A study of the vibrational characteristics of two multistory buildings

Forced vibration tests and associated analysis of two multistory buildings are described. In one case, the dynamic properties of the building measured during the tests are compared to those predicted by simple analytical models. A three-dimensional finite element model of the second building was constructed for the purpose of evaluating the accuracy of this type of analysis for predicting the observed dynamic properties of the structure. Forced vibration tests were performed on Millikan Library, a nine-story reinforced concrete shear wall building. Measurements of three-dimensional motions of approximately 50 points on each of six floors (including the basement) were taken for excitation in the N-S and E-W directions. The results revealed a complex interaction between lateral and vertical load carrying systems in both directions The results also suggest that a significant change in the foundation response of the structure occurred in the stiffer N-S direction during the San Fernando earthquake. This phenomenon was investigated through the use of two analytical models of the building which included the effects of soil-structure interaction. The Ralph M. Parsons World Headquarters building, a twelvestory steel frame structure, was also tested. The natural frequencies, three-dimensional mode shapes, and damping coefficients of nine modes of vibration were determined. Other features of this investigation included the study of nonlinearities associated with increasing levels of response and the measurement of strain in one of the columns of the structure during forced excitation. The dynamic characteristics of the building determined by these tests are compared to those predicted by a finite element model of the structure. The properties of primarily translational modes are predicted reasonably well; but adequate predictions of torsional motions were not obtained. The comparison between measured and predicted strains suggests that estimates of stress obtained from finite element analyses of buildings should be within 25 percent of those experienced by the structure for a known excitation

Citizen Science and the recovery of the Salish Sea: How volunteers can play a vital role filling unmet scientific needs.

Recovery of the Salish Sea ecosystem is facing a harsh reality. Limited funds and capacity throughout the Salish Sea’s scientific community severely reduces timely and concerted progress on a majority of identified scientific needs. A critical piece to successful Salish Sea restoration is ensuring that these identified scientific needs are able to be met, before it is too late. One creative solution to this issue is to engage citizens to participate in scientific monitoring. This presentation will use a case study to explore lessons learned around how collaboration among citizens, scientific experts, and agencies can produce a robust scientific monitoring program that not only produces credible and usable data, but also gives citizens the opportunity to take ownership in the restoration of the Salish Sea. Specifically we will examine the lessons learned by four Aquatic Reserve Citizen Stewardship Committees. The Committees have worked in collaboration with state agencies and scientific experts to develop three ongoing citizen science projects that provide strategic and usable data. These lessons intend to forward a larger conversation in the scientific community about the necessary role of citizen science in the effort to restore the Salish Sea to health

Size and Shape of Solid Fuel Diffusion Flames in Very Low Speed Flows

The effect of very low speed forced flows on the size and shape of a solid fuel diffusion flame are investigated experimentally. Flows due to natural convection are eliminated by performing the experiment in low gravity. The range of velocities tested is 1.5 cm/s to 6.3 cm/s and the mole fraction of oxygen in the O2/N2 atmosphere ranges from 0.15 to 0.19. The flames did not reach steady state in the 5.2 sec to which the experiment was limited. Despite limited data, trends in the transient flame temperature and, by means of extrapolation, the steady state flame size are deduced. As the flow velocity is reduced, the flames move farther from the fuel surface, and the transient flame temperature is lowered. As the oxygen concentration is reduced the flames move closer to the fuel sample and the transient flame temperature is reduced. With stand off distances up to 8.5 + or - 0.7 mm and thicknesses around 1 or 2 mm, these flames are much weaker than flames observed at normal gravity. Based on the performance of the equipment and several qualitative observations, suggestions for future work are made

GENDER AND OVARIAN HORMONE EFFECTS ON THE RELATIVE CONTRIBUTION OF CHROMATICITY TO BRIGHTNESS

PURPOSE: The chromatic contribution to brightness perception was compared in males and females. METHODS: Direct brightness matching (DBM) and heterochromatic flicker photometry (HFP) were used to measure relative luminous efficiency, and DBM/HFP ratios were predicted to be higher for females than males on repeated measures and for each primary color. No gender differences were predicted in DBM or HFP measures. Within-females effects of estradiol (E2) and progesterone (PG) levels, contraceptive use, and menstrual cycle phase were also investigated. It was expected that E2 would directly predict DBM/HFP ratios and that PG would antagonize that relationship. Based on that prediction, DBM/HFP ratios would be at a maximum during the ovulatory phase, intermediate during the menstrual phase and minimum during the luteal phase. No effects were predicted for DBM or HFP measures. RESULTS: DBM/HFP ratios were significantly higher for female subjects than male subjects. Contraceptive use had no effect on overall DBM/HFP ratios. There were limited effects of hormone levels, menstrual cycle phase and contraceptive use on DBM/HFP ratios and on DBM and HFP measures analyzed separately. However, hormone effects on DBM/HFP ratios and DBM measures at 650 nm agree with previous findings involving long-wavelength sensitive (L-) cone mechanisms. CONCLUSIONS: The present findings supporting a female advantage in chromatic contribution to brightness are robust. The significant results are discussed in the context of previous findings suggesting organizational and short-term effects of ovarian steroid hormones

A New Partner in the Process: The Role of a Librarian on a Faculty Research Team

Academic librarians have tremendous opportunity to demonstrate their worth to the institutions they serve. One successful approach is for faculty and librarians to collaborate on a research project; however the frequency of such partnerships has not been readily documented in academic library literature. This paper shows how the addition of an academic librarian to a faculty research team led to a better understanding of how faculty projects operate, and how the process can lead the way for librarians to be seen as valuable research partners in the academic landscape

Bringing Students into the Picture: Teaching with Tableaux Vivants

This article explores a recent experiment in implementing tableaux vivants as a college-level art history assignment, in which students researched works of art and also assumed the pose, posture, and attributes of the work; students were also invited to reconceptualize and think transformatively about these historical works. Drawing upon the principles of Universal Design for Learning, the assignment offers an impetus for close looking, research, critical thinking, interpretation and creativity, and an engagement in metacognitive and embodied experiences, as will be demonstrated by the resulting assignments and students’ written self-reflections. While the assignment was originally designed for a course focused on American culture prior to 1830, this approach could apply to a broad chronological and geographical range to encompass nearly any figurative art

The Grief of Comfort

This poem is a reflection on the author’s deployment experiences aboard the United States Naval hospital ship, the USNS COMFORT, in support of a humanitarian mission to seven countries over a period of four months. The ten-member eye care team was often tasked with providing care for over 800 patients a day. This poem chronicles the author’s journey from enthusiasm, through exhaustion, sadness, guilt, shame, anxiety, post-traumatic stress to recovery. The author shares this work as part of his recovery process and hopes it provides encouragement to other short- and long-term mission workers experiencing some of the same