26 resultados para corrosion rate

em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report describes how Iowa compares to other states in the nation. To promote consistency, the Iowa totals and the other states’ information have been taken entirely from the FBI’s national publication called Crime in the United States; 1999. The Iowa information in Crime in the United States; 1999 is based upon actual summary totals for selected reporting jurisdictions and produced by the U.S. Department of Justice, F.B.I. These Iowa totals cannot be compared to the 1999 Incident-Based Iowa Uniform Crime Reports, which are based on actual totals for all reporting Iowa law enforcement jurisdictions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report describes how Iowa compares to other states in the nation. To promote consistency, the Iowa totals and the other states’ information have been taken entirely from the FBI’s national publication called Crime in the United States; 2000. The Iowa information in Crime in the United States; 2000 is based upon actual summary totals for selected reporting jurisdictions and produced by the U.S. Department of Justice, F.B.I. These Iowa totals cannot be compared to the 2000 Incident-Based Iowa Uniform Crime reports, which are based on actual totals for all reporting Iowa law enforcement jurisdictions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report describes how Iowa compares to other states in the nation. To promote consistency, the Iowa totals and the other states’ information have been taken entirely from the FBI’s national publication called Crime in the United States; 2001. The Iowa information in Crime in the United States; 2001 is based upon actual summary totals for selected reporting jurisdictions and produced by the U.S. Department of Justice, F.B.I. These Iowa totals cannot be compared to the 2001 Incident-Based Iowa Uniform Crime Reports, which are based on actual totals for all reporting Iowa law enforcement jurisdictions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report describes how Iowa compares to other states in the nation. To promote consistency, the Iowa totals and the other states’ information have been taken entirely from the FBI’s national publication called Crime in the United States; 1998. The Iowa information in Crime in the United States; 1998 is based upon actual summary totals for selected reporting jurisdictions and produced by the U.S. Department of Justice, F.B.I. These Iowa totals cannot be compared to the 1998 Incident-Based Iowa Uniform Crime Reports which are based on actual totals for all reporting Iowa law enforcement jurisdictions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nitrogen (N) is typically one of the largest corn fertilization expenses. Nitrogen application is critical because it signifi cantly improves corn yield in many crop rotations. When choosing N rates, producers need to carefully consider both achieving most profi table economic return and advancing environmental stewardship. In 2004, university agronomists from the Corn Belt states began discussions regarding N rate use for corn production. The reasons for the discussions centered on apparent differences in methods for determining N rates across states, misperceptions regarding N rate guidelines, and concerns about application rates as corn yields have climbed to historic levels. An outcome of those discussions was an effort with the objectives to: ▪ develop N rate guidelines that could be applicable on a regional basis and ▪ identify the most profi table fertilizer N rates for corn production across the Corn Belt. This publication provides an overview of corn N fertilization in regard to rate of application, investigates concepts for determining economic application rates, and describes a suggested regional approach for developing corn N rate guidelines directly from recent research data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Iowa Department of Corrections has set a goal to reduce the rate of return to prison – whether due to new convictions or technical violations – to 33.3%. Preliminary findings show that that goal has been achieved for FY 07 releasees, with recidivism rates the lowest among the three years studied.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Iowa Department of Corrections has set a goal to reduce the rate of return to prison – whether due to new convictions or technical violations – to 33.3%. Preliminary findings show that that goal has been achieved for FY 07 releasees, with recidivism rates the lowest among the three years studied.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the key statistics that Iowa Corrections maintains to measure the success of our efforts is the three-year return-to-prison rate for offenders leaving prison and reentering the community. As the chart below shows, the rate for the three-year period from FY 2009 through FY 2012 is the lowest since this measure has been calculated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Technical challenges exist with infrastructure that can be addressed by nondestructive evaluation (NDE) methods, such as detecting corrosion damage to reinforcing steel that anchor concrete bridge railings to bridge road decks. Moisture and chloride ions reach the anchors along the cold joint between the rails and deck, causing corrosion that weakens the anchors and ultimately the barriers. The Center for Nondestructive Evaluation at Iowa State University has experience in development of measurement techniques and new sensors using a variety of interrogating energies. This research evaluated feasibility of three technologies — x-ray radiation, ground-penetrating radar (GPR), and magnetic flux leakage (MFL) — for detection and quantification of corrosion of embedded reinforcing steel. Controlled samples containing pristine reinforcing steel with and without epoxy and reinforcing steel with 25 percent and 50 percent section reduction were embedded in concrete at 2.5 in. deep for laboratory evaluation. Two of the techniques, GPR and MFL, were used in a limited field test on the Iowa Highway 210 Bridge over Interstate 35 in Story County. The methods provide useful and complementary information. GPR provides a rapid approach to identify reinforcing steel that has anomalous responses. MFL provides similar detection responses but could be optimized to provide more quantitative correlation to actual condition. Full implementation could use either GPR or MFL methods to identify areas of concern, followed by radiography to give a visual image of the actual condition, providing the final guidance for maintenance actions." The full 103 page report and the 2 page Tech Transfer Summary are included in this link.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chloride ion penetration through concrete to reinforcing steel is causing the premature deterioration of numerous bridge decks in Iowa. The purpose of the research reported in this paper was to determine whether any of several additives or alternative deicing chemicals could inhibit corrosion of reinforcing steel. The deicers tested were calcium magnesium acetate (CMA), CMA plus NaCl (NaCl: sodium chloride), Quicksalt plus PCI, and CG-90, a polyphosphate solution being developed by Cargill. Two tests were established. First, steel coupons were placed in a 15% solution of a deicer and distilled water to determine which alternative deicer would cause the least amount of corrosion in solution. The coupons were weighed periodically to determine each coupon's weight loss from corrosion. The second test involved ponding a 15% solution of each material on reinforced concrete blocks. Weekly copper-copper sulfate electrical half-cell (CSE) potential readings were taken on each block to determine whether corrosive activity was occurring at the steel surface. When the ponding research was concluded, concrete samples were taken from one of the three blocks ponded with each deicer. The samples were used to determine the chloride ion content at the level of the steel. Results show that all the deicers were less corrosive than NaCl. Only pure CMA, however, significantly inhibited the corrosion of steel embedded in concrete.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Concrete bridge decks subjected to corrosive environment because of the application of de-icing chemical could deteriorate at a rapid rate. In an effort to minimize corrosion of the reinforcement and the corresponding delaminations and spalls, the Iowa Department of Transportation started using epoxy-coated rebars (ECR) in the top mat of reinforcing around 1976 and in both mats 10 years later. The overall objective of this research was to determine the impact of deck cracking on durability and estimate the remaining functional service life of a bridge deck. This was accomplished by conducting a literature review, visually inspecting several bridge decks, collecting and sampling test cores from cracked and uncracked areas of bridge decks, determining the extent to which epoxy-coated rebars deteriorate at the site of cracks, and evaluating the impact of cracking on service life.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In reinforced concrete systems, ensuring that a good bond between the concrete and the embedded reinforcing steel is critical to long-term structural performance. Without good bond between the two, the system simply cannot behave as intended. The bond strength of reinforcing bars is a complex interaction between localized deformations, chemical adhesion, and other factors. Coating of reinforcing bars, although sometimes debated, has been commonly found to be an effective way to delay the initiation of corrosion in reinforced concrete systems. For many years, the standard practice has been to coat reinforcing steel with an epoxy coating, which provides a barrier between the steel and the corrosive elements of water, air, and chloride ions. Recently, there has been an industry-led effort to use galvanizing to provide the protective barrier commonly provided by traditional epoxy coatings. However, as with any new structural product, questions exist regarding both the structural performance and corrosion resistance of the system. In the fall of 2013, Buchanan County, Iowa constructed a demonstration bridge in which the steel girders and all internal reinforcing steel were galvanized. The work completed in this project sought to understand the structural performance of galvanized reinforcing steel as compared to epoxy-coated steel and to initiate a long-term corrosion monitoring program. This work consisted of a series of controlled laboratory tests and the installation of a corrosion monitoring system that can be observed for years in the future. The results of this work indicate there is no appreciable difference between the bond strength of epoxy-coated reinforcing steel and galvanized reinforcing steel. Although some differences were observed, no notable difference in either peak load, slip, or failure mode could be identified. Additionally, a long-term monitoring system was installed in this Buchanan County bridge and, to date, no corrosion activity has been identified.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In 2002, Senate File 2318, Insurance Premium Tax Reduction Act, the Iowa General Assembly approved a reduction in the insurance premium tax rate from 2 percent to 1 percent. The reduction was phased in at the rate of 1/4 percent annual increments over a five-year period, beginning with life and health insurance policy payments made on or after January 1st, 2003. Calendar year 2007 was the first year all premiums were taxed at 1 percent and fiscal year 2008 was the first full fiscal year at the 1 percent rate. Insurance premiums tax is paid only by insurance companies. The companies that benefit from the tax reduction are uniquely identified in government employment statistics. This allows for a unique opportunity to evaluate both the revenue impact and the employment impact of the tax rate reduction in Senate File 2318. This issue review focuses on the General Fund revenue impact of the rate reduction and the Iowa employment trends for the insurance industry since the rate reduction legislation was approved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Iowa Department of Transportation initiated this research to evaluate the reliability, benefit and application of the corrosion detection device. Through field testing prior to repair projects and inspection at the time of repair, the device was shown to be reliable. With the reliability established, twelve additional devices were purchased so that this evaluation procedure could be used routinely on all repair projects. The corrosion detection device was established as a means for determining concrete removal for repair. Removal of the concrete down to the top reinforcing steel is required for all areas exhibiting electrical potentials greater than 0.45 Volt. It was determined that the corrosion detection device was not applicable to membrane testing. The corrosion detection device has been used to evaluate corrosion of reinforcing steel in continuously reinforced concrete pavement.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Materials and Research Departments cooperated in planning and performing Research Project HR-1004 during the summer of 1974. The Research Department agreed to accept responsibility for the final report; it has been delayed because of our efforts to obtain a maximum amount of information from the data by means of various statistical analyses. This memorandum contains all of the data, hopefully in a manner that will permit you to proceed with your consideration of an experimental project using cathodic protection for the CRCP steel. A more detailed report will be prepared at a later date.