From its inception, NASA has pushed the boundaries of science and engineering and prided itself on knowing how to manage these engineering innovations. However, pushing the management boundaries requires a careful adaptation of risks, resources, and procedures, and projects must clearly assess the complexities and uncertainties of the task. Too often attempts to resolve errors in these areas ar...

Using the formula of shear bearing force of oblique cross section in eccentrically loaded column, we analyze the stress acting on short-leg shear wall and conventional eccentrically loaded column. We propose the formula for calculating the shear bearing force of oblique cross section of short-leg shear wall that considers the action of vertical reinforcing steel bars, flange and axial compressi...

We evaluated the effects of a major ice storm on understory light conditions (%PPFD, photosynthetic photon flux density) in an old-growth Acer–Fagus forest in Quebec, based on preand post-disturbance light measurements taken until the seventh growing season after the event (which occurred in January 1998). Before the ice storm, most microsites received between 2 and 4%PPFD. Following the ice st...

In a recent paper, Polchinski and Strassler found a string theory dual of a gauge theory with reduced supersymmetry. Motivated by their approach, we perturb the N = 8 theory living on a set of N M2 branes to N = 2, by adding fermion mass terms. We obtain M-theory duals corresponding to M2 branes polarized into M5 branes, in AdS4 × S7. In the course of doing this we come across an interesting fe...

Monotonic and fatigue tests were carried out in four-point bending on a glass fabric/epoxy composite, using two different stress ratios. Ultimate failure both in monotonic tests and in fatigue was precipitated by microbuckling phenomena happening at the compression side of the specimens. The experimental results were evaluated adopting a fatigue model statistically implemented, based on the hyp...

background: the purpose of this study was to evaluate the influence of three different luting protocols on shear bond strength of computer aided design/computer aided manufacturing (cad/cam) resin nanoceramic (rnc) material to dentin. materials and methods: in this in vitro study, 30 disks were milled from rnc blocks (lava ultimate/3m espe) with cad/cam technology. the disks were subsequently c...

life quality of all people in society has been the ultimate aim of development programs, thus, the present research deals with the spatial analysis and evaluation of inductor of development in township of fars provinces. the quantitative- analytical method has been used in this research. the statistical society of the research included 24 township of fars provinces in 1385 and 43inductor were u...

the determination of the ultimate pit limit (upl) is the first step in the open pit mine planning process. in this stage that parts of the mineral deposit that are economic to mine are determined. there are several mathematical, heuristic and meta-heuristic algorithms to determine upl. the optimization criterion in these algorithms is maximization of the total profit whilst satisfying the...