10 resultados para Event Scale
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
Infectious livestock disease creates externalities for proximate animal production enterprises. The distribution of production scale within a region should influence and be influenced by these disease externalities. Taking the distribution of the unit costs of stocking an animal as primitive, we show that an increase in the variance of these unit costs reduces consumer surplus. The effect on producer surplus, total surplus, and animal concentration across feedlots depends on the demand elasticity. A subsidy to smaller herds can reduce social welfare and immiserize the farm sector by increasing the extent of disease. While Nash behavior involves excessive stocking, disease effects can be such that aggregate output declines relative to first-best. Disease externalities can induce more adoption of a cost-reducing technology by larger herds so that animals become more concentrated across herds. For strategic reasons, excess overall adoption of the innovation may occur. Larger herds are also more likely to adopt biosecurity innovations, explaining why larger herds may be less diseased in equilibrium.
Resumo:
Currently, many drivers experience some difficulty in viewing the road ahead of them during times of reduced visibility, such as rain, snow, fog, or the darkness of night- Recent studies done by the National Safety Council provide a detailed contrast between fatal accidents occurring during the day and night. Revealed was that the motor vehicle night death rate (4.41 deaths per 100 million miles driven) was sharply higher than the corresponding death rate during daylight hours (1.21). By providing a delineating system powered by the natural resource of solar power, a constant source of visibility may be maintained throughout the evening. Along with providing enough light to trace the outline of the road, other major goals defined in producing this delineator system are as follows: 1. A strong and durable design that would protect the internal components and survive extreme weather conditions. 2. A low maintenance system where components need few repairs or replacements. 3. A design which makes all components accessible in the event that maintenance is needed, but also prevents vandalism. 4. A design that provides greater visibility to drivers and will not harm a vehicle or its passengers in the event of a collision. This solar powered highway delineator consists of an adjustable solar array, a light fixture, and a standard delineator pole. The solar array houses and protects the solar panels, and can be easily adjusted to obtain a maximum amount of sunlight. The light fixture primarily houses the battery, the circuit and the light assembly. Both components allow for easy accessibility and reduce vandalism using internal connections for bolts and wires. The delineator mounting pole is designed to extensively deform in the event of a collision, therefore reducing any harm caused to the vehicle and/or the passengers. The cost of a single prototype to be produced is approximately $70.00 excluding labor costs. However, these material and labor costs will be greatly reduced if a large number of delineators are produced. It is recommended that the Iowa Department of Transportation take full advantage of the research and development put into this delineator design. The principles used in creating this delineator can be used to provide an outline for drivers to follow, or on a larger scale, provide actual roadway lighting in areas where it was never before possible or economically feasible. In either event, the number of fatal accidents will be decreased due to the improved driver visibility in the evening.
Resumo:
As a result of the construction of the Saylorville Dam and Reservoir on the Des Moines River, six highway bridges are scheduled for removal. Five of these are old high-truss single-lane bridges, each bridge having several simple spans. The other bridge is a fairly modern (1955) double 4-span continuous beam-and-slab composite highway bridge. The availability of these bridges affords an unusual opportunity for study of the behavior of full-scale bridges. Because of the magnitude of the potential testing program, a feasibility study was initiated and the results are presented in this two-part final report. Part I summarizes the findings and Part II presents the supporting detailed information.
Resumo:
As a result of the construction of the Saylorville Dam and Reservoir on the Des Moines River, six highway bridges crossing the river were scheduled for removal. One of these, an old pin-connected, high-truss, single-lane bridge, was selected for a comprehensive testing program which included ultimate load tests, service load tests, and a supplementary test program. A second bridge was used for a limited service load test program. The results of the research are detailed in two interim reports. The first interim report outlines the ultimate load tests and the second interim report details the results of the service load and supplementary test program. This report presents a summary of these findings along with recommendations for implementation of the findings.
Resumo:
A laboratory investigation was undertaken to determine the limiting model Reynolds number above which the scour behavior of rock protected structures can be reproduced in hydraulic models scaled according to the Froude criterion. A submerged jet was passed over an initially full scour pocket containing uniform glass spheres and the rate of scour was measured as a function of time. The dimensions of the scour pocket and jet and the particle diameters were varied as needed to maintain strict geometric similarity. For each of two different Froude numbers the Reynolds number was varied over a wide range. The normalized scour rate was found to be practically independent of the Reynolds number, R, (based on the jet velocity and particle diameter) at values of R above about 2.5 x 10^3, and to decrease with Rat smaller values. A grid placed in the jet was found to have a very strong effect on the scour rate. In an attempt to explain the effect of R on the scour behavior, turbulent pressure and velocity fluctuations were measured in air flows and water flows, respectively, over rigid scour pockets having the same geometry as those formed in the scour experiments. The normalized spectra of the fluctuations were found to be nearly independent of R, but the flow pattern was found to be very sensitive to the inlet condition, the jet deflecting upward or downward in a not wholly explainable manner. This indicates that scour behavior can be modeled only if the approach flow is also accurately modeled.
Resumo:
This publication was prepared to describe how the Iowa State University distillery has been operating, including information on distillery size, equipment, tanks, condenser, heat exchanger, pumps and the process. Photos and diagrams are also included.
Resumo:
Summary of water monitoring conducted by the City of Bondurant and Bondurant-Farrar school students of sites in and around Bondurant.
Resumo:
This project analyzes the characteristics and spatial distributions of motor vehicle crash types in order to evaluate the degree and scale of their spatial clustering. Crashes occur as the result of a variety of vehicle, roadway, and human factors and thus vary in their clustering behavior. Clustering can occur at a variety of scales, from the intersection level, to the corridor level, to the area level. Conversely, other crash types are less linked to geographic factors and are more spatially “random.” The degree and scale of clustering have implications for the use of strategies to promote transportation safety. In this project, Iowa's crash database, geographic information systems, and recent advances in spatial statistics methodologies and software tools were used to analyze the degree and spatial scale of clustering for several crash types within the counties of the Iowa Northland Regional Council of Governments. A statistical measure called the K function was used to analyze the clustering behavior of crashes. Several methodological issues, related to the application of this spatial statistical technique in the context of motor vehicle crashes on a road network, were identified and addressed. These methods facilitated the identification of crash clusters at appropriate scales of analysis for each crash type. This clustering information is useful for improving transportation safety through focused countermeasures directly linked to crash causes and the spatial extent of identified problem locations, as well as through the identification of less location-based crash types better suited to non-spatial countermeasures. The results of the K function analysis point to the usefulness of the procedure in identifying the degree and scale at which crashes cluster, or do not cluster, relative to each other. Moreover, for many individual crash types, different patterns and processes and potentially different countermeasures appeared at different scales of analysis. This finding highlights the importance of scale considerations in problem identification and countermeasure formulation.
Resumo:
As a result of the construction of the Saylorville Dam and Reservoir on the Des Moines River, six highway bridges crossing the river were scheduled for removal. One of these, an old pinconnected high-truss single-lane bridge, was selected for a testing program which included ultimate load tests. The purpose of the ultimate load tests, which are summarized in this report, was to relate design and rating procedures presently used in bridge design to the field behavior of this type of truss bridge. The ultimate load tests consisted of ultimate load testing of one span of the bridge, of two I-shaped floorbeams, and of two panels of the timber deck. The theoretical capacity of each of these components is compared with the results from the field tests.
Resumo:
As a result of the construction of the Saylorville Dam and Reservoir on the Des Moines River, six highway bridges crossing the river were scheduled for removal. Two of these were incorporated into a comprehensive test program to study the behavior of old pin-connected high-truss single-lane bridges. The test program consisted of ultimate load tests, service load tests and a supplementary test program. The results reported in this report cover the service load tests on the two bridges as well as the supplementary tests, both static and fatigue, of eyebar members removed from the two bridges. The field test results of the service loading are compared with theoretical results of the truss analysis.