Slope measurement from contour maps

Estimating slope gradients from digitized contour ma

Web-crippling Strength Of Cold-formed Steel Beams

The structural behavior of high-strength cold-formed steel beams subjected primarily to web crippling is investigated analytically and experimentally. Hat sections and I-beams, formed from five different types of high-strength sheet steels, are investigated under various loading conditions. In addition to the test data gathered in this phase of study, the experimental results obtained from the beam tests conducted at various companies are carefully evaluated. The evaluation indicates that the present available design criteria are not suitable for high-strength materials with yield strengths exceeding 80 ksi (552 MPa). New design formulas are derived for different types of loading conditions on the basis of available test data with material yield strengths ranging from 30 to 165 ksi (207 to 1,138 MPa). These empirical equations distinguish between web crippling failure caused by overstressing (bearing failure) and web buckling. Interaction formulas are derived for sections under combined web crippling and bending moment. The newly proposed design equations are verified by test results. © ASCE

Building a Stronger System for Tracking Nutrition-Sensitive Spending: A Methodology and Estimate of Global Spending for Nutrition-Sensitive Foreign Aid

Background: There is growing awareness that the necessary solutions for improving nutrition outcomes are multisectorial. As such, investments are increasingly directed toward nutrition-sensitive approaches that not only address an underlying or basic determinant of nutrition but also seek to achieve an explicit nutrition goal or outcome. Understanding how and where official development assistance (ODA) for nutrition is invested remains an important but complex challenge, as development projects components vary in their application to nutrition outcomes. Currently, no systematic method exists for tracking nutrition-sensitive ODA. Objective: To develop a methodology for classifying and tracking nutrition-sensitive ODA and to produce estimates of the amount of nutrition-sensitive aid received by countries with a high burden of undernutrition. Methods: We analyzed all financial flows reported to the Organization for Economic Co-Operation and Development\u27s Development Assistance Committee Creditor Reporting Service in 2010 to estimate these investments. We assessed the relationships between national stunting prevalence, stunting burden, under-5 mortality, and the amount of nutrition-specific and nutrition-sensitive ODA. Results: We estimate that, in 2010, a total of $379.4 million (M) US dollars (USD) was committed to nutrition-specific projects and programs of which 25 designated beneficiaries (countries and regions) accounted for nearly 85$320 M). A total of $1.79 billion (B) was committed to nutrition-sensitive spending, of which the top 25 countries/regions accounted for$1.4 B (82%). Nine categories of development activities accounted for 75% of nutrition-sensitive spending, led by Reproductive Health Care (30.4%), Food Aid/Food Security Programs (14.1%), Emergency Food Aid (13.2%), and Basic Health Care (5.0%). Multivariate linear regression models indicate that the amount of nutrition-sensitive (P = .001) and total nutrition ODA was significantly predicted by stunting prevalence (P = .001). The size of the total population of stunted children significantly predicted the amount of nutrition-specific ODA (P \u3c .001). Conclusion: The recipient profile of nutrition-specific and nutrition-sensitive ODA is related but distinct. Nutrition indicators are associated with the level of nutrition-related ODA commitments to recipient countries. A reliable estimate of nutrition spending is critical for effective planning by both donors and recipients and key for success, as the global development community recommits to a new round of goals to address the interrelated causes of undernutrition in low-income countries

Weak Values with Decoherence

The weak value of an observable is experimentally accessible by weak measurements as theoretically analyzed by Aharonov et al. and recently experimentally demonstrated. We introduce a weak operator associated with the weak values and give a general framework of quantum operations to the W operator in parallel with the Kraus representation of the completely positive map for the density operator. The decoherence effect is also investigated in terms of the weak measurement by a shift of a probe wave function of continuous variable. As an application, we demonstrate how the geometric phase is affected by the bit flip noise.Comment: 17 pages, 3 figure

Fluoride-Salt-Cooled High-Temperature Reactor (FHR) Using British Advanced Gas-Cooled Reactor (AGR) Refueling Technology and Decay Heat Removal Systems That Prevent Salt Freezing

The FHR uses graphite-matrix coated-particle fuel (same as high-temperature gas-cooled reactors (HTGRs)) and a clean liquid salt coolant. It delivers heat to industry or the power cycle at temperatures between 600 and 700°C with higher average heat delivery temperatures than other reactors. The liquid- salt-coolant melting point is above 450°C. The high minimum temperatures present refueling challenges and require special features to control temperatures—avoiding excessively high temperatures and freezing of the coolant that could impact decay heat cooling systems. We describe herein a pre-conceptual FHR design that addresses many of these challenges by adopting features from the British AGR and alternative decay heat cooling systems. The basis for specific design choices are described. The AGRs are carbon-dioxide cooled and graphite-moderated reactors that use cylindrical fuel subassemblies with vertical refueling at 650°C—meeting FHR high-temperature refueling requirements. The 14 AGRs have operated for many decades. The AGR uses 8 cylindrical fuel sub-assemblies each a meter tall coupled axially together by a metal stringer to create a long fuel assembly. The stringer assemblies are in vertical channels in a graphite core that provides neutron moderation. This geometric core design is compatible with an FHR using graphite-matrix coated-particle fuel. The FHR uses a once- through fuel cycle. The design minimizes used nuclear fuel volumes relative to other FHR and HTGR designs. The primary system is inside a secondary liquid-salt-filled tank that (1) provides an added heat sink for decay heat, (2) helps ensure no freezing of primary system salt, and (3) helps ensure no major fuel failures in a beyond-design-basis accident. The refueling standpipes above each stringer fuel assembly in the AGR core with modifications can be used in an FHR for refueling and provide efficient heat transfer between the primary system and the secondary liquid-salt-filled tank. The passive decay heat removal system uses heat-pipes that turn on and off at a preset temperature to avoid overheating the core in a reactor accident and avoid freezing the salt coolant as decay heat decreases after reactor shutdown

An application of simulated annealing to the optimum design of reinforced concrete retaining structures

This paper reports on the application of a simulated annealing algorithm to the minimum cost design of reinforced concrete retaining structures. Cantilever retaining walls are investigated, being representative of reinforced concrete retaining structures that are required to resist a combination of earth and hydrostatic loading. To solve such a constrained optimisation problem, a modified simulated annealing algorithm is proposed that avoids the simple rejection of infeasible solutions and improves convergence to a minimum cost. The algorithm was implemented using an object-orientated visual programming language, offering facilities for continual monitoring, assessing and changing of the simulated annealing control parameters. Results show that the simulated annealing can be successfully applied to the minimum cost design of reinforced concrete retaining walls, overcoming the difficulties associated with the practical and realistic assessment of the structural costs and their complex inter-relationship with the imposed constraints on the solution space

Magnetosheath excursion and the relevant transport process at the magnetopause

A large-amplitude excursion of the magnetosheath (MS) in quiet solar wind conditions on 17 March 2004 was recorded simultaneously by the Cluster and TC-1 spacecraft. During this period, the IMF <I>B<sub>z</sub></I> was entirely northward. The coherence between the bow shock motion and magnetopause (MP) motion is revealed and the excursion velocities of the bow shock motion are analyzed. In addition, the relevant plasma transport phenomenon in the form of flux fluctuations below the ion gyrofrequency at the MP is exposed and is interpreted as manifestation of the drift instability. Correlated observations on charge accumulation and electrostatic potential perturbation are recorded by electron measurements in high energy regime, and also the eventual cross-field vortex motion in the nonlinear stage and the consequential mass exchange are exhibited. The present investigation gives some new insight into the MS plasma transport mechanism across the subsolar MP region in quiet solar wind conditions during a period of northward IMF

Deformations at Earth's dayside magnetopause during quasi-radial IMF conditions: Global kinetic simulations and soft X-ray imaging

The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is an ESA-CAS joint mission. Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind (SW) impact via simultaneous in situ magnetosheath (MS) plasma and magnetic field measurements, X-Ray images of the magnetosheath and magnetic cusps, and UV images of global auroral distributions. Magnetopause (MP) deformations associated with MS high speed jets (HSJs) under a quasi-parallel interplanetary magnetic field condition are studied using a three-dimensional (3-D) global hybrid simulation. Soft X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is compared. We obtain key findings concerning deformations at the MP: (1) MP deformations are highly coherent with the MS HSJs generated at the quasiparallel region of the bow shock, (2) X-ray intensities estimated using solar wind H+ and self-consistent O7+ ions are consistent with each other, (3) Visual spacecraft are employed to check the discrimination ability for capturing MP deformations on Lunar and polar orbits, respectively. The SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane. A striking point is that SMILE has the potential to capture small-scale MP deformations and MS transients, such as HSJs, at medium altitudes on its orbit