Entity

Time filter

Source Type

College Place, WA, United States

Walla Walla University is a University offering liberal arts, professional, and technical programs located in College Place, Washington, just a few miles from Walla Walla. The current President is John McVay. It was founded in 1892 and is affiliated with the Seventh-day Adventist Church.The University has an annual enrollment of around 1,500 students. It is regionally accredited by the Northwest Association of Schools and Colleges and is also denominationally accredited. Walla Walla offers 36 majors, seven master’s degrees, and an associate of science degree. The Edward F. Cross School of Engineering is an ABET accredited program that offers bachelor of science and engineering degrees. No published research is regularly done at the school.Students are organized as the Associated Students of Walla Walla University or ASWWU. ASWWU operates the student newspaper The Collegian, the annual Mountain Ash , an online radio station, and the student directory the Mask. Both the men's and the women's on-campus dormitories operate their own clubs. The women's club is named Aleph Gimel Ain ; the men's club is named Omicron Pi Sigma . In athletics, Walla Walla U competes as a member of the NAIA Association of Independent Institutions . Their team nickname is "The Wolves". WWU also has a club men's ice-hockey team, "The Pack," which competes in the American Collegiate Hockey Association. Wikipedia.


Ma Q.,Walla Walla University | Levy C.,Florida International University | Perl M.,Ben - Gurion University of the Negev
Journal of Pressure Vessel Technology, Transactions of the ASME | Year: 2012

Our previous studies have shown that stress intensity factors (SIFs) are influenced considerably from the presence of the Bauschinger Effect (BE) in thick-walled pressurized cracked cylinders. For some types of pressure vessels, such as gun barrels, working in corrosive environment, in addition to acute temperature gradients and repetitive high-pressure impulses, erosions can be practically induced. Those erosions cause stress concentration at the bore, where cracks can readily initiate and propagate. In this study, the BE on the SIFs will be investigated for a crack emanating from an erosion's deepest point in a multiply eroded autofrettaged, pressurized thick-walled cylinder. A commercial finite element package, ansys, was employed to perform this type of analysis. A two-dimensional model, analogous to the authors' previous studies, has been adopted for this new investigation. Autofrettage with and without BE, based on von Mises yield criterion, is simulated by thermal loading and the SIFs are determined by the nodal displacement method. The SIFs are evaluated for a variety of relative crack lengths, a 0t= 0.01-0.45 emanating from the tip of the erosion of different geometries including (a) semicircular erosions of relative depths of 1-10 of the cylinder's wall thickness, t; (b) arc erosions for several dimensionless radii of curvature, r′t= 0.05-0.4; and (c) semi-elliptical erosions with ellipticities of dh= 0.5-1.5, and erosion span angle, , from 6 deg to 360 deg. The effective SIFs for relatively short cracks are found to be increased by the presence of the erosion and further increased due to the BE, which may result in a significant decrease in the vessel's fatigue life. Deep cracks are found to be almost unaffected by the erosion, but are considerably affected by BE. © 2012 American Society of Mechanical Engineers.


Haynal S.,College Place | Haynal H.,Walla Walla University
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings | Year: 2013

Recent research presents a technique to enumerate all valid assignments of 'twiddle factors' for power-of-two fast Fourier transform (FFT) flow graphs. Brute-force search employing state-of-the-art Boolean satisfiability (SAT) solvers can then be used to find FFT algorithms within this large solution space which have desirable characteristics. Surprisingly, this approach has discovered FFT algorithms requiring fewer operations than the split-radix algorithm even when all twiddle factors are nth roots of unity. This paper reviews and then extends this prior research to examine fast discrete convolution algorithms when implemented via FFT and inverse FFT (IFFT) algorithms. In particular, we find that the combination of FFT and IFFT algorithms in fast convolution permits greater freedom when selecting valid twiddle factor assignments. We exploit this freedom and use SAT solvers to find new fast convolution algorithms with the lowest operation counts known. © 2013 IEEE.


Buchheim H.P.,Loma Linda University | Cushman Jr. R.A.,Walla Walla University | Biaggi R.E.,Adventist University of Plata
Rocky Mountain Geology | Year: 2011

The Eocene Green River Formation in Fossil Basin, Wyoming provides a detailed record of the paleoecology and depositional history of ancient Fossil Lake. Fossil Lake was one of three Eocene lakes that formed an extensive lake system in Wyoming, Utah, and Colorado. It began as a flood-plain lake in the southern part of Fossil Basin and expanded northward as the lake evolved. Fossil Lake went through the major stages of lake evolution, including the overfilled (Road Hollow Member), balanced-fill (Fossil Butte Member), and underfilled (Angelo Member) stages. These stages are represented in the sedimentary record by a complete suite of lake-margin to lake-center facies. This study establishes the Road Hollow Member of the Green River Formation as representing the earliest stage of lake evolution in Fossil Lake. We also revise the boundaries for the Fossil Butte and Angelo Members of the Green River Formation, which clearly delineate the latest two stages of lake evolution. These revisions not only describe and add a previously unrecognized and thick sequence of lacustrine rocks in Fossil Basin, but help us to better understand the depositional systems that existed during each stage of lake evolution.


Onthank K.L.,Washington State University | Cowles D.L.,Walla Walla University
Marine Biology | Year: 2011

This study explores the relationship between energy budgeting and prey choice of Octopus rubescens. Seventeen male Octopus rubescens were collected between June 2006 and August 2007 from Admiralty Bay, Washington. Prey choices made by individuals in the laboratory deviated widely from those expected from a simple optimal foraging model. O. rubescens chose the crab Hemigrapsus nudus over the clam Nuttallia obscurata as prey by a ratio of 3:1, even though prey energy content and handling times suggested that this octopus could obtain 10 times more energy intake per unit time when choosing the latter compared to the former prey species. Octopus energy budgets were similar when consuming either of the prey species except for lipid extraction efficiency that was significantly higher in octopuses consuming H. nudus. This suggests that lipid digestibility may play an important role in the prey choice of O. rubescens. © 2011 Springer-Verlag.


Ma Q.,Walla Walla University | Levy C.,Florida International University | Perl M.,Ben - Gurion University of the Negev
Journal of Pressure Vessel Technology, Transactions of the ASME | Year: 2010

Due to acute temperature gradients and repetitive high-pressure impulses, extremely dense internal surface cracks can be practically developed in highly pressurized thick-walled vessels, typically in gun barrels. In the authors' previous studies, networks of typical radial and longitudinal-coplanar, semi-elliptical, internal surface cracks have been investigated assuming both ideal and realistic full autofrettage residual stress fields (ε=100%). The aim of the present work is to extend the analysis twofold: to include various levels of partially autofrettaged cylinders and to consider configurations of closely and densely packed radial crack arrays. To accurately assess the stress intensity factors (SIFs), significant computational efforts and strategies are necessary, especially for networks with closely and densely packed cracks. This study focuses on the determination of the distributions along the crack fronts of KI P, the stress intensity factor due to internal pressure KI A, the negative stress intensity factor resulting from the residual stress field due to ideal or realistic autofrettage, and KI N, the combined SIF KI N = KI P - KI A . The analysis is performed for over 1000 configurations of closely and densely packed semicircular and semi-elliptical networked cracks affected by pressure and partial-to-full autofrettage levels of ε=30-100%, which is of practical benefit in autofrettaged thick-walled pressure vessels. The 3-D analysis is performed via the finite element method and the submodeling technique employing singular elements along the crack front and the various symmetries of the problem. The network cracks will include up to 128 equally spaced cracks in the radial direction: with relative longitudinal crack spacing, 2c/d, from 0.1 to 0.99; autofrettage level of 30-100%; crack depth to wall thickness ratios, a/t, from 0.01 to 0.4; and, cracks with various ellipticities of crack depth to semicrack length, a/c, from 0.2 to 2. The results clearly indicate that the combined SIFs are considerably influenced by the three dimensionality of the problem and the Bauschinger effect (BE). The Bauschinger effect is found to have a dramatic effect on the prevailing combined stress intensity factors, resulting in a considerable reduction of the fatigue life of the pressure vessel. While the fatigue life can be finite for ideal autofrettage, it is normally finite for realistic autofrettage for the same crack network. Furthermore, it has been found that there are differences in the character of the SIFs between closely packed and densely packed crack networks, namely, more dramatic drop-offs in KI A and KI N at the crack-inner bore interface for densely packed cracks further influenced by crack depth. © 2010 American Society of Mechanical Engineers.

Discover hidden collaborations