Force and cavitation characteristics of the NACA 4412 hydrofoil

This report covers Water Tunnel measurements of the infinite aspect ratio characteristics and cavitation characteristics of a hydrofoil section. The profile tested is identical to the 4412 airfoil section of the National Advisory Committee for Aeronautics and is called the NACA 4412 hydrofoil in this report. Measurements and observations include lift, drag, and pitching moment and the inception and development of cavitation as functions of the angle of attack, velocity, and pressure of the flow. The purpose of this report is to present these measurements of the characteristics of this section in water, to compare the results with other available information on this shape, and to evaluate the Water Tunnel method for obtaining the complte hydrodynamic characteristics of hydrofoils

Spotlight: Midland and Odessa: Permian Basin cities ride oil boom again

Economic conditions - Texas ; Cities and towns ; Gas industry ; Petroleum industry and trade

New Minimal Distortion Shift Gauge

Based on the recent understanding of the role of the densitized lapse function in Einstein's equations and of the proper way to pose the thin sandwich problem, a slight readjustment of the minimal distortion shift gauge in the 3+1 approach to the dynamics of general relativity allows this shift vector to serve as the vector potential for the longitudinal part of the extrinsic curvature tensor in the new approach to the initial value problem, thus extending the initial value decomposition of gravitational variables to play a role in the evolution as well. The new shift vector globally minimizes the changes in the conformal 3-metric with respect to the spacetime measure rather than the spatial measure on the time coordinate hypersurfaces, as the old shift vector did.Comment: 5 page ReVTeX4 twocolumn latex file, no figures; slight revision: last sentence of section 2 deleted and replaced, citations reordered, additonal paragraph added to introduction with short explanation of the initial value problem and its thin sandwich variation, Yvonne Choquet-Bruhat reference added and acknowledgment expanded to include he

The Impact of Driver Cell Phone Use on Accidents

Cell phone use is increasing worldwide, leading to a concern that cell phone use while driving increases accidents. We develop a new approach for estimating the relationship between cell phone use while driving and accidents, based on new survey data. We test for selection effects, such as whether drivers who use cell phones are inherently less safe drivers, even when not on the phone. The paper has two key findings. First, the impact of cell phone use on accidents varies across the population. This result implies that previous estimates of the impact of cell phone use on risk for the population, based on accident-only samples, may therefore be overstated by 36%. Second, once we correct for endogeneity, there is no significant effect of hands-free or hand-held cell phone use on accidents.cellular telephones and driving, safety regulation, selection effects

Income growth shows Houston's economic strength and maturity

Metropolitan areas ; Economics ; Wages ; Natural gas

The Impact of Driver Cell Phone Use on Accidents

Cell phone use is increasing worldwide, leading to a concern that cell phone use while driving increases accidents. Several countries, three states and Washington, D.C. have banned the use of hand-held cell phones while driving. In this paper, we develop a new approach for estimating the relationship between cell phone use while driving and accidents. Our approach is the first to allow for the direct estimation of the impact of a cell phone ban while driving. It is based on new survey data from over 7,000 individuals. This paper differs from previous research in two significant ways: first, we use a larger sample of individual-level data; and second, we test for selection effects, such as whether drivers who use cell phones are inherently less safe drivers, even when not on the phone. The paper has two key findings. First, the impact of cell phone use on accidents varies across the population. This result implies that previous estimates of the impact of cell phone use on risk for the population, based on accident-only samples, may be overstated by about one-third. Second, once we correct for endogeneity, there is no significant effect of hands-free or hand-held cell phone use on accidents.

Tracking productivity in real time

Because volatile short-term movements in productivity growth obscure the underlying trend, shifts in this trend may go unrecognized for years - a lag that can lead to policy mistakes and hence economic instability. This study develops a model for tracking productivity that brings in additional variables to help reveal the trend. The model's success is evident in its ability to detect changes in trend productivity within a year or two of their occurrence. Currently, the model indicates that the underlying trend remains strong despite recent weak productivity data.Industrial productivity - Measurement ; Economic policy ; Econometric models

Risk, Research, and Returns: Valuation of the Potential of Improved Citrus Cultivars

Replaced with revised version of paper 02/04/08.Crop Production/Industries, Research Methods/ Statistical Methods, Risk and Uncertainty,

Advanced Communications Technology Satellite (ACTS). Phase 1: Industrial/academic experimenters

This report presents the work done at Arizona State University under the ACTS Experimenters Program. The main thrust of the Program was to develop experiments to test, evaluate, and prove the commercial worthiness of the ACTS satellite which is scheduled for launch in 1993. To accomplish this goal, meetings were held with various governmental, industrial, and academic units to discuss the ACTS satellite and its technology and possible experiments that would generate industrial interest and support for ASU's efforts. Several local industries generated several experiments of their own. The investigators submitted several experiments of educational, medical, commercial, and technical value and interest. The disposition of these experimental proposals is discussed in this report

Technology -- Climate Interactions in the Green Revolution in India

This paper present a model of the Green Revolution in India, in which the development and diffusion of HYVs, the expansion of irrigation and the expansion of multiple-cropping are treated as endogenous responses to more basic investments in agricultural technology and infrastructure, as well as to climate and edaphic endowments. We incorporate explicit climate-technology interactions in the model, in order to identify climate effects on the diffusion of HYVs, irrigation and multiple- cropping, and on Net Revenue to agriculture. We find that climate affects technology development and diffusion, and that technology development and diffusion affect the impacts of climate on agricultural productivity in India.Green Revolution, India, HYV, Rice, Wheat, Climate, Agricultural Research