4 resultados para Prolonged Exposure

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


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Steel reinforcing bar (rebar) corrosion due to chlorine ingress is the primary degradation mechanism for bridge decks. In areas where rock salt is used as a de-icing agent, salt water seeps into the concrete through cracks, causing corrosion of the rebar and potentially leading to catastrophic failure if not repaired. This project explores the use of radio frequency identification (RFID) tags as low-cost corrosion sensors. RFID tags, when embedded in concrete, will fail due to corrosion in the same manner as rebar after prolonged exposure to salt water. In addition, the presence of salt water interferes with the ability to detect the tags, providing a secondary mechanism by which this method can work. During this project, a fieldable RFID equipment setup was constructed and tested. In addition to a number of laboratory experiments to validate the underlying principles, RFID tags were embedded and tested in several actual bridge decks. Two major challenges were addressed in this project: issues associated with tags not functioning due to being in close proximity to rebar and issues associated with portland concrete coming in direct contact with the tags causing a detuning effect and preventing the tags from operating properly. Both issues were investigated thoroughly. The first issue was determined to be a problem only if the tags are placed in close proximity to rebar. The second issue was resolved by encapsulating the tag. Two materials, polyurethane spray foam and extruded polystyrene, were identified as providing good performance after testing, both in the lab and in the field.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This letter has been prepared as a consultation to determine some potential health concerns raised by a resident of Spencer from exposure to wire shredder fluff material emitted by Shine Brothers metal salvaging facility in Spencer, Iowa on July 10, 2011 and, a concern regarding the health impacts from the level of noise measured by a resident near the metal salvaging facility.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Iowa Department of Public Health (IDPH) has been asked by several citizens of Clinton, Iowa to evaluate potential health effects from exposure to benzene from an above ground tank located near a residential area. The above ground tank is managed by Equistar Chemicals, LP (Equistar) and is use to store pyrolysis gasoline prior to off-loading onto barges. The IDPH in cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to review the air quality monitoring provided by Equistar and provide an evaluation of the health effects from exposure to benzene at the levels detected in ambient air near the tank. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This document is about the different ways Mercury can poison a person and the exposure in Iowa.