Applications of FEM and BEM in two-dimensional fracture mechanics problems

A comparison of the finite element method (FEM) and boundary element method (BEM) for the solution of two-dimensional plane strain problems in fracture mechanics is presented in this paper. Stress intensity factors (SIF's) were calculated using both methods for elastic plates with either a single-edge crack or an inclined-edge crack. In particular, two currently available programs, ANSYS for finite element analysis and BEASY for boundary element analysis, were used

Theorizing Information Systems as Evolving Technology

Information systems scholars have struggled with the field’s fundamental relationship to technology. In particular, they have debated whether the IT artifact is unwisely taken for granted and whether or not it lies at the field’s core. Here, applying Brian Arthur’s general theory of technology, I suggest that one may theorize IS itself as an evolving family of technologies. From this perspective, one may open new avenues for IS research—for, in particular, historical and other related studies where the unit of analysis is the technology itself and the focus is its evolution

Illuminating Organizing Vision Careers Through Case Studies

Three case studies that illuminate the careers of organizing visions also help us understand important case boundary choices characteristic of this type of research. The choices involve: time frames, cast of characters, action focus, observational means, lines of interpretation, and contextual anchors. We argue that these choices are best regarded as open-ended and provisional, subject to being reconsidered over the course of a study, to maximize insights gained. We relate the choices to major challenges in making cumulative research progress from studies of organizing vision careers

A Simple Research Impacts Model Applied to the Information Systems Field

Research in the information systems (IS) field is presently under pressure to justify its value by speaking to its impact on professional practice. This paper presents a simple model that enables researchers to identify and differentiate their research’s impacts. More specifically, I distinguish between those impacts that occur through directly engaging academic practice with professional practice, and those that occur through diffusion of practices, both academic and professional. I also discuss several conjectures about IS research impacts after analyzing my model

Investigations of electron emission characteristics of low work function surfaces Final report, 27 Sep. 1964 - 28 Sep. 1966

Electron emission characteristics of low work function surface

Geologic map of the east-central Meadow Valley Mountains, and implications for reconstruction of the Mormon Peak detachment, Nevada

The role of low-angle faults in accommodating extension within the upper crust remains controversial because the existence of these faults markedly defies extant continuum theories of how crustal faults form, and once initiated, how they continue to slip. Accordingly, for many proposed examples, basic kinematic problems like slip direction, dip angle while active, and magnitude of offset are keenly debated. A well-known example is the Miocene Mormon Peak detachment and overlying Mormon Peak allochthon of southern Nevada (USA), whose origin and evolution have been debated for several decades. Here, we use geologic mapping in the Meadow Valley Mountains to help define the geometry and kinematics of emplacement of the Mormon Peak allochthon, the hanging wall of the Mormon Peak detachment. Pre-exten­sion structural markers, inherited from the east-vergent Sevier thrust belt of Meso­zoic age, are well suited to constrain the geometry and kine­matics of the detachment. In this study, we add to these markers a newly mapped Sevier-­age monoclinal flexure preserved in the hanging wall of the detachment. The bounding axial surfaces of the flexure can be readily matched to the base and top of the frontal Sevier thrust ramp, which is exposed in the footwall of the detachment to the east in the Mormon Mountains and Tule Springs Hills. Multiple proxies for the slip direction of the detachment, including the mean tilt direction of hanging wall fault blocks, the trend of striations measured on the fault plane, and other structural features, indicate that it is approximately S77°W (257°). Given the observed structural separation lines between the hanging wall and footwall, this slip direction indicates 12–13 km of horizontal displacement on the detachment (14–15 km net slip), lower than a previous estimate of 20–22 km, which was based on erroneous assumptions in regard to the geometry of the thrust system. Based on a new detailed map compilation of the region and recently published low-temperature thermochronologic data, palinspastic constraints also preclude earlier suggestions that the Mormon Peak allochthon is a composite of diachronously emplaced, surficial landslide deposits. Although earlier suggestions that the initiation angle of the detachment in the central Mormon Mountains is ∼ 20°–25° remain valid, the geometry of the Sevier-age monocline in the Meadow Valley Mountains and other structural data suggest that the initial dip of the detachment steepens toward the north beneath the southernmost Clover Mountains, where the hanging wall includes kilometer-scale accumulations of volcanic and volcaniclastic strata

Investigations of electron emission characteristics of low work function surfaces Quarterly report, 28 Sep. - 27 Dec. 1966

Coadsorption of cesium and fluorine on tungsten, and analysis of mechanisms leading to decay of field emission current from low work function zirconium/oxygen coated tungsten emitte

Investigations of electron emission characteristics of low work function surfaces Final report, 28 Sep. 1966 - 13 Nov. 1967

Electron emission characteristics of low work function surface