One- and Two-Dimensional Moisture Profiles in Red Oak

Differential moisture losses during the early stages of drying are critical to the development of stresses that result in checking and associated degrade. This research was conducted to determine the shape of the moisture profiles in flat sawn red oak (Quercus sp.) under several different conditions early in drying. In addition, both one- and two-dimensional profiles were compared graphically and statistically to determine if moisture loss from the narrow (nearly radial) surfaces was significant. The results indicate that the moisture profiles are continuous and nearly parabolic after one day of drying under mild or severe conditions. The one- and two-dimensional profiles were essentially the same when compared both graphically and statistically, which indicates that moisture losses from the narrow faces can be neglected when developing drying models for flat sawn red oak having a width at least four times its thickness

Transfer Student-Athletes: Prominent but Vulnerable

Transfer students play a prominent role in Division I athletics, but the effects of transferring can often be detrimental to their academic performance. Providing a formal orientation course especially designed for new transfer student-athletes can be an effective means of helping them bridge the intercollegiate experience. This gives an example transfer orientation program from Oregon State University

Off-Fault Plasticity and Earthquake Rupture Dynamics: 2. Effects of Fluid Saturation

We present an analysis of inelastic off-fault response in fluid-saturated material during earthquake shear rupture. The analysis is conducted for 2-D plane strain deformation using an explicit dynamic finite element formulation. Along the fault, linear slip-weakening behavior is specified, and the off-fault material is described using an elastic-plastic description of the Drucker-Prager form, which characterizes the brittle behavior of rocks under compressive stress when the primary mode of inelastic deformation is frictional sliding of fissure surfaces, microcracking and granular flow. In this part (part 1), pore pressure changes were neglected in materials bordering the fault. In part 2, we more fully address the effects of fluid saturation. During the rapid stressing by a propagating rupture, the associated undrained response of the surrounding fluid-saturated material may be either strengthened or weakened against inelastic deformation. We consider poroelastoplastic materials with and without plastic dilation. During nondilatant undrained response near a propagating rupture, large increases in pore pressure on the compressional side of the fault decrease the effective normal stress and weaken the material, and decreases in pore pressure on the extensional side strengthen the material. Positive plastic dilatancy reduces pore pressure, universally strengthening the material. Dilatantly strengthened undrained deformation has a diffusive instability on a long enough timescale when the underlying drained deformation is unstable. Neglecting this instability on the short timescale of plastic straining, we show that undrained deformation is notably more resistant to shear localization than predicted by neglect of pore pressure changes.Earth and Planetary SciencesEngineering and Applied Science

Machine direction registration dynamics model of a rotary printing press

We derive an analytical model of the machine direction registration dynamics of a continuous-web, electronic line shaft (ELS) rotary printing press. We use the model to quantify the affect of tension disturbances on machine direction registration dynamics with different control schemes. With standard ELS registration control schemes, we show the benefits of using a compensator roller vs. electronic differential gear (advance or retard print cylinder's angular position). Next, we develop a novel cascaded reference control scheme for an electronic differential gear controlled ELS printing press that allows it to rival the performance of a compensator roller controlled ELS printing press. Finally, we demonstrate the benefits of using a cascaded reference empirically on a 6-station rotogravure ELS printing press

Threshold Effect In Mg-doped Lithium Niobate

Optical absorption spectra were obtained after reducing (i.e., vacuum annealing) a series of LiNbO3 crystals grown from melts having various Mg concentrations and Li/Nb ratios. A band peaking at 500 nm, and assigned to oxygen vacancies containing two electrons, was the only absorption present in one set of crystals following reduction. In contrast, two overlapping bands peaking near 1200 and 760 nm were present in the other set of crystals immediately after the reduction. The 1200-nm band is assigned to a previously unreported electron trap and the 760-nm band to oxygen vacancies containing only one electron. These data are interpreted in terms of a threshold level for Mg doping; however, the threshold Mg doping level is not a constant but depends on the ratio of Mg ions to Li vacancies

The Influence of Personality, Safety Attitudes, and Risk Perception of Pilots: A Modeling and Mediation Perspective

Objective: The purpose of the current study was to assess the influence of personality traits on safety attitudes and risk perceptions. Background: The ability to accurately assess risk remains a focal point of aviation training. This research seeks to understand if safety attitudes serve as a mediator. Method: Using a sample of 2,857 pilots, a statistical model was created through two independent stages. In stage 1, approximately 50% of the data were used to create the model using structural equation modeling techniques, and in stage 2, the model was independently validated. Results: The findings indicated that personality factors positively influenced risk perception, whereas personality increased, so did the pilot\u27s perception of the risk level. Self-confidence was negatively related to risk perceptions, indicating that a pilot\u27s self-confidence increases their perception of risk decreases. Additionally, self-confidence was a significant mediator to the relationship between personality factors and risk perception. Conclusion: The original scales had some validity issues, but the re-specified model provided some meaningful findings, especially in the relationships between personality traits, self-confidence, and risk perception. The model explained 26.4% of the variance in self-confidence and 9.5% of risk perception variance. Application: The findings highlight the importance for pilots to be aware of how increased self-confidence may influence their perceptions of risk. As pilots gain experience and self-confidence, care needs to be given to ensure greater risks are not taken, offsetting the value of the experience and self-confidence

Bayesian analysis of polarization measurements

A detailed and formal account of polarization measurements using Bayesian analysis is given based on the assumption of gaussian error for the Stokes parameters. This analysis is crucial for the measurement of the polarization degree and angle at very low (and very high) signal-to-noise. The treatment serves as a framework for customized analysis of data based on a particular prior suited to the experiment.Comment: 15 page

Observation and analysis of in situ carbonaceous matter in Nakhla: Part I

New analyses of indigenous secondary material in the martian meteorite Nakhla reveal amorphous carbon-rich veins and dendrites. The texture and chemistry of this material resembles that of biogenically altered sub-ocean basaltic glasses

Observation and analysis of in situ carbonaceous matter in Nakhla: part II

Analysis of in situ carbonaceous matter in the Nakhla SNC meteorite has been carried out using a variety of techniques. Laser raman data shows the carbonaceous matter to be highly complex and static mass spectrometry has shown it to have an isotopic composition of '18 to '20' C