus niger; M.R Samara and J.C. Linden
Biological and Latex Particle Partitioning in Aqueous Two-Phase Systems; D.T.L. Hawker, RH. Davis, P.W. Todd, and R Lawson
Novel Bioreactor /Separator for Microbial Desulfurization of Coal; H. Gecol, RH. Davis, and J .R Mattoon
Effect of Plants and Trees on the Fate, Transport and Biodegradation of Contaminants in the Soil and Ground Water; W. Huang, E. Lee, J.F. Shimp, L.C. Davis, L.E. Erickson, and J.C. Tracy
Sound Production by Interfacial Effects in Airlift Reactors; J. Hua, T.-Y. Yiin, LA Glasgow, and L.E. Erickson
Soy Yogurt Fermentation of Rapid Hydration Hydrothermal Cooked Soy Milk; P. Tuitemwong, L.E. Erickson, and D.Y.C. Fung
Influence of Carbon Source on Pentachlorophenol Degradation by Phanerochaete chrysosportum in Soil; C.-Y.M. Hsieh, RK. Bajpai, and S.K. Banerji
Cellular Responses of Insect Cells Spodopiera frugiperda -9 to Hydrodynamic Stresses; P.L.-H. Yeh and RK. Bajpa1
A Mathematical Model for Ripening of Cheddar Cheese; J. Kim, M. Starzak, G.W. Preckshoi, and R.K. Bajpaihttps://lib.dr.iastate.edu/bce_proceedings/1020/thumbnail.jp
The Widening Academic Achievement Gap Between the Rich and the Poor: New Evidence and Possible Explanations
Analyzes growth in income inequality and the "income achievement gap" in test scores of children in high- and low-income families over fifty years. Examines parents' education and investment in cognitive development as factors in children's achievement
Interview with Michael Reardon
Dr. Michael Reardon discusses his career at Portland State from his start as an Assistant Professor in the Department of History in 1964 through his many administrative roles to his eventual service as Interim President of the University from 2007 to 2008.
A transcript of this interview is available for download.https://pdxscholar.library.pdx.edu/rememberpsu_oralhist/1001/thumbnail.jp
Approximate analysis and stability of pressure oscillations in ramjets
This paper summarizes work accomplished during the past five years on analysis of stability related to
recent experimental results on combustion instabilities in dump combustors. The primary purpose is to provide
the information in a form useful to those concerned with design and development of operational systems. Thus
most substantial details are omitted; the material is presented in a qualitative fashion
Thermal and structural tests of Rene 41 honeycomb integral-tank concept for future space transportation systems
Two flat 12 by 72 inch Rene 41 honeycomb sandwich panels were tested in a manner to produce combined thermal and mechanical longitudinal stresses that simulated those that would occur in a larger, more complex integral tank and fuselage structure of an earth to orbit vehicle. Elastic strains measured at temperatures below 400 F are compared with calculated values obtained from a linear elastic finite element analysis to verify the analytical model and to establish confidence in the calculated strains. Elastic strain measurement at higher temperatures (between 600 F and 1400 F), where strain measurement is more difficult and less certain, are also compared with calculated strains. Agreement between measured and calculated strains for the lower temperatures is good, but agreement for the higher temperatures is poor because of unreliable strain measurements. Test results indicate that an ascent and entry life cycle of 500 is attainable under high combined thermal and mechanical elastic strains
Theorizing Blue-Collar Response to Imposed Technological Change
A study was conducted at twelve manufacturing facilities. The data from this study indicated the response of blue-collar workers to imposed technological change can be conceptualized as having seven factors: Disgruntlement, Job-security concerns, Accommodation, Informal learning, Resistance, Discussion, and Formal learning. Cluster analysis of the data identified three types of blue collar workers: Complainers, Team players, and Loners. In this study, membership in the Team players cluster increased as a function of age
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