Addendum to the post-closure permit application for the Bear Creek hydrogeologic regime at the Y-12 plant: Walk-in pits

International Nuclear Information System (INIS)

1995-04-01

In June 1987, the Resource Conservation and Recovery Act (RCRA) Closure/Post-Closure Plan for the Bear Creek Burial Grounds (BCBG) located at the Y-12 Plant on the Oak Ridge Reservation in Oak Ridge, Tennessee was submitted to the Tennessee Department of Environment and Conservation (TDEC) for review and approval.The Closure Plan has been modified and revised several times. This document is an addendum to the Post-Closure Permit Application submitted to TDEC in June, 1994. This addendum contains information on the Walk-In Pits of the BCBG which is meant to supplement the information provided in the Post-Closure Permit Application submitted for the BCBG. This document is not intended to be a stand-alone document.

Baseline Risk Assessment for the F-Area Burning/Rubble Pits and Rubble Pit

Energy Technology Data Exchange (ETDEWEB)

Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1996-03-01

This document provides an overview of the Savannah River Site (SRS) and a description of the F-Area Burning/Rubble Pits (BRPs) and Rubble Pit (RP) unit. It also describes the objectives and scope of the baseline risk assessment (BRA).

PIT 9 Project: A private sector initiative

International Nuclear Information System (INIS)

Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

1993-01-01

The Pit 9 Comprehensive Demonstration is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Lab. (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA). Pit 9 is an inactive waste disposal pit located in the northeastern corner of the SDA at the INEL's Radioactive Waste Management Complex (RWMC). It covers approximately 1 acre. The waste within Pit 9 is primarily transuranic waste generated at the Rocky Flats Plant and additional wastes, both hazardous and low-level radioactive, from generators at the INEL

Increased risk of acute angle closure in retinitis pigmentosa: a population-based case-control study.

Directory of Open Access Journals (Sweden)

Yu-Chieh Ko

Full Text Available To investigate the association between retinitis pigmentosa (RP and acute angle closure during a 15-year follow-up period.Using the Taiwan Longitudinal Health Insurance Database 2000, we identified 382 RP patients based on the diagnostic code of RP (International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM 362.74 made during 1996-2010, excluding subjects under age of 20 years at diagnosis or subjects undergoing lens extraction before the index date. The control group included 3820 randomly selected non-RP subjects matched with the RP patients in age, gender and the index date of diagnosis. The incidence of acute angle closure during the study period was observed based on an ICD-9-CM code of 365.22. Cochran-Mantel-Haenszel test was used to determine the odds ratio (OR of having acute angle closure in RP patients.The mean age at the diagnosis of RP was 51.1 years (standard deviation [SD] 16.7. Acute angle closure occurred in 5 RP patients (1.3% and in 15 controls (0.4%. The mean age with the acute angle closure was 53.3 years (SD 8.0 in RP patients and 64.6 years (SD 8.4 in controls (P = 0.015. After adjusting for age, gender and comorbid disorders, RP patients had 3.64-fold (95% confidence interval [CI], 1.29-10.25, P<0.001 greater odds of having acute angle closure. After stratification for gender and age, the risk of acute angle closure in RP was higher in patients under age of 60 years (adjusted OR 11.84; 95% CI, 2.84-49.48 and male patients (adjusted OR 19.36; 95% CI, 3.43-109.40 (both P = 0.001.RP patients had increased risk of acute angle closure than controls. Contrary to the fact that angle closure disease is more prevalent in elderly females in general population, acute angle closure attack occurred earlier in life and the risk was higher in males among RP patients.

Risk-based approach to appraise valve closure in the clam Corbicula fluminea in response to waterborne metals

International Nuclear Information System (INIS)

Liao, C.-M.; Jou, L.-J.; Chen, B.-C.

2005-01-01

We developed a risk-based approach to assess how the valve closure behavior of Asiatic clam Corbicula fluminea responds to waterborne copper (Cu) and cadmium (Cd). We reanalyzed the valve closure response data from published literature to reconstruct the response time-dependent dose-response profiles based on an empirical three-parameter Hill equation model. We integrated probabilistic exposure profiles of measured environmental Cu and Cd concentrations in the western coastal areas of Taiwan with the reconstructed dose-response relationships at different integration times of response to quantitatively estimate the valve response risk. The risk assessment results implicate exposure to waterborne Cu and Cd may pose no significant risk to clam valve activity in the short-time response periods (e.g., <30 min), yet a relative high risk for valve closure response to waterborne Cu at response times greater than 120 min is alarming. We successfully linked reconstructed dose-response profiles and EC50-time relationships associated with the fitted daily valve opening/closing rhythm characterized by a three-parameter lognormal function to predict the time-varying bivalve closure rhythm response to waterborne metals. We parameterized the proposed predictive model that should encourage a risk-management framework for discussion of future design of biological monitoring systems. - A model was developed to link valve closure in clams to concentrations of metals in water

RCRA closure plan for the Bear Creek Burial Grounds B Area and Walk-In Pits at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1992-11-01

The Bear Creek Burial Grounds (BCBG) are located on the southwest flank of Pine Ridge ∼1.5 miles west of the Oak Ridge Y-12 Plant in Bear Creek Valley. This facility consists of several contiguous disposal sites identified as Burial Grounds A, B, C, and D. Each burial site consists of a series of trenches used for disposal of solid wastes and, in some cases, liquid wastes. Initially, the RCRA Closure/Postclosure plan for the BCBG was intended to apply to A Area, C-West, B Area, and the walk-in pits for BCBG. However, a plan was provided to include the B Area in the walk-in pits so that both areas cold be closed under one cap. The closure plan for B Area and the walk-in pits is presented in this document. The actual quantity and identity of materials is uncertain. The largest volume of material disposed in BCBG consists of uranium-contaminated industrial trash (paper, wood, steel, glass, and rubble)

Remedial Action Work Plan Amchitka Island Mud Pit Closures

Energy Technology Data Exchange (ETDEWEB)

DOE/NV

2001-04-05

This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

Area 2 Photo Skid Wastewater Pit corrective action decision document Corrective Action Unit Number 332: Part 1, and Closure report: Part 2

International Nuclear Information System (INIS)

1997-01-01

The Area 2 Photo Skid Wastewater Pit, Corrective Action Site (CAS) Number 02-42-03, the only CAS in Corrective Action Unit (CAU) Number 332, has been identified as a source of unquantified, uncontrolled, and unpermitted wastewater discharge. The Photo Skid was used for photographic processing of film for projects related to weapons testing, using Kodak RA4 and GPX film processing facilities for black and white and color photographs. The CAU is located in Area 2 of the Nevada Test Site, Nye County, Nevada. The CAS consists of one unlined pit which received discharged photographic process wastewater from 1984 to 1991. The Corrective Action Decision Document (CADD) and the Closure Report (CR) have been developed to meet the requirements of the Federal Facility Agreement and Consent Order (FFACO, 1996). The CADD and the CR for this CAS have been combined because sample data collected during the site investigation do not exceed regulatory limits established during the Data Quality Objectives (DQO) process. The purpose of the CADD and the CR is to justify why no corrective action is necessary at the CAU based on process knowledge and the results of the corrective action investigation and to request closure of the CAU. This document contains Part 1 of the CADD and Part 2 of the CR

Closure Report for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2012-02-21

This Closure Report (CR) presents information supporting closure of the 92-Acre Area, which includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' This CR provides documentation supporting the completed corrective actions and confirmation that the closure objectives were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996 [as amended March 2010]). Closure activities began in January 2011 and were completed in January 2012. Closure activities were conducted according to Revision 1 of the Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for the 92-Acre Area and CAU 111 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2010). The following closure activities were performed: (1) Construct an engineered evapotranspiration cover over the boreholes, trenches, and pits in the 92-Acre Area; (2) Install use restriction (UR) warning signs, concrete monuments, and subsidence survey monuments; and (3) Establish vegetation on the covers. UR documentation is included as Appendix C of this report. The post-closure plan is presented in detail in Revision 1 of the CADD/CAP for the 92-Acre Area and CAU 111, and the requirements are summarized in Section 5.2 of this document. When the next request for modification of Resource Conservation and Recovery Act Permit NEV HW0101 is submitted to the Nevada Division of Environmental Protection (NDEP), the requirements for post-closure monitoring of the 92-Acre Area will be included. NNSA/NSO requests the following: (1) A Notice of Completion from NDEP to NNSA/NSO for closure of CAU 111; and (2) The transfer of CAU 111 from Appendix III to Appendix IV, Closed Corrective Action Units, of the FFACO.

Closure Report for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada

International Nuclear Information System (INIS)

2012-01-01

This Closure Report (CR) presents information supporting closure of the 92-Acre Area, which includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' This CR provides documentation supporting the completed corrective actions and confirmation that the closure objectives were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996 (as amended March 2010)). Closure activities began in January 2011 and were completed in January 2012. Closure activities were conducted according to Revision 1 of the Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for the 92-Acre Area and CAU 111 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), 2010). The following closure activities were performed: (1) Construct an engineered evapotranspiration cover over the boreholes, trenches, and pits in the 92-Acre Area; (2) Install use restriction (UR) warning signs, concrete monuments, and subsidence survey monuments; and (3) Establish vegetation on the covers. UR documentation is included as Appendix C of this report. The post-closure plan is presented in detail in Revision 1 of the CADD/CAP for the 92-Acre Area and CAU 111, and the requirements are summarized in Section 5.2 of this document. When the next request for modification of Resource Conservation and Recovery Act Permit NEV HW0101 is submitted to the Nevada Division of Environmental Protection (NDEP), the requirements for post-closure monitoring of the 92-Acre Area will be included. NNSA/NSO requests the following: (1) A Notice of Completion from NDEP to NNSA/NSO for closure of CAU 111; and (2) The transfer of CAU 111 from Appendix III to Appendix IV, Closed Corrective Action Units, of the FFACO.

Pit 9 project: A private sector initiative

International Nuclear Information System (INIS)

Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

1993-01-01

This report discusses the Pit 9 Comprehensive Demonstration which is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Laboratory (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA)

Post-Closure Inspection and Monitoring Report for Corrective Action Unit 342: Area 23 Mercury Fire Training Pit, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2006-01-01

This report provides a summary and analysis of visual site inspections and soil gas sampling results for Corrective Action Unit (CAU) 342, Area 23 Mercury Fire Training Pit. CAU 342 is identified in the Federal Facility Agreement and Consent Order of 1996 and consists of Corrective Action Site 23-56-01, Former Mercury Fire Training Pit. This report covers calendar years 2004 and 2005. Visual site inspections were conducted on May 20 and November 14, 2004, and May 17 and November 15, 2005. No significant findings were observed during these inspections. The site was in good condition, and no repair activities were required. Soil gas samples were collected on November 29, 2005, for analysis of volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs), and samples were collected on December 1, 2005, for analysis of base gases. Base gas concentrations in the monitoring well show a high concentration of carbon dioxide and a low concentration of oxygen, which is an indication of biodegradation of total petroleum hydrocarbons (TPH) in the soil. Results for VOCs and SVOCs are unchanged, with VOCs below or near laboratory method detection limits and no SVOCs detected above laboratory method detection limits. Post-closure monitoring was required for six years after closure of the site. Therefore, since 2005 was the sixth year of monitoring, the effectiveness of natural attenuation of the TPH-impacted soil by biodegradation was evaluated. The base gas concentrations indicate that biodegradation of TPH in the soil is occurring; therefore, it is recommended that monitoring be discontinued. Visual site inspections should continue to be performed biannually to ensure that the signs are in place and readable and that the use restriction has been maintained. The results of the site inspections will be documented in a letter report and submitted annually

Plantar pitted keratolysis: a study from non-risk groups

Directory of Open Access Journals (Sweden)

Asli Feride Kaptanoglu

2012-02-01

Full Text Available Pitted keratolysis is an acquired, superficial bacterial infection of the skin which is characterized by typical malodor and pits in the hyperkeratotic areas of the soles. It is more common in barefooted people in tropical areas, or those who have to wear occlusive shoes, such as soldiers, sailors and athletes. In this study, we evaluated 41 patients who had been diagnosed with plantar pitted keratolysis. The patients were of high socioeconomic status, were office-workers, and most had a university degree. Malodor and plantar hyperhydrosis were the most frequently reported symptoms. The weight-bearing metatarsal parts of the feet were those most affected. Almost half the women in the study gave a history of regular pedicure and foot care in a spa salon. Mean treatment duration was 19 days. All patients were informed about the etiology of the disease, predisposing factors and preventive methods. Recurrences were observed in only 17% of patients during the one year follow-up period. This study emphasizes that even malodorous feet among non-risk city dwellers may be a sign of plantar pitted keratolysis. A study of the real incidence of the disease in a large population-based series is needed.

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada Test Site, Nevada, Revision 0

Energy Technology Data Exchange (ETDEWEB)

Mark Krauss

2010-07-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 544, Cellars, Mud Pits, and Oil Spills, identified in the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 544 comprises the following 20 corrective action sites (CASs) located in Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada Test Site (NTS): • 02-37-08, Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mud Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills This plan provides the methodology for field activities needed to gather the necessary information for closing each CAS. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 544 using the SAFER process. Using the approach approved for previous mud pit investigations (CAUs 530–535), 14 mud pits have been identified that • are either a single mud pit or a system of mud pits, • are not located in a radiologically posted area, and • have no evident biasing factors based on visual inspections. These 14 mud pits are recommended for no further action (NFA), and further field investigations will not be conducted. For the sites that do not meet the previously approved closure criteria, additional information will be obtained by conducting a field investigation before selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible

Catheter-based closure of the patent ductus arteriosus in lower weight infants.

Science.gov (United States)

Pavlek, Leeann R; Slaughter, Jonathan L; Berman, Darren P; Backes, Carl H

2018-06-13

Risks associated with drug therapy and surgical ligation have led health care providers to consider alternative strategies for patent ductus arteriosus (PDA) closure. Catheter-based PDA closure is the procedure of choice for ductal closure in adults, children, and infants ≥6kg. Given evidence among older counterparts, interest in catheter-based closure of the PDA in lower weight (closure devices; (3) review the technical success (feasibility); (4) review the risks (safety profile); (5) discuss the quality of evidence on procedural efficacy; (6) consider areas for future research. The review provided herein suggests that catheter-based PDA closure is technically feasible, but the lack of comparative trials precludes determination of the optimal strategy for ductal closure in this subgroup of infants. Copyright © 2018 Elsevier Inc. All rights reserved.

Human Health and Ecological Risk Assessment Work Plan Mud Pit Release Sites, Amchitka Island, Alaska

Energy Technology Data Exchange (ETDEWEB)

DOE/NV

2001-03-12

This Work Plan describes the approach that will be used to conduct human health and ecological risk assessments for Amchitka Island, Alaska, which was utilized as an underground nuclear test site between 1965 and 1971. During this period, the U.S. Atomic Energy Commission (now the U.S. Department of Energy) conducted two nuclear tests (known as Long Shot and Milrow) and assisted the U.S. Department of Defense with a third test (known as Cannikin). Amchitka Island is approximately 42 miles long and located 1,340 miles west-southwest of Anchorage, Alaska, in the western end of the Aleutian Island archipelago in a group of islands known as the Rat Islands. Historically including deep drilling operations required large volumes of drilling mud, a considerable amount of which was left on the island in exposed mud pits after testing was completed. Therefore, there is a need for drilling mud pit remediation and risk assessment of historical mud pit releases. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies that will be utilized for the site characterization of the constituents in soil, surface water, and sediment at these former testing sites. Its goal is the collection of data in sufficient quantity and quality to determine current site conditions, support a risk assessment for the site surfaces, and evaluate what further remedial action is required to achieve permanent closure of these three sites that will protect both human health and the environment. Suspected compounds of potential ecological concern for investigative analysis at these sites include diesel-range organics, polyaromatic hydrocarbons, polychlorinated biphenyls, volatile organic compounds, and chromium. The results of these characterizations and risk assessments will be used to evaluate corrective action alternatives to include no further action, the implementation of institutional controls, capping on site, or off-sit e

Tank Riser Pit Decontamination System (Pit Viper) Return on Investment and Break-Even Analysis

International Nuclear Information System (INIS)

Young, Joan K.; Weimar, Mark R.; Balducci, Patrick J.; Fassbender, Linda L.; Hernandez, Melissa

2003-01-01

This study assessed the cost benefit of Pit Viper deployment for 80 tank farm pits between October 1, 2003 and September 30, 2012 under the technical baseline for applicable double-shell tank (DST) and single-shell tank (SST) projects. After this assessment had been completed, the U.S. Department of Energy (DOE) Richland Operations Office (RL) and Office of River Protection (ORP) published the Hanford Performance Management Plan (August 2003), which accelerated the schedule for SST retrieval. Then, DOE/CH2M HILL contract modification M064 (October 2002) and The Integrated Mission Acceleration Plan (March 2003) further accelerated SST retrieval and closure schedules. Twenty-six to 40 tanks must be retrieved by 2006. Thus the schedule for SST pit entries is accelerated and the number of SST pit entries is increased. This study estimates the return on investment (ROI) and the number of pits where Pit Viper deployment would break even or save money over current manual practices. The results of the analysis indicate a positive return on the federal investment for deployment of the Pit Viper provided it is used on a sufficient number of pits

Pitting corrosion as a mixed system: coupled deterministic-probabilistic simulation of pit growth

Science.gov (United States)

Ibrahim, Israr B. M.; Fonna, S.; Pidaparti, R.

2018-05-01

Stochastic behavior of pitting corrosion poses a unique challenge in its computational analysis. However, it also stems from electrochemical activity causing general corrosion. In this paper, a framework for corrosion pit growth simulation based on the coupling of the Cellular Automaton (CA) and Boundary Element Methods (BEM) is presented. The framework assumes that pitting corrosion is controlled by electrochemical activity inside the pit cavity. The BEM provides the prediction of electrochemical activity given the geometrical data and polarization curves, while the CA is used to simulate the evolution of pit shapes based on electrochemical activity provided by BEM. To demonstrate the methodology, a sample case of local corrosion cells formed in pitting corrosion with varied dimensions and polarization functions is considered. Results show certain shapes tend to grow in certain types of environments. Some pit shapes appear to pose a higher risk by being potentially significant stress raisers or potentially increasing the rate of corrosion under the surface. Furthermore, these pits are comparable to commonly observed pit shapes in general corrosion environments.

Mining-induced earthquakes monitored during pit closure in the Midlothian Coalfield

Energy Technology Data Exchange (ETDEWEB)

Redmayne, D.W.; Richards, J.A.; Wild, P.W. [British Geological Survey, Edinburgh (United Kingdom). Global Seismology and Geomagnetism Group

1998-06-01

The British Geological Survey installed a seismometer network to monitor earthquakes around Rosslyn Chapel in the Midlothian Coalfield from November 1987 until January 1990. Accurate locations were obtained for 247 events and a close spatial and temporal association with concurrent coal mining, with a rapid decay of earthquake activity following pit closure, was demonstrated, indicating a mining-induced cause. Residual stress from past mining appears to have been an important factor in generating seismicity, and observations indicate that limiting the width of the workings or rate of extraction may significantly reduce or eliminate mining-induced earthquake activity. A frequency-magnitude analysis indicates a relatively high abundance of small events in this coalfield area. The maximum magnitude of a mining-induced earthquake likely to have been experienced during the life of the coalfield (maximum credible magnitude) was 3.0 M-L, although an extreme event (maximum possible magnitude) as large as 3.4 M-L was remotely possible. Significant seismic amplification was observed at Rosslyn Chapel, which is founded on sand and gravel, compared with a nearby bedrock site. As a consequence, relatively small magnitude events caused high, and occasionally damaging, seismic intensities at the chapel.

Congenital pits of the optic nerve head and retinochoroidal colobomas.

Science.gov (United States)

Brown, G C; Augsburger, J J

1980-07-01

A 45-year-old man presented with bilateral retinochoroidal colobomas associated with an inferonasal congenital pit of the optic nerve head in each eye. Different theories on the origin of such pits are discussed. This case supports the theory that some congenital optic pits occur as a result of failure of closure of the superior end of the embryonic fissure.

Closure Report for Corrective Action Unit 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site, Nevada, Revision 0

International Nuclear Information System (INIS)

Al Wickline

2007-01-01

This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 553 are located within Areas 19 and 20 of the Nevada Test Site. Corrective Action Unit 553 is comprised of the following CASs: 19-99-01, Mud Spill 19-99-11, Mud Spill 20-09-09, Mud Spill 20-99-03, Mud Spill. The purpose of this CR is to provide documentation supporting the completed corrective actions and provide data confirming that the closure objectives for CASs within CAU 553 were met. To achieve this, the following actions were or will be performed: Review the current site conditions including the concentration and extent of contamination. Implement any corrective actions necessary to protect human health and the environment. Properly dispose of corrective action and investigation wastes. Document the Notice of Completion and closure of CAU 553 to be issued by Nevada Division of Environmental Protection

Risk Based Corrosion Studies at SRS

International Nuclear Information System (INIS)

Hoffman, E.

2010-01-01

TYPE I and II (ASTM 285-B) - Experienced stress corrosion cracking (SCC), 2 have been closed; 22 scheduled for closure by 2017, and No active leak sites today. TYPE III (ASTM A516-70 and A537 Class I) - Post-fabrication relief of weld residual stresses, Improved resistance to SCC and brittle fracture, No leakage history, and Receives new waste. The objectives are to utilize statistical methods to reduce conservatism in current chemistry control program; and express nitrite inhibitor limits in terms of pitting risk on waste tank steel. Conclusions are: (1) A statistically designed experimental study has been undertaken to improve the effectiveness of the minimum nitrite concentrations to inhibit pitting corrosion; (2) Mixture/amount model supports that pitting depends on the ratio of aggressive to inhibitive anions, as well as the concentration of each species; (3) Secondary aggressive species, Cl - and SO 4 2- , significantly effect the corrosion response; and (4) Results support the reduction of the chemistry control nitrite inhibitor concentrations in the regime of 0.8-1.0 M nitrate.

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

Science.gov (United States)

Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

Addendum to the post-closure permit application for the Bear Creek Hydrogeologic Regime at the Y-12 Plant: Walk-in pits. Revision 2

International Nuclear Information System (INIS)

1995-04-01

The revised Closure Plan was initially intended to apply to A Area, C-West, B Area, and the Walk-In Pits (WIPs) of the Bear Creek Burial Grounds (BCBG). However, a strategy was developed to include the B Area [a solid waste management unit (SWMU)] with the WIPs so that both areas would be closed under one cap. The plan was presented to the State of Tennessee on March 8, 1990, and the Department of Energy was requested to review other unique alternatives to close the site. Therefore, in November 1992, the Closure Plan for B Area and the WIPs was prepared separately from that of the other sites associated with the BCBG and was presented in a RCRA Closure Plan. The Closure Plan revision issued April 1993 was intended to reflect the placement of the Kerr Hollow Quarry debris at the WIPs, revise the closure data, and acknowledge that the disposition of a monitoring well within the closure site could not be verified. A Post-Closure Permit Application (PCPA) was to include the WIPs; however, at the time of submittal, closure of the WIPs had not been certified. This addendum contains information on the WIPs to accompany the BCBG PCPA. The purpose of this document is to supplement the information provided in the BCBG PCPA. This document is not intended to be a stand-alone document. Only additional information regarding the WIPs is included in the sections of this document, which correspond to sections of the PCPA submitted in June 1994

Risk assessment of occupational groups working in open pit mining: Analytic Hierarchy Process

Directory of Open Access Journals (Sweden)

Yaşar Kasap

2017-01-01

Full Text Available In open pit mining it is possible to prevent industrial accidents and the results of industrial accidents such as deaths, physical disabilities and financial loss by implementing risk analyses in advance. If the probabilities of different occupational groups encountering various hazards are determined, workers’ risk of having industrial accidents and catching occupational illnesses can be controlled. In this sense, the aim of this study was to assess the industrial accidents which occurred during open pit coal production in the Turkish Coal Enterprises (TCE Garp Lignite unit between 2005 and 2010 and to analyze the risks using the Analytic Hierarchy Process (AHP. The analyses conducted with AHP revealed that the greatest risk in open pit mining is landslides, the most risky occupational group is unskilled labourers and the most common hazards are caused by landslides and transportation/hand tools/falling.

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

International Nuclear Information System (INIS)

Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

1997-12-01

A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above)

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

Energy Technology Data Exchange (ETDEWEB)

Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

1997-12-01

A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above).

Understanding the Risk Factors of Trauma Center Closures

Science.gov (United States)

Shen, Yu-Chu; Hsia, Renee Y.; Kuzma, Kristen

2011-01-01

Objectives We analyze whether hazard rates of shutting down trauma centers are higher due to financial pressures or in areas with vulnerable populations (such as minorities or the poor). Materials and Methods This is a retrospective study of all hospitals with trauma center services in urban areas in the continental US between 1990 and 2005, identified from the American Hospital Association Annual Surveys. These data were linked with Medicare cost reports, and supplemented with other sources, including the Area Resource File. We analyze the hazard rates of trauma center closures among several dimensions of risk factors using discrete-time proportional hazard models. Results The number of trauma center closures increased from 1990 to 2005, with a total of 339 during this period. The hazard rate of closing trauma centers in hospitals with a negative profit margin is 1.38 times higher than those hospitals without the negative profit margin (P lower hazard of shutting down trauma centers (ratio: 0.58, P penetration face a higher hazard of trauma center closure (ratio: 2.06, P < 0.01). Finally, hospitals in areas with higher shares of minorities face a higher risk of trauma center closure (ratio: 1.69, P < 0.01). Medicaid load and uninsured populations, however, are not risk factors for higher rates of closure after we control for other financial and community characteristics. Conclusions Our findings give an indication on how the current proposals to cut public spending could exacerbate the trauma closure particularly among areas with high shares of minorities. In addition, given the negative effect of health maintenance organizations on trauma center survival, the growth of Medicaid managed care population should be monitored. Finally, high shares of Medicaid or uninsurance by themselves are not independent risk factors for higher closure as long as financial pressures are mitigated. Targeted policy interventions and further research on the causes, are needed to

Closure report for CAU No. 416: Project Shoal Area

International Nuclear Information System (INIS)

1998-01-01

This Closure Report provides the documentation for closure of the US Department of Energy/Nevada Operations Office (DOE/NV) Project Shoal Area (PSA) Surface Corrective Action Unit (CAU) 416. CAU 416 consists of a mud pit, muckpile, and housekeeping site. The PSA is located approximately 48.3 kilometers (30 miles) southeast of Fallon, Nevada. The mud pit was the result of drilling activities at the PSA in 1963. Investigation activities completed in 1996 determined drilling mud in the mud pit was impacted with petroleum hydrocarbons in excess of the State of Nevada 100 milligram per kilogram (mg/kg). The muckpile consists of broken granite from emplacement shaft and drift (tunnel) mining activities at the PSA in 1963. The housekeeping site consisted of approximately 20 used, empty, rusted, steel 0.9 liter (1 quart) oil cans

CMP [Chemicals, Metals, and Pesticides] Pits: Environmental information document

International Nuclear Information System (INIS)

Scott, S.C.; Kolb, N.L.; Price, V.; Bledsoe, H.W.

1986-12-01

This document provides environmental information on postulated closure options for the Chemicals, Metals, and Pesticides (CMP) Pits at the Savannah River Plant and was developed as background technical documentation for the Department of Energy's proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (40 CFR 1500-1508). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a regulatory closure plan or other regulatory document to comply with required federal or state environmental regulations

Corrective action investigation plan: Area 2 Photo Skid 16 Wastewater Pit, Corrective Action Unit 332. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

This Corrective Action Investigation Plan (CAIP) contains a detailed description and plan for an environmental investigation of the Area 2 Photo Skid 16 Wastewater Pit. The site is located in Area 2 of the Nevada Test Site. The Photo Skid Wastewater Pit was used for disposal of photochemical process waste, and there is a concern that such disposal may have released photochemicals and metals to the soil beneath the pit and adjacent to it. The purpose of this investigation is to identify the presence and nature of contamination present in and adjacent to the wastewater pit and to determine the appropriate course of environmental response action for the site. The potential courses of action for the site are clean closure through remediation, closure in place (with or without remediation), or no further action.

Ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Kamalov, D.D.; Mirsaidov, U.M.

2010-01-01

Present article is devoted to assessment ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit. Authors set as their purpose the investigation of ecological risk of reprocessing of uranium wastes of the Gafurov-city's tailing pit. Having carried out their investigations, the authors came to the conclusion that the effect of radon gas during reprocessing to workers and specialists is minimal if they follow all the required safety rules.

32 CFR 989.25 - Base closure and realignment.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Base closure and realignment. 989.25 Section 989... PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.25 Base closure and realignment. Base closure or realignment may entail special requirements for environmental analysis. The permanent base closure...

Lower early postnatal oxygen saturation target and risk of ductus arteriosus closure failure.

Science.gov (United States)

Inomata, Kei; Taniguchi, Shinji; Yonemoto, Hiroki; Inoue, Takeshi; Kawase, Akihiko; Kondo, Yuichi

2016-11-01

Early postnatal hyperoxia is a major risk factor for retinopathy of prematurity (ROP) in extremely premature infants. To reduce the occurrence of ROP, we adopted a lower early postnatal oxygen saturation (SpO 2 ) target range (85-92%) from April 2011. Lower SpO 2 target range, however, may lead to hypoxemia and an increase in the risk of ductus arteriosus (DA) closure failure. The aim of this study was therefore to determine whether a lower SpO 2 target range, during the early postnatal stage, increases the risk of DA closure failure. Infants born at closure failure in period 2 (21%) was significantly higher than that in period 1 (1%). On multivariate logistic regression analysis, the lower oxygen saturation target range was an independent risk factor for DA closure failure. Lower early postnatal oxygen saturation target range increases the risk of DA closure failure. © 2016 Japan Pediatric Society.

75 FR 29322 - Base Closure and Realignment

Science.gov (United States)

2010-05-25

... DEPARTMENT OF DEFENSE Office of the Secretary Base Closure and Realignment AGENCY: Office of...)(ii) of the Defense Base Closure and Realignment Act of 1990. It provides a partial list of military installations closing or realigning pursuant to the 2005 Base Closure and Realignment (BRAC) Report. It also...

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 356: Mud Pits and Disposal Sites, Nevada Test Site, Nevada (Revision No. 0, August 2001); FINAL

International Nuclear Information System (INIS)

2001-01-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions necessary for the characterization and closure of Corrective Action Unit (CAU) 356, Mud Pits and Disposal Sites, as identified in the Federal Facility Agreement and Consent Order (FFACO). The CAU, located on the Nevada Test Site in Nevada, consists of seven Corrective Action Sites (CASs): CAS 03-04-01, Area 3 Change House Septic System; CAS 03-09-01, Mud Pit Spill Over; CAS 03-09-03, Mud Pit; CAS 03-09-04, Mud Pit; CAS 03-09-05, Mud Pit; CAS 20-16-01, Landfill; CAS 20-22-21, Drums. Sufficient information and process knowledge from historical documentation and investigations are the basis for the development of the phased approach chosen to address the data collection activities prior to implementing the preferred closure alternative for each CAS. The Phase I investigation will determine through collection of environmental samples from targeted populations (i.e., mud/soil cuttings above textural discontinuity) if contaminants of potential concern (COPCs) are present in concentrations exceeding preliminary action levels (PALs) at each of the CASs. If COPCs are present above PALs, a Phase II investigation will be implemented to determine the extent of contamination to support the appropriate corrective action alternative to complete closure of the site. Groundwater impacts from potentially migrating contaminants are not expected due to the depths to groundwater and limiting hydrologic drivers of low precipitation and high evaporation rates. Future land-use scenarios limit future uses to industrial activities; therefore, future residential uses are not considered. Potential exposure routes to site workers from contaminants of concern in septage and soils include oral ingestion, inhalation, or dermal contact (absorption) through in-advertent disturbance of contaminated structures and/or soils. Diesel within drilling muds is expected to be the primary COPC based on process

Closure Report for Corrective Action Unit 139: Waste Disposal Sites, Nevada Test Site, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2009-07-31

Corrective Action Unit (CAU) 139 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Waste Disposal Sites' and consists of the following seven Corrective Action Sites (CASs), located in Areas 3, 4, 6, and 9 of the Nevada Test Site: CAS 03-35-01, Burn Pit; CAS 04-08-02, Waste Disposal Site; CAS 04-99-01, Contaminated Surface Debris; CAS 06-19-02, Waste Disposal Site/Burn Pit; CAS 06-19-03, Waste Disposal Trenches; CAS 09-23-01, Area 9 Gravel Gertie; and CAS 09-34-01, Underground Detection Station. Closure activities were conducted from December 2008 to April 2009 according to the FFACO (1996, as amended February 2008) and the Corrective Action Plan for CAU 139 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2007b). The corrective action alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. Closure activities are summarized. CAU 139, 'Waste Disposal Sites,' consists of seven CASs in Areas 3, 4, 6, and 9 of the NTS. The closure alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. This CR provides a summary of completed closure activities, documentation of waste disposal, and confirmation that remediation goals were met. The following site closure activities were performed at CAU 139 as documented in this CR: (1) At CAS 03-35-01, Burn Pit, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (2) At CAS 04-08-02, Waste Disposal Site, an administrative UR was implemented. No postings or post-closure monitoring are required. (3) At CAS 04-99-01, Contaminated Surface Debris, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (4) At CAS 06-19-02, Waste Disposal Site/Burn Pit, no work was performed. (5) At CAS 06-19-03, Waste Disposal Trenches, a native soil cover was installed

Closure Report for Corrective Action Unit 139: Waste Disposal Sites, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

2009-01-01

Corrective Action Unit (CAU) 139 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Waste Disposal Sites' and consists of the following seven Corrective Action Sites (CASs), located in Areas 3, 4, 6, and 9 of the Nevada Test Site: CAS 03-35-01, Burn Pit; CAS 04-08-02, Waste Disposal Site; CAS 04-99-01, Contaminated Surface Debris; CAS 06-19-02, Waste Disposal Site/Burn Pit; CAS 06-19-03, Waste Disposal Trenches; CAS 09-23-01, Area 9 Gravel Gertie; and CAS 09-34-01, Underground Detection Station. Closure activities were conducted from December 2008 to April 2009 according to the FFACO (1996, as amended February 2008) and the Corrective Action Plan for CAU 139 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2007b). The corrective action alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. Closure activities are summarized. CAU 139, 'Waste Disposal Sites,' consists of seven CASs in Areas 3, 4, 6, and 9 of the NTS. The closure alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. This CR provides a summary of completed closure activities, documentation of waste disposal, and confirmation that remediation goals were met. The following site closure activities were performed at CAU 139 as documented in this CR: (1) At CAS 03-35-01, Burn Pit, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (2) At CAS 04-08-02, Waste Disposal Site, an administrative UR was implemented. No postings or post-closure monitoring are required. (3) At CAS 04-99-01, Contaminated Surface Debris, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (4) At CAS 06-19-02, Waste Disposal Site/Burn Pit, no work was performed. (5) At CAS 06-19-03, Waste Disposal Trenches, a native soil cover was installed, and a UR was

Risk and Performance Analyses Supporting Closure of WMA C at the Hanford Site in Southeast Washington

International Nuclear Information System (INIS)

Eberlein, Susan J.; Bergeron, Marcel P.; Kemp, Christopher J.; Hildebrand, R. Douglas; Aly, Alaa; Kozak, Matthew; Mehta, Sunil; Connelly, Michael

2013-01-01

The Office of River Protection under the U.S. Department of Energy (DOE) is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C as stipulated by the Hanford Federal Facility Agreement and Consent Order (HFFACO) under federal requirements and work tasks will be done under the State-approved closure plans and permits. An initial step in meeting the regulatory requirements is to develop a baseline risk assessment representing current conditions based on available characterization data and information collected at the WMA C location. The baseline risk assessment will be supporting a Resource Conservation and Recovery Act of 1976 (RCRA) Field Investigation (RFI)/Corrective Measures Study (CMS) for WMA closure and RCRA corrective action. Complying with the HFFACO conditions also involves developing a long-term closure Performance Assessment (PA) that evaluates human health and environmental impacts resulting from radionuclide inventories in residual wastes remaining in WMA C tanks and ancillary equipment. This PA is being developed to meet the requirements necessary for closure authorization under DOE Order 435.1 and Washington State Hazardous Waste Management Act. To meet the HFFACO conditions, the long-term closure risk analysis will include an evaluation of human health and environmental impacts from hazardous chemical inventories along with other performance Comprehensive Environmental Response, Compensation, and Liability Act Appropriate and Applicable Requirements (CERCLA ARARs) in residual wastes left in WMA C facilities after retrieval and removal. This closure risk analysis is needed to needed to comply with the requirements for permitted closure. Progress to date in developing a baseline risk assessment of WMA C has involved aspects of an evaluation of soil characterization and groundwater monitoring data collected as a part of the RFI/CMS and RCRA monitoring. Developing the long-term performance assessment aspects has involved the

Risk and Performance Analyses Supporting Closure of WMA C at the Hanford Site in Southeast Washington

Energy Technology Data Exchange (ETDEWEB)

Eberlein, Susan J.; Bergeron, Marcel P.; Kemp, Christopher J.

2013-11-11

The Office of River Protection under the U.S. Department of Energy (DOE) is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C as stipulated by the Hanford Federal Facility Agreement and Consent Order (HFFACO) under federal requirements and work tasks will be done under the State-approved closure plans and permits. An initial step in meeting the regulatory requirements is to develop a baseline risk assessment representing current conditions based on available characterization data and information collected at the WMA C location. The baseline risk assessment will be supporting a Resource Conservation and Recovery Act of 1976 (RCRA) Field Investigation (RFI)/Corrective Measures Study (CMS) for WMA closure and RCRA corrective action. Complying with the HFFACO conditions also involves developing a long-term closure Performance Assessment (PA) that evaluates human health and environmental impacts resulting from radionuclide inventories in residual wastes remaining in WMA C tanks and ancillary equipment. This PA is being developed to meet the requirements necessary for closure authorization under DOE Order 435.1 and Washington State Hazardous Waste Management Act. To meet the HFFACO conditions, the long-term closure risk analysis will include an evaluation of human health and environmental impacts from hazardous chemical inventories along with other performance Comprehensive Environmental Response, Compensation, and Liability Act Appropriate and Applicable Requirements (CERCLA ARARs) in residual wastes left in WMA C facilities after retrieval and removal. This closure risk analysis is needed to needed to comply with the requirements for permitted closure. Progress to date in developing a baseline risk assessment of WMA C has involved aspects of an evaluation of soil characterization and groundwater monitoring data collected as a part of the RFI/CMS and RCRA monitoring. Developing the long-term performance assessment aspects has involved the

NPV risk simulation of an open pit gold mine project under the O'Hara cost model by using GAs

Institute of Scientific and Technical Information of China (English)

Franco-Sepulveda Giovanni; Campuzano Carlos; Pineda Cindy

2017-01-01

This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV.

Performance Objective for Tank Farm Closure Risk Assessments

International Nuclear Information System (INIS)

MANN, F.M.; KNEPP, A.J.; BADDEN, J.

2003-01-01

quotations are taken from other documents (e.g., regulations) the quotation will not be changed from the more standard terminology. According to the Hanford Federal Facility Agreement and Consent Order (HFACCO 1989), a number of risk assessments will be required to analyze the environmental and human health impacts from retrieval and closure activities. This document is based on the Performance Objectives for the 2005 Immobilized Low-Activity Waste Performance Assessment (ILAW PA) (Mann 2002). The performance objectives in this document will be used in future risk assessments for tank waste retrieval or tank closure activities. These risk assessments are described in the Contents of Risk Assessments to Support the Retrieval and Closure of Tanks for the Washington State Department of Ecology (Mann et al. 2003) and summarized in Table 1.1. Requirements for ecological assessments are not yet presented in this document. As the requirements for such assessments are defined, this document will be revised to include the appropriate performance objectives

Environmental risk assessment as the basis for mine closure at Iscor Mining

Energy Technology Data Exchange (ETDEWEB)

Swart, S.J.; Pulles, W.; Boer, R.H.; Kirkaldy, J.; Pettit, C. [Iscor Mining, Pretoria (South Africa). Environmental Management Services

1998-01-01

This paper discusses the principles and application of risk assessment and management as the basis for environmental management within the mining industry. Unlike in other industries, mines are required to obtain closure certificates in terms of section 12 for the South African Minerals Act, which should ultimately release them from further environmental responsibilities. The focus shifts from conventional minimum legal compliance management to management of real environmental risks. The risk assessment approach has been applied to the planning of mine closure at Iscor`s Durban Navigation Collieries (Durnacol) in Kwa-Zulu Natal and certain key risk issues such as the long-term risk of water pollution from coal discard dumps have already progressed to fully quantitative risk assessment. This paper discussed the process which has been followed to date, with particular emphasis on the most recent phase, namely quantitative risk assessment and management of pollution from coal discard dumps. it is believed that the approach that is being pioneered at Durnacoal and which overcomes some of the more obvious deficineices of both the Environmental Risk Assessment Management (EMPR) and the traditional process will ultimately serve as the mode for all responsible mines in South Africa. It is also believed that this approach will enable the authorities to issue closure certificates with the confidence that there will be no unforeseen surprises in the years after closure. 9 figs., 1 tab.

Ecologic assessment of closure options for Savannah River Plant waste sites: Task 38, AX-681812

International Nuclear Information System (INIS)

1987-01-01

Ecologic assessment of closure options is one of several analyses being documented in the EIDs (along with analysis of relative potential health risks, accident risks, and costs). This information will serve as a basis for choosing the best option for closing a particular waste facility. This report presents the methodology adopted for SRP waste site ecological assessment, and the results of its application. The results of the ecologic assessment indicated that no impacts are expected for any of the closure options at eleven sites. Significant ecologic impacts are possible at the eight waste sites or groups of waste sites including the Radioactive Waste Burial Grounds, Old TNX Seepage Basin, CMP Pits, F-Area Seepage Basins, H-Area Seepage Basins, SRL Seepage Basins, R-Reactor Seepage Basins, and L-Area Oil and Chemical Basin. 104 refs., 22 figs., 241 tabs

Resource Conservation and Recovery Act closure report: Area 2, Bitcutter and Postshot Containment Shops

Energy Technology Data Exchange (ETDEWEB)

Petrello, Jaclyn [Nevada Field Office, Las Vegas, NV (United States)

1996-12-01

Post-closure monitoring requirements for CASs 02-20-01 (Bitcutter/Ps Inj.) and Wells (3) (RCRA) and CAS 02-20-03 (Wastewater Pit) are managed through the RCRA permit, which is renewed every 5 years. Post-closure monitoring requirements are described in that permit.

Resource Conservation and Recovery Act closure report: Area 2, Bitcutter and Postshot Containment Shops

International Nuclear Information System (INIS)

Petrello, Jaclyn

1996-01-01

Post-closure monitoring requirements for CASs 02-20-01 (Bitcutter/Ps Inj.) and Wells (3) (RCRA) and CAS 02-20-03 (Wastewater Pit) are managed through the RCRA permit, which is renewed every 5 years. Post-closure monitoring requirements are described in that permit.

RCRA closure of eight land-based units at the Y-12 plant

International Nuclear Information System (INIS)

Stone, J.E.; Welch, S.H.

1988-01-01

Eight land-based hazardous waste management units at the Oak Ridge Y-12 Plant are being closed under an integrated multi-year program. Closure plans for the units have been submitted and are in various stages of revision and regulatory review. These units will be closed by various combinations of methods, including liquid removal and treatment, sludge stabilization, contaminated sludge and/or soil removal, and capping. The closure of these sites will be funded by a new Department of Energy budget category, the Environmental Restoration Budget Category (ERBC), which is intended to provide greater flexibility in the response to closure and remedial activities. A major project, Closure and Post-Closure Activities (CAPCA), has been identified for ERBC funding to close and remediate the land units in accordance with RCRA requirements. Establishing the scope of this program has required the development of risk assessments and the preparation of an integrated schedule

Risk assessment to groundwater of pit latrine rural sanitation policy in developing country settings.

Science.gov (United States)

Back, Jan O; Rivett, Michael O; Hinz, Laura B; Mackay, Nyree; Wanangwa, Gift J; Phiri, Owen L; Songola, Chrispine Emmanuel; Thomas, Mavuto A S; Kumwenda, Steve; Nhlema, Muthi; Miller, Alexandra V M; Kalin, Robert M

2018-02-01

Parallel global rise in pit-latrine sanitation and groundwater-supply provision is of concern due to the frequent spatial proximity of these activities. Study of such an area in Malawi has allowed understanding of risks posed to groundwater from the recent implementation of a typical developing-country pit-latrine sanitation policy to be gained. This has assisted the development of a risk-assessment framework approach pragmatic to regulatory-practitioner management of this issue. The framework involves water-supply and pit-latrine mapping, monitoring of key groundwater contamination indicators and surveys of possible environmental site-condition factors and culminates in an integrated statistical evaluation of these datasets to identify the significant factors controlling risks posed. Our approach usefully establishes groundwater-quality baseline conditions of a potentially emergent issue for the study area. Such baselines are foundational to future trend discernment and contaminant natural attenuation verification critical to policies globally. Attribution of borehole contamination to pit-latrine loading should involve, as illustrated, the use of the range of contamination (chemical, microbiological) tracers available recognising none are ideal and several radial and capture-zone metrics that together may provide a weight of evidence. Elevated, albeit low-concentration, nitrate correlated with some radial metrics and was tentatively suggestive of emerging latrine influences. Longer term monitoring is, however, necessary to verify that the commonly observed latrine-borehole separation distances (29-58m), alongside statutory guidelines, do not constitute significant risk. Borehole contamination was limited and correlation with various environmental-site condition factors also limited. This was potentially ascribed to effectiveness of attenuation to date, monitoring of an emergent problem yet to manifest, or else contamination from other sources. High borehole usage

Closure Report for Corrective Action Unit 417: Central Nevada Test Area Surface, Nevada; TOPICAL

International Nuclear Information System (INIS)

K. B. Campbell

2001-01-01

The following site closure activities were performed at the 34 Corrective Action Sites (CASs) comprising Corrective Action Unit (CAU) 417 and are documented in this report: (1) No closure action was taken at 13 CASs (17 sites): 58-05-01,58-07-01,58-05-04, 58-09-05 (Mud Pits C and D only), 58-35-01,58-05-02,58-09-06 (Mud Pits A, B, C, and D), 58-10-06,58-19-01,58-35-02,58-44-04,58-05-04, and 58-09-03 (Mud Pit E only). (2) Housekeeping activities, collecting scrap materials, and transporting to approved landfill sites at the NTS were used to close seven CASs: 58-44-01,58-44-02,58-44-05, 58-98-03,58-98-01,58-98-02, and 58-98-04. (3) Two CASs (58-05-03 and 58-99-01) were closed by excavation and removal of USTs. (4) Two septic tanks (CASs 58-05-05 and 58-05-06) were closed by backfilling with clean fill. (5) Site posting with above-grade monuments and attached warning signs and land-use restrictions were used to close seven CASs (nine sites): 58-09-02,58-09-05 (Mud Pit E only), 58-09-06 (Mud Pit E only), 58-10-01,58-25-01,58-09-03 (Mud Pits A, B, and D), and 58-10-05. (6) Clean closure by excavation soil with TPH levels greater than the NDEP action level of 100 mg/kg and limited regrading was used to close five CASs: 58-10-03,58-44-06, 58-44-03,58-10-02, and 58-10-04. (7) Construction of engineered covers was used to close in place two CASs: 58-09-01 and 58-09-03 (Mud Pit C only). Following construction, a fence was constructed around each cover to prevent damage to the cover or intrusion by wildlife

Randomized clinical trial of intestinal ostomy takedown comparing pursestring wound closure vs conventional closure to eliminate the risk of wound infection.

Science.gov (United States)

Camacho-Mauries, Daniel; Rodriguez-Díaz, José Luis; Salgado-Nesme, Noel; González, Quintín H; Vergara-Fernández, Omar

2013-02-01

The use of temporary stomas has been demonstrated to reduce septic complications, especially in high-risk anastomosis; therefore, it is necessary to reduce the number of complications secondary to ostomy takedowns, namely wound infection, anastomotic leaks, and intestinal obstruction. To compare the rates of superficial wound infection and patient satisfaction after pursestring closure of ostomy wound vs conventional linear closure. Patients undergoing colostomy or ileostomy closure between January 2010 and February 2011 were randomly assigned to linear closure (n = 30) or pursestring closure (n = 31) of their ostomy wound. Wound infection within 30 days of surgery was defined as the presence of purulent discharge, pain, erythema, warmth, or positive culture for bacteria. Patient satisfaction, healing time, difficulty managing the wound, and limitation of activities were analyzed with the Likert questionnaire. The infection rate for the control group was 36.6% (n = 11) vs 0% in the pursestring closure group (p ostomy wound closure (shorter healing time and improved patient satisfaction).

Is Playing in the Pit Really the Pits?: Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras.

Science.gov (United States)

Kenny, Dianna T; Driscoll, Tim; Ackermann, Bronwen J

2016-03-01

Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether orchestra environment was a risk factor affecting musician wellbeing. Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA), workplace satisfaction, and bullying. Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength, while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. There were few differences in the objective physical measures between musicians in the different orchestra types. However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately

Military Base Closures: Updated Status of Prior Base Realignments and Closures

Science.gov (United States)

As the Department of Defense (DOD) prepares for the 2005 base realignment and closure (BRAC) round, questions continue to be raised about the transfer and environmental cleanup of unneeded property arising from the prior four BRAC rounds and their impact on cost and savings and on local economies.

Corrective Action Decision Document/Closure Report for Corrective Action Unit 504: 16a-Tunnel Muckpile, Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2010-03-15

This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 504, 16a-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. Corrective Action Unit 504 is comprised of four Corrective Action Sites (CASs): • 16-06-01, Muckpile • 16-23-01, Contaminated Burial Pit • 16-23-02, Contaminated Area • 16-99-01, Concrete Construction Waste Corrective Action Site 16-23-01 is not a burial pit; it is part of CAS 16-06-01. Therefore, there is not a separate data analysis and assessment for CAS 16-23-01; it is included as part of the assessment for CAS 16-06-01. In addition to these CASs, the channel between CAS 16-23-02 (Contaminated Area) and Mid Valley Road was investigated with walk-over radiological surveys and soil sampling using hand tools. The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 504. A CADD was originally submitted for CAU 504 and approved by the Nevada Division of Environmental Protection (NDEP). However, following an agreement between NDEP, DTRA, and the DOE, National Nuclear Security Administration Nevada Site Office to change to a risk-based approach for assessing the corrective action investigation (CAI) data, NDEP agreed that the CAU could be re-evaluated using the risk-based approach and a CADD/CR prepared to close the site.

A Bayesian approach to modeling and predicting pitting flaws in steam generator tubes

International Nuclear Information System (INIS)

Yuan, X.-X.; Mao, D.; Pandey, M.D.

2009-01-01

Steam generators in nuclear power plants have experienced varying degrees of under-deposit pitting corrosion. A probabilistic model to accurately predict pitting damage is necessary for effective life-cycle management of steam generators. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Markov chain Monte Carlo simulation-based Bayesian method, enhanced by a data augmentation technique, is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. The study also reveals the significance of inspection uncertainties in the modeling of pitting flaws using the ISI data: Without considering the probability-of-detection issues and measurement errors, the leakage risk resulted from the pitting corrosion would be under-estimated, despite the fact that the actual pit depth would usually be over-estimated.

Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

Science.gov (United States)

Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

2016-07-01

The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

Ecological risk of reprocessing of uranium wastes of the Gafurov-city's tailing pit

International Nuclear Information System (INIS)

Hakimov; Nazarov, H.M.; Mirsaidov, U.M.

2005-01-01

The authors set as their purpose the investigation of ecological risk of reprocessing of uranium wastes of the Gafurov-city's tailing pit. Having carried out their investigations, the authors came to the conclusion that the effect of radon gas during reprocessing to workers and specialists is minimal if they follow all the required safety rules

Understanding the risk factors of trauma center closures: do financial pressure and community characteristics matter?

Science.gov (United States)

Shen, Yu-Chu; Hsia, Renee Y; Kuzma, Kristen

2009-09-01

We analyze whether hazard rates of shutting down trauma centers are higher due to financial pressures or in areas with vulnerable populations (such as minorities or the poor). This is a retrospective study of all hospitals with trauma center services in urban areas in the continental US between 1990 and 2005, identified from the American Hospital Association Annual Surveys. These data were linked with Medicare cost reports, and supplemented with other sources, including the Area Resource File. We analyze the hazard rates of trauma center closures among several dimensions of risk factors using discrete-time proportional hazard models. The number of trauma center closures increased from 1990 to 2005, with a total of 339 during this period. The hazard rate of closing trauma centers in hospitals with a negative profit margin is 1.38 times higher than those hospitals without the negative profit margin (P lower hazard of shutting down trauma centers (ratio: 0.58, P penetration face a higher hazard of trauma center closure (ratio: 2.06, P < 0.01). Finally, hospitals in areas with higher shares of minorities face a higher risk of trauma center closure (ratio: 1.69, P < 0.01). Medicaid load and uninsured populations, however, are not risk factors for higher rates of closure after we control for other financial and community characteristics. Our findings give an indication on how the current proposals to cut public spending could exacerbate the trauma closure particularly among areas with high shares of minorities. In addition, given the negative effect of health maintenance organizations on trauma center survival, the growth of Medicaid managed care population should be monitored. Finally, high shares of Medicaid or uninsurance by themselves are not independent risk factors for higher closure as long as financial pressures are mitigated. Targeted policy interventions and further research on the causes, are needed to address these systems-level disparities.

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 1: Results of treatability study

International Nuclear Information System (INIS)

Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A.

1997-12-01

A treatability study was initiated in October 1993 to apply in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was later extended to include all of Pit 1 and was performed to support a possible Interim Record of Decision or removal action for closure of one or more of the seepage pits and trenches beginning as early as FY 1997. This treatability study was carried out to establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlap of melt settings which will be necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. In April 1996 an expulsion of an estimated 10% of the 196 Mg (216 tons) melt body occurred resulting in significant damage to ISV equipment and, ultimately, led to an indefinite suspension of further ISV operations at Pit 1. This report summarizes the technical accomplishments and status of the project in fulfilling these objectives through September 1997

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 1: Results of treatability study

Energy Technology Data Exchange (ETDEWEB)

Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Tixier, J.S. [Pacific Northwest National Lab., Richland, WA (United States)

1997-12-01

A treatability study was initiated in October 1993 to apply in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was later extended to include all of Pit 1 and was performed to support a possible Interim Record of Decision or removal action for closure of one or more of the seepage pits and trenches beginning as early as FY 1997. This treatability study was carried out to establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlap of melt settings which will be necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. In April 1996 an expulsion of an estimated 10% of the 196 Mg (216 tons) melt body occurred resulting in significant damage to ISV equipment and, ultimately, led to an indefinite suspension of further ISV operations at Pit 1. This report summarizes the technical accomplishments and status of the project in fulfilling these objectives through September 1997.

Modeling and management of pit lake water chemistry 1: Theory

International Nuclear Information System (INIS)

Castendyk, D.N.; Eary, L.E.; Balistrieri, L.S.

2015-01-01

Highlights: • Review of pit lake literature in the context of pit lake predictions. • Review of approaches used to predict pit wall-rock runoff and leachate. • Review of approaches used to generate a pit lake water balance. • Review of approaches used to generate a hydrodynamic prediction. • Review of approaches used to generate a geochemical prediction of a future pit lake. - Abstract: Pit lakes are permanent hydrologic/landscape features that can result from open pit mining for metals, coal, uranium, diamonds, oil sands, and aggregates. Risks associated with pit lakes include local and regional impacts to water quality and related impacts to aquatic and terrestrial ecosystems. Stakeholders rely on predictive models of water chemistry to prepare for and manage these risks. This paper is the first of a two part series on the modeling and management of pit lakes. Herein, we review approaches that have been used to quantify wall-rock runoff geochemistry, wall-rock leachate geochemistry, pit lake water balance, pit lake limnology (i.e. extent of vertical mixing), and pit lake water quality, and conclude with guidance on the application of models within the mine life cycle. The purpose of this paper is to better prepare stakeholders, including future modelers, mine managers, consultants, permitting agencies, land management agencies, regulators, research scientists, academics, and other interested parties, for the challenges of predicting and managing future pit lakes in un-mined areas

The Availability of Judicial Review Regarding Military Base Closures and Realignments

Science.gov (United States)

2005-06-30

held that the President is not subject to the APA, due to separation of powers principles.37 Base Closure Act Claims The Dalton Court distinguished...that the 1988 Base Closure Act violated the non-delegation doctrine and the separation of powers doctrine.53 However, the Base Closure Act has not yet been held unconstitutional by any federal appellate courts.

The economics of pit and fissure sealants in preventive dentistry: a review.

Science.gov (United States)

Kitchens, Dinah H

2005-08-15

Oral diseases are progressive, cumulative, and become more intricate to treat with advancement. While dental caries is an infectious transmissible disease with children being at the highest risk, primary prevention can reduce this risk. Primary prevention in dentistry is usually considered to be community fluoridated water supplies, professional fluoride treatments, and pit and fissure sealants. While community fluoridated water supplies have been proven to be cost-effective, the cost-effectiveness of pit and fissure sealants has primarily been studied in school-based programs of children from low socio-economic backgrounds. Dental sealant programs are just one way to help increase primary prevention in the oral health disparities of children. The purpose of this paper is to review the literature regarding the cost-effectiveness of pit and fissure sealants as a preventive strategy in preventive dentistry.

A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

Science.gov (United States)

Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

2018-06-01

Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

Stomal Closure: Strategies to Prevent Incisional Hernia

Science.gov (United States)

Harries, Rhiannon L.; Torkington, Jared

2018-01-01

Incisional hernias following ostomy reversal occur frequently. Incisional hernias at the site of a previous stoma closure can cause significant morbidity, impaired quality of life, lead to life-threatening hernia incarceration or strangulation and result in a significant financial burden on health care systems Despite this, the evidence base on the subject is limited. Many recognised risk factors for the development of incisional hernia following ostomy reversal are related to patient factors such as age, malignancy, diabetes, COPD, hypertension and obesity, and are not easily correctable. There is a limited amount of evidence to suggest that prophylactic mesh reinforcement may be of benefit to reduce the post stoma closure incisional hernia rate but a further large scale randomised controlled trial is due to report in the near future. There appears to be weak evidence to suggest that surgeons should favour circular, or “purse-string” closure of the skin following stoma closure in order to reduce the risk of SSI, which in turn may reduce incisional hernia formation. There remains the need for further evidence in relation to suture technique, skin closure techniques, mechanical bowel preparation and oral antibiotic prescription focusing on incisional hernia development as an outcome measure. Within this review, we discuss in detail the evidence base for the risk factors for the development of, and the strategies to prevent ostomy reversal site incisional hernias. PMID:29670882

Stomal Closure: Strategies to Prevent Incisional Hernia

Directory of Open Access Journals (Sweden)

Rhiannon L. Harries

2018-04-01

Full Text Available Incisional hernias following ostomy reversal occur frequently. Incisional hernias at the site of a previous stoma closure can cause significant morbidity, impaired quality of life, lead to life-threatening hernia incarceration or strangulation and result in a significant financial burden on health care systems Despite this, the evidence base on the subject is limited. Many recognised risk factors for the development of incisional hernia following ostomy reversal are related to patient factors such as age, malignancy, diabetes, COPD, hypertension and obesity, and are not easily correctable. There is a limited amount of evidence to suggest that prophylactic mesh reinforcement may be of benefit to reduce the post stoma closure incisional hernia rate but a further large scale randomised controlled trial is due to report in the near future. There appears to be weak evidence to suggest that surgeons should favour circular, or “purse-string” closure of the skin following stoma closure in order to reduce the risk of SSI, which in turn may reduce incisional hernia formation. There remains the need for further evidence in relation to suture technique, skin closure techniques, mechanical bowel preparation and oral antibiotic prescription focusing on incisional hernia development as an outcome measure. Within this review, we discuss in detail the evidence base for the risk factors for the development of, and the strategies to prevent ostomy reversal site incisional hernias.

Special Analysis: Disposal Plan for Pit 38 at Technical Area 54, Area G

Energy Technology Data Exchange (ETDEWEB)

French, Sean B. [Los Alamos National Laboratory; Shuman, Rob [URS Coporation

2012-06-26

Los Alamos National Laboratory (LANL) generates radioactive waste as a result of various activities. Operational waste is generated from a wide variety of research and development activities including nuclear weapons development, energy production, and medical research; environmental restoration (ER), and decontamination and decommissioning (D&D) waste is generated as contaminated sites and facilities at LANL undergo cleanup or remediation. The majority of this waste is low-level radioactive waste (LLW) and is disposed of at the Technical Area 54 (TA-54), Area G disposal facility. U.S. Department of Energy (DOE) Order 435.1 (DOE, 2001) requires that radioactive waste be managed in a manner that protects public health and safety, and the environment. To comply with this order, DOE field sites must prepare site-specific radiological performance assessments for LLW disposal facilities that accept waste after September 26, 1988. Furthermore, sites are required to conduct composite analyses that account for the cumulative impacts of all waste that has been (or will be) disposed of at the facilities and other sources of radioactive material that may interact with the facilities. Revision 4 of the Area G performance assessment and composite analysis was issued in 2008 (LANL, 2008). These analyses estimate rates of radionuclide release from the waste disposed of at the facility, simulate the movement of radionuclides through the environment, and project potential radiation doses to humans for several on- and off-site exposure scenarios. The assessments are based on existing site and disposal facility data, and on assumptions about future rates and methods of waste disposal. The Area G disposal facility consists of Material Disposal Area (MDA) G and the Zone 4 expansion area. To date, disposal operations have been confined to MDA G and are scheduled to continue in that region until MDA G undergoes final closure at the end of 2013. Given its impending closure, efforts have

Special Analysis: Disposal Plan for Pit 38 at Technical Area 54, Area G

International Nuclear Information System (INIS)

French, Sean B.; Shuman, Rob

2012-01-01

Los Alamos National Laboratory (LANL) generates radioactive waste as a result of various activities. Operational waste is generated from a wide variety of research and development activities including nuclear weapons development, energy production, and medical research; environmental restoration (ER), and decontamination and decommissioning (D and D) waste is generated as contaminated sites and facilities at LANL undergo cleanup or remediation. The majority of this waste is low-level radioactive waste (LLW) and is disposed of at the Technical Area 54 (TA-54), Area G disposal facility. U.S. Department of Energy (DOE) Order 435.1 (DOE, 2001) requires that radioactive waste be managed in a manner that protects public health and safety, and the environment. To comply with this order, DOE field sites must prepare site-specific radiological performance assessments for LLW disposal facilities that accept waste after September 26, 1988. Furthermore, sites are required to conduct composite analyses that account for the cumulative impacts of all waste that has been (or will be) disposed of at the facilities and other sources of radioactive material that may interact with the facilities. Revision 4 of the Area G performance assessment and composite analysis was issued in 2008 (LANL, 2008). These analyses estimate rates of radionuclide release from the waste disposed of at the facility, simulate the movement of radionuclides through the environment, and project potential radiation doses to humans for several on- and off-site exposure scenarios. The assessments are based on existing site and disposal facility data, and on assumptions about future rates and methods of waste disposal. The Area G disposal facility consists of Material Disposal Area (MDA) G and the Zone 4 expansion area. To date, disposal operations have been confined to MDA G and are scheduled to continue in that region until MDA G undergoes final closure at the end of 2013. Given its impending closure, efforts

Development of a risk-based mine closure cost calculation model

CSIR Research Space (South Africa)

Du Plessis, A

2006-06-01

Full Text Available . This research is important because currently there are a number of mines that do not have sufficient financial provision to close and rehabilitate the mines. The magnitude of the lack of funds could be reduced or eliminated if the closure cost calculation...

Environmental assessment for the expansion and operation of the Central Shops Borrow Pit at the Savannah River Site

International Nuclear Information System (INIS)

1997-03-01

The Department of Energy (DOE) prepared this Environmental Assessment (EA) to assess the potential environmental impacts of the proposed expansion and operation of an existing borrow pit at the Savannah River Site (SRS), located near Aiken, South Carolina. A borrow pit is defined as an excavated area where material has been dug for use as fill at another location. The proposed action would entail the areal enlargement, continued operation, and eventual close-out of the established facility known as the Central Shops Borrow Pit. Operations at SRS supporting waste site closure and the construction and maintenance of site facilities and infrastructure require readily available suitable soil for use as fill material. With the recent depletion of the other existing on-site sources for such material, DOE proposes to expand the existing facility. The National Environmental Policy Act requires the assessment of environmental consequences of Federal actions that may affect the quality of the human environment. Based on the potential for impacts described herein, DOE will either publish a Finding of No Significant Impact or prepare an Environmental Impact Statement (EIS)

Evapotranspiration Cover for the 92-Acre Area Retired Mixed Waste Pits, Area 5 Waste Management Division, Nevada National Security Site, Final CQA Report

International Nuclear Information System (INIS)

2012-01-01

The report is the Final Construction Quality Assurance (CQA) Report for the 92-Acrew Evapotranspiration Cover, Area 5 Waste Management Division Retired Mixed Waste Pits, Nevada National Security Site, Nevada, for the period of January 20, 2011, to January 31, 2012 The Area 5 RWMS uses engineered shallow-land burial cells to dispose of packaged waste. The 92-Acre Area encompasses the southern portion of the Area 5 RWMS, which has been designated for the first final closure operations. This area contains 13 Greater Confinement Disposal (GCD) boreholes, 16 narrow trenches, and 9 broader pits. With the exception of two active pits (P03 and P06), all trenches and pits in the 92-Acre Area had operational covers approximately 2.4 meters thick, at a minimum, in most areas when this project began. The units within the 92-Acre Area are grouped into the following six informal categories based on physical location, waste types and regulatory requirements: (1) Pit 3 Mixed Waste Disposal Unit (MWDU); (2) Corrective Action Unit (CAU) 111; (3) CAU 207; (4) Low-level waste disposal units; (5) Asbestiform low-level waste disposal units; and (6) One transuranic (TRU) waste trench.

Corrective action plan for corrective action Unit 342: Area 23 Mercury Fire Training Pit, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

Nacht, S.

1999-01-01

The Mercury Fire Training Pit is a former fire training area located in Area 23 of the Nevada Test Site (NTS). The Mercury Fire Training Pit was used from approximately 1965 to the early 1990s to train fire-fighting personnel at the NTS, and encompasses an area approximately 107 meters (m) (350 feet [ft]) by 137 m (450 ft). The Mercury Fire Training Pit formerly included a bermed burn pit with four small burn tanks, four large above ground storage tanks an overturned bus, a telephone pole storage area, and areas for burning sheds, pallets, and cables. Closure activities will include excavation of the impacted soil in the aboveground storage tank and burn pit areas to a depth of 1.5 m (5 ft), and excavation of the impacted surface soil downgradient of the former ASTs and burnpit areas to a depth of 0.3 m (1 ft). Excavated soil will be disposed in the Area 6 Hydrocarbon Landfill at the NTS

EIS pitting temperature determination of A182 nickel based alloy in simulated BWR environment containing dilute seawater

International Nuclear Information System (INIS)

Lavigne, Olivier; Shoji, Tetsuo; Takeda, Yoichi

2014-01-01

Graphical abstract: - Highlights: • Stable pitting events in function of the temperature are monitored by electrochemical impedance spectroscopy. • The pitting temperature for the nickel based alloy A182 in solution containing 450 ppm Cl − is defined as above 160 °C. • The presented method can be applied for others passive alloys as stainless steel in solution containing aggressive anions. - Abstract: A method based on electrochemical impedance spectroscopy (EIS) measurements to monitor the pitting temperature of passive alloys in a given media is developed in this communication. The pitting corrosion behavior of the nickel based alloy 182 in water containing 450 ppm by weight of chloride is presented in this study. The analysis of the EIS fit parameters from the proposed equivalent electrical circuit allows to determine the temperature from which stable pitting event occurs at open circuit potential. For the A182 sample this temperature is measured above 160 °C

Why do Pit-Hours outlive the Pit?

NARCIS (Netherlands)

S.R. Ozturk (Sait); M. van der Wel (Michel); D.J.C. van Dijk (Dick)

2015-01-01

markdownabstract__Abstract__ We study why a majority of trades still happen during the pit hours, i.e. when the trading pit is open, even after the pit ceased to be a liquid and informative venue. We investigate the case of 30-year U.S. Treasury futures using a ten-years-long intraday data set

Optic Nerve Pit

Science.gov (United States)

... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

Chemical Waste Landfill Annual Post-Closure Care Report Calendar Year 2014

Energy Technology Data Exchange (ETDEWEB)

Mitchell, Michael Marquand [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Little, Bonnie Colleen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-03-01

The CWL is a 1.9-acre remediated interim status landfill located in the southeastern corner of SNL/NM Technical Area III (Figures 2-1 and 2-2) undergoing post-closure care in accordance with the PCCP (NMED October 2009 and subsequent revisions). From 1962 until 1981, the CWL was used for the disposal of chemical and solid waste generated by SNL/NM research activities. Additionally, a small amount of radioactive waste was disposed of during the operational years. Disposal of liquid waste in unlined pits and trenches ended in 1981, and after 1982 all liquid waste disposal was terminated. From 1982 through 1985, only solid waste was disposed of at the CWL, and after 1985 all waste disposal ended. The CWL was also used as a hazardous waste drum-storage facility from 1981 to 1989. A summary of the CWL disposal history is presented in the Closure Plan (SNL/NM December 1992) along with a waste inventory based upon available disposal records and information.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2009

International Nuclear Information System (INIS)

2010-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2009 and includes inspection and repair activities completed at the following seven CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 426: Cactus Spring Waste Trenches (TTR); (5) CAU 453: Area 9 UXO Landfill (TTR); (6) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR); and (7) CAU 487: Thunderwell Site (TTR). The annual post-closure inspections were conducted May 5-6, 2009. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2009, and the vegetation monitoring report is included in Attachment F. Maintenance was performed at CAU 453. Animal burrows observed during the annual inspection were backfilled, and a depression was restored to grade on June 25, 2009. Post-closure site inspections should continue as scheduled. Vegetation survey inspections have been conducted annually at CAUs 400, 404, 407, and 426. Discontinuation of vegetation surveys is recommended at the CAU 400 Bomblet Pit and CAU 426, which have been successfully revegetated. Discontinuation of vegetation surveys is also recommended at CAU 404, which has been changed to an administrative closure with no inspections

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2009

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2010-05-28

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2009 and includes inspection and repair activities completed at the following seven CAUs: · CAU 400: Bomblet Pit and Five Points Landfill (TTR) · CAU 407: Roller Coaster RadSafe Area (TTR) · CAU 424: Area 3 Landfill Complexes (TTR) · CAU 426: Cactus Spring Waste Trenches (TTR) · CAU 453: Area 9 UXO Landfill (TTR) · CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) · CAU 487: Thunderwell Site (TTR) The annual post-closure inspections were conducted May 5–6, 2009. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2009, and the vegetation monitoring report is included in Attachment F. Maintenance was performed at CAU 453. Animal burrows observed during the annual inspection were backfilled, and a depression was restored to grade on June 25, 2009. Post-closure site inspections should continue as scheduled. Vegetation survey inspections have been conducted annually at CAUs 400, 404, 407, and 426. Discontinuation of vegetation surveys is recommended at the CAU 400 Bomblet Pit and CAU 426, which have been successfully revegetated. Discontinuation of vegetation surveys is also recommended at CAU 404, which has been changed to an administrative closure with no inspections required. Vegetation

Template measurement for plutonium pit based on neural networks

International Nuclear Information System (INIS)

Zhang Changfan; Gong Jian; Liu Suping; Hu Guangchun; Xiang Yongchun

2012-01-01

Template measurement for plutonium pit extracts characteristic data from-ray spectrum and the neutron counts emitted by plutonium. The characteristic data of the suspicious object are compared with data of the declared plutonium pit to verify if they are of the same type. In this paper, neural networks are enhanced as the comparison algorithm for template measurement of plutonium pit. Two kinds of neural networks are created, i.e. the BP and LVQ neural networks. They are applied in different aspects for the template measurement and identification. BP neural network is used for classification for different types of plutonium pits, which is often used for management of nuclear materials. LVQ neural network is used for comparison of inspected objects to the declared one, which is usually applied in the field of nuclear disarmament and verification. (authors)

Post-pit optimization strategic alignment

OpenAIRE

Breed, M.F.; van Heerden, D.

2016-01-01

Successful development of projects or life-of-mine strategies requires an understanding of the relative sensitivity of value drivers such as grade, tonnage, energy costs, direct operational costs, and recoveries. For example, the results could vary significantly depending on the grade strategy, given a specific orebody amenable to open pitting. Pit optimization is a very powerful tool widely used in the industry to determine the pit shell with the most attractive value potential. Based on the...

Pitting corrosion on a copper canister

International Nuclear Information System (INIS)

Hermansson, H.P.; Beverskog, B.

1996-02-01

It is demonstrated that normal pitting can occur during oxidizing conditions in the repository. It is also concluded that a new theory for pitting corrosion has to be developed, as the present theory is not in accordance with all practical and experimental observations. A special variant of pitting, based on the growth of sulfide whiskers, is suggested to occur during reducing conditions. However, such a mechanism needs to be demonstrated experimentally. A simple calculational model of canister corrosion was developed based on the results of this study. 69 refs, 3 figs

An AFM-based pit-measuring method for indirect measurements of cell-surface membrane vesicles

International Nuclear Information System (INIS)

Zhang, Xiaojun; Chen, Yuan; Chen, Yong

2014-01-01

Highlights: • Air drying induced the transformation of cell-surface membrane vesicles into pits. • An AFM-based pit-measuring method was developed to measure cell-surface vesicles. • Our method detected at least two populations of cell-surface membrane vesicles. - Abstract: Circulating membrane vesicles, which are shed from many cell types, have multiple functions and have been correlated with many diseases. Although circulating membrane vesicles have been extensively characterized, the status of cell-surface membrane vesicles prior to their release is less understood due to the lack of effective measurement methods. Recently, as a powerful, micro- or nano-scale imaging tool, atomic force microscopy (AFM) has been applied in measuring circulating membrane vesicles. However, it seems very difficult for AFM to directly image/identify and measure cell-bound membrane vesicles due to the similarity of surface morphology between membrane vesicles and cell surfaces. Therefore, until now no AFM studies on cell-surface membrane vesicles have been reported. In this study, we found that air drying can induce the transformation of most cell-surface membrane vesicles into pits that are more readily detectable by AFM. Based on this, we developed an AFM-based pit-measuring method and, for the first time, used AFM to indirectly measure cell-surface membrane vesicles on cultured endothelial cells. Using this approach, we observed and quantitatively measured at least two populations of cell-surface membrane vesicles, a nanoscale population (<500 nm in diameter peaking at ∼250 nm) and a microscale population (from 500 nm to ∼2 μm peaking at ∼0.8 μm), whereas confocal microscopy only detected the microscale population. The AFM-based pit-measuring method is potentially useful for studying cell-surface membrane vesicles and for investigating the mechanisms of membrane vesicle formation/release

Integration of OHS into Risk Management in an Open-Pit Mining Project in Quebec (Canada

Directory of Open Access Journals (Sweden)

Adel Badri

2011-09-01

Full Text Available Despite undeniable progress, the mining industry remains the scene of serious accidents revealing disregard for occupational health and safety (OHS and leaving open the debate regarding the safety of its employees. The San José mine last collapse near Copiapó, Chile on 5 August 2010 and the 69-day rescue operation that followed in order to save 33 miners trapped underground show the serious consequences of neglecting worker health and safety. The aim of this study was to validate a new approach to integrating OHS into risk management in the context of a new open-pit mining project in Quebec, based on analysis of incident and accident reports, semi-structured interviews, questionnaires and collaborative field observations. We propose a new concept, called hazard concentration, based on the number of hazards and their influence. This concept represents the weighted fraction of each category of hazards related to an undesirable event. The weight of each category of hazards is calculated by AHP, a multicriteria method. The proposed approach included the creation of an OHS database for facilitating expert risk management. Reinforcing effects between hazard categories were identified and all potential risks were prioritized. The results provided the company with a rational basis for choosing a suitable accident prevention strategy for its operational activities.

Evapotranspiration Cover for the 92-Acre Area Retired Mixed Waste Pits:Interim CQA Report

International Nuclear Information System (INIS)

2011-01-01

This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. Construction was approved by the Nevada Division of Environmental Protection (NDEP) under the Approval of Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for Corrective Action Unit (CAU) 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada, on January 6, 2011, pursuant to Subpart XII.8a of the Federal Facility Agreement and Consent Order. The project is located in Area 5 of the Radioactive Waste Management Complex (RWMC) at the Nevada National Security Site (NNSS), formerly known as the Nevada Test Site, located in southern Nevada, approximately 65 miles northwest of Las Vegas, Nevada, in Nye County. The project site, in Area 5, is located in a topographically closed basin approximately 14 additional miles north of Mercury Nevada, in the north-central part of Frenchman Flat. The Area 5 RWMS uses engineered shallow-land burial cells to dispose of packaged waste. The 92-Acre Area encompasses the southern portion of the Area 5 RWMS, which has been designated for the first final closure operations. This area contains 13 Greater Confinement Disposal (GCD) boreholes, 16 narrow trenches, and 9 broader pits. With the exception of two active pits (P03 and P06), all trenches and pits in the 92-Acre Area had operational covers approximately 2.4 meters thick, at a minimum, in most areas when this project began. The units within the 92-Acre Area are grouped into the following six informal categories based on physical location

Evapotranspiration Cover for the 92-Acre Area Retired Mixed Waste Pits:Interim CQA Report

Energy Technology Data Exchange (ETDEWEB)

The Delphi Groupe, Inc., and J. A. Cesare and Associates, Inc.

2011-06-20

This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. Construction was approved by the Nevada Division of Environmental Protection (NDEP) under the Approval of Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for Corrective Action Unit (CAU) 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada, on January 6, 2011, pursuant to Subpart XII.8a of the Federal Facility Agreement and Consent Order. The project is located in Area 5 of the Radioactive Waste Management Complex (RWMC) at the Nevada National Security Site (NNSS), formerly known as the Nevada Test Site, located in southern Nevada, approximately 65 miles northwest of Las Vegas, Nevada, in Nye County. The project site, in Area 5, is located in a topographically closed basin approximately 14 additional miles north of Mercury Nevada, in the north-central part of Frenchman Flat. The Area 5 RWMS uses engineered shallow-land burial cells to dispose of packaged waste. The 92-Acre Area encompasses the southern portion of the Area 5 RWMS, which has been designated for the first final closure operations. This area contains 13 Greater Confinement Disposal (GCD) boreholes, 16 narrow trenches, and 9 broader pits. With the exception of two active pits (P03 and P06), all trenches and pits in the 92-Acre Area had operational covers approximately 2.4 meters thick, at a minimum, in most areas when this project began. The units within the 92-Acre Area are grouped into the following six informal categories based on physical location

The Great Bear Flare Pit Project : review of work to date

International Nuclear Information System (INIS)

Ridal, J.; Lean, D.; Findlay, S.C.

1998-01-01

Published information regarding potential toxic agents associated with flare emissions and a study to determine the risk posed to Treaty 8 First Nations (T8FN) peoples and wildlife was reviewed as part of the Great Bear Flare Pit Project (GBFPP). The project is concerned with the study of water and soil contamination in the immediate vicinity of flare pits in the Del Rio, Doig basin, Blueberry River, and Halfway River regions of T8FN lands in Alberta. The GBFPP has established good baseline data on metal contamination, and other contaminants such as benzene, toluene, ethylbenzene, xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in the immediate vicinity of selected flare pits. Based on a critical assessment of reports published to date a series of prioritized recommendations for further research are made. 18 refs., 2 tabs

ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

International Nuclear Information System (INIS)

1998-02-01

This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill

ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-02-01

This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill.

218 E-8 Borrow Pit Demolition Site clean closure soil evaluation report

International Nuclear Information System (INIS)

Korematsu-Olund, D.M.

1995-01-01

This report summarizes the sampling activities undertaken and the analytical results obtained in a soil sampling and analyses study performed for the 218 E-8 Borrow Pit Demolition Site (218 E-8 Demolition Site). The 218 E-8 Demolition Site is identified as a Resource Conservation and Recovery Act (RCRA) treatment unit that will be closed in accordance with the applicable laws and regulations. The site was used for the thermal treatment of discarded explosive chemical products. No constituents of concern were found in concentrations indicating contamination of the soil by 218 E-8 Demolition Site activities

Financial risks of post-closure custodial care for the Barnwell radioactive waste disposal facility - 16155

International Nuclear Information System (INIS)

Baird, Robert D.; Newberry, William F.

2009-01-01

This paper reports evaluations of the adequacy of the Barnwell Extended Care Fund in light of identified risks, with the conclusion that the fund is sufficient to cover the costs and uncertainties associated with planned post-closure care of the Barnwell, South Carolina low-level radioactive waste disposal facility. It reviews background information pertinent to the facility's post-closure monitoring and maintenance and describes financial responsibility for post-closure activities. It identifies and briefly characterizes the activities planned to be conducted following facility closure and presents the midrange estimate of planned post-closure costs. The paper identifies and quantifies sources of uncertainty in activities and costs planned for post-closure care and presents 50-, 80-, and 95-percent confidence levels of planned costs. The fund is currently sufficient to cover some but not all of the costs that might be incurred as a result of unplanned events. The paper identifies, characterizes, and quantifies unplanned events, possible consequences, and probabilities of occurrence. The paper presents costs that might be incurred in responding to the unplanned initiating events and identifies levels of confidence that the fund is adequate to cover such costs. (authors)

Corrective Action Decision Document for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada, Revision 1 with ROTC 1

International Nuclear Information System (INIS)

Boehlecke, Robert

2004-01-01

This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site (NTS), Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit 140 is located within Areas 5, 22, and 23 of the NTS and is comprised of the following corrective action sites (CASs): 05-08-01, Detonation Pits; 05-08-02, Debris Pits; 05-17-01, Hazardous Waste Accumulation Site (Buried); 05-19-01, Waste Disposal Site; 05-23-01, Gravel Gertie; 05-35-01, Burn Pit; 05-99-04, Burn Pit; 22-99-04, Radioactive Waste Dump; and 23-17-01, Hazardous Waste Storage Area. The purpose of this CADD is to identify and provide a rationale for the recommendation of a corrective action alternative for each CAS within CAU 140. Corrective action investigation activities were performed from November 13 through December 11, 2002. Additional sampling to delineate the extent of contaminants of concern (COCs) was conducted on February 4 and March 18 and 19, 2003. Corrective action investigation activities were performed as set forth in the Corrective Action Investigation Plan for CAU 140. Analytes detected during the corrective action investigation were evaluated against appropriate preliminary action levels to identify COCs for each CAS. Assessment of the data generated from investigation activities revealed the following: (1) CAS 05-08-01 contains the COCs lead and the radioisotope thorium-234 in the surface soil at sample location A05. (2) CAS 05-23-01 did not have any COCs identified during the field investigation; however, based on historical knowledge of activities at this site, the interior of the Gravel Gertie is considered contaminated with uranium. (3) CAS 23-17-01 contains the COC total petroleum hydrocarbons (diesel-range organics) at location J20 at a depth of 9 to 10 feet below ground surface. (4) No COCs were identified at CASs 05-08-02, 05-17-01, 05-19-01, 05

Statement of basis/proposed plan for the Central Shops Burning/Rubble Pit (631-6G). Revision 1, Final

International Nuclear Information System (INIS)

Palmer, E.

1996-01-01

The purpose of this plan is to describe the preferred alternative for addressing the Central Shops Burning/Rubble Pit 631-6G (BRP6G) located at SRS, in northwestern Barnwell County, South Carolina and to provide an opportunity for public input into the remedial action selection process. Arsenic, beryllium, iron, and octachloro-dibenzo-p-dioxin isomers (OCDD) concentrations in the pit soil are at levels consistent with those found in the background. Therefore, the only contamination attributable to actions in BRP6G is PCB-1254. After the risk contributions of these chemicals are eliminated, the only remaining risk attributable to the pit soil is from PCB-1254 (about 2 x 10 -6 via ingestion of vegetables grown on-site). The maximum concentration of PCB-1254 detected in the pit was 0.115 mg/kg, approximately 10% of the residential action level for PCBs of 1 mg/kg. Based on the results of the remedial investigation and the BRA, it is proposed that No Action be performed for the BRP6G. Considering the low levels of residual contamination present principally below 1.2 meters (4 feet) within the pit and the associated risks (about 2 x 10 -6 ) within the lower level of EPA's target risk range, action is not warranted for this unit

Sandwich wound closure reduces the risk of cerebrospinal fluid leaks in posterior fossa surgery

Directory of Open Access Journals (Sweden)

Verena Heymanns

2016-07-01

Full Text Available Posterior fossa surgery is demanding and hides a significant number of obstacles starting from the approach to the wound closure. The risk of cerebrospinal fluid (CSF leakage in posterior fossa surgery given in the literature is around 8%. The present study aims to introduce a sandwich closure of the dura in posterior fossa surgery, which reduces significantly the number of CSF leaks (3.8% in the patients treated in our department. Three hundred and ten patients treated in our hospital in the years 2009-2013 for posterior fossa pathologies were retrospectively evaluated. The dura closure method was as following: lyophilized dura put under the dura and sealed with fibrin glue and sutures, dura adapting stitches, TachoSil® (Takeda Pharma A/S, Roskilde, Denmark, Gelfoam® (Pfizer Inc., New York, NY, USA and polymethylmethacrylate (osteoclastic craniotomy. The incidence of postsurgical complications associated with the dural closure like CSF leakage, infections, bleeding is evaluated. Only 3.8% of patients developed CSF leakage and only 0.5% needed a second surgery for CSF leakage closure. Two percent had a cerebellar bleeding with no need for re-operation and 3% had a wound infection treated with antibiotics. The sandwich wound closure we are applying for posterior fossa surgery in our patients correlates with a significant reduction of CSF leaks compared to the literature.

Device closure of secundum atrial septal defect's and the risk of cardiac erosion.

Science.gov (United States)

Thomson, J D R; Qureshi, S A

2015-12-01

Cardiac erosion related to transcatheter atrial septal defect closure devices is of increasing concern. Erosion is reported to have occurred with most of currently available occluder devices. Perhaps due to the very large number of implants worldwide, the Amplatzer (St Jude) occluder is associated with the majority of cardiac erosion events reported in the literature. Best current estimates of the incidence of erosion with the St Jude device are between one and three cases per 1000 implants. Most events occur early after implantation and it is rare, although not unheard of, for events to occur after a year following device insertion. It is important that those involved with closure programmes are vigilant for the problem, because device-related erosion is associated with a significant mortality risk. Despite considerable debate, the risk factors (either patient or device) for erosion remain unclear and require further investigation. Currently available data sets have focussed largely on erosion cohorts and are unable to place these cases in appropriate context with non-erosion closure cases. What is certain is that programmes implanting these devices must take care to implant appropriately sized devices and have in place plans to ensure that patients are both well informed and can access help and advice in the event of developing symptoms.

U.S. Small Business HUBZone Base Closure Areas

Data.gov (United States)

Small Business Administration — HUBZone Qualitified Base Closure Areas - the lands within the boundaries of a military installation that was closed through a privatization process under the Federal...

Baseline Risk Assessment Supporting Closure at Waste Management Area C at the Hanford Site Washington

International Nuclear Information System (INIS)

Singleton, Kristin M.

2015-01-01

The Office of River Protection under the U.S. Department of Energy is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C under the requirements of the Hanford Federal Facility Agreement and Consent Order (HFFACO). A baseline risk assessment (BRA) of current conditions is based on available characterization data and information collected at WMA C. The baseline risk assessment is being developed as a part of a Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI)/Corrective Measures Study (CMS) at WMA C that is mandatory under Comprehensive Environmental Response, Compensation, and Liability Act and RCRA corrective action. The RFI/CMS is needed to identify and evaluate the hazardous chemical and radiological contamination in the vadose zone from past releases of waste from WMA C. WMA C will be under Federal ownership and control for the foreseeable future, and managed as an industrial area with restricted access and various institutional controls. The exposure scenarios evaluated under these conditions include Model Toxics Control Act (MTCA) Method C, industrial worker, maintenance and surveillance worker, construction worker, and trespasser scenarios. The BRA evaluates several unrestricted land use scenarios (residential all-pathway, MTCA Method B, and Tribal) to provide additional information for risk management. Analytical results from 13 shallow zone (0 to 15 ft. below ground surface) sampling locations were collected to evaluate human health impacts at WMA C. In addition, soil analytical data were screened against background concentrations and ecological soil screening levels to determine if soil concentrations have the potential to adversely affect ecological receptors. Analytical data from 12 groundwater monitoring wells were evaluated between 2004 and 2013. A screening of groundwater monitoring data against background concentrations and Federal maximum concentration levels was used to determine vadose zone

Baseline Risk Assessment Supporting Closure at Waste Management Area C at the Hanford Site Washington

Energy Technology Data Exchange (ETDEWEB)

Singleton, Kristin M. [Washington River Protection Solutions LLC, Richland, WA (United States)

2015-01-07

The Office of River Protection under the U.S. Department of Energy is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C under the requirements of the Hanford Federal Facility Agreement and Consent Order (HFFACO). A baseline risk assessment (BRA) of current conditions is based on available characterization data and information collected at WMA C. The baseline risk assessment is being developed as a part of a Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI)/Corrective Measures Study (CMS) at WMA C that is mandatory under Comprehensive Environmental Response, Compensation, and Liability Act and RCRA corrective action. The RFI/CMS is needed to identify and evaluate the hazardous chemical and radiological contamination in the vadose zone from past releases of waste from WMA C. WMA C will be under Federal ownership and control for the foreseeable future, and managed as an industrial area with restricted access and various institutional controls. The exposure scenarios evaluated under these conditions include Model Toxics Control Act (MTCA) Method C, industrial worker, maintenance and surveillance worker, construction worker, and trespasser scenarios. The BRA evaluates several unrestricted land use scenarios (residential all-pathway, MTCA Method B, and Tribal) to provide additional information for risk management. Analytical results from 13 shallow zone (0 to 15 ft. below ground surface) sampling locations were collected to evaluate human health impacts at WMA C. In addition, soil analytical data were screened against background concentrations and ecological soil screening levels to determine if soil concentrations have the potential to adversely affect ecological receptors. Analytical data from 12 groundwater monitoring wells were evaluated between 2004 and 2013. A screening of groundwater monitoring data against background concentrations and Federal maximum concentration levels was used to determine vadose zone

Resistance to pitting corrosion in ferritic and austenitic/ferritic steels

International Nuclear Information System (INIS)

De Bouvier, O.

1995-01-01

Stainless steel tubes carrying raw water are potentially vulnerable to pitting corrosion. With a view to minimizing the corrosion risk in the river-water-cooled condensers at PWR power plant, a study was conducted to determine initiation conditions and incubation durations for pitting corrosion in stagnant water. As a result, condenser tubes in Z2 CI 18 (439) or Z2 CT 18-10 (304L) steels were phased out in favour of Z2 CND 16-32 (316L) stainless steel. The same question can be yield for other applications and especially for all types of exchangers for use in electrical applications. This study sought to assess alternative methods for estimating pitting corrosion, and to check the results of these methods against the actual behaviour of studied steels. The study covered ferritic steels (439, 444, 290Mo), austenitic steel (316L) and austenitic/ferritic steels (Uranus 35N, 45N, 47N, 52N). Two approaches were adopted: laboratory tests to compare pitting corrosion risks on different materials, and tests for characterizing the behaviour of steels exposed to river water. The study begins with a laboratory tests that yield an arbitrary parameter for quantifying pitting corrosion resistance. One method involves measuring the pitting temperature in an aggressive ferric chloride solution. Other methods measure the pitting potential, either statistically (Multipit method) or deterministically (polarization curve). We then go on to discuss tests under simulated life-like conditions, involving repeated immersions in water from the Seine. (author). 9 refs., 13 figs, 9 tabs

A New Algorithm for Determining Ultimate Pit Limits Based on Network Optimization

Directory of Open Access Journals (Sweden)

Ali Asghar Khodayari

2013-12-01

Full Text Available One of the main concerns of the mining industry is to determine ultimate pit limits. Final pit is a collection of blocks, which can be removed with maximum profit while following restrictions on the slope of the mine’s walls. The size, location and final shape of an open-pit are very important in designing the location of waste dumps, stockpiles, processing plants, access roads and other surface facilities as well as in developing a production program. There are numerous methods for designing ultimate pit limits. Some of these methods, such as floating cone algorithm, are heuristic and do not guarantee to generate optimum pit limits. Other methods, like Lerchs–Grossmann algorithm, are rigorous and always generate the true optimum pit limits. In this paper, a new rigorous algorithm is introduced. The main logic in this method is that only positive blocks, which can pay costs of their overlying non-positive blocks, are able to appear in the final pit. Those costs may be paid either by positive block itself or jointly with other positive blocks, which have the same overlying negative blocks. This logic is formulated using a network model as a Linear Programming (LP problem. This algorithm can be applied to two- and three-dimension block models. Since there are many commercial programs available for solving LP problems, pit limits in large block models can be determined easily by using this method.

Development and test of Nb(3)Sn cos-theta dipoles based on PIT strands

International Nuclear Information System (INIS)

Zlobin, A.V.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bossert, R.; Carcagno, R.; Chichili, D.R.; Elementi, L.; Feher, S.; Kashikhin, V.V.; Lamm, M.J.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Yamada, R.

2004-01-01

Fermilab is involved in the development of new generation high-field accelerator magnets using state-of-the-art Nb 3 Sn strands produced using different technologies. Two 1-m long models--mirror configuration and dipole magnet--were fabricated recently at Fermilab based on powder-in-tube (PIT) Nb 3 Sn strands with small effective filament size. This paper describes the parameters of superconducting strands and cable, the details of magnet design and fabrication procedure, and reports the results of PIT coil testing

A clinical study of space closure with nickel-titanium closed coil springs and an elastic module.

Science.gov (United States)

Samuels, R H; Rudge, S J; Mair, L H

1998-07-01

A previous study has shown that a 150-gram nickel-titanium closed coil spring (Sentalloy, GAC International Inc.) closed spaces more quickly and more consistently than an elastic module (Alastik, Unitec/3M). This study used the same friction sensitive sliding mechanics of pitting the six anterior teeth against the second bicuspid and first molars, to examine the rate of space closure of 100-gram and 200-gram nickel-titanium closed coil springs. The results for the three springs and elastic module were compared. The nickel-titanium closed coil springs produced a more consistent space closure than the elastic module. The 150- and 200-gram springs produced a faster rate of space closure than the elastic module or the 100-gram spring. No significant difference was noted between the rates of closure for the 150- and the 200-gram springs.

Pitting morphologies of zirconium base alloys in aqueous and non aqueous chloride media

International Nuclear Information System (INIS)

Palit, G.C.; Gadiyar, H.S.

1988-01-01

Pitting morphology of zirconium and Zr-Cr alloys in aqueous chloride and nonaqueous methanol + 0.4 per cent HCl solution was investigated and observed to follow different modes in these two environments. While in aqueous chloride solution pitting was transgranular and randomly oriented, in methanol-chloride solution pits were observed to initiate and propagate along the grain boundaries. In aqueous chloride solution very irregular and sponge like zirconium metal was formed inside the pit while in methanol-chloride solution the pits were crystallographic in nature. Optical microscopy has revealed that pits preferentially initiate and propagate along scratch line in aqueous chloride solution, but such was not the case in nonaqueous methanol-chloride solution. The nature and the mechanism operating in the catastropic failure of these materials are investigated. (author). 10 refs., 11 figs

Closure plan for the proposed Millennium Project

International Nuclear Information System (INIS)

Tuttle, S.; Sisson, R.

1999-01-01

A $2.2 billion expansion of the current oil sands operation has been proposed by Suncor Energy Inc. The expansion would more than double the productive capacity of the present facility. As part of the application for this expansion, called Project Millennium, a comprehensive closure plan has been developed and filed by the Corporation. The Plan includes a systematic evaluation of the area to be developed, a description of the development activities planned, and the goals and objectives of the Corporation in re-establishing the landforms and ecosystems concurrently with running the operation. The Plan envisages surface contouring as early as practicable during the mine development, soil reconstruction, and re-establishment of vegetation, surface drainage and wetlands. The Corporation undertakes to monitor the performance of the reclaimed areas based on landform performance, the impact of chemical constituents on the landscape and ecosystem sustainability. An annual monitoring report assessing herbaceous vegetation growth, major species composition, tree and shrub survival and growth rate, groundwater conditions, amount of precipitation, the utility of constructed wetlands for treatment of reclamation area seepage and runoff waters, and wildlife population changes, will be prepared annually. A future research program associated with the Reclamation and Closure Plan will also examine the effectiveness of the reclamation drainage system as fish habitat, and the potential of the proposed end-pit lake to provide a viable aquatic ecosystem. 8 refs., 2 figs

Predição de "bitter pit" em maçãs 'gala' Por meio da infiltração dos frutos com magnésio Prediction of bitter pit in 'gala'apples by means of fruit infiltration with magnesium

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2009-12-01

Full Text Available O "bitter pit" é considerado um dos principais distúrbios fisiológicos pós-colheita que ocorrem em maçãs. A análise nutricional dos frutos (concentrações de Ca, Mg, K e N, normalmente utilizada na avaliação do risco de ocorrência de "bitter pit", apresenta custo elevado e tem-se mostrado pouco eficiente para este fim. Isto tem estimulado o desenvolvimento de métodos alternativos para a predição em pré-colheita do risco de ocorrência pós-colheita de "bitter pit". Este trabalho foi conduzido com o objetivo de avaliar a viabilidade de utilização do método de infiltração de maçãs 'Gala'com magnésio (Mg, na predição do risco de ocorrência de "bitter pit" durante o armazenamento refrigerado. Em adição a isto, os valores de Ca na casca e na polpa (mg kg-1 de peso fresco, relacionados aos diferentes níveis de severidade e incidência de "bitter pit", em frutos infiltrados com Mg ou armazenados em câmara fria, foram representados graficamente, com o objetivo de predizer o risco de "bitter pit" com base nas concentrações de Ca. Os frutos foram colhidos em pomar com histórico de elevada incidência de "bitter pit", em Lages (SC, na safra 2003/2004, de 20 plantas previamente marcadas aleatoriamente. Os frutos utilizados para a infiltração (30 frutos por planta foram colhidos 20 dias antes da maturação comercial, enquanto os frutos armazenados em câmaras frigoríficas (100 frutos por planta foram colhidos na maturação comercial. Os valores de Ca nos frutos, acima dos quais houve baixo risco de ocorrência de "bitter pit", foram similares entre frutos infiltrados e não infiltrados com Mg, correspondendo a 55 e 192 mg kg-1, na polpa e na casca, respectivamente. A concentração de Ca quantificada no tecido da casca mostrou-se melhor indicador do risco de "bitter pit" em relação ao tecido da polpa. Os dados obtidos demonstram que o método de infiltração com Mg representa uma alternativa viável visando a avaliar

Development and test of Nb(3)Sn cos-theta dipoles based on PIT strands

Energy Technology Data Exchange (ETDEWEB)

Zlobin, A.V.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bossert, R.; Carcagno, R.; Chichili, D.R.; Elementi, L.; Feher, S.; Kashikhin, V.V.; Lamm, M.J.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Yamada, R.; /Fermilab

2004-11-01

Fermilab is involved in the development of new generation high-field accelerator magnets using state-of-the-art Nb{sub 3}Sn strands produced using different technologies. Two 1-m long models--mirror configuration and dipole magnet--were fabricated recently at Fermilab based on powder-in-tube (PIT) Nb{sub 3}Sn strands with small effective filament size. This paper describes the parameters of superconducting strands and cable, the details of magnet design and fabrication procedure, and reports the results of PIT coil testing.

A preliminary investigation of the initiation of pitting corrosion in austenitic stainless steels and nickel-based alloys

International Nuclear Information System (INIS)

Higginson, A.

1984-01-01

Pitting corrosion in a number of austenitic stainless steels and nickel-based alloys that differ widely in their resistance to corrosion was studed by electrochemical and electron-optical techniques. The effect of contamination of the sulphuric acid electrolyte by chloride ions was also investigated. Preliminary results for the surface analysis of samples of 316 stainless steel by Auger electron spectroscopy are presented, and suggestions are included for further application of this technique to the examination of pitting corrosion. A comprehensive review of the literature concerning the initiation of pitting corrosion is included

Mechanism of Pitting Corrosion Prevention by Nitrite in Carbon Steel Exposed to Dilute Salt Solutions

International Nuclear Information System (INIS)

Zapp, Philip E.; Zee, John W. van

2002-01-01

The research has developed a broad fundamental understanding of the inhibition action of nitrite ions in preventing nitrate pitting corrosion of carbon steel tanks containing high-level radioactive waste. This fundamental understanding can be applied to specific situations during waste removal for permanent disposition and waste tank closure to ensure that the tanks are maintained safely. The results of the research provide the insight necessary to develop solutions that prevent further degradation

Corrective Action Decision Document/Closure Report for Corrective Action Unit 367: Area 10 Sedan, Ess and Uncle Unit Craters Nevada National Security Site, Nevada, Revision 0

Energy Technology Data Exchange (ETDEWEB)

Patrick Matthews

2011-06-01

Corrective Action Unit 367 comprises four corrective action sites (CASs): • 10-09-03, Mud Pit • 10-45-01, U-10h Crater (Sedan) • 10-45-02, Ess Crater Site • 10-45-03, Uncle Crater Site The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation of the corrective actions and site closure activities implemented at CAU 367. A corrective action of closure in place with use restrictions was completed at each of the three crater CASs (10-45-01, 10-45-02, and 10-45-03); corrective actions were not required at CAS 10-09-03. In addition, a limited soil removal corrective action was conducted at the location of a potential source material release. Based on completion of these correction actions, no additional corrective action is required at CAU 367, and site closure is considered complete. Corrective action investigation (CAI) activities were performed from February 2010 through March 2011, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 367: Area 10 Sedan, Ess and Uncle Unit Craters, Nevada Test Site, Nevada. The approach for the CAI was divided into two facets: investigation of the primary release of radionuclides, and investigation of non-test or other releases (e.g., migration in washes and potential source material). Based on the proximity of the Uncle, Ess, and Sedan craters, the impact of the Sedan test on the fallout deposited from the two earlier tests, and aerial radiological surveys, the CAU 367 investigation was designed to study the releases from the three crater CASs as one combined release (primary release). Corrective Action Site 10-09-03, Mud Pit, consists of two mud pits identified at CAU 367. The mud pits are considered non-test releases or other releases and were investigated independent of the three crater CASs. The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 367 dataset of

The Influence of Radiation on Pit Solution Chemistry as it Pertains to the Transition from Metastable to Stable Pitting in Steels

International Nuclear Information System (INIS)

Galuszka-Muga, Barbara; Muga, Luis M.

2006-01-01

Previous work relevant to current efforts is summarized. A description of an improved version of a new electrochemical probe, the ArtPit, is given. The distinct feature of the probe for investigating metastable pitting of carbon steels is specified and compared to other approaches. The electrochemical response of the ArtPit under the gamma irradiation and elevated temperature conditions that occur at high level waste (HLW) storage tanks is presented. In particular, the Tafel slope determinations and chemical analyses of the ArtPit confined volume electrolyte are described. Based on results a possible approach for reducing the corrosion rate of HLW tank walls is suggested. Additional statistical analysis of the occurrence of short duration (passivated pits) and long term (stable pitting) electrochemical pulses (current surges) during exposure confirm that radiation enhances the occurrence of both more and smaller sized pits due to increased likelihood of repassivation

LabVIEW 2010 Computer Vision Platform Based Virtual Instrument and Its Application for Pitting Corrosion Study.

Science.gov (United States)

Ramos, Rogelio; Zlatev, Roumen; Valdez, Benjamin; Stoytcheva, Margarita; Carrillo, Mónica; García, Juan-Francisco

2013-01-01

A virtual instrumentation (VI) system called VI localized corrosion image analyzer (LCIA) based on LabVIEW 2010 was developed allowing rapid automatic and subjective error-free determination of the pits number on large sized corroded specimens. The VI LCIA controls synchronously the digital microscope image taking and its analysis, finally resulting in a map file containing the coordinates of the detected probable pits containing zones on the investigated specimen. The pits area, traverse length, and density are also determined by the VI using binary large objects (blobs) analysis. The resulting map file can be used further by a scanning vibrating electrode technique (SVET) system for rapid (one pass) "true/false" SVET check of the probable zones only passing through the pit's centers avoiding thus the entire specimen scan. A complete SVET scan over the already proved "true" zones could determine the corrosion rate in any of the zones.

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada Test Site, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2009-07-31

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada Test Site (NTS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre Area. After closure activities are complete, a request for the modification of the Resource Conservation and Recovery Act Permit that governs waste management activities at the NTS will be submitted to the Nevada Division of Environmental Protection to incorporate the requirements for post-closure monitoring. Four CAAs, ranging from No Further Action to Clean Closure, were evaluated for the 92-Acre Area. The CAAs were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. Based on the evaluation of the data used to develop the conceptual site model; a review of past, current, and future operations at the site; and the detailed and comparative

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

2009-01-01

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada Test Site (NTS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre Area. After closure activities are complete, a request for the modification of the Resource Conservation and Recovery Act Permit that governs waste management activities at the NTS will be submitted to the Nevada Division of Environmental Protection to incorporate the requirements for post-closure monitoring. Four CAAs, ranging from No Further Action to Clean Closure, were evaluated for the 92-Acre Area. The CAAs were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. Based on the evaluation of the data used to develop the conceptual site model; a review of past, current, and future operations at the site; and the detailed and comparative analysis of the

Prospective assessment of chronic multisymptom illness reporting possibly associated with open-air burn pit smoke exposure in Iraq.

Science.gov (United States)

Powell, Teresa M; Smith, Tyler C; Jacobson, Isabel G; Boyko, Edward J; Hooper, Tomoko I; Gackstetter, Gary D; Phillips, Christopher J; Smith, Besa

2012-06-01

To investigate the relationship between chronic multisymptom illness (CMI) and possible exposure to an open-air burn pit at three selected bases among those deployed to operations in Iraq and Afghanistan. Chronic multisymptom illness (reporting at least one symptom in at least two of the following symptom constructs: general fatigue; mood and cognition problems; and musculoskeletal discomfort) was assessed, differentiating by potential burn pit exposure, among deployers who completed 2004 and 2007 Millennium Cohort questionnaires. More than 21,000 Cohort participants were deployed in support of the current operations, including more than 3000 participants with at least one deployment within a 3-mile radius of a documented burn pit. After adjusting for covariates, no elevated risk of CMI was observed among those exposed. There was no increase in CMI symptom reporting in those deployed to three selected bases with documented burn pits compared with other deployers.

Base Closure: A Road Map for Completion

Science.gov (United States)

1991-03-22

leadership . At the same time, he should issue written press releases. Selected senior leaders from the base should be briefed separately from key community...they will hold with other agencies on base. These matters should be the commander’s call; they will reflect his style of leadership and preference for...base closure. He alone must foresee what can most likely go wrong as well as what should go right in this arduous process. DCNSIZING AN ORGANIZATIN The

Percutaneous closure of patent foramen ovale in patients with presumed paradoxical embolism: periprocedural results and midterm risk of recurrent neurologic events.

Science.gov (United States)

Balbi, Manrico; Casalino, Laura; Gnecco, Giovanni; Bezante, Gian Paolo; Pongiglione, Giacomo; Marasini, Maurizio; Del Sette, Massimo; Barsotti, Antonio

2008-08-01

To report our data on selected patients with previous paradoxical embolism who underwent transcatheter patent foramen ovale (PFO) closure. Between July 2001 and July 2007, percutaneous PFO closure was performed on 128 patients (65 women, mean age: 46 +/- 12.8 years). Patent foramen ovale closure was recommended for secondary prevention in patients with previous transient ischemic attacks (52.5%), stroke (46%), or peripheral embolism (1.5%). Implantation was successful in all patients, and at the end of intervention, complete PFO closure was achieved in 70.3% of them. There were no "major" complications (ie, deaths, device embolization or thrombosis, need for cardiac surgery). The overall incidence of complications (mostly hemorrhagic) was 7%. The mean follow-up period was 32 months. Complete closure had been achieved in 78.4% and in 82.5% of patients at the third month of transesophageal echocardiography examination and at the sixth month of transcranial Doppler examination, respectively. There were no recurrent thromboembolic events during the follow-up period. Percutaneous closure of PFO is a feasible procedure, but it is not a risk-free technique. However, in correctly selected patients (ie, large PFO and those at risk for neurologic relapse), nearly complete PFO closure seems to provide protection from future neurologic ischaemic events at midterm follow-up.

CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

Energy Technology Data Exchange (ETDEWEB)

Adamson, P. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Austin, J. [Univ. of Minnesota, Duluth, MN (United States); Cao, S. V. [Univ. of Texas, Austin, TX (United States); Coelho, J. A. B. [Tufts Univ., Medford, MA (United States); Davies, G. S. [Iowa State Univ., Ames, IA (United States); Evans, J. J. [Univ. of Manchester (United Kingdom); Guzowski, P. [Univ. of Manchester (United Kingdom); Habig, A. [Univ. of Minnesota, Duluth, MN (United States); Holin, A. [Univ. College London, London (United Kingdom); Huang, J. [Univ. of Texas, Austin, TX (United States); Johnson, R. [Univ. of Cincinnati, OH (United States); St. John, J. [Univ. of Cincinnati, OH (United States); Kreymer, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kordosky, M. [College of William and Mary, Williamsburg, VA (United States); Lang, K. [Univ. of Texas, Austin, TX (United States); Marshak, M. L. [Univ. of Minnesota, Minneapolis, MN (United States); Mehdiyev, R. [Univ. of Texas, Austin, TX (United States); Meier, J. [Univ. of Minnesota, Minneapolis, MN (United States); Miller, W. [Univ. of Minnesota, Minneapolis, MN (United States); Naples, D. [Univ. of Pittsburgh, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nichol, R. J. [Univ. College London, London (United Kingdom); Patterson, R. B. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paolone, V. [Univ. of Pittsburgh, PA (United States); Pawloski, G. [Univ. of Minnesota, Minneapolis, MN (United States); Perch, A. [Univ. College London, London (United Kingdom); Pfutzner, M. [Univ. College London, London (United Kingdom); Proga, M. [Univ. of Texas, Austin, TX (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Radovic, A. [Univ. College London, London (United Kingdom); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Schreiner, S. [Univ. of Minnesota, Minneapolis, MN (United States); Soldner-Rembold, S. [Univ. of Manchester (United Kingdom); Sousa, A. [Univ. of Cincinnati, OH (United States); Thomas, J. [Univ. College London, London (United Kingdom); Vahle, P. [College of William and Mary, Williamsburg, VA (United States); Wendt, C. [Univ. of Wisconsin, Madison, WI (United States); Whitehead, L. H. [Univ. College London, London (United Kingdom); Wojcicki, S. [Stanford Univ., CA (United States)

2013-12-30

This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

Primary closure after carotid endarterectomy is not inferior to other closure techniques.

Science.gov (United States)

Avgerinos, Efthymios D; Chaer, Rabih A; Naddaf, Abdallah; El-Shazly, Omar M; Marone, Luke; Makaroun, Michel S

2016-09-01

Primary closure after carotid endarterectomy (CEA) has been much maligned as an inferior technique with worse outcomes than in patch closure. Our purpose was to compare perioperative and long-term results of different CEA closure techniques in a large institutional experience. A consecutive cohort of CEAs between January 1, 2000, and December 31, 2010, was retrospectively analyzed. Closure technique was used to divide patients into three groups: primary longitudinal arteriotomy closure (PRC), patch closure (PAC), and eversion closure (EVC). End points were perioperative events, long-term strokes, and restenosis ≥70%. Multivariate regression models were used to assess the effect of baseline predictors. There were 1737 CEA cases (bilateral, 143; mean age, 71.4 ± 9.3 years; 56.2% men; 35.3% symptomatic) performed during the study period with a mean clinical follow-up of 49.8 ± 36.4 months (range, 0-155 months). More men had primary closure, but other demographic and baseline symptoms were similar between groups. Half the patients had PAC, with the rest evenly distributed between PRC and EVC. The rate of nerve injury was 2.7%, the rate of reintervention for hematoma was 1.5%, and the length of hospital stay was 2.4 ± 3.0 days, with no significant differences among groups. The combined stroke and death rate was 2.5% overall and 3.9% and 1.7% in the symptomatic and asymptomatic cohort, respectively. Stroke and death rates were similar between groups: PRC, 11 (2.7%); PAC, 19 (2.2%); EVC, 13 (2.9%). Multivariate analysis showed baseline symptomatic disease (odds ratio, 2.4; P = .007) and heart failure (odds ratio, 3.1; P = .003) as predictors of perioperative stroke and death, but not the type of closure. Cox regression analysis demonstrated, among other risk factors, no statin use (hazard ratio, 2.1; P = .008) as a predictor of ipsilateral stroke and severe (glomerular filtration rate <30 mL/min/1.73 m(2)) renal insufficiency (hazard ratio, 2.6; P�

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada

International Nuclear Information System (INIS)

2010-01-01

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada National Security Site (NNSS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre Area. After closure activities are complete, a request for the modification of the Resource Conservation and Recovery Act Permit that governs waste management activities at the NNSS will be submitted to the Nevada Division of Environmental Protection to incorporate the requirements for post-closure monitoring. Four CAAs, ranging from No Further Action to Clean Closure, were evaluated for the 92-Acre Area. The CAAs were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. Based on the evaluation of the data used to develop the conceptual site model; a review of past, current, and future operations at the site; and the detailed and comparative

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2010-11-22

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada National Security Site (NNSS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre Area. After closure activities are complete, a request for the modification of the Resource Conservation and Recovery Act Permit that governs waste management activities at the NNSS will be submitted to the Nevada Division of Environmental Protection to incorporate the requirements for post-closure monitoring. Four CAAs, ranging from No Further Action to Clean Closure, were evaluated for the 92-Acre Area. The CAAs were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. Based on the evaluation of the data used to develop the conceptual site model; a review of past, current, and future operations at the site; and the detailed

Model-Based Comprehensive Analysis of School Closure Policies for Mitigating Influenza Epidemics and Pandemics.

Science.gov (United States)

Fumanelli, Laura; Ajelli, Marco; Merler, Stefano; Ferguson, Neil M; Cauchemez, Simon

2016-01-01

School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome.

Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

International Nuclear Information System (INIS)

Valor, A.; Caleyo, F.; Alfonso, L.; Rivas, D.; Hallen, J.M.

2007-01-01

In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion

Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

Energy Technology Data Exchange (ETDEWEB)

Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 Havana (Cuba); Caleyo, F. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)]. E-mail: fcaleyo@gmail.com; Alfonso, L. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Rivas, D. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Hallen, J.M. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

2007-02-15

In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion.

Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi)

Science.gov (United States)

Chipeta, W. C.; Holm, R. H.; Kamanula, J. F.; Mtonga, W. E.; de los Reyes, F. L.

2017-08-01

A lack of effective options in local technology poses challenges when onsite household sanitation facilities are eventually filled to capacity in unplanned settlement areas within Mzuzu City, located in northern Malawi. Vacuum trucks currently dominate the market but focus on emptying septic tanks in the more easily accessible planned settlement areas, rather than servicing the pit latrines common in unplanned settlement areas. As a result, households in the unplanned settlement areas within Mzuzu rely primarily on manual pit emptying (i.e., shoveling by hand) or digging a new pit latrine. These practices have associated health risks and are limited by space constraints. This research focused on filling the technological gap through the design, development, and testing of a pedal powered modified Gulper pump using locally available materials and fabrication. A modified pedal powered Gulper technology was developed and demonstrated to be capable of lifting fecal sludge from a depth of 1.5 m with a mean flow rate of 0.00058 m3/s. If the trash content was low, a typical pit latrine with a volume of 1-4 m3 could be emptied within 1-2 h. Based on the findings in our research Phase IV, the pedal powered Gulper modification is promising as a potential emptying technology for lined pit latrines in unplanned settlement areas. The success rate of the technology is about 17% (5 out 30 sampled lined pit latrines were successful) and reflects the difficulty in finding a single technology that can work well in all types of pit latrines with varying contents. We note that cost should not be the only design criteria and acknowledge the challenge of handling trash in pit latrines.

Pitting corrosion and crevice corrosion of an advanced chromium-based stainless steel

International Nuclear Information System (INIS)

Kohler, M.

1999-01-01

Alloy 33 is a (wt. %) 33 Cr-32Fe-31Ni-1.6Mo-0.6CU-0.4N austenitic stainless steel combining high yield strength of min. 380 N/mm 2 (55 KSI) with high resistance to local corrosion and superior resistance to stress corrosion cracking. Ranking the material according to its PRE (pitting resistance equivalent) value, the new alloy fits in between the advanced 6% Mo superaustenitics and the nickel-base Alloy 625 but due to the balanced chemical composition the alloy shows a lot less sensitivity to segregation in the base material as well as in welded structures. It is recommended to weld the material with matching filler. The critical pitting temperature of such joints in the 10% FeCl 3 · 6H 2 O solution is reduced by only 10 C in comparison to the base material. Corrosion tests in artificial seawater (20 g/l Cl - ) with additions of chloride up to 37 g/l as well as in a NaCl-CaCl 2 , solution with 62 g/l Cl - --revealed that the critical pitting temperature does not differentiate from the 6% Mo austenitic steel Alloy 926. With respect to crevice corrosion the depassivation pH value has been determined in 1 M NaCl solution according to Crolet and again there was no difference between Alloy 33 and Alloy 926. SCC tests performed on Alloy 33 in the solution annealed condition as well as after heavy cold work up to R PO,2 ∼ 1,100--1,200 N/mm 2 (160--174 KSI) indicate the high resistance to stress corrosion cracking in hot sodium chloride solutions

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2014

Energy Technology Data Exchange (ETDEWEB)

Silvas, A. J. [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site; Lantow, Tiffany A. [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site

2015-03-25

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2014 and includes inspection and repair activities completed at the following CAUs; CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports and subsequent correspondence with the Nevada Division of Environmental Protection. The post-closure inspection plans and subsequent correspondence modifying the requirements for each CAU are included in Appendix B. The inspection checklists are included in Appendix C. Photographs taken during inspections are included in Appendix D. The annual post-closure inspections were conducted on May 28, 2014. Maintenance was required at CAU 407. Animal burrows were backfilled and erosion repairs were performed. Vegetation monitoring was performed at CAU 407 in June 2014. The vegetation monitoring report is included in Appendix E.

Optimization and large scale computation of an entropy-based moment closure

Science.gov (United States)

Kristopher Garrett, C.; Hauck, Cory; Hill, Judith

2015-12-01

We present computational advances and results in the implementation of an entropy-based moment closure, MN, in the context of linear kinetic equations, with an emphasis on heterogeneous and large-scale computing platforms. Entropy-based closures are known in several cases to yield more accurate results than closures based on standard spectral approximations, such as PN, but the computational cost is generally much higher and often prohibitive. Several optimizations are introduced to improve the performance of entropy-based algorithms over previous implementations. These optimizations include the use of GPU acceleration and the exploitation of the mathematical properties of spherical harmonics, which are used as test functions in the moment formulation. To test the emerging high-performance computing paradigm of communication bound simulations, we present timing results at the largest computational scales currently available. These results show, in particular, load balancing issues in scaling the MN algorithm that do not appear for the PN algorithm. We also observe that in weak scaling tests, the ratio in time to solution of MN to PN decreases.

A New Algorithm for Determining Ultimate Pit Limits Based on Network Optimization

OpenAIRE

Ali Asghar Khodayari

2013-01-01

One of the main concerns of the mining industry is to determine ultimate pit limits. Final pit is a collection of blocks, which can be removed with maximum profit while following restrictions on the slope of the mine’s walls. The size, location and final shape of an open-pit are very important in designing the location of waste dumps, stockpiles, processing plants, access roads and other surface facilities as well as in developing a production program. There are numerous methods for designing...

Eyelid closure at death

Directory of Open Access Journals (Sweden)

A D Macleod

2009-01-01

Full Text Available Aim: To observe the incidence of full or partial eyelid closure at death. Materials and Methods: The presence of ptosis was recorded in 100 consecutive hospice patient deaths. Results: Majority (63% of the patients died with their eyes fully closed, however, 37% had bilateral ptosis at death, with incomplete eye closure. In this study, central nervous system tumor involvement and/or acute hepatic encephalopathy appeared to be pre-mortem risk factors of bilateral ptosis at death. Conclusion: Organicity and not psychogenicity is, therefore, the likely etiology of failure of full eyelid closure at death.

Inhibition of Copper Pitting Corrosion in Aggressive Potable Waters

Directory of Open Access Journals (Sweden)

Emily Sarver

2012-01-01

Full Text Available Copper pitting corrosion can lead to premature plumbing failures, and can be caused by aggressive potable waters characterized by high pH, free chlorine residual and low alkalinity. In such waters and under continuous flow, certain inhibitors including phosphate, silica or natural organic matter may greatly reduce pitting occurrence. In the current work, 1 mg/L phosphate (as P completely prevented initiation of pits, and 5 mg/L silica (as Si significantly decelerated pitting. However, much lower doses of these inhibitors had little benefit and actually accelerated the rate of attack in some cases. Effects of organic matter were dependent on both the type (e.g., natural versus ozonated humic substances and dosage. Dose-response effects of free chlorine and alkalinity were also investigated. Based on electrochemical data, pits initiated more rapidly with increased free chlorine, but even moderate levels of chlorine (~0.4 mg/L eventually caused severe pitting. High alkalinity decreased pit propagation rates but did not prevent pit formation.

Transcatheter closure, mini-invasive closure and open-heart surgical repair for treatment of perimembranous ventricular septal defects in children: a protocol for a network meta-analysis.

Science.gov (United States)

You, Tao; Yi, Kang; Ding, Zhao-Hong; Hou, Xiao-Dong; Liu, Xing-Guang; Wang, Xin-Kuan; Ge, Long; Tian, Jin-Hui

2017-06-21

Both transcatheter device closure and surgical repair are effective treatments with excellent midterm outcomes for perimembranous ventricular septal defects (pmVSDs) in children. The mini-invasive periventricular device occlusion technique has become prevalent in research and application, but evidence is limited for the assessment of transcatheter closure, mini-invasive closure and open-heart surgical repair. This study comprehensively compares the efficacy, safety and costs of transcatheter closure, mini-invasive closure and open-heart surgical repair for treatment of pmVSDs in children using Bayesian network meta-analysis. A systematic search will be performed using Chinese Biomedical Literature Database, China National Knowledge Infrastructure, PubMed, EMBASE.com and the Cochrane Central Register of Controlled Trials to include random controlled trials, prospective or retrospective cohort studies comparing the efficacy, safety and costs of transcatheter closure, mini-invasive closure and open-heart surgical repair. The risk of bias for the included prospective or retrospective cohort studies will be evaluated according to the risk of bias in non-randomised studies of interventions (ROBINS-I). For random controlled trials, we will use risk of bias tool from Cochrane Handbook version 5.1.0. A Bayesian network meta-analysis will be conducted using R-3.3.2 software. Ethical approval and patient consent are not required since this study is a network meta-analysis based on published trials. The results of this network meta-analysis will be submitted to a peer-reviewed journal for publication. CRD42016053352. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Study of ex-vessel steam explosion risk of Reactor Pit Flooding System and structural response of containment for CPR1000"+ Unit

International Nuclear Information System (INIS)

Zhang Juanhua; Chen Peng

2015-01-01

Reactor Pit Flooding System is one of the special mitigation measures for severe accident for CPR1000"+ Unit. If the In-Vessel Relocation function of Reactor Pit Flooding System is failed, there is the steam explosion risk in reactor cavity. This paper firstly adopts MC3D code to build steam explosion model in order to calculate the pressure load and impulses of steam explosion that are as the input data of containment structural response analysis. The next step is to model the containment structure and analyze the structural response by ABAQUS code. The analysis results show that the integral damage induced by steam explosion to the external containment wall is shallow, and the containment structural integrity can be maintained. The risk and damage to the containment integrity reduced by steam explosion of RPF is small, and it does not influence the design and implementation of RPF. (author)

Rehabilitation of the Mary Kathleen uranium mine site after closure

International Nuclear Information System (INIS)

Ward, T.A.; Flannagan, J.C.; Hubery, R.W.

1983-01-01

The Mary Kathleen uranium mine and treatment plant ceased operation in late 1982 and a plan for the closure and rehabilitation of the area was developed. The object of the plan is to make all areas safe, remove all non-permanent structures and encourage natural revegetation. The plan has been accepted by the Queensland Mines Department. The mine pit will be left stable, inaccessible to vehicles, and containing about 50 metres of water. Mine waste and borrow areas will be contoured, ripped and seeded to encourage revegetation. The treatment plant area will be cleared of all equipment and light structures, decontaminated and revegetated. The evaporation ponds will be dried out, precipitate and contaminated soil will be removed to the tailings dam, and the area will be contoured and revegetated. The tailings will be covered with one metre of waste rock and boreholes will be used to recover groundwater containing salts for storage in the pit

Research process of nondestructive testing pitting corrosion in metal material

Directory of Open Access Journals (Sweden)

Bo ZHANG

2017-12-01

Full Text Available Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

Inconsistent identification of pit bull-type dogs by shelter staff.

Science.gov (United States)

Olson, K R; Levy, J K; Norby, B; Crandall, M M; Broadhurst, J E; Jacks, S; Barton, R C; Zimmerman, M S

2015-11-01

Shelter staff and veterinarians routinely make subjective dog breed identification based on appearance, but their accuracy regarding pit bull-type breeds is unknown. The purpose of this study was to measure agreement among shelter staff in assigning pit bull-type breed designations to shelter dogs and to compare breed assignments with DNA breed signatures. In this prospective cross-sectional study, four staff members at each of four different shelters recorded their suspected breed(s) for 30 dogs; there was a total of 16 breed assessors and 120 dogs. The terms American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier, pit bull, and their mixes were included in the study definition of 'pit bull-type breeds.' Using visual identification only, the median inter-observer agreements and kappa values in pair-wise comparisons of each of the staff breed assignments for pit bull-type breed vs. not pit bull-type breed ranged from 76% to 83% and from 0.44 to 0.52 (moderate agreement), respectively. Whole blood was submitted to a commercial DNA testing laboratory for breed identification. Whereas DNA breed signatures identified only 25 dogs (21%) as pit bull-type, shelter staff collectively identified 62 (52%) dogs as pit bull-type. Agreement between visual and DNA-based breed assignments varied among individuals, with sensitivity for pit bull-type identification ranging from 33% to 75% and specificity ranging from 52% to 100%. The median kappa value for inter-observer agreement with DNA results at each shelter ranged from 0.1 to 0.48 (poor to moderate). Lack of consistency among shelter staff indicated that visual identification of pit bull-type dogs was unreliable. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pit Water Storage Ottrupgaard

DEFF Research Database (Denmark)

Heller, Alfred

2000-01-01

The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

On the applicability of extreme value statistics in the prediction of maximum pit depth in heavily corroded non-piggable buried pipelines

Energy Technology Data Exchange (ETDEWEB)

Alfonso, L. [Universidad Autonoma de la Ciudad de Mexico, Mexico D.F. 09790 (Mexico); Caleyo, F.; Hallen, J. M.; Araujo, J. [ESIQIE, Instituto Politecnico Nacional, Mexico D.F. (Mexico)

2010-07-01

Pitting corrosion entails serious risks in industrial plants, since a perforation resulting from a single pit can cause the failure of in-service components like water pipes, heat exchangers or oil tanks. A number of statistical methods have been suggested to estimate the maximum pit depth. Over the years, a successful application of extreme value analysis has been found in the application of the Gumbel distribution to predict the maximum pit depth from a smaller number of samples with small area. There is a lack of studies devoted to the applicability of the Gumbel method to the prediction of maximum pitting-corrosion depth. The aim of the work presented in this paper is to introduce a new strategy for the application of the Gumbel method in real pipelines. The methodology proposed is based on the fact that the clustered pattern of the pit depth distribution is less pronounced when the analysis is restricted to sections of the pipeline that exhibits similar characteristics.

Geotechnical approach for occupational safety risk analysis of critical slope in open pit mining as implication for earthquake hazard

Science.gov (United States)

Munirwansyah; Irsyam, Masyhur; Munirwan, Reza P.; Yunita, Halida; Zulfan Usrina, M.

2018-05-01

Occupational safety and health (OSH) is a planned effort to prevent accidents and diseases caused by work. In conducting mining activities often occur work accidents caused by unsafe field conditions. In open mine area, there is often a slump due to unstable slopes, which can disrupt the activities and productivity of mining companies. Based on research on stability of open pit slopes conducted by Febrianti [8], the Meureubo coal mine located in Aceh Barat district, on the slope of mine was indicated unsafe slope conditions, it will be continued research on OSH for landslide which is to understand the stability of the excavation slope and the shape of the slope collapse. Plaxis software was used for this research. After analyzing the slope stability and the effect of landslide on OSH with Job Safety Analysis (JSA) method, to identify the hazard to work safety, risk management analysis will be conducted to classified hazard level and its handling technique. This research aim is to know the level of risk of work accident at the company and its prevention effort. The result of risk analysis research is very high-risk value that is > 350 then the activity must be stopped until the risk can be reduced to reach the risk value limit < 20 which is allowed or accepted.

An inverse analysis of weak structural plane parameters for a limestone foundation pit based on critical stability

Science.gov (United States)

yan, LIU Jun; hua, SONG Xiang; Yan, LIU

2017-11-01

The article uses the Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) to make an analysis of the deformation characteristics of the structural plane, which is based on a real rock foundation pit in Jinan city. It makes an inverse analysis of the strength of the surface structure and the occurrence of the parameters by Mohr-Coulomb strength criterion value criterion in the way of numerical simulation, which explores the change of stress field of x-z oblique section of pit wall and the relation between the exposed height of structural plane and the critical cohesion, the exposed height and critical inclination angle of the structure surface. We can find that when the foundation pit is in the critical stable state and the inclination angle of the structural plane is constant, the critical cohesive force of the structural plane increases with the increase of the exposed surface height. And when the foundation pit in the critical stability of the situation and the structural surface of the cohesive force is constant, the structural surface exposed height increases and the structural angle of inclination is declining. The conclusion can provide theoretical basis for the design and construction of the rock foundation pit with structural plane.

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution.

Science.gov (United States)

Jiang, Jin-Yang; Liu, Yao; Chu, Hong-Yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-08-04

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state.

Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

Directory of Open Access Journals (Sweden)

Silwamba C

2015-08-01

Full Text Available Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the start Nchanga mining license surface already had NUG and many watershed divides with the Nchanga and Chingola streams being the main streams feeding into Zambias second largest river Kafue river and 42 of the year was characterised by heavy rains ranging between 800mm to 1300mm per annum. In this paper the presence of very significant amounts of seasonal rain and subsurface water in the mining area was identified as both a curse and a blessing. An excess in seasonal rain and subsurface water would disrupt both open pit and underground mining operations. In order for NOP to be operated successfully stable and free from flooding coping water management tactics were adopted from 1955 to 2015 including 1. Underground mine pump chamber pumping system 2. Piezometer instrumented boreholes 3. Underground mine 1500-ft sub-haulage east borehole dewatering beneath the open pit 4. Nchanga and Chingola stream diversionary tunnel and open drains 5. Nchanga stream causeway and embankment dam in the Matero School Golf Club area 6. Pit perimeter borehole pumping 7. Outer and inner pit perimeter drains and bund walls 8. In-pit ramp side drains 9. In-pit sub-horizontal borehole geo-drains and water and 10. Pit bottom sump pumps. Application of grout curtains along the Vistula River Poland was noted as a possibility in the right circumstances although it had never been used at Nchanga Open Pit. An additional conclusion was that forward health safety and environmental end

Defense Base Realignment and Closure Budget Data for the Closure of Marine Corps Air Station El Toro and Tustin, California, and the Realignment to Naval Air Station Miramar, California

National Research Council Canada - National Science Library

1994-01-01

... requested for each military construction project associated with base realignment and closure does not exceed the original estimated cost provided to the Commission on Defense Base Closure and Realignment (the Commission...

Fokker-Planck modeling of pitting corrosion in underground pipelines

Energy Technology Data Exchange (ETDEWEB)

Camacho, Eliana Nogueira [Risco Ambiental Engenharia, Rio de Janeiro, RJ (Brazil); Melo, Paulo F. Frutuoso e [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Saldanha, Pedro Luiz C. [Comissao Nacional de Energia Nuclear (CGRC/CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Reatores e Ciclo do Combustivel; Silva, Edson de Pinho da [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. of Physics

2011-07-01

with drift term. A Fokker-Planck modeling of pitting corrosion can also be modeled for any component of a nuclear power plant for which corrosion depth data are available. The above proposed approach provides a precise and easy way in which the distribution of pit depths and corrosion rate can be obtained, which is critical for developing reliability, risk-informed and risk-based models for inspection and maintenance planning of corroded pipelines. (author)

Markov chain modelling of pitting corrosion in underground pipelines

Energy Technology Data Exchange (ETDEWEB)

Caleyo, F. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)

2009-09-15

A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

Markov chain modelling of pitting corrosion in underground pipelines

International Nuclear Information System (INIS)

Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

2009-01-01

A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

The Use of Pit and Fissure Sealants—A Literature Review

Directory of Open Access Journals (Sweden)

Reem Naaman

2017-12-01

Full Text Available This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use.

The Use of Pit and Fissure Sealants—A Literature Review

Science.gov (United States)

Naaman, Reem; El-Housseiny, Azza A.; Alamoudi, Najlaa

2017-01-01

This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use. PMID:29563440

ON THE PROPAGATION OF OPEN AND COVERED PIT IN 316L STAINLESS STEEL

International Nuclear Information System (INIS)

Heurtault, Stéphane; Robin, Raphaël; Rouillard, Fabien; Vivier, Vincent

2016-01-01

Highlights: • The propagation of a single pit was investigated with a flow micro-device. • Both in depth and radial pit propagation were characterized. • The formation of a salt film in the pit was discussed. - Abstract: Pitting corrosion on stainless steel has been widely studied during the last decades, but since it is a stochastic process, it remains difficult to analyze experimentally such a phenomenon. In this work, reproducible single pits were performed on 316L steel by using an experimental setup based on the use of a glass microcapillary to locally supply chloride ions on the steel surface in order to characterize the pit propagation. This original approach allowed obtaining new results about pit propagation. Indeed, it was possible to control the presence of a metallic cap covering the pit by adjusting the experimental parameters (potential – chloride to sulfate ratio – temperature). The presence of this cover was shown to be an important issue concerning the propagation mechanism. It was also possible to study the evolution of both the pit depth and the pit diameter as a function of various parameters. Then, based on the simulation of the current densities at the pit bottom and at the pit aperture, a special attention has been paid for the investigation of the local propagation mechanism.

Research on horizontal displacement monitoring method of deep foundation pit based on laser projecting sensing technology

Science.gov (United States)

Liu, Peng; Xie, Shulin; Zhang, Lixiao; Zhou, Guangyi; Zhao, Xuefeng

2018-03-01

A certain level of horizontal displacement will occur during excavation or subsequent construction of deep foundation pit. If the support is improper and the horizontal displacement of the foundation pit is too large, it will cause collapse and even affect the buildings around the foundation pit, which will endanger people's life and property. Therefore, the horizontal displacement monitoring of deep foundation pit becomes more and more important. At present, the electronic total station is often used to monitor the horizontal displacement of the foundation pit, but this monitoring method is expensive, prone to accidental errors, and can not be used for real-time monitoring. Therefore, a method of monitoring the horizontal displacement of deep foundation pit by using laser projection sensing technique is proposed in this paper. The horizontal displacement of the foundation pit is replaced by the displacement of the laser spot emitted by the laser, and the horizontal displacement of the foundation pit can be obtained by identifying the displacement of the laser spot projected on the screen. A series of experiments show that the accuracy of this monitoring method meets the engineering requirements and greatly reduces the cost, which provides a new technology for the displacement monitoring of deep foundation pit.

A GIS-based, confined aquifer, hypothetical model of ground-water seepage into a former mining open pit

International Nuclear Information System (INIS)

Salama, A; Negeed, E.R.

2010-01-01

Groundwater seepage into a former mining site in Egypt is proposed for simulation. This site was used for basalt extraction. After the mining activities had stopped a large open pit was left over and groundwater seeped into the pit forming a lake. The pit has a dimension of approximately 1200 x 600 x 30 m. Because of the lack of field data, several scenarios may be hypothesized to explain the filling of these open pits with water. In this paper, one of these scenarios is studied. It is suggested that this water comes from an underneath confined aquifer. Through fractures in the host rock, water seeped upwards into the open pit. To estimate the rate at which water seeps into the lake, numerical study based on the finite element method is performed. Firstly, geo-referencing of the site was performed using GIS. The boundary of the lake was then digitized and elevation contours was defined. These data was then imported into grid-builder software to generate a two-dimensional triangular mesh which was then used by hydro-geosphere software to build the three-dimensional mesh and solve the problem. It was found that the set of discrete fractures was insufficient to fill the lake in the time span that was actually elapsed to fill up the lake which is on the order of two to three years.

Risk Analysis of the Long-Term Outcomes of the Surgical Closure of Secundum Atrial Septal Defects

Directory of Open Access Journals (Sweden)

Hong Rae Kim

2017-04-01

Full Text Available Background: Closure of a secundum atrial septal defect (ASD is possible through surgical intervention or device placement. During surgical intervention, concomitant pathologies are corrected. The present study was conducted to investigate the outcomes of surgical ASD closure, to determine the risk factors of mortality, and establish the effects of concomitant disease correction. Methods: Between October 1989 and October 2009, 693 adults underwent surgery for secundum ASD. Their mean age was 40.9±13.1 years, and 199 (28.7% were male. Preoperatively, atrial fibrillation was noted in 39 patients (5.6% and significant tricuspid regurgitation (TR in 137 patients (19.8%. The mean follow-up duration was 12.4±4.7 years. Results: There was no 30-day mortality. The 1-, 5-, 10-, and 20-year survival rates were 99.4%, 96.8%, 94.5%, and 81.6%, respectively. In multivariate analysis, significant preoperative TR (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.09 to 3.16; p=0.023 and preoperative age (HR, 1.04; 95% CI, 1.01 to 1.06; p=0.001 were independent risk factors for late mortality. The TR grade significantly decreased after ASD closure with tricuspid repair. However, in patients with more than mild TR, repair was not associated with improved long-term survival (p=0.518. Conclusion: Surgical ASD closure is safe. Significant preoperative TR and age showed a strong negative correlation with survival. Our data showed that tricuspid valve repair improved the TR grade effectively. However, no effect on long-term survival was found. Therefore, early surgery before the development of significant TR mat be beneficial for improving postoperative survival.

Effect of microcrystallization on pitting corrosion of pure aluminium

International Nuclear Information System (INIS)

Meng Guozhe; Wei Liyan; Zhang Tao; Shao Yawei; Wang Fuhui; Dong Chaofang; Li Xiaogang

2009-01-01

A microcrystalline aluminium film with grain size of about 400 nm was prepared by magnetron sputtering technique. Its corrosion behaviour was investigated in NaCl containing acidic solution by means of potentiodynamic polarization curves and electrochemical noise (EN). The polarization results indicated that the corrosion potential of the sample shifted towards more positive direction, while its corrosion current density decreased compared with that of pure coarse-grain Al. The EN analysis based on stochastic model demonstrated that there existed two kinds of effect of microcrystallization on the pitting behaviour of pure aluminium: (1) the rate of pit initiation is accelerated, (2) the pit growth process was impeded. This leads to the enhancement of pitting resistance for the microcrystallized aluminium.

NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

Energy Technology Data Exchange (ETDEWEB)

Cowan, Catherine M. [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Wu, Benjamin [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Ting, Kang [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Soo, Chia, E-mail: bsoo@ucla.edu [UCLA and Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic, Hospital Research Center, University of California, Los Angeles, 2641 Charles E. Young Dr. South, Los Angeles, CA 90095 (United States)

2012-06-08

Highlights: Black-Right-Pointing-Pointer NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. Black-Right-Pointing-Pointer NELL-1 significantly increases intracellular inorganic phosphate levels. Black-Right-Pointing-Pointer NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

International Nuclear Information System (INIS)

Cowan, Catherine M.; Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole; Wu, Benjamin; Ting, Kang; Soo, Chia

2012-01-01

Highlights: ► NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. ► NELL-1 significantly increases intracellular inorganic phosphate levels. ► NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. ► NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

Assessment of Concrete Repair Techniques for Radiologically-Contaminated Tank Farm Pump and Valve Pits

International Nuclear Information System (INIS)

MINTEER, D.J.

2000-01-01

As part of the scope of Project W-314, ''Tank Farm Restoration and Safe Operations,'' the condition of pump and valve pit walls and floors is being assessed, and repairs made as needed, to support upgrading the infrastructure necessary to safely transfer tank waste for treatment. Flaws in the surfaces of the pits (e.g., concrete crack/faults, protective coating deterioration) must be repaired to ensure containment integrity and to facilitate future decontamination of the pits. This engineering study presents a cost/risk/benefit evaluation of concrete and protective coating repair methods in pump and valve pits using various manual and remote tool systems

The effects of exposure to documented open-air burn pits on respiratory health among deployers of the Millennium Cohort Study.

Science.gov (United States)

Smith, Besa; Wong, Charlene A; Boyko, Edward J; Phillips, Christopher J; Gackstetter, Gary D; Ryan, Margaret A K; Smith, Tyler C

2012-06-01

To investigate respiratory illnesses and potential open-air burn pit exposure among Millennium Cohort participants who deployed to Iraq or Afghanistan. Using multivariable logistic regression, newly reported chronic bronchitis or emphysema, newly reported asthma, and self-reported respiratory symptoms and possible burn pit exposure within 2, 3, or 5 miles were examined among Army and Air Force deployers surveyed in 2004 to 2006 and 2007 to 2008 (n = 22,844). Burn pit exposure within 3 or 5 miles was not associated with respiratory outcomes after statistical adjustment. Increased symptom reporting was observed among Air Force deployers located within 2 miles of Joint Base Balad; however, this finding was marginally significant with no evidence of trend. In general, these findings do not support an elevated risk for respiratory outcomes among personnel deployed within proximity of documented burn pits in Iraq.

AREA COMPLETION STRATEGIES AT SAVANNAH RIVER SITE: CHARACTERIZATION FOR CLOSURE AND BEYOND

International Nuclear Information System (INIS)

Bagwell, L; Mark Amidon, M; Sadika Baladi, S

2007-01-01

During the first four decades of its 56 year existence, the Savannah River Site (SRS) was a key supplier of nuclear material for national defense. During the 1990s, the site's primary missions became waste site closure, environmental restoration, and deactivation and decommissioning (D and D) of remnant cold war apparatus. Since 1989, with the approval of State and Federal regulatory agencies and with the participation of interested stakeholders, SRS has implemented a final remedy for a majority of the more than 500 individual waste sites at the former nuclear materials complex. These waste sites range from small, inert rubble pits to large, heavy industrial areas and radioactive waste disposal grounds. The closure and final remediation of these waste sites mark significant progress toward achieving SRS's overarching goal of reducing or eliminating future environmental damage and human health threats. However, larger challenges remain. For example, what are appropriate and achievable end-states for decommissioned nuclear facilities? What environmental and human health risks are associated with these end-states? To answer these questions within the strictures of smaller budgets and accelerated schedules, SRS is implementing an ''area completion'' strategy that: (1) unites several discrete waste units into one conceptual model, (2) integrates historically disparate environmental characterization and D and D activities, (3) reduces the number of required regulatory documents, and (4) in some cases, compresses schedules for achieving a stakeholder-approved end-state

AREA COMPLETION STRATEGIES AT SAVANNAH RIVER SITE: CHARACTERIZATION FOR CLOSURE AND BEYOND

Energy Technology Data Exchange (ETDEWEB)

Bagwell, L; Mark Amidon, M; Sadika Baladi, S

2007-06-11

During the first four decades of its 56 year existence, the Savannah River Site (SRS) was a key supplier of nuclear material for national defense. During the 1990s, the site's primary missions became waste site closure, environmental restoration, and deactivation and decommissioning (D&D) of remnant cold war apparatus. Since 1989, with the approval of State and Federal regulatory agencies and with the participation of interested stakeholders, SRS has implemented a final remedy for a majority of the more than 500 individual waste sites at the former nuclear materials complex. These waste sites range from small, inert rubble pits to large, heavy industrial areas and radioactive waste disposal grounds. The closure and final remediation of these waste sites mark significant progress toward achieving SRS's overarching goal of reducing or eliminating future environmental damage and human health threats. However, larger challenges remain. For example, what are appropriate and achievable end-states for decommissioned nuclear facilities? What environmental and human health risks are associated with these end-states? To answer these questions within the strictures of smaller budgets and accelerated schedules, SRS is implementing an ''area completion'' strategy that: (1) unites several discrete waste units into one conceptual model, (2) integrates historically disparate environmental characterization and D&D activities, (3) reduces the number of required regulatory documents, and (4) in some cases, compresses schedules for achieving a stakeholder-approved end-state.

Single pit propagation on austenitic stainless steel

International Nuclear Information System (INIS)

Heurtault, Stephane

2016-01-01

The electrochemical characterization of metastable events such as pitting corrosion of stainless steel in chloride electrolyte remains complex because many individual processes may occur simultaneously on the alloy surface. To overcome these difficulties, an experimental setup, the flow micro-device, has been developed to achieve the initiation of a single pit and to propagate the single pit in three dimensions. In this work, we take advantage of such a device in order to revisit the pitting process on a 316L stainless steel in a chloride - sulphate bulk. In a first step, the time evolution of the pit geometry (depth, radius) and the chemical evolution of the pit solution investigated using in situ Raman spectroscopy have shown that the pit depth propagation depends on the formation of a metal chloride and sulphate gel in the pit solution, and is controlled by the metallic cations diffusion from the pit bottom to the pit mouth. The pit radius growth is defined by the initial surface de-passivation, by the presence of a pit cover and by the gel development in the solution. all of these phenomena are function of applied potential and chemical composition of the solution. In a last step, it was demonstrated that a critical chloride concentration is needed in order to maintain the pit propagation. This critical concentration slightly increases with the pit depth. From statistical analysis performed on identical experiments, a zone diagram showing the pit stability as a function of the chloride concentration and the pit dimensions was built. (author) [fr

Development and test of Nb3Sn cos-theta magnets based on RRp and PIT strands

International Nuclear Information System (INIS)

Feher, S.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bordini, B.; Bossert, R.; Carcagno, R.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Turrioni, D.; Yamada, R.; Zlobin, A.V.; Fermilab

2005-01-01

As part of the High Field Magnet program at Fermilab three cos(Θ) magnets--two mirror dipole magnets utilizing RRP cable and one dipole magnet utilizing PIT cable--have been designed, fabricated and tested recently. Both mirror magnets with RRP strands only reached ∼50-60% of their estimated critical current limit. The PIT conductor based dipole however reached its critical current limit producing over 10 T magnetic field in the bore of the magnet. This paper describes the parameters of superconducting strands and cable, the details of magnet design and fabrication procedure, and reports the results

Development and test of Nb3Sn cos-theta magnets based on RRP and PIT strands

Energy Technology Data Exchange (ETDEWEB)

Feher, S.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bordini, B.; Bossert, R.; Carcagno, R.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Turrioni, D.; Yamada, R.; Zlobin, A.V.; /Fermilab

2005-09-01

As part of the High Field Magnet program at Fermilab three cos({theta}) magnets--two mirror dipole magnets utilizing RRP cable and one dipole magnet utilizing PIT cable--have been designed, fabricated and tested recently. Both mirror magnets with RRP strands only reached {approx}50-60% of their estimated critical current limit. The PIT conductor based dipole however reached its critical current limit producing over 10 T magnetic field in the bore of the magnet. This paper describes the parameters of superconducting strands and cable, the details of magnet design and fabrication procedure, and reports the results.

Interacting Effects Induced by Two Neighboring Pits Considering Relative Position Parameters and Pit Depth

Directory of Open Access Journals (Sweden)

Yongfang Huang

2017-04-01

Full Text Available For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ and pit depth (d with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively.

Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant.

Directory of Open Access Journals (Sweden)

Fan Yu

Full Text Available Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea; a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™, a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05, whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane

What Were the Reasons for the Rapid Landslide Occurrence in “Piaseczno” Open Pit? – Analysis of the Landslide Process

Directory of Open Access Journals (Sweden)

Jakóbczyk Joanna

2015-03-01

Full Text Available Landslides are major natural hazards occurring in opencast mining. The problem of slope stability failure in the existing open pit mines as well as in those which are at a stage of technical closure is current issue in Poland and all over the world. This problem requires conducting in-depth and meaningful analysis which will identify the causes of processes characterized by a very rapid course and large extent.

Rehabilitation of residual pits in post-mining area: a goal of Czech brown coal opencast mining industry

International Nuclear Information System (INIS)

Svoboda, I.

1997-01-01

The closure of surface brown coal mines is a complex process with many specific considerations. In the Czech Republic a special project was proposed to analyze the types of environmental disturbance generated by surface mining operations and suggest procedures for the affected areas. It also aims to propose rehabilitation techniques for residual pits, considering their future use for recreational or development purposes. A Chabarovice mine case study demonstrates how to solve the problem of water flooding and utilization of the future residual lake. 2 figs

Assessment of erecting nuclear power plants below ground in an open building pit

International Nuclear Information System (INIS)

Kroeger, W.; Altes, J.; Bongartz, R.; David, P.H.; Escherich, K.H.; Kasper, K.; Koschmieder, D.; Roethig, K.D.; Schwarzer, K.; Wolters, J.

1978-01-01

The technical feasibility, costs and safety potential of siting a nuclear power plant below ground level have been assessed. The reference plant was a 1,300 MWsub(e) PWR and the siting was based on a 'cut-and-cover' design in soil. The 'cut-and-cover' design enhances the safety potential of the site both with regard to extreme internal accidents and to external impacts inclusive of hostile attack. The measures required to 'harden' the site against these extreme conditions do not cancel each other. The realization of the safety potential is strongly dependent on the reliability of the closure equipment on routes to the atmosphere. These closures represent the remaining vulnerable feature of the design, as all other release paths are through soil which prevents any immediate danger to the public. The concepts considered include partial or complete lowering of the reactor. The thickness of the coverage depends on the degree of protection required and is typically between 8 and 13 m. The essential systems of the above-ground design are unchanged and therefore prior experience and existing designs can be applied. The concepts appear to be technically feasible including, in particular, the large pits and the additional closures; the technical difficulties, however, should not be underestimated. The depth of lowering does not determine the gain in safety because a well designed coverage can act as natural soil. Partial lowering, in fact, appears to be the more economic method. According to the degree of protection and the variations of design, the concepts would cost between 8 and 14% more than the capital cost of an equivalent above-ground plant. The construction time would be extended by 1.4 years for the concepts investigated. (orig./HP) [de

Bitter pit in apples: pre- and postharvest factors: A review

International Nuclear Information System (INIS)

Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

2016-01-01

Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

Bitter pit in apples: pre- and postharvest factors: A review

Energy Technology Data Exchange (ETDEWEB)

Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

2016-07-01

Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

Interferometric Imaging Directly with Closure Phases and Closure Amplitudes

Science.gov (United States)

Chael, Andrew A.; Johnson, Michael D.; Bouman, Katherine L.; Blackburn, Lindy L.; Akiyama, Kazunori; Narayan, Ramesh

2018-04-01

Interferometric imaging now achieves angular resolutions as fine as ∼10 μas, probing scales that are inaccessible to single telescopes. Traditional synthesis imaging methods require calibrated visibilities; however, interferometric calibration is challenging, especially at high frequencies. Nevertheless, most studies present only a single image of their data after a process of “self-calibration,” an iterative procedure where the initial image and calibration assumptions can significantly influence the final image. We present a method for efficient interferometric imaging directly using only closure amplitudes and closure phases, which are immune to station-based calibration errors. Closure-only imaging provides results that are as noncommittal as possible and allows for reconstructing an image independently from separate amplitude and phase self-calibration. While closure-only imaging eliminates some image information (e.g., the total image flux density and the image centroid), this information can be recovered through a small number of additional constraints. We demonstrate that closure-only imaging can produce high-fidelity results, even for sparse arrays such as the Event Horizon Telescope, and that the resulting images are independent of the level of systematic amplitude error. We apply closure imaging to VLBA and ALMA data and show that it is capable of matching or exceeding the performance of traditional self-calibration and CLEAN for these data sets.

Criticality safety evaluation report for the 100 KE Basin sandfilter backwash pit

International Nuclear Information System (INIS)

Erickson, D.G.

1995-01-01

This analysis presents the technical basis for establishing a safe mass limit for continued operations of the KE Basin sandfilter backwash pit. The main analysis is based on a very conservative UO 2 -PuO 2 -H 2 O system using the measured isotopic concentrations of uranium and plutonium in the sludge. Appendix C contains analyses of the sandfilter backwash pit utilizing all verified materials presently in the pit, and gives new limits based on assumptions made

ICPP tank farm closure study. Volume III: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

International Nuclear Information System (INIS)

1998-02-01

This volume contains information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the six options described in Volume 1, Section 2: Option 1 -- Total removal clean closure; No subsequent use; Option 2 -- Risk-based clean closure; LLW fill; Option 3 -- Risk-based clean closure; CERCLA fill; Option 4 -- Close to RCRA landfill standards; LLW fill; Option 5 -- Close to RCRA landfill standards; CERCLA fill; and Option 6 -- Close to RCRA landfill standards; Clean fill. This volume is divided into two portions. The first portion contains the cost and planning schedule estimates while the second portion contains life-cycle costs and yearly cash flow information for each option

Impacts of swine manure pits on groundwater quality

International Nuclear Information System (INIS)

Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D.

2002-01-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and δ 15 N and δ 18 O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal

Impacts of swine manure pits on groundwater quality

Energy Technology Data Exchange (ETDEWEB)

Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D

2002-12-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and {delta}{sup 15}N and {delta}{sup 18}O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human

Post-Closure Inspection Report for the Tonopah Test Range, Nevada. For Calendar Year 2015, Revision 0

International Nuclear Information System (INIS)

Matthews, Patrick; Petrello, Jaclyn

2016-01-01

This report provides the results of the annual post-closure inspections conducted at the closed corrective action units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2015 and includes inspection and repair activities completed at the following CAUs; CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved closure reports and subsequent correspondence with the Nevada Division of Environmental Protection. The post-closure inspection plans and subsequent correspondence modifying the requirements for each CAU are included in Appendix B. The inspection checklists are included in Appendix C. Field notes are included in Appendix D. The annual post-closure inspections were conducted on May 12, 2015. Maintenance was required at CAU 453. Cracking along the north trench was repaired. One monument is missing at CAU 424; it will be replaced in 2016. Postings at CAUs 407, 424, 453, and 487 contain contact information for TTR Security. It was noted that protocols may not be in place to ensure that the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) is notified if access is needed at these sites. NNSA/NFO is working with the U.S. Air Force and Sandia to determine whether more appropriate contact information or new protocols are warranted for each CAU. Based on these inspections, there has not been a significant change in vegetation, and vegetation monitoring was not recommended at CAU 400 or CAU 407 in 2015.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada. For Calendar Year 2015, Revision 0

Energy Technology Data Exchange (ETDEWEB)

Matthews, Patrick [Navarro, Las Vegas, NV (United States); Petrello, Jaclyn [Navarro, Las Vegas, NV (United States)

2016-03-01

This report provides the results of the annual post-closure inspections conducted at the closed corrective action units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2015 and includes inspection and repair activities completed at the following CAUs; CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved closure reports and subsequent correspondence with the Nevada Division of Environmental Protection. The post-closure inspection plans and subsequent correspondence modifying the requirements for each CAU are included in Appendix B. The inspection checklists are included in Appendix C. Field notes are included in Appendix D. The annual post-closure inspections were conducted on May 12, 2015. Maintenance was required at CAU 453. Cracking along the north trench was repaired. One monument is missing at CAU 424; it will be replaced in 2016. Postings at CAUs 407, 424, 453, and 487 contain contact information for TTR Security. It was noted that protocols may not be in place to ensure that the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) is notified if access is needed at these sites. NNSA/NFO is working with the U.S. Air Force and Sandia to determine whether more appropriate contact information or new protocols are warranted for each CAU. Based on these inspections, there has not been a significant change in vegetation, and vegetation monitoring was not recommended at CAU 400 or CAU 407 in 2015.

Studies in pitting corrosion on archaeological bronzes. Copper

International Nuclear Information System (INIS)

Bresle, Aa.; Saers, J.; Arrhenius, B.

1983-01-01

Copper has been proposed as a canister material for use in the long-term storage of radioactive waste from nuclear power reactors. The storage period has been set to at least 100 000 years, during which time the copper cylinders must remain intact so that the contained waste has no possibility of leaking out. In this work, the pitting factor in archaelogical copper objects have been determined. The absolute values of the pitting factor obtained are generally very low. In the case of the most thoroughly studied material the pitting factor is only slightly more than three units. Nor does the native copper, with a presumed burial period of about 8000 years, exhibit particularly high values. In summary, it can therefore be concluded that the present study does not provide support for the assumption of extremely high pitting factors in copper-base material that has been buried for periods of several millenia. (G.B.)

Professional Closure Beyond State Authorization

Directory of Open Access Journals (Sweden)

Gitte Sommer Harrits

2014-03-01

Full Text Available For decades, the Weberian approach to the study of professions has been strong, emphasizing state authorization and market monopolies as constituting what is considered a profession. Originally, however, the Weberian conception of closure, or the ways in which a profession is constituted and made separate, was broader. This article suggests a revision of the closure concept, integrating insights from Pierre Bourdieu, and conceptualizing professional closure as the intersection of social, symbolic and legal closure. Based on this revision, this article demonstrates how to apply such a concept in empirical studies. This is done by exploring social, symbolic and legal closure across sixteen professional degree programs. The analyses show a tendency for some overlap between different forms of closure, with a somewhat divergent pattern for legal closure. Results support the argument that we need to study these processes as an intersection of different sources of closure, including capital, lifestyles and discourse

Assessing Health Outcomes After Environmental Exposures Associated With Open Pit Burning in Deployed US Service Members.

Science.gov (United States)

Rohrbeck, Patricia; Hu, Zheng; Mallon, Col Timothy M

2016-08-01

This study assessed the long-term health impact of environmental exposures associated with open pit burning in deployed US service members. Two hundred individuals deployed to Balad, Iraq, and Bagram, Afghanistan, with known exposure to open pits, were matched to 200 non-deployed service members. Both cohorts were observed for adverse health outcomes after returning from deployment. Slight increased risks were observed for respiratory diseases in the Bagram cohort (adj RR: 1.259), and for cardiovascular disease in the Balad cohort (adj RR: 1.072), but the findings were not significant. The combined deployed cohort showed lower risks for adverse health outcomes, suggesting a healthy deployer effect. In conclusion, this study did not find significantly increased risks for selected health outcomes after burn pit exposure during deployment among two deployed cohorts compared with a non-deployed cohort.

Creating Nanoscale Pits on Solid Surfaces in Aqueous Environment with Scanning Tunnelling Microscopy

DEFF Research Database (Denmark)

Chi, Qijin; Zhang, Jingdong; Friis, Esben P.

2000-01-01

of the pits can be controlled well in aqueous environments, and the operations are simple. Parameters affecting the pit formation and size have been systematically characterized to show that pit formation is dominated by bias voltage. A mechanism is proposed based on local surface reconstruction induced...

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2012

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2013-01-28

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2012 and includes inspection and repair activities completed at the following CAUs: · CAU 400: Bomblet Pit and Five Points Landfill (TTR) · CAU 407: Roller Coaster RadSafe Area (TTR) · CAU 424: Area 3 Landfill Complexes (TTR) · CAU 453: Area 9 UXO Landfill (TTR) · CAU 487: Thunderwell Site (TTR)

Closure certification report: TA-35 TSL-125 surface impoundment

International Nuclear Information System (INIS)

1991-01-01

This closure report documents closure activities for the TA-35 TSL-125 surface impoundment and associated structures at Los Alamos National Laboratory (the Laboratory). Prior to formal approval of the closure plan, the decision was made to proceed with closure activities to prevent any further releases from the site following informal discussions with New Mexico Environment Department (NMED) personnel. The closure plan is a revision of the previously submitted draft dated July 1988. Clean closure of the TSL-125 site was accomplished through: Removal and proper disposal of all wastes contained within the surface impoundment system; Decontamination and/or removal and proper disposal of the surface impoundment, its associated structures, and contaminated soil underlying the impoundment area; Sampling and analysis of soil to determine the presence and concentrations of any hazardous constituents remaining in the soil at the TSL-125 site; and Demonstration through a risk assessment that any constituents remaining in the soil at the TSL-125 site pose no threat to human health and the environment. All remaining soil concentrations of hazardous constituents were below health-based action levels. Analytical results indicated that benzidine, n-nitrosodimethylamine, and n-nitrosodi-n-propylamine were not detected at or above their limits of quantitation and beryllium was not present at or above its laboratory detection limit. However, the limits of quantitation and detection for these constituents were greater than their calculated health-based action levels. To demonstrate that these constituents were not present, historical data was researched and it was determined that the constituents were not utilized at the Building 125 site. 4 refs., 8 figs., 1 tab

Cormorant predation on PIT-tagged lake fish

DEFF Research Database (Denmark)

Skov, Christian; Jepsen, Niels; Baktoft, Henrik

2014-01-01

The present study use data from recovered PIT (Passive Integrated Transponder) tags to explore species-and size-specific annual predation rates by cormorants on three common lacustrine fishes (size range 120-367 mm) in a European lake; roach (Rutilus rutilus), common bream (Abramis brama) and perch...... (Perca fluviatilis). In addition, we quantify the level of age/size truncation that cormorant predation could introduce in a population of perch, an important fish for recreational angling as well as for trophic interactions and ecosystem function in European lakes. Based on three years of PIT tagging...... of fish in Lake Viborg and subsequent recoveries of PIT tags from nearby cormorant roosting and breeding sites, we show that cormorants are major predators of roach, bream and perch within the size groups we investigated and for all species larger individuals had higher predation rates. Perch appear...

Stochastic modeling of pitting corrosion in underground pipelines using Markov chains

Energy Technology Data Exchange (ETDEWEB)

Velazquez, J.C.; Caleyo, F.; Hallen, J.M.; Araujo, J.E. [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE); Valor, A. [Universidad de La Habana, La Habana (Cuba)

2009-07-01

A non-homogenous, linear growth (pure birth) Markov process, with discrete states in continuous time, has been used to model external pitting corrosion in underground pipelines. The transition probability function for the pit depth is obtained from the analytical solution of the forward Kolmogorov equations for this process. The parameters of the transition probability function between depth states can be identified from the observed time evolution of the mean of the pit depth distribution. Monte Carlo simulations were used to predict the time evolution of the mean value of the pit depth distribution in soils with different physicochemical characteristics. The simulated distributions have been used to create an empirical Markov-chain-based stochastic model for predicting the evolution of pitting corrosion from the observed properties of the soil in contact with the pipeline. Real- life case studies, involving simulated and measured pit depth distributions are presented to illustrate the application of the proposed Markov chains model. (author)

Ecological geology environmental assessment of open-pit mines

International Nuclear Information System (INIS)

Dong Shuangfa; Jiang Xue

2010-01-01

In this paper, there is a detail description of ecological geology environmental assessment of open-pit mines, including method, process and results. We took ecological geology environmental assessment work on the base of the results of some open-pit mines such as extremely low content magnetite in Hebei Province, inducted and summarized the ecological geology environment quality. The results are reasonable. It provides basic data for the second mines programming in Hebei Province. (authors)

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

Science.gov (United States)

Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

2003-01-01

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

Probabilistic models for steel corrosion loss and pitting of marine infrastructure

International Nuclear Information System (INIS)

Melchers, R.E.; Jeffrey, R.J.

2008-01-01

With the increasing emphasis on attempting to retain in service ageing infrastructure models for the description and prediction of corrosion losses and for maximum pit depth are of increasing interest. In most cases assessment and prediction will be done in a probabilistic risk assessment framework and this then requires probabilistic corrosion models. Recently, novel models for corrosion loss and maximum pit depth under marine immersion conditions have been developed. The models show that both corrosion loss and pit depth progress in a non-linear fashion with increased exposure time and do so in a non-monotonic manner as a result of the controlling corrosion process changing from oxidation to being influenced by bacterial action. For engineers the importance of this lies in the fact that conventional 'corrosion rates' have no validity, particularly for the long-term corrosion effects as relevant to deteriorated infrastructure. The models are consistent with corrosion science principles as well as current understanding of the considerable influence of bacterial processes on corrosion loss and pitting. The considerable practical implications of this are described

Congenital upper lip pit: A rare case report

Directory of Open Access Journals (Sweden)

Leena James

2015-01-01

Full Text Available One of the rarest developmental malformations of the lip is congenital lip pits. They are usually seen as bilateral depressions in the vermilion zone of the lip and occur on the paramedian portion of the vermilion border of the lip. They are extremely rare in the upper lip. Lip pits are due to the failure of complete union of embryonic lateral sulci of the lip/notching of lip at an early stage of development with fixation of tissues of the base of the notch. Lip pits have also been associated with a variety of other congenital disorders and other malformations. The clinical and pathologic picture and the therapeutic aspects of this condition are discussed in this paper.

Revisit to Grad's Closure and Development of Physically Motivated Closure for Phenomenological High-Order Moment Model

International Nuclear Information System (INIS)

Myong, R. S.; Nagdewe, S. P.

2011-01-01

The Grad's closure for the high-order moment equation is revisited and, by extending his theory, a physically motivated closure is developed for the one-dimensional velocity shear gas flow. The closure is based on the physical argument of the relative importance of various terms appearing in the moment equation. Also, the closure is derived such that the resulting theory may be inclusive of the well established linear theory (Navier-Stokes-Fourier) as limiting case near local thermal equilibrium.

Pitting growth modelling in buried oil and gas pipelines using statistical techniques

International Nuclear Information System (INIS)

Velazquez, J. C.; Caleyo, F.; Valorm, A.; Hallen, J. M.

2011-01-01

New deterministic and stochastic predictive models are proposed for external pitting corrosion in underground pipelines. The deterministic model takes into consideration the local chemical and physical properties of the soil as well as the pipeline coating to predict the time dependence of pitting depth and rate in a range of soils. This model, based on results from a field study, was used to conduct Monte Carlo simulations that established the probability distribution of pitting depth and growth rate in the studied soils and their evolution over the life of the pipeline. In the last stage of the study, an empirical Markov chain-based stochastic model was developed for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. (Author) 18 refs.

Bilateral optic disc pit with maculopathy in a patient with cleft lip and cleft palate

Directory of Open Access Journals (Sweden)

Anisha Seth

2015-01-01

Full Text Available Optic disc pit (ODP is small, gray-white, oval depression found at the optic nerve head. It is a congenital defect that occurs due to imperfect closure of superior edge of the embryonic fissure. Cleft lip and palate are also congenital midline abnormalities occurring due to defect in the fusion of frontonasal prominence, maxillary prominence and mandibular prominence. There is only one case report describing the occurrence of ODP in a young patient with cleft lip and palate who also had basal encephalocele. We describe a 52-year-old patient with congenital cleft lip and palate with bilateral ODP with maculopathy but without any other midline abnormality.

Acute limb ischemia caused by incorrect deployment of a clip-based arterial closure device

Directory of Open Access Journals (Sweden)

Łukasz Dzieciuchowicz

2016-04-01

Full Text Available Failure of a vascular closure device most commonly results in a hemorrhage or pseudoaneurysm formation. In this paper a rare case of severe acute limb ischemia following incorrect deployment of a clip-based closure device (Starclose SE, Abbott Vascular in a 31-year-old woman is presented. Symptoms of acute limb ischemia occurred at the start of the ambulation, 6 h after completion of the procedure. Because of the severity of ischemia the patient was treated surgically, and limb perfusion was successfully restored. An attempt of closure of an inadvertently punctured narrow superficial femoral artery was identified as the cause of this complication.

The kinetics of pitting corrosion of carbon steel

International Nuclear Information System (INIS)

Marsh, G.P.; Taylor, K.J.; Sooi, Z.

1988-02-01

The development of an improved statistical method for analysing pit growth data to take account of the difference in area of laboratory specimens and full sized high level nuclear waste containers is described. Statistical analysis of data from pit growth experiments with large area (460 cm 2 ) plates of BS 4360 steel have indicated that the depth distributions correlate most closely with a limited distribution function. This correlation implies that previous statistical analyses to estimate the maximum pit depths in full size containers, which were made using unlimited distribution functions, will be pessimistic. An evaluation of the maximum feasible pitting period based on estimating the period during which the oxygen diffusion flux is sufficient to stabilise a passive film on carbon steel containers has indicated that this is of the order of 125 years rather than the full 1000 year container life. The estimate is sensitive to the value of the leakage current assumed to flow through the passive film, and therefore work is planned to measure this accurately in relevant granitic environments. (author)

Parturition pit: the bony imprint of vaginal birth

International Nuclear Information System (INIS)

McArthur, Tatum A.; Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J.; Larrison, Matthew C.

2016-01-01

To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. (orig.)

Efficient algorithms and implementations of entropy-based moment closures for rarefied gases

International Nuclear Information System (INIS)

Schaerer, Roman Pascal; Bansal, Pratyuksh; Torrilhon, Manuel

2017-01-01

We present efficient algorithms and implementations of the 35-moment system equipped with the maximum-entropy closure in the context of rarefied gases. While closures based on the principle of entropy maximization have been shown to yield very promising results for moderately rarefied gas flows, the computational cost of these closures is in general much higher than for closure theories with explicit closed-form expressions of the closing fluxes, such as Grad's classical closure. Following a similar approach as Garrett et al. (2015) , we investigate efficient implementations of the computationally expensive numerical quadrature method used for the moment evaluations of the maximum-entropy distribution by exploiting its inherent fine-grained parallelism with the parallelism offered by multi-core processors and graphics cards. We show that using a single graphics card as an accelerator allows speed-ups of two orders of magnitude when compared to a serial CPU implementation. To accelerate the time-to-solution for steady-state problems, we propose a new semi-implicit time discretization scheme. The resulting nonlinear system of equations is solved with a Newton type method in the Lagrange multipliers of the dual optimization problem in order to reduce the computational cost. Additionally, fully explicit time-stepping schemes of first and second order accuracy are presented. We investigate the accuracy and efficiency of the numerical schemes for several numerical test cases, including a steady-state shock-structure problem.

Efficient algorithms and implementations of entropy-based moment closures for rarefied gases

Science.gov (United States)

Schaerer, Roman Pascal; Bansal, Pratyuksh; Torrilhon, Manuel

2017-07-01

We present efficient algorithms and implementations of the 35-moment system equipped with the maximum-entropy closure in the context of rarefied gases. While closures based on the principle of entropy maximization have been shown to yield very promising results for moderately rarefied gas flows, the computational cost of these closures is in general much higher than for closure theories with explicit closed-form expressions of the closing fluxes, such as Grad's classical closure. Following a similar approach as Garrett et al. (2015) [13], we investigate efficient implementations of the computationally expensive numerical quadrature method used for the moment evaluations of the maximum-entropy distribution by exploiting its inherent fine-grained parallelism with the parallelism offered by multi-core processors and graphics cards. We show that using a single graphics card as an accelerator allows speed-ups of two orders of magnitude when compared to a serial CPU implementation. To accelerate the time-to-solution for steady-state problems, we propose a new semi-implicit time discretization scheme. The resulting nonlinear system of equations is solved with a Newton type method in the Lagrange multipliers of the dual optimization problem in order to reduce the computational cost. Additionally, fully explicit time-stepping schemes of first and second order accuracy are presented. We investigate the accuracy and efficiency of the numerical schemes for several numerical test cases, including a steady-state shock-structure problem.

Efficient algorithms and implementations of entropy-based moment closures for rarefied gases

Energy Technology Data Exchange (ETDEWEB)

Schaerer, Roman Pascal, E-mail: schaerer@mathcces.rwth-aachen.de; Bansal, Pratyuksh; Torrilhon, Manuel

2017-07-01

We present efficient algorithms and implementations of the 35-moment system equipped with the maximum-entropy closure in the context of rarefied gases. While closures based on the principle of entropy maximization have been shown to yield very promising results for moderately rarefied gas flows, the computational cost of these closures is in general much higher than for closure theories with explicit closed-form expressions of the closing fluxes, such as Grad's classical closure. Following a similar approach as Garrett et al. (2015) , we investigate efficient implementations of the computationally expensive numerical quadrature method used for the moment evaluations of the maximum-entropy distribution by exploiting its inherent fine-grained parallelism with the parallelism offered by multi-core processors and graphics cards. We show that using a single graphics card as an accelerator allows speed-ups of two orders of magnitude when compared to a serial CPU implementation. To accelerate the time-to-solution for steady-state problems, we propose a new semi-implicit time discretization scheme. The resulting nonlinear system of equations is solved with a Newton type method in the Lagrange multipliers of the dual optimization problem in order to reduce the computational cost. Additionally, fully explicit time-stepping schemes of first and second order accuracy are presented. We investigate the accuracy and efficiency of the numerical schemes for several numerical test cases, including a steady-state shock-structure problem.

Numerical Investigation on Stress Concentration of Tension Steel Bars with One or Two Corrosion Pits

Directory of Open Access Journals (Sweden)

Jian Hou

2015-01-01

Full Text Available Pitting corrosion has been observed in steel bars of existing reinforced concrete (RC structures in different erosion environments and has been identified as a potential origin for fatigue crack nucleation. In the present study, under uniaxial tension loading, stress distribution in the steel bars with one or two semiellipsoidal corrosion pits has systematically been investigated by conducting a series of three-dimensional semiellipsoidal pitted models. Based on the finite element analyses, it is shown that stress concentration factor (SCF increases linearly with increasing pit aspect ratio (a/b and increases nonlinearly with increasing pit relative depth (a/R for single corrosion pit problem. For double corrosion pits problem, the SCF decreases nonlinearly with increasing angle of two transverse pits (θ. The interaction of two longitudinal pits can be ignored in the calculation of SCF even if the distance of two pits (d is very small.

Machine Learning-based discovery of closures for reduced models of dynamical systems

Science.gov (United States)

Pan, Shaowu; Duraisamy, Karthik

2017-11-01

Despite the successful application of machine learning (ML) in fields such as image processing and speech recognition, only a few attempts has been made toward employing ML to represent the dynamics of complex physical systems. Previous attempts mostly focus on parameter calibration or data-driven augmentation of existing models. In this work we present a ML framework to discover closure terms in reduced models of dynamical systems and provide insights into potential problems associated with data-driven modeling. Based on exact closure models for linear system, we propose a general linear closure framework from viewpoint of optimization. The framework is based on trapezoidal approximation of convolution term. Hyperparameters that need to be determined include temporal length of memory effect, number of sampling points, and dimensions of hidden states. To circumvent the explicit specification of memory effect, a general framework inspired from neural networks is also proposed. We conduct both a priori and posteriori evaluations of the resulting model on a number of non-linear dynamical systems. This work was supported in part by AFOSR under the project ``LES Modeling of Non-local effects using Statistical Coarse-graining'' with Dr. Jean-Luc Cambier as the technical monitor.

Influence of Pitting Corrosion on Fatigue and Corrosion Fatigue of Ship and Offshore Structures, Part II: Load - Pit - Crack Interaction

Directory of Open Access Journals (Sweden)

Jakubowski Marek

2015-09-01

Full Text Available In the paper has been discussed influence of stresses on general corrosion rate and corrosion pit nucleation rate and growth , whose presence has been questioned by some authors but accepted by most of them. Influence of roughness of pit walls on fatigue life of a plate suffering pit corrosion and presence of the so called „ non-damaging” pits which never lead to initiation of fatigue crack, has been presented. Possibility of prediction of pit-to-crack transition moment by two different ways, i.e. considering a pit a stress concentrator or an equivalent crack, has been analyzed. Also, influence of statistical distribution of depth of corrosion pits as well as anticorrosion protection on fatigue and corrosion fatigue has been described.

Therapy of spinal wound infections using vacuum-assisted wound closure: risk factors leading to resistance to treatment.

Science.gov (United States)

Ploumis, Avraam; Mehbod, Amir A; Dressel, Thomas D; Dykes, Daryll C; Transfeldt, Ensor E; Lonstein, John E

2008-07-01

This study retrospectively reviewed spine surgical procedures complicated by wound infection and managed by a protocol including the use of vacuum-assisted wound closure (VAC). To define factors influencing the number of debridements needed before the final wound closure by applying VAC for patients with postoperative spinal wound infections. VAC has been suggested as a safe and probably effective method for the treatment of spinal wound infections. The risk factors for infection resistance and need for debridement revisions after VAC placement are unknown. Seventy-three consecutive patients with 79 wound infections after undergoing spine surgery were studied (6 of them had recurrence of infection). All patients were taken to the operating room for irrigation and debridement under general anesthesia followed by placement of the VAC with subsequent delayed closure of the wound. Linear regression and t test were used to identify if the following variables were risk factors for the resistance of infection to VAC treatment: timing of clinical appearance of infection, depth of infection (deep or superficial), presence of instrumentation, positive culture for methicillin-resistant Staphylococcus aureus (MRSA) or more than 1 microorganism, age of the patient, and presence of other comorbidities. There were 34 males and 39 females with an average age of 58.4 years (21 to 82). Once the VAC was initiated, there was an average of 1.4 procedures until and including closure of the wound. The wound was closed an average of 7 days (range 5 to 14) after the placement of the initial VAC on the wound. The average follow-up was 14 months (range 12 to 28). All of the patients but 2 achieved a clean, closed wound without removal of instrumentation at a minimum follow-up of 1 year. Sixty patients had implants (instrumentation or allograft) within the site of wound infection. Thirteen patients had a decompression with exposed dura. Sixty-four infections (81%) presented with a draining

RCRA land unit closures at the Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Welch, S.H.; Kelly, B.A.; Delozier, M.F.P.; Manrod, W.E.

1987-01-01

Eight land-based hazardous waste management units at the Y-12 Plant are being closed under an integrated multi-year program. Closure plans for the units have been submitted and are in various stages of revision and regulatory review. These units will be closed by various combinations of methods, including liquid removal and treatment, sludge stabilization, contaminated sludge and/or soil removal, and capping. The closure of these sites will be funded by a new Department of Energy budget category, the Environmental Restoration Budget Category (ERBC), which is intended to provide greater flexibility in the response to closure and remedial activities. A major project, Closure and Post-Closure Activities (CAPCA), has been identified for ERBC funding to close and remediate the land units in accordance with RCRA requirements. Establishing the scope of this program has required the development of a detailed set of assumptions and a confirmation program for each assumption. Other significant activities in the CAPCA program include the development of risk assessments and the preparation of an integrated schedule

pitting corrosion susceptibility pitting corrosion susceptibility of aisi

African Journals Online (AJOL)

eobe

2DEPARTMENT OF MECHANICAL ENGINEERING, UNIVERSITY OF BENIN, BENIN- CITY, EDO STATE, NIGERIA. E-mail addresses: ... fluids and aggressive chemicals. Pitting corrosion ... the kitchen, food manufacturing and dispensing and.

PFO closuRE and CryptogenIc StrokE (PRECISE) registry

DEFF Research Database (Denmark)

Wöhrle, Jochen; Bertrand, Bernard; Søndergaard, Lars

2012-01-01

The Premere™ PFO closure device has a special design for closure of patent foramen ovale (PFO) including a flexible distance and angulation between the right and left disc providing minimal septal distortion. The primary objective of the study was to determine the degree of risk for stroke or tra...... or transient ischemic attack (TIA) in patients after Premere™ PFO closure device implantation....

Predicting Financial Distress and Closure in Rural Hospitals.

Science.gov (United States)

Holmes, George M; Kaufman, Brystana G; Pink, George H

2017-06-01

Annual rates of rural hospital closure have been increasing since 2010, and hospitals that close have poor financial performance relative to those that remain open. This study develops and validates a latent index of financial distress to forecast the probability of financial distress and closure within 2 years for rural hospitals. Hospital and community characteristics are used to predict the risk of financial distress 2 years in the future. Financial and community data were drawn for 2,466 rural hospitals from 2000 through 2013. We tested and validated a model predicting a latent index of financial distress (FDI), measured by unprofitability, equity decline, insolvency, and closure. Using the predicted FDI score, hospitals are assigned to high, medium-high, medium-low, and low risk of financial distress for use by practitioners. The FDI forecasts 8.01% of rural hospitals to be at high risk of financial distress in 2015, 16.3% as mid-high, 46.8% as mid-low, and 28.9% as low risk. The rate of closure for hospitals in the high-risk category is 4 times the rate in the mid-high category and 28 times that in the mid-low category. The ability of the FDI to discriminate hospitals experiencing financial distress is supported by a c-statistic of .74 in a validation sample. This methodology offers improved specificity and predictive power relative to existing measures of financial distress applied to rural hospitals. This risk assessment tool may inform programs at the federal, state, and local levels that provide funding or support to rural hospitals. © 2016 National Rural Health Association.

Mycotoxin occurrence on baled and pit silages collected in Co. Meath

Directory of Open Access Journals (Sweden)

McElhinney C.

2015-12-01

Full Text Available Recent studies of baled silages produced in Ireland have identified considerable filamentous fungal contamination. Many of these fungi are toxigenic, capable of producing secondary metabolites, namely mycotoxins. Mycotoxins are potentially detrimental to livestock health and some can pose a risk to consumers of animal products. Baled (n=20 and pit (n=18 silages from a sample of farms (n=38 in Co. Meath were examined to assess the occurrence of mycotoxins and ascertain whether sampling position within the pit silos (feed face vs. 3 m behind the feed face has an effect on mycotoxin content or other chemical compositional variables. Of the 20 mycotoxins assayed, baled silages contained [mean of positive values (no. of values in mean] mycotoxin concentrations (μg/kg dry matter of beauvericin 36 (2, enniatin (enn. A 9.3 (3, enn. A1 54 (8, enn. B 351 (9, enn. B1 136 (10, mycophenolic acid (MPA 11,157 (8 and roquefortine C (Roq. C 1037 (8 and pit silages contained beauvericin 25 (2 enn. A1 18 (2, enn. B 194 (9, enn. B1 57 (3, MPA 287 (6, Roq. C 3649 (6 and zearalenone 76 (1. There was no difference (P>0.05 observed in the mycotoxin concentrations between baled and pit silages, and 11 of the 20 mycotoxins assayed were below the limits of detection. The position of sampling had no effect on the mycotoxin concentration detected in pit silages. It is concluded that mycotoxin concentrations detected in these pit and baled silages in Co. Meath did not exceed EU regulation or guidance limits, and that similar chemical composition and mycotoxin concentration values occurred at the pit silage feed face and 3 m behind this feed face.

Impact of Different Standard Type A7A Drum Closure-Ring Practices on Gasket Contraction and Bolt Closure Distance– 15621

Energy Technology Data Exchange (ETDEWEB)

Ketusky, Edward [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Blanton, Paul [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bobbitt, John H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-03-11

The Department of Energy, the Savannah River National Laboratory, several manufacturers of specification drums, and the United States Department of Transportation (DOT) are collaborating in the development of a guidance document for DOE contractors and vendors who wish to qualify containers to DOT 7A Type A requirements. Currently, the effort is focused on DOT 7A Type A 208-liter (55-gallons) drums with a standard 12-gauge bolted closure ring. The U.S. requirements, contained in Title 49, Part 178.350 “Specification 7A; general packaging, Type A specifies a competent authority review of the packaging is not required for the transport of (Class 7) radioactive material containing less than Type A quantities of radioactive material. For Type AF drums, a 4 ft. regulatory free drop must be performed, such that the drum “suffers maximum damage.” Although the actual orientation is not defined by the specification, recent studies suggest that maximum damage would result from a shallow angle top impact, where kinetic energy is transferred to the lid, ultimately causing heavy damage to the lid, or even worse, causing the lid to come off. Since each vendor develops closure recommendations/procedures for the drums they manufacture, key parameters applied to drums during closing vary based on vendor. As part of the initial phase of the collaboration, the impact of the closure variants on the ability of the drum to suffer maximum damage is investigated. Specifically, closure testing is performed varying: 1) the amount of torque applied to the closure ring bolt; and, 2) stress relief protocol, including: a) weight of hammer; and, b) orientation that the hammer hits the closure ring. After closure, the amount of drum lid gasket contraction and the distance that the closure bolt moves through the closure ring is measured.

Natural radioactivity in lignite samples from open pit mines “Kolubara”, Serbia – risk assessment

International Nuclear Information System (INIS)

Đurašević, M.; Kandić, A.; Stefanović, P.; Vukanac, I.; Šešlak, B.; Milošević, Z.; Marković, T.

2014-01-01

Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and 40 K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines “Kolubara” and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation. - Highlights: • Activity concentrations of natural radionuclides in coal samples were determined. • Effect on population health due to the activity of these radionuclides was estimated. • All samples were collected at different locations of the open pit mines “Kolubara”. • All measured and calculated values were below the recommended limits. • There is no enhanced radiation hazard for population nearby open pit mines

Association of iris crypts with acute primary angle closure.

Science.gov (United States)

Koh, Victor; Chua, Jacqueline; Shi, Yuan; Thakku, Sri Gowtham; Lee, Ryan; Nongpiur, Monisha E; Baskaran, Mani; Kumar, Rajesh S; Perera, Shamira; Aung, Tin; Cheng, Ching-Yu

2017-10-01

To determine the relationship between iris surface features and acute primary angle closure (APAC) in eyes with angle closure. Case-control study involving Asian patients diagnosed with previous APAC, primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) at an eye centre in Singapore between August 2012 and January 2015. Participants underwent ophthalmic examination and digital slit-lamp iris photography. Iris surface features were graded based on crypts, furrows and colour. Fellow eyes of APAC were compared with PACS and PAC/PACG eyes with regard to their iris surface features. Occurrence of APAC. A total of 309 patients (71 APAC, 139 PACS, 47 PAC and 52 PACG) were included (mean age: 67.7±7.2 years and 36.6% male). Compared with PACS, higher crypt grade was significantly associated with lower odds of APAC (OR=0.58 for one grade higher in crypt grade; p=0.027, adjusted for age, gender, ethnicity and pupil diameter). The results remained similar when compared with PAC/PACG group (OR=0.58 for one grade higher in crypt grade; p=0.043). We did not observe any significant associations between iris furrows or colour with presence of APAC. Our study comprising Asian eyes with angle closure suggests that the presence of a higher crypt grading may be protective for APAC. As such, assessing iris surface architecture for crypts could be a new measure for risk stratification of developing APAC in eyes with angle closure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Transcatheter Closure of Patent Foramen Ovale: Devices and Technique.

Science.gov (United States)

Price, Matthew J

2017-10-01

Transcatheter closure of a patent foramen ovale (PFO) reduces the risk of recurrent cryptogenic stroke compared with medical therapy. PFO closure is a prophylactic procedure, and will not provide the patient with symptomatic improvement, except in cases of hypoxemia due to right-to-left shunt or possibly migraine headaches. Therefore, appropriate patient selection is critical, and procedural safety is paramount. Herein, we review key characteristics of the devices currently available for transcatheter PFO closure within the United States, and highlight key technical aspects of the PFO closure procedure that will maximize procedural success. Copyright © 2017 Elsevier Inc. All rights reserved.

Oxygen pitting failure of a bagasse boiler tube

CSIR Research Space (South Africa)

Heyes, AM

2001-04-01

Full Text Available Examination of a failed roof tube from a bagasse boiler showed transverse through-cracks and extensive pitting. The pitting was typically oxygen induced pitting and numerous fatigue cracks had started within these pits. It is highly probable...

Accountability Quality Shuffler Measurements on Pits

International Nuclear Information System (INIS)

Rinard, P.M.

2000-01-01

Pits have generally been treated as accountable units that are intact if merely present and they are excluded from the more demanding nondestructive assay requirements. As pits begin to flow into disposition streams, there may be more incentive to measure the masses of their fissile components for accountability purposes. This Department of Energy Office of Safeguards and Security (OSS) Lifecycle Project has explored some ways in which such measurements may be done successfully. The active neutron instrument called a shuffler has been used to measure a variety of actual pits, and a calculational technique has been developed to accurately predict such count rates. Passive multiplicity counting has previously been applied to pits for determining their plutonium contents. This combination of measurement and calculational techniques provide powerful and accurate tools for determining the fissile contents of pits with the quality needed for accountability purposes

3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

Directory of Open Access Journals (Sweden)

Ik-Seon Hong

2015-06-01

Full Text Available When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

Science.gov (United States)

Hong, Ik-Seon; Yi, Yu; Yu, Jaehyung; Haruyama, Junichi

2015-06-01

When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP) competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

Corrosion pit depth extreme value prediction from limited inspection data

International Nuclear Information System (INIS)

Najjar, D.; Bigerelle, M.; Iost, A.; Bourdeau, L.; Guillou, D.

2004-01-01

Passive alloys like stainless steels are prone to localized corrosion in chlorides containing environments. The greater the depth of the localized corrosion phenomenon, the more dramatic the related damage that can lead to a structure weakening by fast perforation. In practical situations, because measurements are time consuming and expensive, the challenge is usually to predict the maximum pit depth that could be found in a large scale installation from the processing of a limited inspection data. As far as the parent distribution of pit depths is assumed to be of exponential type, the most successful method was found in the application of the statistical extreme-value analysis developed by Gumbel. This study aims to present a new and alternative methodology to the Gumbel approach with a view towards accurately estimating the maximum pit depth observed on a ferritic stainless steel AISI 409 subjected to an accelerated corrosion test (ECC1) used in automotive industry. This methodology consists in characterising and modelling both the morphology of pits and the statistical distribution of their depths from a limited inspection dataset. The heart of the data processing is based on the combination of two recent statistical methods that avoid making any choice about the type of the theoretical underlying parent distribution of pit depths: the Generalized Lambda Distribution (GLD) is used to model the distribution of pit depths and the Bootstrap technique to determine a confidence interval on the maximum pit depth. (authors)

A method for opening a mine field which is adjacent to a pit

Energy Technology Data Exchange (ETDEWEB)

Onishchenko, V.I.; Grebenyuk, V.K.; Kukharev, V.N.; Martynenko, V.P.; Omelnitskiy, A.G.; Sallin, V.I.; Sidorov, A.S.

1982-01-01

The method for opening a mine field adjacent to a pit includes the construction of the main and auxiliary opening drifts in the pit and the surface complex of the mine through assembling a support with subsequent filling of them by tailings of the covering rock. In order to increase the productive capacity of the mine, to reduce capital expenditures and to increase the safety of underground operations, a base is first formed from the tailing rock along the front of the open mining operations, from the bottom of the pit at the level of the stratum being opened to the surface with simultaneous layer by layer packing of the cited base, after which the opening drifts are built on this base. The mouth of the main opening drifts and the surface complex of the mine are positioned in the region of the pit.

Statistical characterization of pitting corrosion process and life prediction

International Nuclear Information System (INIS)

Sheikh, A.K.; Younas, M.

1995-01-01

In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a structure. Considerable scatter is observed in corrosion processes. The probabilities nature and kinetics of pitting process makes in necessary to use statistical method to forecast the residual life of machine of structures. The focus of this paper is to characterization pitting as a time-dependent random process, and using this characterization the prediction of life to reach a critical level of pitting damage can be made. Using several data sets from literature on pitting corrosion, the extreme value modeling of pitting corrosion process, the evolution of the extreme value distribution in time, and their relationship to the reliability of machines and structure are explained. (author)

Preliminary quantification of a shape model for etch-pits formed during natural weathering of olivine

International Nuclear Information System (INIS)

Nowicki, M. Anna; Velbel, Michael A.

2011-01-01

Many etch-pits on olivine grains occur as a pair of cone-shaped pits sharing a base, which consequently appear as diamond-shaped etch-pits in cross-section. Quantitative image analysis of back-scattered electron images establishes empirical dimensions of olivine etch-pits in naturally weathered samples from Hawaii and North Carolina. Images of naturally etched olivine were acquired from polished thin-sections by scanning electron microscopy. An average cone-radius-to-height ratio (r:h) of 1.78 was determined for diamond-shaped cross-sections of etch-pits occurring in naturally weathered olivine grains, largely consistent with previous qualitative results. Olivine etch-pit shape as represented by r:h varies from slightly more than half the average value to slightly more than twice the average. Etch-pit shape does not appear to vary systematically with etch-pit size.

Study of pitting corrosion in line-pipe steel under the influence of remanent magnetization

Energy Technology Data Exchange (ETDEWEB)

Espina-Hernandez, J H; Caleyo, F; Hallen, J M [Instituto Politecnico Nacional (IPN), Zacatenco (Mexico)

2009-07-01

The influence of remanent magnetization on pitting corrosion in line-pipe steels is studied. Pitting corrosion experiments have been carried out on samples of an API 5L grade 52 steel under a magnetization level of the same order of magnitude of the remanent magnetization in the pipeline wall after in-line inspection based on magnetic flux leakage. The samples were magnetized using rings of the same grade as the investigated steel. Immediately after magnetization, the investigated samples were subjected to pitting by immersing them in a solution containing dissolved Cl{sup -} and SO{sup 2-}{sub 4} and ions. The pitting experiments were conducted during a seven days period. The pit depth distribution and the maximum pit depth in each sample were recorded and used to conduct extreme value analyses of the pitting process in magnetized and non-magnetized control samples. The statistical assessment of the pitting corrosion data collected during this study shows that the magnetic field reduces the average depth of the pit population and also the extreme pit depth values that can be predicted from the maximum values observed in the magnetized samples in comparison with to the non-magnetized control samples. Scanning electron microscopy observations show that the magnetic field alters the pit morphology by increasing the pit mouth opening. (author)

Pitting and stress corrosion cracking of stainless steel

Science.gov (United States)

Saithala, Janardhan R.

An investigation has been performed to determine the pitting resistance of stainless steels and stress corrosion cracking of super duplex stainless steels in water containing chloride ions from 25 - 170°C. The steels studied are 12% Cr, FV520B, FV566, 304L, Uranus65, 2205, Ferallium Alloy 255, and Zeron 100. All these commercial materials used in very significant industrial applications and suffer from pitting and stress corrosion failures. The design of a new experimental setup using an autoclave enabled potentiodynamic polarisation experiments and slow strain rate tests in dilute environments to be conducted at elevated temperatures. The corrosion potentials were controlled using a three electrode cell with computer controlled potentiostat.The experimental programme to determine pitting potentials was designed to simulate the service conditions experienced in most industrial plants and develop mathematical model equations to help a design engineer in material selection decision. Stress corrosion resistance of recently developed Zeron100 was evaluated in dilute environments to propose a mechanism in chloride solutions at high' temperatures useful for the nuclear and power generation industry. Results have shown the significance of the composition of alloying elements across a wide range of stainless steels and its influence on pitting. Nitrogen and molybdenum added to modern duplex stainless steels was found to be unstable at higher temperatures. The fractographic results obtained using the scanning electron microscope (SEM) has given insight in the initiation of pitting in modem duplex and super duplex stainless steels. A mathematical model has been proposed to predict pitting in stainless steels based on the effect of environmental factors (temperature, chloride concentration, and chemical composition). An attempt has been made to identify the mechanism of SCC in Zeron100 super duplex stainless steel.The proposed empirical models have shown good correlation

Design review report: AN valve pit upgrades for Project W-314, tank farm restoration and safe operations

International Nuclear Information System (INIS)

Boes, K.A.

1998-01-01

This Design Review Report (DRR) documents the contractor design verification methodology and records associated with project W-314's AN Valve Pit Upgrades design package. The DRR includes the documented comments and their respective dispositions for this design. Acceptance of the comment dispositions and closure of the review comments is indicated by the signatures of the participating reviewers. Project W-314, Tank Farm Restoration and Safe Operations, is a project within the Tank Waste Remediation System (TWRS) Tank Waste Retrieval Program. This project provides capital upgrades for the existing Hanford tank farms' waste transfer, instrumentation, ventilation, and electrical infrastructure systems. To support established TWRS programmatic objectives, the project is organized into two distinct phases. The initial focus of the project (i.e., Phase 1) is on waste transfer system upgrades needed to support the TWRS Privatization waste feed delivery system. Phase 2 of the project will provide upgrades to support resolution of regulatory compliance issues, improve tank infrastructure reliability, and reduce overall plant operating/maintenance costs. Within Phase 1 of the W-314 project, the waste transfer system upgrades are further broken down into six major packages which align with the project's work breakdown structure. Each of these six sub-elements includes the design, procurement, and construction activities necessary to accomplish the specific tank farm upgrades contained within the package. The first package to be performed is the AN Valve Pit Upgrades package. The scope of the modifications includes new pit cover blocks, valve manifolds, leak detectors, transfer line connections (for future planned transfer lines), and special protective coating for the 241-AN-A and 241-AN-B valve pits

Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

International Nuclear Information System (INIS)

Dwyer, B.P.; Gilbert, J.; Heiser, J.

1999-01-01

In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site

Experimental Stress Analysis at Railway Inspection Pit

Directory of Open Access Journals (Sweden)

Nicuşor Laurentiu Zaharia

2008-10-01

Full Text Available Railway inspection pits are used in railway halls. The purpose of inspection pits is to allow the working under the vehicle. Inspection pits can be found in locomotive depots, factories etc. The new design for a inspection pit in a railway hall involve tests in purpose of homologations the railway infrastructure. Before the homologation committee meeting, tests are made; after the test, a testing report is made which it will be part at homologation documents.

Early Closure of a Temporary Ileostomy in Patients With Rectal Cancer

DEFF Research Database (Denmark)

Danielsen, Anne K; Park, Jennifer; Jansen, Jens E

2017-01-01

OBJECTIVE: The objective was to study morbidity and mortality associated with early closure (8-13 days) of a temporary stoma compared with standard procedure (closure after > 12 weeks) after rectal resection for cancer. BACKGROUND: A temporary ileostomy may reduce the risk of pelvic sepsis after .......0001. CONCLUSIONS: It is safe to close a temporary ileostomy 8 to 13 days after rectal resection and anastomosis for rectal cancer in selected patients without clinical or radiological signs of anastomotic leakage.......OBJECTIVE: The objective was to study morbidity and mortality associated with early closure (8-13 days) of a temporary stoma compared with standard procedure (closure after > 12 weeks) after rectal resection for cancer. BACKGROUND: A temporary ileostomy may reduce the risk of pelvic sepsis after...... creation) of a temporary ileostomy was compared with late closure (>12 weeks) in a multicenter randomized controlled trial, EASY (www.clinicaltrials.gov, NCT01287637) including patients undergoing rectal resection for cancer. Patients with a temporary ileostomy without signs of postoperative complications...

Pits on Ascraeus

Science.gov (United States)

2005-01-01

24 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows collapse pits and troughs on the lower northeast flank of the giant martian volcano, Ascraeus Mons. Layers of volcanic rock are evident in some of the pit and valley walls, and boulders the size of houses and trucks that were liberated from these walls by gravity can be seen on the floors of the depressions. Location near: 13.6oN, 102.6oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

On the detection of corrosion pit interactions using two-dimensional spectral analysis

International Nuclear Information System (INIS)

Jarrah, Adil; Nianga, Jean-Marie; Iost, Alain; Guillemot, Gildas; Najjar, Denis

2010-01-01

A statistical methodology for detecting pits interactions based on a two-dimensional spectral analysis is presented. This method can be used as a tool for the exploratory analysis of spatial point patterns and can be advanced as an alternative of classical methods based on distance. One of the major advantages of the spectral analysis approach over the use of classical methods is its ability to reveal more details about the spatial structure like the scale for which pits corrosion can be considered as independent. Furthermore, directional components of pattern can be investigated. The method is validated in a first time using numerical simulations on random, regular and aggregated structures. The density of pits, used in the numerical simulations, corresponds to that assessed from a corroded aluminium sheet. In a second time, this method is applied to verify the independence of the corrosion pits observed on the aforementioned aluminium sheet before applying the Gumbel theory to determine the maximum pit depth. Indeed, the property of independence is a prerequisite of the Gumbel theory which is one of the most frequently used in the field of safety and reliability.

New Generation Energy Efficient Refractory Application in Soaking Pits of Bhilai Steel Plant, Sail

Science.gov (United States)

Roy, Indranil; Chintaiah, Perumetla; Bhattacharya, Ajoy Kr.; Garai, Swapan Kr.; Ray Choudhury, Pankaj Kr.; Tiwari, Laksman

In Bhilai Steel Plant (BSP), soaking pits are used for heating ingots for successive rolling into blooms. Pits are operated at a temperature of around 1350°C. Mixed gas (Mixture of Blast Furnace gas & Coke Oven gas) of calorific value around 2040 kcal/Nm3 is used as fuel. The walls of soaking pits were lined with traditional 38% Al2O3 firebricks and top 500mm was cast with 70% Al2O3 low cement castable (LCC). This type of lining results in frequent damages due to hitting by ingots while being lifted from pit by overhead cranes thus affecting the availability of pit. Life of pits was 2 to 2.5 years in BSP with 3-4 cold repairs and 3-4 hot repairs. Energy loss through the wall is also quite high in this type of lining. To triumph over the limitations of the conventional lining, a lining design was developed for the walls which consist of special 70% Al2O3 LCC having high hot strength (HMOR) in combination with specially design flexible SS-304 anchors. Ceramic fiber blanket and insulation bricks were provided between castable and the metallic shell of the pit to minimize the heat loss. A heating schedule was developed and introduced based on available infrastructure at BSP for proper curing of modified LCC based lining. After introduction of modified lining, pit no. 14/2 is running for more than 2.5 years without any repair. To capitalize the success, two more pits i.e. 12/1 and 9/2 were converted to modified lining. These pits are also running satisfactorily for more than 1.5 years. The modification has resulted in higher availability with substantial increase in production. Shell temperature of the modified pits reduced to 90° - 140°C from 120° - 200°C of conventional pits. This shows reduction in heat loss through walls, resulting less fuel consumption and energy saving of about 18%.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2007-01-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2006 and includes inspection and repair activities completed at the following nine CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 404: Roller Coaster Lagoons and Trench (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 426: Cactus Spring Waste Trenches (TTR); CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR). Post-closure inspections were conducted on May 9, 2006, May 31, 2006, and November 15, 2006. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2006, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 400, CAU 407, CAU 426, CAU 453, and CAU 487 in 2006. During the May inspection of CAU 400, it was identified that the east and west sections of chickenwire fencing beyond the standard fencing were damaged; they were repaired in June 2006. Also in June 2006, the southeast corner fence post and one warning sign at CAU 407 were reinforced and reattached, the perimeter fencing adjacent to the gate at CAU 426 was tightened, and large animal

Post-Closure Inspection Report for the Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2007-06-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2006 and includes inspection and repair activities completed at the following nine CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 404: Roller Coaster Lagoons and Trench (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 426: Cactus Spring Waste Trenches (TTR); CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR). Post-closure inspections were conducted on May 9, 2006, May 31, 2006, and November 15, 2006. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in June 2006, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 400, CAU 407, CAU 426, CAU 453, and CAU 487 in 2006. During the May inspection of CAU 400, it was identified that the east and west sections of chickenwire fencing beyond the standard fencing were damaged; they were repaired in June 2006. Also in June 2006, the southeast corner fence post and one warning sign at CAU 407 were reinforced and reattached, the perimeter fencing adjacent to the gate at CAU 426 was tightened, and large animal

Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

Energy Technology Data Exchange (ETDEWEB)

Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

2017-04-01

Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

New diagnostic technology and hidden pits and fissures caries

Directory of Open Access Journals (Sweden)

Fabrizio Guerra

2015-10-01

Full Text Available The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany is a novel dental diagnostic tool for quantitative assessment of dental caries with high specificity for carious lesions detection. In the presented cases photographic images, representing the visual diagnostic approach, are applied as integration to VistaCam iX Proof images. A step-by-step sequence of inspection and assessment of operative treatment need is presented in a case of hidden pit and fissure caries on a permanent molar. Based on the reported case, it could be observed that VistaCam iX Proof shows promising results in hidden pits and fissures caries detection and could be considered a non-invasive examination method that facilitate the detection of early lesions and a potential diagnostic aid.

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site, Nevada, Rev. No. 0

International Nuclear Information System (INIS)

Boehlecke, Robert F.

2006-01-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions necessary for the closure of Corrective Action Unit (CAU) 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site (NTS), Nevada. It has been developed in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996) that was agreed to by the State of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense. A SAFER may be performed when the following criteria are met: (1) Conceptual corrective actions are clearly identified (although some degree of investigation may be necessary to select a specific corrective action before completion of the Corrective Action Investigation [CAI]); (2) Uncertainty of the nature, extent, and corrective action must be limited to an acceptable level of risk; (3) The SAFER Plan includes decision points and criteria for making data quality objective (DQO) decisions. The purpose of the investigation will be to document and verify the adequacy of existing information; to affirm the decision for clean closure, closure in place, or no further action; and to provide sufficient data to implement the corrective action. The actual corrective action selected will be based on characterization activities implemented under this SAFER Plan. This SAFER Plan identifies decision points developed in cooperation with the Nevada Department of Environmental Protection (NDEP), where the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) will reach consensus with the NDEP before beginning the next phase of work. Corrective Action Unit 553 is located in Areas 19 and 20 of the NTS, approximately 65 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 553 is comprised of the four Corrective Action Sites (CASs) shown on Figure 1-1 and listed below: 19-99-01, Mud Spill; 19-99-11, Mud Spill; 20-09-09, Mud Spill; and 20-99-03, Mud Spill. There is sufficient information and process

Powder-in-Tube (PIT) Nb3Sn conductors for high-field magnets

NARCIS (Netherlands)

Lindenhovius, J.H.; Hornsveld, E.M.; den Ouden, A.; Wessel, Wilhelm A.J.; ten Kate, Herman H.J.

2000-01-01

New Nb3Sn conductors, based on the powder-in-tube (PIT) process, have been developed for application in accelerator magnets and high-field solenoids. For application in accelerator magnets, SMI has developed a binary 504 filament PIT conductor by optimizing the manufacturing process and adjustment

Detection of Pitting in Gears Using a Deep Sparse Autoencoder

Directory of Open Access Journals (Sweden)

Yongzhi Qu

2017-05-01

Full Text Available In this paper; a new method for gear pitting fault detection is presented. The presented method is developed based on a deep sparse autoencoder. The method integrates dictionary learning in sparse coding into a stacked autoencoder network. Sparse coding with dictionary learning is viewed as an adaptive feature extraction method for machinery fault diagnosis. An autoencoder is an unsupervised machine learning technique. A stacked autoencoder network with multiple hidden layers is considered to be a deep learning network. The presented method uses a stacked autoencoder network to perform the dictionary learning in sparse coding and extract features from raw vibration data automatically. These features are then used to perform gear pitting fault detection. The presented method is validated with vibration data collected from gear tests with pitting faults in a gearbox test rig and compared with an existing deep learning-based approach.

Stochastic modeling of inspection uncertainties and applications to pitting flaws in steam generator tubes

International Nuclear Information System (INIS)

Mao, D.; Yuan, X.-X.; Pandey, M.D.

2009-01-01

Steam generators (SG) are a major pressure retaining component of great safety significance in nuclear power plants. Due to various manufacturing, operation and maintenance activities, as well as material interaction with the surrounding chemical environment, the SG tubes have been subject to a number of degradation modes. Among them, the under-deposit pitting corrosion at outside surfaces of the SG tubes just on top of the tubesheet support plates has had a serious impact on the integrity of the SG tubes. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Bayesian method based on Markov Chain Monte Carlo (MCMC) simulation is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. (author)

Treatability study work plan for in situ vitrification of seepage pit 1 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Spalding, B.P.

1994-07-01

A treatability study is described that encompasses the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage pit 1 by the end of fiscal year 1995. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlapping melt settings that are necessary to achieve fused melt segments; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. The initial step of this treatability study will be to gather the required site characterization data about pit 1 so that the in situ vitrification can be effectively and safely planned. The second phase will be the field ISV operations at pit 1 employing at least two settings to achieve overlapping and fused melts. Such field operations are likely to require 6 to 8 weeks. Following termination of ISV melting operations at pit 1 and demobilization of portable ISV equipment and the off-gas hood, posttest characterization activities will begin

Analysis on the stress corrosion crack inception based on pit shape and size of the FV520B tensile specimen

Science.gov (United States)

Xiang, Longhao; Pan, Juyi; Chen, Songying

2018-06-01

The influence of pit shape and size on local stress concentration in the tensile specimen and the stress corrosion cracks inception was studied by employing the element remove technique. The maximum stress located in the bottom of pit on FV520B tensile specimen. The location of maximum strain was near the mouth of the pit or the shoulder and plastic strain existed in this region. Stress concentration factor and plastic deformation on four different geometrical shape pits of hemisphere, semi-ellipsoid, bullet and butterfly were numerically investigated, respectively. The simulation results showed that butterfly pit got the biggest stress concentration factor. The plastic strain rate during pit growth was in the sensitivity range of stress corrosion cracks inception, indicating that stress corrosion cracks were more likely to nucleate near the pit tip or the shoulder.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2013

Energy Technology Data Exchange (ETDEWEB)

Silvas, A. J.

2014-03-03

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2013 and includes inspection and repair activities completed at the following CAUs: • CAU 400: Bomblet Pit and Five Points Landfill (TTR) • CAU 407: Roller Coaster RadSafe Area (TTR) • CAU 424: Area 3 Landfill Complexes (TTR) • CAU 453: Area 9 UXO Landfill (TTR) • CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports and subsequent correspondence with the Nevada Division of Environmental Protection. The post-closure inspection plans and subsequent correspondence modifying the requirements for each CAU are included in Appendix B. The inspection checklists are included in Appendix C. Field notes are included in Appendix D. Photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted on May 14, 2013. Maintenance was performed at CAU 400, CAU 424, and CAU 453. At CAU 400, animal burrows were backfilled. At CAU 424, erosion repairs were completed at Landfill Cell A3-3, subsidence was repaired at Landfill Cell A3-4, and additional lava rock was placed in high-traffic areas to mark the locations of the surface grade monuments at Landfill Cell A3-3 and Landfill Cell A3-8. At CAU 453, two areas of subsidence were repaired and animal burrows were backfilled. Vegetation monitoring was performed at the CAU 400 Five Points Landfill and CAU 407 in June 2013. The vegetation monitoring report is included in Appendix F.

Computer simulation of pitting potential measurements

International Nuclear Information System (INIS)

Laycock, N.J.; Noh, J.S.; White, S.P.; Krouse, D.P.

2005-01-01

A deterministic model for the growth of single pits in stainless steel has been combined with a purely stochastic model of pit nucleation. Monte-Carlo simulations have been used to compare the predictions of this model with potentiodynamic experimental measurements of the pitting potential. The quantitative agreement between model and experiment is reasonable for both 304 and 316 stainless steel, and the effects of varying surface roughness, solution chloride concentration and potential sweep rate have been considered

Analysis of BY-106 pump pit cover plate

International Nuclear Information System (INIS)

Coverdell, B.L.

1994-01-01

A new cover for the pump pit of Tank 241-BY-106 has been designed to allow the rotary core exhauster to be hooked up without requiring pit entry, riser modification, or equipment removal. The new pit cover is necessary to allow installation of two risers for reducing exposure, contamination, and waste. Computer analysis indicates that the safety margin of the pit cover plate with two risers is adequate. The computer stress model and input files are attached. The pit cover plate is a replacement for an existing plate; therefore seismic and wind loads were considered for the plate only

Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

Science.gov (United States)

Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

2017-02-01

Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Closure Report for Corrective Action Unit 537: Waste Sites, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2007-01-01

Corrective Action Unit (CAU) 537 is identified in the ''Federal Facility Agreement and Consent Order'' (FFACO) of 1996 as Waste Sites. CAU 537 is located in Areas 3 and 19 of the Nevada Test Site, approximately 65 miles northwest of Las Vegas, Nevada, and consists of the following two Corrective Action Sites (CASs): CAS 03-23-06, Bucket; Yellow Tagged Bags; and CAS 19-19-01, Trash Pit. CAU 537 closure activities were conducted in April 2007 according to the FFACO and Revision 3 of the Sectored Clean-up Work Plan for Housekeeping Category Waste Sites (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2003). At CAS 03-23-06, closure activities included removal and disposal of a 15-foot (ft) by 15-ft by 8-ft tall wooden shed containing wood and metal debris and a 5-gallon plastic bucket containing deteriorated plastic bags with yellow radioactive contamination tape. The debris was transported to the Area 9 U10c Landfill for disposal after being screened for radiological contamination according to the ''NV/YMP Radiological Control Manual'' (NNSA/NSO, 2004). At CAS 19-19-01, closure activities included segregation, removal, and disposal of non-friable, non-regulated asbestos-containing material (ACM) and construction debris. The ACM was determined to be non-friable by waste characterization samples collected prior to closure activities. The ACM was removed and double-bagged by licensed, trained asbestos workers and transported to the Area 9 U10c Landfill for disposal. Construction debris was transported in end-dump trucks to the Area 9 U10c Landfill for disposal. Closure activities generated sanitary waste/construction debris and ACM. Waste generated during closure activities was appropriately managed and disposed. Waste characterization sample results are included as Appendix A of this report, and waste disposition documentation is included as Appendix B of this report. Copies of the Sectored Housekeeping Site Closure

Numerical approximation of the Boltzmann equation : moment closure

NARCIS (Netherlands)

Abdel Malik, M.R.A.; Brummelen, van E.H.

2012-01-01

This work applies the moment method onto a generic form of kinetic equations to simplify kinetic models of particle systems. This leads to the moment closure problem which is addressed using entropy-based moment closure techniques utilizing entropy minimization. The resulting moment closure system

Expediting site closures using a risk-based corrective action approach

International Nuclear Information System (INIS)

Sims, J.T.; Douthit, T.

1995-01-01

A new tool, the Risk Analysis Testing Laboratory (RATL), extends the opportunity for collection of high accuracy data on-site during the risk analysis and remediation feasibility stages of subsurface corrective action. The RATL system is driven by onboard data acquisition and processing hardware and software which provides necessary site parameters to determine potential exposure, prioritize sites, and if necessary, design remediation systems on-site in one mobilization. During the removal of underground storage tanks (USTs) at an abandoned service station facility, elevated concentrations of hydrocarbon compounds in the soils surrounding the USTs, as well as a hydrocarbon sheen were identified on the groundwater at the bottom of the UST excavation area. Although 1,000 tons of hydrocarbon-impacted soils had been removed from the UST area, the vertical and lateral extent of subsurface hydrocarbon impact had not been sufficiently delineated. Groundwater sampling was performed with a modified narrow diameter sampling device at 24 locations in a two day period. A total of 32 soil samples were collected in conjunction with groundwater sampling. The soil samples were field screened on-site using a photoionization detector (PID) for volatile organic compounds (VOC) and were classified by the site hydrogeologists. Based on the field screening, selected soil samples were submitted for GC analysis in the RATL

Regulatory issues associated with closure of the Hanford AX Tank Farm ancillary equipment

International Nuclear Information System (INIS)

Becker, D.L.

1998-01-01

Liquid mixed, high-level radioactive waste has been stored in underground single-shell tanks at the US Department of Energy's (DOE's) Hanford Site. After retrieval of the waste from the single-shell tanks, the DOE will proceed with closure of the tank farm. The 241-AX Tank Farm includes four one-million gallon single-shell tanks in addition to sluice lines, transfer lines, ventilation headers, risers, pits, cribs, catch tanks, buildings, well and associated buried piping. This equipment is classified as ancillary equipment. This document addresses the requirements for regulatory close of the ancillary equipment in the Hanford Site 241-AX Tank Farm. The options identified for physical closure of the ancillary equipment include disposal in place, disposal in place after treatment, excavation and disposal on site in an empty single-shell tank, and excavation and disposal outside the AX Tank Farm. The document addresses the background of the Hanford Site and ancillary equipment in the AX Tank Farm, regulations for decontamination and decommissioning of radioactively contaminated equipment, requirements for the cleanup and disposal of radioactive wastes, cleanup and disposal requirements governing hazardous and mixed waste, and regulatory requirements and issues associated with each of the four physical closure options. This investigation was conducted by the Sandia National Laboratories, Albuquerque, New Mexico, during Fiscal Year 1998 for the Hanford Tanks Initiative Project

Pit Viper strikes at the Hanford site. Pit maintenance using robotics at the Hanford Tank Farms

International Nuclear Information System (INIS)

Roeder-Smith, Lynne

2002-01-01

The Pit Viper--a remote operations waste retrieval system--was developed to replace manual operations in the valve pits of waste storage tanks at the Hanford Site. The system consists of a typical industrial backhoe fitted with a robotic manipulator arm and is operated remotely from a control trailer located outside of the tank farm. Cameras mounted to the arm and within the containment tent allow the operator to view the entire pit area and operate the system using a joystick. The arm's gripper can grasp a variety of tools that allow personnel to perform cleaning, debris removal, and concrete repair tasks--a more efficient and less dose-intensive process than the previous 'long-pole' method. The project team overcame a variety of obstacles during development and testing of the Pit Viper system, and deployment occurred in Hanford Tank C-104 in December 2001

Advantages and limitations for users of double pit pour-flush latrines: a qualitative study in rural Bangladesh.

Science.gov (United States)

Hussain, Faruqe; Clasen, Thomas; Akter, Shahinoor; Bawel, Victoria; Luby, Stephen P; Leontsini, Elli; Unicomb, Leanne; Barua, Milan Kanti; Thomas, Brittany; Winch, Peter J

2017-05-25

In rural Bangladesh, India and elsewhere, pour-flush pit latrines are the most common sanitation system. When a single pit latrine becomes full, users must empty it themselves and risk exposure to fresh feces, pay an emptying service to remove pit contents or build a new latrine. Double pit pour-flush latrines may serve as a long-term sanitation option including high water table areas because the pits do not need to be emptied immediately and the excreta decomposes into reusable soil. Double pit pour-flush latrines were implemented in rural Bangladesh for 'hardcore poor' households by a national NGO, BRAC. We conducted interviews, focus groups, and spot checks in two low-income, rural areas of Bangladesh to explore the advantages and limitations of using double pit latrines compared to single pit latrines. The rural households accepted the double pit pour-flush latrine model and considered it feasible to use and maintain. This latrine design increased accessibility of a sanitation facility for these low-income residents and provided privacy, convenience and comfort, compared to open defecation. Although a double pit latrine is more costly and requires more space than a single pit latrine the households perceived this sanitation system to save resources, because households did not need to hire service workers to empty pits or remove decomposed contents themselves. In addition, the excreta decomposition process produced a reusable soil product that some households used in homestead gardening. The durability of the latrine superstructures was a problem, as most of the bamboo-pole superstructure broke after 6-18 months of use. Double pit pour-flush latrines are a long-term improved sanitation option that offers users several important advantages over single pit pour-flush latrines like in rural Bangladesh which can also be used in areas with high water table. Further research can provide an understanding of the comparative health impacts and effectiveness of the model

Advantages and limitations for users of double pit pour-flush latrines: a qualitative study in rural Bangladesh

Directory of Open Access Journals (Sweden)

Faruqe Hussain

2017-05-01

Full Text Available Abstract Background In rural Bangladesh, India and elsewhere, pour-flush pit latrines are the most common sanitation system. When a single pit latrine becomes full, users must empty it themselves and risk exposure to fresh feces, pay an emptying service to remove pit contents or build a new latrine. Double pit pour-flush latrines may serve as a long-term sanitation option including high water table areas because the pits do not need to be emptied immediately and the excreta decomposes into reusable soil. Methods Double pit pour-flush latrines were implemented in rural Bangladesh for ‘hardcore poor’ households by a national NGO, BRAC. We conducted interviews, focus groups, and spot checks in two low-income, rural areas of Bangladesh to explore the advantages and limitations of using double pit latrines compared to single pit latrines. Results The rural households accepted the double pit pour-flush latrine model and considered it feasible to use and maintain. This latrine design increased accessibility of a sanitation facility for these low-income residents and provided privacy, convenience and comfort, compared to open defecation. Although a double pit latrine is more costly and requires more space than a single pit latrine the households perceived this sanitation system to save resources, because households did not need to hire service workers to empty pits or remove decomposed contents themselves. In addition, the excreta decomposition process produced a reusable soil product that some households used in homestead gardening. The durability of the latrine superstructures was a problem, as most of the bamboo-pole superstructure broke after 6–18 months of use. Conclusions Double pit pour-flush latrines are a long-term improved sanitation option that offers users several important advantages over single pit pour-flush latrines like in rural Bangladesh which can also be used in areas with high water table. Further research can provide an

Proposed modifications to the RCRA post-closure permit for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-05-01

This report presents proposed modifications to several conditions of the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit (PCP) for the Bear Creek Hydrogeologic Regime (BCHR). These permit conditions define the requirements for RCRA post-closure corrective action groundwater monitoring at the S-3 Ponds, the Oil Landfarm, and the Bear Creek Burial Grounds (units A, C-West, and Walk-in Pits). Modification of these PCP conditions is requested to: (1) clarify the planned integration of RCRA post-closure corrective action groundwater monitoring with the monitoring program to be established in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Record of Decision (ROD) for the Bear Creek Valley (BCV) Watershed, (2) revise several of the current technical requirements for groundwater monitoring based on implementation of the RCRA post-closure corrective action monitoring program during 1996, and (3) update applicable technical procedures with revised versions recently issued by the Y-12 Plant Groundwater Protection Program (GWPP). With these modifications, the Y-12 Plant will continue to meet the full intent of all regulatory obligations for post-closure care of these facilities. Section 2.0 provides the technical justification for each proposed permit modification. The proposed changes to permit language are provided in Section 3.0 (S-3 Ponds), Section 4.0 (Oil Landfarm), and Section 5.0 (Bear Creek Burial Grounds). Sections 6.0 and 7.0 reference updated and revised procedures for groundwater sampling, and monitoring well plugging and abandonment, respectively. Appendix A includes all proposed revisions to the PCP Attachments

Proposed modifications to the RCRA post-closure permit for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-05-01

This report presents proposed modifications to several conditions of the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit (PCP) for the Bear Creek Hydrogeologic Regime (BCHR). These permit conditions define the requirements for RCRA post-closure corrective action groundwater monitoring at the S-3 Ponds, the Oil Landfarm, and the Bear Creek Burial Grounds (units A, C-West, and Walk-in Pits). Modification of these PCP conditions is requested to: (1) clarify the planned integration of RCRA post-closure corrective action groundwater monitoring with the monitoring program to be established in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Record of Decision (ROD) for the Bear Creek Valley (BCV) Watershed, (2) revise several of the current technical requirements for groundwater monitoring based on implementation of the RCRA post-closure corrective action monitoring program during 1996, and (3) update applicable technical procedures with revised versions recently issued by the Y-12 Plant Groundwater Protection Program (GWPP). With these modifications, the Y-12 Plant will continue to meet the full intent of all regulatory obligations for post-closure care of these facilities. Section 2.0 provides the technical justification for each proposed permit modification. The proposed changes to permit language are provided in Section 3.0 (S-3 Ponds), Section 4.0 (Oil Landfarm), and Section 5.0 (Bear Creek Burial Grounds). Sections 6.0 and 7.0 reference updated and revised procedures for groundwater sampling, and monitoring well plugging and abandonment, respectively. Appendix A includes all proposed revisions to the PCP Attachments.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2007

International Nuclear Information System (INIS)

NSTec Environmental Restoration

2008-01-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2007 and includes inspection and repair activities completed at the following nine CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 404: Roller Coaster Lagoons and Trench (TTR); (3) CAU 407: Roller Coaster RadSafe Area (TTR); (4) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); (5) CAU 424: Area 3 Landfill Complexes (TTR); (6) CAU 426: Cactus Spring Waste Trenches (TTR); (7) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); (8) CAU 453: Area 9 UXO Landfill (TTR); and (9) CAU 487: Thunderwell Site (TTR). In a letter from the Nevada Division of Environmental Protection (NDEP) dated December 5, 2006, NDEP concurred with the request to reduce the frequency of post-closure inspections of CAUs at TTR to an annual frequency. This letter is included in Attachment B. Post-closure inspections were conducted on May 15-16, 2007. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in May 2007, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 453. Animal burrows observed during the annual inspection at CAU 453 were backfilled on August 1, 2007. At this time, the TTR post-closure site inspections should continue as

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2007

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2008-06-01

This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2007 and includes inspection and repair activities completed at the following nine CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 404: Roller Coaster Lagoons and Trench (TTR); (3) CAU 407: Roller Coaster RadSafe Area (TTR); (4) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); (5) CAU 424: Area 3 Landfill Complexes (TTR); (6) CAU 426: Cactus Spring Waste Trenches (TTR); (7) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); (8) CAU 453: Area 9 UXO Landfill (TTR); and (9) CAU 487: Thunderwell Site (TTR). In a letter from the Nevada Division of Environmental Protection (NDEP) dated December 5, 2006, NDEP concurred with the request to reduce the frequency of post-closure inspections of CAUs at TTR to an annual frequency. This letter is included in Attachment B. Post-closure inspections were conducted on May 15-16, 2007. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are included in Attachment D, and the site photographs are included in Attachment E. Vegetation monitoring of CAU 400, CAU 404, CAU 407, and CAU 426 was performed in May 2007, and the vegetation monitoring report is included in Attachment F. Maintenance and/or repairs were performed at CAU 453. Animal burrows observed during the annual inspection at CAU 453 were backfilled on August 1, 2007. At this time, the TTR post-closure site inspections should continue as

Joint Cross-Service Group for Laboratories 1995 Defense Base Realignment and Closure Process

National Research Council Canada - National Science Library

Reed, Donald

1995-01-01

This report is one in a series of reports that discusses the Joint Cross-Service Group implementation of the internal control plan developed by the 1995 Defense Base Closure and Realignment Steering Group (the Steering Group...

Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

Directory of Open Access Journals (Sweden)

A. Valor

2013-01-01

Full Text Available The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure birth Markov process is used to model external pitting corrosion in underground pipelines. A closed-form solution of the system of Kolmogorov's forward equations is used to describe the transition probability function in a discrete pit depth space. The transition probability function is identified by correlating the stochastic pit depth mean with the empirical deterministic mean. In the second model, the distribution of maximum pit depths in a pitting experiment is successfully modeled after the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time is simulated as the realization of a Weibull process. Pit growth is simulated using a nonhomogeneous Markov process. An analytical solution of Kolmogorov's system of equations is also found for the transition probabilities from the first Markov state. Extreme value statistics is employed to find the distribution of maximum pit depths.

Software development for geologic information management system on open-pit production

Energy Technology Data Exchange (ETDEWEB)

Li, K.; Tian, A.; Ren, Z.; Pang, Y. [China University of Mining and Technomogy, Xuzhou (China). College of Mineral and Energy Resources

2001-09-01

A software, including geological data gathering and processing, deposit modelling, reserves calculating and mine map plotting, for geologic information management of open-pit production was developed. Based on the interactive technique, CAD, the object-oriented simulation, and the characteristics of geologic structures, all the geologic information databases and geologic mapping sub-systems have been established for open-pit production, planning and management. 6 refs., 1 fig.

W-12 valve pit decontamination demonstration

International Nuclear Information System (INIS)

Benson, C.E.; Parfitt, J.E.; Patton, B.D.

1995-12-01

Waste tank W-12 is a tank in the ORNL Low-Level Liquid Waste (LLLW) system that collected waste from Building 3525. Because of a leaking flange in the discharge line from W-12 to the evaporator service tank (W-22) and continual inleakage into the tank from an unknown source, W-12 was removed from service to comply with the Federal Facilities Agreement requirement. The initial response was to decontaminate the valve pit between tank W-12 and the evaporator service tank (W-22) to determine if personnel could enter the pit to attempt repair of the leaking flange. Preventing the spread of radioactive contamination from the pit to the environment and to other waste systems was of concern during the decontamination. The drain in the pit goes to the process waste system; therefore, if high-level liquid waste were generated during decontamination activities, it would have to be removed from the pit by means other than the available liquid waste connection. Remote decontamination of W-12 was conducted using the General Mills manipulator bridge and telescoping trolley and REMOTEC RM-10 manipulator. The initial objective of repairing the leaking flange was not conducted because of the repair uncertainty and the unknown tank inleakage. Rather, new piping was installed to empty the W-12 tank that would bypass the valve pit and eliminate the need to repair the flange. The radiological surveys indicated that a substantial decontamination factor was achieved

Pitting corrosion of copper. Further model studies

International Nuclear Information System (INIS)

Taxen, C.

2002-08-01

The work presented in this report is a continuation and expansion of a previous study. The aim of the work is to provide background information about pitting corrosion of copper for a safety analysis of copper canisters for final deposition of radioactive waste. A mathematical model for the propagation of corrosion pits is used to estimate the conditions required for stationary propagation of a localised anodic corrosion process. The model uses equilibrium data for copper and its corrosion products and parameters for the aqueous mass transport of dissolved species. In the present work we have, in the model, used a more extensive set of aqueous and solid compounds and equilibrium data from a different source. The potential dependence of pitting in waters with different compositions is studied in greater detail. More waters have been studied and single parameter variations in the composition of the water have been studied over wider ranges of concentration. The conclusions drawn in the previous study are not contradicted by the present results. However, the combined effect of potential and water composition on the possibility of pitting corrosion is more complex than was realised. In the previous study we found what seemed to be a continuous aggravation of a pitting situation by increasing potentials. The present results indicate that pitting corrosion can take place only over a certain potential range and that there is an upper potential limit for pitting as well as a lower. A sensitivity analysis indicates that the model gives meaningful predictions of the minimum pitting potential also when relatively large errors in the input parameters are allowed for

Bidirectional Barbed Sutures for Wound Closure: Evolution and Applications

Science.gov (United States)

Paul, Malcolm D.

2009-01-01

Traditionally, wound closure sutures have in common the need to tie knots with the inherent risk of extrusion, palpability, microinfarcts, breakage, and slippage. Bidirectional barbed sutures have barbs arrayed in a helical fashion in opposing directions on either side of an unbarbed midsegment. This suture is inserted at the midpoint of a wound and pulled through till resistance is encountered from the opposing barbs; each half of the suture is then advanced to the lateral ends of the wound. This design provides a method of evenly distributing tension along the incision line, a faster suture placement and closure time with no need to tie knots, and the possibility of improved cosmesis. Bidirectional barbed sutures, which are available in both absorbable and nonabsorbable forms, can be used for simple closures, multilayered closures, and closure of high-tension wounds in a variety of surgical settings. PMID:24527114

Assessment and remediation of earthen pits in Alberta

International Nuclear Information System (INIS)

Lye, D.E.; Deibert, L.

1999-01-01

The proper decommissioning of abandoned earthen pits and the elimination of the associated environmental liabilities were discussed. An earthen pit is an excavated pit used by upstream oil and gas companies to contain/store/burn produced fluids and gases from either gas or oil producing operations. Produced fluids may include liquid hydrocarbons, process chemicals and water originating from oil wells, gas wells, and associated batteries and processing facilities. Improper operation and management at some pits has resulted in soil and/or groundwater contamination. In response to regulatory direction, petroleum operators in Alberta have begun the process of replacing earthen pits with alternative flaring and liquid storage facilities, and embarked on programs to assess, remediate and decommission earthen pits at their operations. This paper describes some of the challenges facing petroleum operators in this regard. It also outlines the regulatory framework within which decommissioning projects must be completed. 2 tabs

Utilization of open pit burned household waste ash--a feasibility study in Dhaka.

Science.gov (United States)

Haque, Md Obaidul; Sharif, Ahmed

2014-05-01

Informal incineration or open pit burning of waste materials is a common practice in the peripheral area of Dhaka, one of the fastest growing mega-cities in the world. This study deals with the effect of open pit burned (i.e. open burned) household waste bottom ash on fired clay bricks. Between 0 to 50% (by weight) of open pit burned household waste bottom ash was mixed with clay to make bricks. The molded specimens were air-dried at room temperature for 24 h and then oven dried at 100 °C for another 24 h to remove the water. The raw bricks were fired in a muffle furnace to a designated temperature (800, 900 and 1000 °C, respectively). The firing behaviour (mechanical strength, water absorption and shrinkage) was determined. The microstructures, phase compositions and leachates were evaluated for bricks manufactured at different firing temperatures. These results demonstrate that open pit burned ash can be recycled in clay bricks. This study also presents physical observations of the incinerated ash particles and determination of the chemical compositions of the raw materials by wet analysis. Open pit burned ash can be introduced easily into bricks up to 20% wt. The concentrations of hazardous components in the leachates were below the standard threshold for inert waste category landfill and their environmental risk during their use-life step can be considered negligible.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2010

International Nuclear Information System (INIS)

2011-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2010 and includes inspection and repair activities completed at the following seven CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 426: Cactus Spring Waste Trenches (TTR); (5) CAU 453: Area 9 UXO Landfill (TTR); (6) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR); and (7) CAU 487: Thunderwell Site (TTR).

The Application of Foundation Pit Monitoring Technology to the Excavation

Directory of Open Access Journals (Sweden)

Qiu Jin

2015-01-01

Full Text Available The foundation pit monitoring plays an important role in the foundation pit supporting projects especially in those deep foundation pit projects. Through the whole monitoring of the foundation pit construction from the excavation to the backfill, we can learn about the forcing and deforming process of the foundation pit supporting system, and grasp the impact of external condition changes on the foundation pit. This paper takes a project in Jinan as an example to establish a specific monitoring program, and then conducts the analysis and evaluation of the monitoring data; the real-time grasp of the foundation pit deformation and internal force changes can help to further ensure the security status of the foundation pit, thus better guiding the construction.

Evolution of regional stress state based on faulting and folding near the pit river, Shasta county, California

Science.gov (United States)

Austin, Lauren Jean

We investigate the evolution of the regional stress state near the Pit River, northern California, in order to understand the faulting style in a tectonic transition zone and to inform the hazard analysis of Fault 3432 near the Pit 3 Dam. By analyzing faults and folds preserved in and adjacent to a diatomite mine north of the Pit River, we have determined principal stress directions preserved during the past million years. We find that the stress state has evolved from predominantly normal to strike slip and most recently to reverse, which is consistent with regional structures such as the extensional Hat Creek Fault to the south and the compressional folding of Mushroom Rock to the north. South of the Pit River, we still observe normal and strike slip faults, suggesting that changes in stress state are moving from north to south through time.

Calcined solids storage facility closure study

International Nuclear Information System (INIS)

Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C.

1998-02-01

The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a open-quotes Settlement Agreementclose quotes (or open-quotes Batt Agreementclose quotes) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed

Calcined solids storage facility closure study

Energy Technology Data Exchange (ETDEWEB)

Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C. [and others

1998-02-01

The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a {open_quotes}Settlement Agreement{close_quotes} (or {open_quotes}Batt Agreement{close_quotes}) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed.

Simulated precipitation diurnal cycles over East Asia using different CAPE-based convective closure schemes in WRF model

Science.gov (United States)

Yang, Ben; Zhou, Yang; Zhang, Yaocun; Huang, Anning; Qian, Yun; Zhang, Lujun

2018-03-01

Closure assumption in convection parameterization is critical for reasonably modeling the precipitation diurnal variation in climate models. This study evaluates the precipitation diurnal cycles over East Asia during the summer of 2008 simulated with three convective available potential energy (CAPE) based closure assumptions, i.e. CAPE-relaxing (CR), quasi-equilibrium (QE), and free-troposphere QE (FTQE) and investigates the impacts of planetary boundary layer (PBL) mixing, advection, and radiation on the simulation by using the weather research and forecasting model. The sensitivity of precipitation diurnal cycle to PBL vertical resolution is also examined. Results show that the precipitation diurnal cycles simulated with different closures all exhibit large biases over land and the simulation with FTQE closure agrees best with observation. In the simulation with QE closure, the intensified PBL mixing after sunrise is responsible for the late-morning peak of convective precipitation, while in the simulation with FTQE closure, convective precipitation is mainly controlled by advection cooling. The relative contributions of different processes to precipitation formation are functions of rainfall intensity. In the simulation with CR closure, the dynamical equilibrium in the free troposphere still can be reached, implying the complex cause-effect relationship between atmospheric motion and convection. For simulations in which total CAPE is consumed for the closures, daytime precipitation decreases with increased PBL resolution because thinner model layer produces lower convection starting layer, leading to stronger downdraft cooling and CAPE consumption. The sensitivity of the diurnal peak time of precipitation to closure assumption can also be modulated by changes in PBL vertical resolution. The results of this study help us better understand the impacts of various processes on the precipitation diurnal cycle simulation.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2011

International Nuclear Information System (INIS)

2012-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2011 and includes inspection and repair activities completed at the following CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 453: Area 9 UXO Landfill (TTR); and (5) CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Appendix B. The inspection checklists are included in Appendix C, field notes are included in Appendix D, and photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted May 3 and 4, 2011. Maintenance was performed at CAU 424, CAU 453, and CAU 487. At CAU 424, two surface grade monuments at Landfill Cell A3-3 could not be located during the inspection. The two monuments were located and marked with lava rock on July 13, 2011. At CAU 453, there was evidence of animal burrowing. Animal burrows were backfilled on July 13, 2011. At CAU 487, one use restriction warning sign was missing, and wording was faded on the remaining signs. A large animal burrow was also present. The signs were replaced, and the animal burrow was backfilled on July 12, 2011. As a best management practice, the use restriction warning signs at CAU 407 were replaced with standard Federal Facility Agreement and Consent Order signs on July 13, 2011. Vegetation monitoring was performed at the CAU 400 Five Points Landfill and CAU 407 in June 2011, and the vegetation monitoring report is included in Appendix F.

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2011

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2012-02-21

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2011 and includes inspection and repair activities completed at the following CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 453: Area 9 UXO Landfill (TTR); and (5) CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Appendix B. The inspection checklists are included in Appendix C, field notes are included in Appendix D, and photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted May 3 and 4, 2011. Maintenance was performed at CAU 424, CAU 453, and CAU 487. At CAU 424, two surface grade monuments at Landfill Cell A3-3 could not be located during the inspection. The two monuments were located and marked with lava rock on July 13, 2011. At CAU 453, there was evidence of animal burrowing. Animal burrows were backfilled on July 13, 2011. At CAU 487, one use restriction warning sign was missing, and wording was faded on the remaining signs. A large animal burrow was also present. The signs were replaced, and the animal burrow was backfilled on July 12, 2011. As a best management practice, the use restriction warning signs at CAU 407 were replaced with standard Federal Facility Agreement and Consent Order signs on July 13, 2011. Vegetation monitoring was performed at the CAU 400 Five Points Landfill and CAU 407 in June 2011, and the vegetation monitoring report is included in Appendix F.

Percutaneous left atrial appendage closure for stroke prevention

DEFF Research Database (Denmark)

De Backer, Ole; Loupis, Anastasia M; Ihlemann, Nikolaj

2014-01-01

INTRODUCTION: In atrial fibrillation (AF) patients with an increased stroke risk, oral anticoagulation (OAC) is the standard treatment for stroke prevention. However, this therapy carries a high risk of major bleeding. Percutaneous closure of the left atrial appendage (LAA) is suggested as an alt...

Detecting pits in tart cherries by hyperspectral transmission imaging

Science.gov (United States)

Qin, Jianwei; Lu, Renfu

2004-11-01

The presence of pits in processed cherry products causes safety concerns for consumers and imposes potential liability for the food industry. The objective of this research was to investigate a hyperspectral transmission imaging technique for detecting the pit in tart cherries. A hyperspectral imaging system was used to acquire transmission images from individual cherry fruit for four orientations before and after pits were removed over the spectral region between 450 nm and 1,000 nm. Cherries of three size groups (small, intermediate, and large), each with two color classes (light red and dark red) were used for determining the effect of fruit orientation, size, and color on the pit detection accuracy. Additional cherries were studied for the effect of defect (i.e., bruises) on the pit detection. Computer algorithms were developed using the neural network (NN) method to classify the cherries with and without the pit. Two types of data inputs, i.e., single spectra and selected regions of interest (ROIs), were compared. The spectral region between 690 nm and 850 nm was most appropriate for cherry pit detection. The NN with inputs of ROIs achieved higher pit detection rates ranging from 90.6% to 100%, with the average correct rate of 98.4%. Fruit orientation and color had a small effect (less than 1%) on pit detection. Fruit size and defect affected pit detection and their effect could be minimized by training the NN with properly selected cherry samples.

Influence of the filler material on the pitting corrosion in welded duplex stainless

International Nuclear Information System (INIS)

Munez, C. J.; Utrilla, M. V.; Urena, A.; Otero, E.

2007-01-01

In this work, it has been studied the pitting corrosion resistance of welding duplex stainless steel 2205. Unions were made by GMAW process with different fillers: duplex ER 2209 and two austenitic (ER 316LSi and ER 308LSi). the microstructure obtained with the duplex ER 2209 filler is similar to the duplex 2205 base material, but the unions produced with the austenitic fillers cause a decrease of the phases relationα/γ. To evaluate the influence of the filler on the weld, the pitting corrosion resistance was determined by electrochemical critical pitting temperature test (TCP) and the mechanical properties by the hardness. The phases imbalance produced for the dissimilar fillers bring out a variation of the pitting corrosion resistance and the mechanical properties. (Author)

Hybrid approach for transcatheter paravalvular leak closure of mitral prosthesis in high-risk patients through transapical access.

Science.gov (United States)

Davidavicius, Giedrius; Rucinskas, Kestutis; Drasutiene, Agne; Samalavicius, Robertas; Bilkis, Valdas; Zakarkaite, Diana; Aidietis, Audrius

2014-11-01

To report "hybrid" procedure feasibility and the clinical success of transcatheter paravalvular leak closure through apical access. Seven patients (73.6±6.1 years; 4 men) with severe mitral prosthesis paravalvular leak were selected. All patients were at high risk for open surgery because of severe comorbidities and heart failure (New York Heart Association class III-IV). The defect size was 25±7.8 mm in the long axis and 9.3±2 mm in the short axis. Two defects were detected in 2 patients. The transapical procedure was performed in a "hybrid" surgery room using minithoracotomy and general anesthesia. Three-dimensional transesophageal echocardiography and fluoroscopy were used for imaging. A total of 19 Amplatzer Vascular Plug III devices (St Jude Medical) were implanted in 7 patients, 2.7/patient and 1 to 3/fistula. The procedure time was 150.7±66.8 minutes. In 6 of 7 patients (85.7%), the paravalvular leak was successfully closed, resulting in no or mild residual regurgitation. One patient had moderate regurgitation despite deployment of 3 Amplatzer Vascular Plug III devices. Two patients required blood transfusion related to procedural blood loss. The patients were discharged at 15.3±6.5 days and followed up at 215.7±138.6 days. All but 1 patient reported symptomatic improvement by ≥1 New York Heart Association class at follow-up. One patient died 216 days postoperatively. A "hybrid approach" for transcatheter paravalvular leak closure of mitral prosthesis from the apical route is effective in reducing the regurgitation grade and improving functional capacity in high-risk patients. Complete closure of the defect was maintained at follow-up in most patients. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Closure requirements

International Nuclear Information System (INIS)

Hutchinson, I.P.G.; Ellison, R.D.

1992-01-01

Closure of a waste management unit can be either permanent or temporary. Permanent closure may be due to: economic factors which make it uneconomical to mine the remaining minerals; depletion of mineral resources; physical site constraints that preclude further mining and beneficiation; environmental, regulatory or other requirements that make it uneconomical to continue to develop the resources. Temporary closure can occur for a period of several months to several years, and may be caused by factors such as: periods of high rainfall or snowfall which prevent mining and waste disposal; economic circumstances which temporarily make it uneconomical to mine the target mineral; labor problems requiring a cessation of operations for a period of time; construction activities that are required to upgrade project components such as the process facilities and waste management units; and mine or process plant failures that require extensive repairs. Permanent closure of a mine waste management unit involves the provision of durable surface containment features to protect the waters of the State in the long-term. Temporary closure may involve activities that range from ongoing maintenance of the existing facilities to the installation of several permanent closure features in order to reduce ongoing maintenance. This paper deals with the permanent closure features

Evaluation of the cranial base in amnion rupture sequence involving the anterior neural tube: implications regarding recurrence risk.

Science.gov (United States)

Jones, Kenneth Lyons; Robinson, Luther K; Benirschke, Kurt

2006-09-01

Amniotic bands can cause disruption of the cranial end of the developing fetus, leading in some cases to a neural tube closure defect. Although recurrence for unaffected parents of an affected child with a defect in which the neural tube closed normally but was subsequently disrupted by amniotic bands is negligible; for a primary defect in closure of the neural tube to which amnion has subsequently adhered, recurrence risk is 1.7%. In that primary defects of neural tube closure are characterized by typical abnormalities of the base of the skull, evaluation of the cranial base in such fetuses provides an approach for making a distinction between these 2 mechanisms. This distinction has implications regarding recurrence risk. The skull base of 2 fetuses with amnion rupture sequence involving the cranial end of the neural tube were compared to that of 1 fetus with anencephaly as well as that of a structurally normal fetus. The skulls were cleaned, fixed in 10% formalin, recleaned, and then exposed to 10% KOH solution. After washing and recleaning, the skulls were exposed to hydrogen peroxide for bleaching and photography. Despite involvement of the anterior neural tube in both fetuses with amnion rupture sequence, in Case 3 the cranial base was normal while in Case 4 the cranial base was similar to that seen in anencephaly. This technique provides a method for determining the developmental pathogenesis of anterior neural tube defects in cases of amnion rupture sequence. As such, it provides information that can be used to counsel parents of affected children with respect to recurrence risk.

Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

OpenAIRE

Silwamba C; Chileshe P R K

2015-01-01

Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the st...

Investigating pitting in X65 carbon steel using potentiostatic polarisation

Science.gov (United States)

Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

2017-11-01

Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

Synchronous Adversarial Feature Learning for LiDAR based Loop Closure Detection

OpenAIRE

Yin, Peng; He, Yuqing; Xu, Lingyun; Peng, Yan; Han, Jianda; Xu, Weiliang

2018-01-01

Loop Closure Detection (LCD) is the essential module in the simultaneous localization and mapping (SLAM) task. In the current appearance-based SLAM methods, the visual inputs are usually affected by illumination, appearance and viewpoints changes. Comparing to the visual inputs, with the active property, light detection and ranging (LiDAR) based point-cloud inputs are invariant to the illumination and appearance changes. In this paper, we extract 3D voxel maps and 2D top view maps from LiDAR ...

Area Completion Strategies at Savannah River Site: Characterization for Closure and Beyond

International Nuclear Information System (INIS)

Bagwell, Laura; O'Quinn, Sadika; Amidon, Mark

2008-01-01

During the first four decades of its 56 year existence, the Savannah River Site (SRS) was a key supplier of nuclear material for national defense. During the 1990's, the site's primary missions became waste site closure, environmental restoration, and deactivation and decommissioning (D and D) of remnant cold war apparatus. Since 1989, with the approval of State and Federal regulatory agencies and with the participation of interested stakeholders, SRS has implemented a final remedy for a majority of the more than 500 individual waste sites at the former nuclear materials complex. These waste sites range from small, inert rubble pits to large, heavy industrial areas and radioactive waste disposal grounds. The closure and final remediation of these waste sites mark significant progress toward achieving SRS's overarching goal of reducing or eliminating future environmental damage and human health threats. However, larger challenges remain. For example, what are appropriate and achievable end-states for decommissioned nuclear facilities? What environmental and human health risks are associated with these end-states? To answer these questions within the strictures of smaller budgets and accelerated schedules, SRS is implementing an 'area completion' strategy that: - unites several discrete waste units into one conceptual model, - integrates historically disparate environmental characterization and D and D activities - reduces the number of required regulatory documents, - and, in some cases, compresses schedules for achieving a stakeholder-approved end-state. The area completion approaches being implemented at SRS reflect an evolution of the traditional RCRA/ CERCLA remedial process. Area completion strategies: - group waste units and/or D and D facilities together for characterization, remediation, and possible reuse; - identify data needs and integrate data collection activities for D and D, characterization, and remediation; - identify problems that require action

Summary Report on the Audit of Defense Base Closure and Realignment Budget Data for FYS 1993 and 1994

Science.gov (United States)

1994-02-14

Jl%«~~ /&■ OFFICE OF THE INSPECTOR GENERAL SUMMARY REPORT ON THE AUDIT OF DEFENSE BASE CLOSURE AND REALIGNMENT BUDGET DATA FOR FYS 1993 AND...COMPTROLLER) AUDITOR GENERAL, DEPARTMENT OF THE ARMY SUBJECT: Summary Report on the Audit of Defense Base Closure and Realignment Budget Data for FYs...Therefore, we are publishing this report in final form. We appreciate the courtesies and cooperation extended to the audit staff. If you have any

Pitting of malaria parasites and spherocyte formation

Directory of Open Access Journals (Sweden)

Gichuki Charity W

2006-07-01

Full Text Available Abstract Background A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA but no intracellular parasites, support the idea of pitting. Methods An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide. Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. Results Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites as opposed to erythrophagocytosis (5.33% ± 0.95% (P Conclusion It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

Land use-based landscape planning and restoration in mine closure areas.

Science.gov (United States)

Zhang, Jianjun; Fu, Meichen; Hassani, Ferri P; Zeng, Hui; Geng, Yuhuan; Bai, Zhongke

2011-05-01

Landscape planning and restoration in mine closure areas is not only an inevitable choice to sustain mining areas but also an important path to maximize landscape resources and to improve ecological function in mine closure areas. The analysis of the present mine development shows that many mines are unavoidably facing closures in China. This paper analyzes the periodic impact of mining activities on landscapes and then proposes planning concepts and principles. According to the landscape characteristics in mine closure areas, this paper classifies available landscape resources in mine closure areas into the landscape for restoration, for limited restoration and for protection, and then summarizes directions for their uses. This paper establishes the framework of spatial control planning and design of landscape elements from "macro control, medium allocation and micro optimization" for the purpose of managing and using this kind of special landscape resources. Finally, this paper applies the theories and methods to a case study in Wu'an from two aspects: the construction of a sustainable land-use pattern on a large scale and the optimized allocation of typical mine landscape resources on a small scale.

Land Use-Based Landscape Planning and Restoration in Mine Closure Areas

Science.gov (United States)

Zhang, Jianjun; Fu, Meichen; Hassani, Ferri P.; Zeng, Hui; Geng, Yuhuan; Bai, Zhongke

2011-05-01

Landscape planning and restoration in mine closure areas is not only an inevitable choice to sustain mining areas but also an important path to maximize landscape resources and to improve ecological function in mine closure areas. The analysis of the present mine development shows that many mines are unavoidably facing closures in China. This paper analyzes the periodic impact of mining activities on landscapes and then proposes planning concepts and principles. According to the landscape characteristics in mine closure areas, this paper classifies available landscape resources in mine closure areas into the landscape for restoration, for limited restoration and for protection, and then summarizes directions for their uses. This paper establishes the framework of spatial control planning and design of landscape elements from "macro control, medium allocation and micro optimization" for the purpose of managing and using this kind of special landscape resources. Finally, this paper applies the theories and methods to a case study in Wu'an from two aspects: the construction of a sustainable land-use pattern on a large scale and the optimized allocation of typical mine landscape resources on a small scale.

Defense Base Realignment and Closure Budget Data for the Closure of Gentile Air Force Station, Dayton, Ohio, and Realignment of Defense Logistics Agency Components to Wright-Patterson Air Force Base, Ohio

National Research Council Canada - National Science Library

1996-01-01

.... This report provides the results of the audit of two projects, valued at $5.5 million, for the closure of Gentile Air Force Station, Dayton, Ohio, and realignment to Wright-Patterson Air Force Base, Ohio, of two Defense Logistics Agency components...

Pitting corrosion of copper. An equilibrium - mass transport study

Energy Technology Data Exchange (ETDEWEB)

Taxen, C

1996-11-01

A mathematical model for the propagation of corrosion pits on copper is described. The model is used to predict the potentials below which copper is immune to pitting. The criteria used for immunity against pitting is that the volume of the cuprous oxide formed at the site of the metal oxidation at the bottom of a corrosion pit must be smaller than the volume of the oxidised metal. Equal volumes would give a complete coverage of the metal in a pit by adherent cuprous oxide and propagation would not be possible. For potentials where copper is not immune to pitting an estimate of the maximum growth rate is given. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles from the bulk water outside a corrosion pit to the site of the metal dissolution at the bottom a corrosion pit. Precipitation of oxides as well as of basic salts of copper is considered. A total of 26 aqueous species are considered in waters with compositions ranging from those of tap waters to that of sea water. Calculations are made for the temperatures 25 deg C and 75 deg C. 38 refs, 60 figs, 17 tabs

Ground movement and deformation due to dewatering and open pit excavation

International Nuclear Information System (INIS)

Liu, B.; Yang, J.; Zhang, J.

1996-01-01

In the application of stochastic medium theory, it is assumed that ground movement process has the property of Markov Process. Based on superposition principle and rock consolidation principle, the ground movement and deformation due to dewatering and open pit excavation can be calculated. The comparison between the field measurements in Morwell Open Pit, Latrobe Valley (Victoria, Australia) and the calculated results shows the validity of the method in this paper. 5 refs

Evaluation of Container Closure System Integrity for Frozen Storage Drug Products.

Science.gov (United States)

Nieto, Alejandra; Roehl, Holger; Brown, Helen; Nikoloff, Jonas; Adler, Michael; Mahler, Hanns-Christian

2016-01-01

Sometimes, drug product for parenteral administration is stored in a frozen state (e.g., -20 °C or -80 °C), particularly during early stages of development of some biotech molecules in order to provide sufficient stability. Shipment of frozen product could potentially be performed in the frozen state, yet possibly at different temperatures, for example, using dry ice (-80 °C). Container closure systems of drug products usually consist of a glass vial, rubber stopper, and an aluminum crimped cap. In the frozen state, the glass transition temperature (Tg) of commonly used rubber stoppers is between -55 and -65 °C. Below their Tg, rubber stoppers are known to lose their elastic properties and become brittle, and thus potentially fail to maintain container closure integrity in the frozen state. Leaks during frozen temperature storage and transportation are likely to be transient, yet, can possibly risk container closure integrity and lead to microbial contamination. After thawing, the rubber stopper is supposed to re-seal the container closure system. Given the transient nature of the possible impact on container closure integrity in the frozen state, typical container closure integrity testing methods (used at room temperature conditions) are unable to evaluate and thus confirm container closure integrity in the frozen state. Here we present the development of a novel method (thermal physical container closure integrity) for direct assessment of container closure integrity by a physical method (physical container closure integrity) at frozen conditions, using a modified He leakage test. In this study, different container closure systems were evaluated with regard to physical container closure integrity in the frozen state to assess the suitability of vial/stopper combinations and were compared to a gas headspace method. In summary, the thermal physical container closure integrity He leakage method was more sensitive in detecting physical container closure

Hamiltonian closures in fluid models for plasmas

Science.gov (United States)

Tassi, Emanuele

2017-11-01

This article reviews recent activity on the Hamiltonian formulation of fluid models for plasmas in the non-dissipative limit, with emphasis on the relations between the fluid closures adopted for the different models and the Hamiltonian structures. The review focuses on results obtained during the last decade, but a few classical results are also described, in order to illustrate connections with the most recent developments. With the hope of making the review accessible not only to specialists in the field, an introduction to the mathematical tools applied in the Hamiltonian formalism for continuum models is provided. Subsequently, we review the Hamiltonian formulation of models based on the magnetohydrodynamics description, including those based on the adiabatic and double adiabatic closure. It is shown how Dirac's theory of constrained Hamiltonian systems can be applied to impose the incompressibility closure on a magnetohydrodynamic model and how an extended version of barotropic magnetohydrodynamics, accounting for two-fluid effects, is amenable to a Hamiltonian formulation. Hamiltonian reduced fluid models, valid in the presence of a strong magnetic field, are also reviewed. In particular, reduced magnetohydrodynamics and models assuming cold ions and different closures for the electron fluid are discussed. Hamiltonian models relaxing the cold-ion assumption are then introduced. These include models where finite Larmor radius effects are added by means of the gyromap technique, and gyrofluid models. Numerical simulations of Hamiltonian reduced fluid models investigating the phenomenon of magnetic reconnection are illustrated. The last part of the review concerns recent results based on the derivation of closures preserving a Hamiltonian structure, based on the Hamiltonian structure of parent kinetic models. Identification of such closures for fluid models derived from kinetic systems based on the Vlasov and drift-kinetic equations are presented, and

Evaluation of a novel trocar-site closure and comparison with a standard Carter-Thomason closure device.

Science.gov (United States)

del Junco, Michael; Okhunov, Zhamshid; Juncal, Samuel; Yoon, Renai; Landman, Jaime

2014-07-01

The aim of this study was to evaluate and compare a novel trocars-site closure device, the WECK EFx™ Endo Fascial Closure System (EFx) with the Carter-Thomason CloseSure System® (CT) for the closure of laparoscopic trocar site defects created by a 12-mm dilating trocar. We created standardized laparoscopic trocars-site abdominal wall defects in cadaver models using a standard 12-mm laparoscopic dilating trocar. Trocar defects were closed in a randomized fashion using one of the two closure systems. We recorded time and number of attempts needed for complete defect closure. In addition, we recorded the ability to maintain pneumoperitoneum, endoscopic visualization, safety, security, and facility based on the surgeon's subjective evaluations. We compared outcomes for the EFx and CT closure systems. We created 72 standardized laparoscopic trocars-site abdominal wall defects. The mean time needed for complete defect closure was 98.53 seconds (±28.9) for the EFx compared with 133.61 seconds (±54.61) for the CT (Psafety were 2.92 for EFx vs 2.19 for CT (Pvs 1.83 for EFx and CT, respectively (Pvs 2.33 for CT (P=0.022). No significant difference was observed between the EFx and the CT systems for endoscopic visualization (2.28 vs 2.50, P=0.080). In this in vitro cadaver trial, the EFx was superior in terms of time needed to complete defect closure, safety, and facility. CT was superior in terms of maintenance of pneumoperitoneum. Both systems were equal in the number of attempts needed to complete the defect closure and endoscopic visualization.

Multicentre study on capsular closure versus non-capsular closure during hip arthroscopy in Danish patients with femoroacetabular impingement (FAI)

DEFF Research Database (Denmark)

Dippmann, Christian; Kraemer, Otto; Lund, Bent

2018-01-01

in patients without additional risk factors for instability such as hypermobility or dysplasia of the hip. We hypothesised that capsular closure will lead to a superior outcome in hip arthroscopy for femoroacetabular impingement syndrome (FAIS) compared with non-capsular closure. METHODS AND ANALYSIS...... years and FAIS according to the Warwick agreement. Exclusion criteria are: previous hip surgery in either hip, previous conditions of Legg-Calvé-Perthes or slipped capital femoral epiphysis, malignant disease, recent hip or pelvic fractures, arthritis, Ehlers-Danlos or Marfan disease, recent (within 6...

A New Methodology for Open Pit Slope Design in Karst-Prone Ground Conditions Based on Integrated Stochastic-Limit Equilibrium Analysis

Science.gov (United States)

Zhang, Ke; Cao, Ping; Ma, Guowei; Fan, Wenchen; Meng, Jingjing; Li, Kaihui

2016-07-01

Using the Chengmenshan Copper Mine as a case study, a new methodology for open pit slope design in karst-prone ground conditions is presented based on integrated stochastic-limit equilibrium analysis. The numerical modeling and optimization design procedure contain a collection of drill core data, karst cave stochastic model generation, SLIDE simulation and bisection method optimization. Borehole investigations are performed, and the statistical result shows that the length of the karst cave fits a negative exponential distribution model, but the length of carbonatite does not exactly follow any standard distribution. The inverse transform method and acceptance-rejection method are used to reproduce the length of the karst cave and carbonatite, respectively. A code for karst cave stochastic model generation, named KCSMG, is developed. The stability of the rock slope with the karst cave stochastic model is analyzed by combining the KCSMG code and the SLIDE program. This approach is then applied to study the effect of the karst cave on the stability of the open pit slope, and a procedure to optimize the open pit slope angle is presented.

Dewatering of planned Key Lake open pits in northern Saskatchewan

International Nuclear Information System (INIS)

Unland, W.; Holl, N.

1980-01-01

The engineering design and experience gained so far with a dewatering system for an open-pit uranium mine planned at Key Lake in Northern Saskatchewan are presented. An extensive unconfined overburden aquifer is hydraulically connected with the underlying Athabasca Formation and basement rocks, both of relatively low hydraulic conductivity. The overburden aquifer is embedded in a bedrock trough, with the deepest depression between the planned pits. Hydrogeological data were used in a numerical dewatering model simulating groundwater flow at different stages of the pit development. Based on the model results, the enginering design had to provide for different pumping rates, varying between 1.0 and 0.21 m 3 /sec. This problem was solved by using a double line pressure system. The design concept for the complete peripheral discharge system and the well design used for 26 dewatering wells are discussed. (auth)

Cleanups In My Community (CIMC) - Base Realignment and Closure (BRAC) Superfund Sites, National Layer

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer provides access to Base Realignment and Closure (BRAC) Superfund Sites as part of the CIMC web service. EPA works with DoD to facilitate the reuse...

Spontaneous Resolution of Optic Disc Pit Maculopathy

OpenAIRE

Tripathy, Koushik

2017-01-01

I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT) does not clearly show typical intraretinal schisis (Figure 1B)1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM) cavity. Such cavities are known to occur f...

Towards Stable Adversarial Feature Learning for LiDAR based Loop Closure Detection

OpenAIRE

Xu, Lingyun; Yin, Peng; Luo, Haibo; Liu, Yunhui; Han, Jianda

2017-01-01

Stable feature extraction is the key for the Loop closure detection (LCD) task in the simultaneously localization and mapping (SLAM) framework. In our paper, the feature extraction is operated by using a generative adversarial networks (GANs) based unsupervised learning. GANs are powerful generative models, however, GANs based adversarial learning suffers from training instability. We find that the data-code joint distribution in the adversarial learning is a more complex manifold than in the...

Site Closure Strategy Model for Creosote Site

International Nuclear Information System (INIS)

Coll, F.R.; Gray, D.R.

2009-01-01

In conjunction with RCRA site corrective action at an active wood preserving facility, a risk-based site closure strategy was developed and incorporated the performance of a dense non-aqueous phase liquid (DNAPL) source recovery remedy, a monitored natural attenuation (MNA) remedy for dissolved phase groundwater, and institutional controls. Innovative creosote DNAPL source recovery has been undertaken at the Site since 1998. Pooled creosote DNAPL is present 90 feet below ground within a transmissive sand and gravel aquifer with a saturated thickness of approximately 80 feet. The creosote DNAPL source is situated on the property boundary of the site and has generated a 1/2 mile off-site dissolved phase plume, creating significant NAPL management and remedial technology verification issues. To date, over 120,000 gallons of creosote DNAPL have been recovered from the subsurface utilizing a modified circulation well technology. A mass discharge flux protocol was developed to serve as a major performance metrics for the continuation of source removal efforts and to support the application of monitored natural attenuation as an associated remedial technology for groundwater. The mass removal success has supported the MNA remedy for dissolved phase groundwater and the associated development of institutional controls. The enacted site management strategy outlines the current and future risk management activities for the Site and represents an appropriate site closure strategy for the Site. (authors)

Post-Closure Report for Closed Resource Conservation and Recovery Act Corrective Action Units, Nevada National Security Site, Nevada, for fiscal year 2013 (October 2012 - September 2013)

International Nuclear Information System (INIS)

2014-01-01

This report serves as the combined annual report for post-closure activities for the following closed Corrective Action Units (CAUs): CAU 90, Area 2 Bitcutter Containment; CAU 91, Area 3 U-3fi Injection Well; CAU 92, Area 6 Decon Pond Facility; CAU 110, Area 3 WMD U-3ax/bl Crater; CAU 111, Area 5 WMD Retired Mixed Waste Pits; and, CAU 112, Area 23 Hazardous Waste Trenches

Post-Closure Report for Closed Resource Conservation and Recovery Act Corrective Action Units, Nevada National Security Site, Nevada for fiscal year 2013 (October 2012 - September 2013)

Energy Technology Data Exchange (ETDEWEB)

None, None

2014-01-31

This report serves as the combined annual report for post-closure activities for the following closed Corrective Action Units (CAUs): CAU 90, Area 2 Bitcutter Containment; CAU 91, Area 3 U-3fi Injection Well; CAU 92, Area 6 Decon Pond Facility; CAU 110, Area 3 WMD U-3ax/bl Crater; CAU 111, Area 5 WMD Retired Mixed Waste Pits; and, CAU 112, Area 23 Hazardous Waste Trenches.

Aspects of the effects of temperature and electrolyte composition on pitting corrosion of stainless steel in dairy fluids

Energy Technology Data Exchange (ETDEWEB)

Perrin, F.X. [Toulon Univ., 83 - La Garde (France). Lab. de Chimie Appliquee; Girard, H.; Pagetti, J. [Universite de Franche-Comte, Besancon (France). Lab. de Corrosion et Traitments de Surfaces; Daufin, G. [INRA, Rennes (France). Lab. de Recherches de Technologie Laitiere

2001-08-01

The pitting corrosion resistance of 304L stainless steel in dairy fluids (milks, wheys, soya juice and peptidic fluids) was studied using electrochemical measurements. The effects of temperature, chloride content and other components of the fluids was particularly investigated. In the range 30- 70 C, the pitting potential in whole milk E{sub p} is related to the temperature by the relation ln(E{sub p} + 100) = aT{sup -1} + b. Above 70 C, a further phenomenon adds to the common activation effect of temperature. Heat induced conformational changes (denaturation) of the proteins were believed to explain such a behaviour. A typical linear relationship was found between E{sub p} and the logarithm of chloride concentration. All fluids are well represented by a single relationship. Therefore, the buffering capacity of casein micelles in milks do not significantly change the pitting resistance of the oxide film. In dairy industry, the corrosion risk is usually estimated from the difference between the pitting potential and the potential of a gold electrode (E{sub g}). It is noteworthy that the pitting risk decreases when temperature increases in the temperature range 50-90 C. Such a trend was due to the strong decrease in dissolved oxygen above 50 C. Besides, in aggressive peptidic solutions, the resistance of the passive film to localized attack is directly related to the Cr, Mo and N alloy content of stainless steel. (orig.)

Understanding of surface pit formation mechanism of GaN grown in MOCVD based on local thermodynamic equilibrium assumption

International Nuclear Information System (INIS)

Gao Zhi-Yuan; Xue Xiao-Wei; Li Jiang-Jiang; Wang Xun; Xing Yan-Hui; Cui Bi-Feng; Zou De-Shu

2016-01-01

Frank’s theory describes that a screw dislocation will produce a pit on the surface, and has been evidenced in many material systems including GaN. However, the size of the pit calculated from the theory deviates significantly from experimental result. Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c -plane GaN, we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same. If the kinetic process is too vigorous or too slow to reach a balance, the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state. When the curvature at the center of the dislocation core reaches the critical value 1/ r 0 , at the edge of the spiral, the accelerating rate of the curvature may not fall to zero, so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit. (paper)

A generic statistical methodology to predict the maximum pit depth of a localized corrosion process

International Nuclear Information System (INIS)

Jarrah, A.; Bigerelle, M.; Guillemot, G.; Najjar, D.; Iost, A.; Nianga, J.-M.

2011-01-01

Highlights: → We propose a methodology to predict the maximum pit depth in a corrosion process. → Generalized Lambda Distribution and the Computer Based Bootstrap Method are combined. → GLD fit a large variety of distributions both in their central and tail regions. → Minimum thickness preventing perforation can be estimated with a safety margin. → Considering its applications, this new approach can help to size industrial pieces. - Abstract: This paper outlines a new methodology to predict accurately the maximum pit depth related to a localized corrosion process. It combines two statistical methods: the Generalized Lambda Distribution (GLD), to determine a model of distribution fitting with the experimental frequency distribution of depths, and the Computer Based Bootstrap Method (CBBM), to generate simulated distributions equivalent to the experimental one. In comparison with conventionally established statistical methods that are restricted to the use of inferred distributions constrained by specific mathematical assumptions, the major advantage of the methodology presented in this paper is that both the GLD and the CBBM enable a statistical treatment of the experimental data without making any preconceived choice neither on the unknown theoretical parent underlying distribution of pit depth which characterizes the global corrosion phenomenon nor on the unknown associated theoretical extreme value distribution which characterizes the deepest pits. Considering an experimental distribution of depths of pits produced on an aluminium sample, estimations of maximum pit depth using a GLD model are compared to similar estimations based on usual Gumbel and Generalized Extreme Value (GEV) methods proposed in the corrosion engineering literature. The GLD approach is shown having smaller bias and dispersion in the estimation of the maximum pit depth than the Gumbel approach both for its realization and mean. This leads to comparing the GLD approach to the GEV one

Echocardiographic predictors of coil vs device closure in patients undergoing percutaneous patent ductus arteriosus closure.

Science.gov (United States)

Roushdy, Alaa; Abd El Razek, Yasmeen; Mamdouh Tawfik, Ahmed

2018-01-01

To determine anatomic and hemodynamic echocardiographic predictors for patent ductus arteriosus (PDA) device vs coil closure. Seventy-six patients who were referred for elective transcatheter PDA closure were enrolled in the study. All patients underwent full echocardiogram including measurement of the PDA pulmonary end diameter, color flow width and extent, peak and end-diastolic Doppler gradients across the duct, diastolic flow reversal, left atrial dimensions and volume, left ventricular sphericity index, and volumes. The study group was subdivided into 2 subgroups based on the mode of PDA closure whether by coil (n = 42) or device (n = 34). Using univariate analysis there was a highly significant difference between the 2 groups as regard the pulmonary end diameter measured in both the suprasternal and parasternal short-axis views as well as the color flow width and color flow extent (P closure group had statistically significant higher end-systolic and end-diastolic volumes indexed, left atrial volume, and diastolic flow reversal. Receiver operating characteristic curve analysis showed a pulmonary end diameter cutoff point from the suprasternal view > 2.5 mm and from parasternal short-axis view > 2.61 mm to have the highest balanced sensitivity and specificity to predict the likelihood for device closure (AUC 0.971 and 0.979 respectively). The pulmonary end diameter measured from the suprasternal view was the most independent predictor of device closure. The selection between PDA coil or device closure can be done on the basis of multiple anatomic and hemodynamic echocardiographic variables. © 2017 Wiley Periodicals, Inc.

Optimization of the seismic pit of the Tokamak building of ITER

International Nuclear Information System (INIS)

Beltran, F.; Combescure, D.; Hanna, G.; Ezeberry, J.

2010-01-01

The Tokamak Complex of ITER is the structure housing the Tokamak machine, the Tritium building and the Diagnostic building. This structure, with a plan of about 120 x 80 m, will be built with a base isolation system formed with over 500 steel reinforced neoprene pads. The pads will be mounted on top of short columns or plinths, supported by a bottom basemat resting directly on rock. Foundation level is about 20 m below grade level. Consequently, a ground supporting system, such as retaining walls, is required to protect the structure. The walls, together with the basemat, form the seismic pit of the Tokamak Complex. After the initial design of the seismic pit walls and basemat was closed, a new report on the water table levels to be expected for different return periods was issued. The report introduced a substantial reduction of ground water levels with respect to the previous design basis. Following this reduction, a new design for the seismic pit walls and basemat was developed. The goal was to introduce the new optimized design as an alternative in the Call for Tenders related to the construction of the seismic pit. The design of the seismic pit is governed by the seismic action, even though the whole pit is embedded in a limestone rock of medium to good quality. For optimizing the design, a review of geotechnical parameters has been carried out first, using the huge body of information generated after more than 20 years of site investigation. Afterwards, seismic thrusts on the walls have been computed using different procedures, from conventional rock wedged equilibrium analyses to more sophisticated techniques based on the interaction of discrete blocks configuring the rock massif. In addition, internal forces and moments have been determined at the basemat from the ground deformation parameters, using finite element models. Finally, steel reinforcement has been obtained for the several sections of the retaining walls and the basemat, complying with the

2727-S Nonradioactive Dangerous Waste Storage Facility clean closure evaluation report

International Nuclear Information System (INIS)

Luke, S.N.

1994-01-01

This report presents the analytical results of 2727-S NRDWS facility closure verification soil sampling and compares these results to clean closure criteria. The results of this comparison will determine if clean closure of the unit is regulatorily achievable. This report also serves to notify regulators that concentrations of some analytes at the site exceed sitewide background threshold levels (DOE-RL 1993b) and/or the limits of quantitation (LOQ). This report also presents a Model Toxics Control Act Cleanup (MTCA) (WAC 173-340) regulation health-based closure standard under which the unit can clean close in lieu of closure to background levels or LOQ in accordance with WAC 173-303-610. The health-based clean closure standard will be closure to MTCA Method B residential cleanup levels. This report reconciles all analyte concentrations reported above background or LOQ to this health-based cleanup standard. Regulator acceptance of the findings presented in this report will qualify the TSD unit for clean closure in accordance with WAC 173-303-610 without further TSD unit soil sampling, or soil removal and/or decontamination. Nondetected analytes require no further evaluation

Modelling assessment of End Pit Lakes meromictic potential

International Nuclear Information System (INIS)

2006-11-01

The use of End Pit Lakes have been proposed as a remediation solution for oil sands reclamation and operational waters. This report modelled the main factors controlling the occurrence of stratification in Pit Lakes in order to establish design and management guidelines for the Cumulative Environmental Management Association's End Pit Lake Sub-group. The study focused on End Pit Lake size, depth, starting lake salinity concentrations, inflow rates and inflow salinity flux, and investigated their influence on density gradients. One-dimensional modelling and limited 2-D modelling simulations were conducted to examine meromictic potential for a large range of End Pit Lake configurations and conditions. Modelling results showed that fall is the governing season for determining meromixis. The expelling of salt from saline water upon ice formation and its effect on stratification potential and the effect of fresh water loading on stratification potential during spring melt events were not observed to be dominant factors governing meromictic potential for the scenarios examined in the study. Results suggested that shallow End Pit Lakes showed a high turn-over rate with seasonal heating and cooling cycles. Moderately deep End Pit Lakes demonstrated a meromictic potential that was inversely proportional to lake size and require higher starting salinities. With a 2 or 10 million m 3 /yr inflow rate and a 5 parts per thousand starting salinity, a 50 m deep End Pit Lake achieved meromixis at all 3 size ranges considered in the study. Results also showed that the rate of influent salinity decrease was the least important of the parameters influencing meromixis. It was observed that meromixis was a temporary condition in all of the End Pit Lake scenarios envisioned due to the lack of a constant, positive salt replenishment over the long term. It was concluded that further 3-D modelling is required to represent littoral areas as well as to account for extreme winter conditions. A

Pit Study, Geographic NAD83, LOSCO (1999) [pit_study_LOSCO_1998

Data.gov (United States)

Louisiana Geographic Information Center — The 'Pit Study' was meant to identify the remnants of former oil extraction sites which pose the threat of creating an oil spill. These remnants include many other...

Treatment of sternal wound infection with vacuum-assisted closure.

Science.gov (United States)

Dezfuli, Bobby; Li, Chin-Shang; Young, J Nilas; Wong, Michael S

2013-02-01

Previous work has demonstrated the efficacy of vacuum-assisted closure (VAC) in the treatment of poststernotomy local wound infections, compared to historical treatment protocol. The negative pressure has been found to protect wounds against contamination, prevent wound fluid retention, increase blood flow, and increase rates of granulation tissue formation. For this study, a retrospective analysis compared patients receiving VAC as definitive treatment versus bridging to delayed flap closure. Sixteen patients developed sternal wound infections after cardiac surgeries at the authors' institution from 2006 to 2008. Data was gathered regarding patient comorbidities, treatment method, and outcome. Study objectives included assessment of risk factors that warranted secondary surgicalclosure and examination of long-term followup where VAC was thedefinitive treatment modality. Group A (n = 12) had VAC as the final treatment modality. Group B (n = 4) required myocutaneous flap closure. One patient in Group B passed away prior to flap surgery. Both groups had similar risk factors, except Group B had a higher risk of body mass index (BMI) > 35 that was near statistically significant (P = 0.085; odds ratio = 0.0, 95% CI = [0.0 - 1.21]). Group A required a shorter hospital stay on average. Long-term follow-up showed the majority of Group A had completely healed sternal wounds 2-3 years from initial cardiac surgery. Vacuum-assisted closure as definitive treatment modality is a successful, first line therapy for local superficial sternal wound infections. When deep infections occur, however, VAC as bridge-to-flap coverage is recommended over attempted secondary healing with VAC. .

Summary Report on the Audit of Defense Base Closure and Realignment Budget Data for Fiscal Year 1992 and 1993

Science.gov (United States)

1993-05-25

OFFICE OF THE INSPECTOR GENERAL SUMMARY REPORT ON THE AUDIT OF DEFENSE BASE CLOSURE AND REALIGNMENT BUDGET DATA FOR FISCAL YEARS 1992 AND 1993...ASSISTANT SECRETARY OF DEFENSE (INSTALLATIONS) SUBJECT: Summary Report on the Audit of Defense Base Closure and Realignment Budget Data for Fiscal Years...1992 and 1993 (Report No. 93-100) We are providing this final summary report for your information and use. The audit was required by Public Law

A stochastic analysis of the effect of hydrostatic pressure on the pit corrosion of Fe-20Cr alloy

International Nuclear Information System (INIS)

Zhang Tao; Yang Yange; Shao Yawei; Meng, Guozhe; Wang, Fuhui

2009-01-01

The effect of hydrostatic pressure on the pit corrosion behavior of Fe-20Cr alloy was investigated in 3.5% NaCl solution by means of potentiodynamic polarization and potentiostatic technology, and the experiment data was analyzed based on stochastic theory. With the increase of hydrostatic pressure, the pit corrosion resistance of Fe-20Cr alloy was deteriorated, which was distinguished by the decrease of critical pit potential (E cirt ) and the increase of passive current density. The results also demonstrated that there exist two effects of hydrostatic pressure on the corrosion behavior of Fe-20Cr alloy: (1) the pit generation rate was evidently increased compared to that under lower hydrostatic pressure, and the metastable pits become faster and larger. However, it seemed that pit generation mechanism shows no hydrostatic pressure dependence; (2) the probability of pit growth increased with the increase of hydrostatic pressure, which implied that the metastable pit on Fe-20Cr alloy exhibited higher probability to become larger pit cavity during shorter time interval than that under lower hydrostatic pressure.

The Microstructure and Pitting Resistance of Weld Joints of 2205 Duplex Stainless Steel

Science.gov (United States)

Wu, Mingfang; Liu, Fei; Pu, Juan; Anderson, Neil E.; Li, Leijun; Liu, Dashuang

2017-11-01

2205 duplex stainless steel (DSS) was welded by submerged arc welding. The effects of both heat input and groove type on the ferrite/austenite ratio and elemental diffusion of weld joints were investigated. The relationships among welding joint preparation, ferrite/austenite ratio, elemental diffusion, and pitting corrosion resistance of weld joints were analyzed. When the Ni content of the weld wire deposit was at minimum 2-4% higher than that of 2205 DSS base metal, the desired ratio of ferrite/austenite and elemental partitioning between the austenite and ferrite phases were obtained. While the pitting sensitivity of weld metal was higher than that of base metal, the self-healing capability of the passive film of weld metal was better than that of the base metal when a single V-type groove was used. Furthermore, the heat input should be carefully controlled since pitting corrosion occurred readily in the coarse-grained heat-affected zone near the fusion line of welded joints.

Seven-year follow-up of percutaneous closure of patent foramen ovale.

Science.gov (United States)

Mirzada, Naqibullah; Ladenvall, Per; Hansson, Per-Olof; Johansson, Magnus Carl; Furenäs, Eva; Eriksson, Peter; Dellborg, Mikael

2013-12-01

Observational studies favor percutaneous closure of patent foramen ovale (PFO) over medical treatment to reduce recurrent stroke while randomized trials fail to demonstrate significant superiority of percutaneous PFO closure. Few long-term studies are available post PFO closure. This study reports long-term clinical outcomes after percutaneous PFO closure. Between 1997 and 2006, 86 consecutive eligible patients with cerebrovascular events, presumably related to PFO, underwent percutaneous PFO closure. All 86 patients were invited to a long-term follow-up, which was carried out during 2011 and 2012. Percutaneous PFO closure was successfully performed in 85 of 86 patients. The follow-up rate was 100%. No cardiovascular or cerebrovascular deaths occurred. Two patients (both women) died from lung cancer during follow-up. Follow-up visits were conducted for 64 patients and the remaining 20 patients were followed up by phone. The mean follow-up time was 7.3 years (5 to 12.4 years). Mean age at PFO closure was 49 years. One patient had a minor stroke one month after PFO closure and a transient ischemic attack (TIA) two years afterwards. One other patient suffered from a TIA six years after closure. No long-term device-related complications were observed. Percutaneous PFO closure was associated with very low risk of recurrent stroke and is suitable in most patients. We observed no mortality and no long-term device-related complications related to PFO closure, indicating that percutaneous PFO closure is a safe and efficient treatment even in the long term.

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.

Science.gov (United States)

Zelinka, Samuel L; Bourne, Keith J; Hermanson, John C; Glass, Samuel V; Costa, Adriana; Wiedenhoeft, Alex C

2015-10-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pits, collected on a mesomechanical testing system. The system consists of a quartz microprobe attached to a microforce sensor that is positioned and advanced with a micromanipulator mounted on an inverted microscope. Membrane displacement is measured from digital image analysis. Unaspirated pits from earlywood of never-dried wood of Larix and Pinus and aspirated pits from earlywood of dried wood of Larix were tested to generate force-displacement curves up to the point of membrane failure. Two failure modes were observed: rupture or tearing of the pit membrane by the microprobe tip, and the stretching of the pit membrane until the torus was forced out of the pit chamber through the pit aperture without rupture, a condition we refer to as torus prolapse. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Reliability assessment of underground shaft closure

International Nuclear Information System (INIS)

Fossum, A.F.; Munson, D.E.

1994-01-01

The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties

Closure Strategy for a Waste Disposal Facility with Multiple Waste Types and Regulatory Drivers at the Nevada Test Site - 8422

International Nuclear Information System (INIS)

D Wieland; V Yucel; L Desotell; G Shott; J Wrapp

2008-01-01

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) plans to close the waste and classified material storage cells in the southeast quadrant of the Area 5 Radioactive Waste Management Site (RWMS), informally known as the '92-Acre Area', by 2011. The 25 shallow trenches and pits and the 13 Greater Confinement Disposal (GCD) borings contain various waste streams including low-level waste (LLW), low-level mixed waste (LLMW), transuranic (TRU), mixed transuranic (MTRU), and high specific activity LLW. The cells are managed under several regulatory and permit programs by the U.S. Department of Energy (DOE) and the Nevada Division of Environmental Protection (NDEP). Although the specific closure requirements for each cell vary, 37 closely spaced cells will be closed under a single integrated monolayer evapotranspirative (ET) final cover. One cell will be closed under a separate cover concurrently. The site setting and climate constrain transport pathways and are factors in the technical approach to closure and performance assessment. Successful implementation of the integrated closure plan requires excellent communication and coordination between NNSA/NSO and the regulators

Corrective Action Investigation Plan for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada, July 2002, Rev. No. 0

International Nuclear Information System (INIS)

2002-01-01

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 140 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 140 consists of nine Corrective Action Sites (CASs): 05-08-01, Detonation Pits; 05-08-02, Debris Pits; 05-17-01, Hazardous Waste Accumulation Site (Buried); 05-19-01, Waste Disposal Site; 05-23-01, Gravel Gertie; 05-35-01, Burn Pit; 05-99-04, Burn Pit; 22-99-04, Radioactive Waste Dump; 23-17-01, Hazardous Waste Storage Area. All nine of these CASs are located within Areas 5, 22, and 23 of the Nevada Test Site (NTS) in Nevada, approximately 65 miles northwest of Las Vegas. This CAU is being investigated because disposed waste may be present without appropriate controls (i.e., use restrictions, adequate cover) and hazardous and/or radioactive constituents may be present or migrating at concentrations and locations that could potentially pose a threat to human health and the environment. The NTS has been used for various research and development projects including nuclear weapons testing. The CASs in CAU 140 were used for testing, material storage, waste storage, and waste disposal. A two-phase approach has been selected to collect information and generate data to satisfy needed resolution criteria and resolve the decision statements. Phase I will determine if contaminants of potential concern (COPCs) are present in concentrations exceeding preliminary action levels. This data will be evaluated at all CASs. Phase II will determine the extent of the contaminant(s) of concern (COCs). This data will only be evaluated for CASs with a COC identified during Phase I. Based on process knowledge, the COPCs for CAU 140 include volatile organics, semivolatile organics, petroleum hydrocarbons, explosive residues

Road Closures

Data.gov (United States)

Montgomery County of Maryland — This is an up to date map of current road closures in Montgomery County.This dataset is updated every few minutes from the Department of Transportation road closure...

Sustainable Environmental Protection Using Modified Pit-Latrines

NARCIS (Netherlands)

Chaggu, E.J.

2004-01-01

Pit-latrines are on-site excreta disposal facilities widely used as anaerobic accumulation system for stabilizing human wastes like excreta, both in rural and urban settlements of developing countries. Flooding of pit-latrines is often a common phenomenon, especially in situations of high water

Pitting corrosion of copper. An equilibrium - mass transport study

International Nuclear Information System (INIS)

Taxen, C.

2002-08-01

A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases

Pitting corrosion of copper. An equilibrium - mass transport study

Energy Technology Data Exchange (ETDEWEB)

Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden)

2002-08-01

A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases.

Testing of intergranular and pitting corrosion in sensitized welded joints of austenitic stainless steel

Directory of Open Access Journals (Sweden)

Bore V. Jegdic

2017-06-01

Full Text Available Pitting corrosion resistance and intergranular corrosion of the austenitic stainless steel X5Cr Ni18-10 were tested on the base metal, heat affected zone and weld metal. Testing of pitting corrosion was performed by the potentiodynamic polarization method, while testing of intergranular corrosion was performed by the method of electrochemical potentiokinetic reactivation with double loop. The base metal was completely resistant to intergranular corrosion, while the heat affected zone showed a slight susceptibility to intergranular corrosion. Indicators of pitting corrosion resistance for the weld metal and the base metal were very similar, but their values are significantly higher than the values for the heat affected zone. This was caused by reduction of the chromium concentration in the grain boundary areas in the heat affected zone, even though the carbon content in the examined stainless steel is low (0.04 wt. % C.

Standardized emissions inventory methodology for open-pit mining areas.

Science.gov (United States)

Huertas, Jose I; Camacho, Dumar A; Huertas, Maria E

2011-08-01

There is still interest in a unified methodology to quantify the mass of particulate material emitted into the atmosphere by activities inherent to open-pit mining. For the case of total suspended particles (TSP), the current practice is to estimate such emissions by developing inventories based on the emission factors recommended by the USEPA for this purpose. However, there are disputes over the specific emission factors that must be used for each activity and the applicability of such factors to cases quite different to the ones under which they were obtained. There is also a need for particulate matter with an aerodynamic diameter less than 10 μm (PM(10)) emission inventories and for metrics to evaluate the emission control programs implemented by open-pit mines. To address these needs, work was carried out to establish a standardized TSP and PM(10) emission inventory methodology for open-pit mining areas. The proposed methodology was applied to seven of the eight mining companies operating in the northern part of Colombia, home to the one of the world's largest open-pit coal mining operations (∼70 Mt/year). The results obtained show that transport on unpaved roads is the mining activity that generates most of the emissions and that the total emissions may be reduced up to 72% by spraying water on the unpaved roads. Performance metrics were defined for the emission control programs implemented by mining companies. It was found that coal open-pit mines are emitting 0.726 and 0.180 kg of TSP and PM(10), respectively, per ton of coal produced. It was also found that these mines are using on average 1.148 m(2) of land per ton of coal produced per year.

A predictive approach to fitness-for-service assessment of pitting corrosion

International Nuclear Information System (INIS)

Shekari, Elahe; Khan, Faisal; Ahmed, Salim

2016-01-01

Pitting corrosion is a localized corrosion that often causes leak and failure of process components. The aim of this work is to present a new fitness-for-service (FFS) assessment methodology for process equipment to track and predict pitting corrosion. In this methodology, pit density is modeled using a non-homogenous Poisson process and induction time for pit initiation is simulated as the realization of a Weibull process. The non-homogenous Markov process is used to estimate maximum pit depth, considering that only the current state of the damage influences its future development. Subsequently, the distributions of the operating pressure and the estimated burst pressure of the defected component are integrated with Monte Carlo simulations and First Order Second Moment (FOSM) method to calculate the reliability index and probability of failure. This methodology provides a more realistic failure assessment and enables consideration of uncertainty associated with estimating pit characteristics. The practical application of the proposed model is demonstrated using a piping case study. - Highlights: • A new model to estimate maximum pit depth and pit density as two main pit characteristics. • Integrating maximum pit depth with failure analysis considering allowable pressure of defected component. • Time dependent failure analysis to determine the remaining life.

Efficient utilization of waste date pits for the synthesis of green diesel and jet fuel fractions

International Nuclear Information System (INIS)

Al-Muhtaseb, Ala’a H.; Jamil, Farrukh; Al-Haj, Lamya; Al-Hinai, Mohab A.; Baawain, Mahad; Myint, Myo Tay Zar; Rooney, David

2016-01-01

Highlights: • Active catalysts Pt/C and Pd/C were developed from waste date pits. • Catalysts showed good activity in hydrodeoxygenation of date pit oil to alkane fuels. • The liquid product fractions lay within the range of the jet fuel and green diesel. • Green diesel fraction obtained by Pd/C was 72.03% and jet fuel was 30.39%. • Date pits can be a promising platform for the production of catalysts and biofuels. - Abstract: Date pits are considered one of the major agricultural wastes in Oman. The present work involves the synthesis of active catalysts from waste date pits carbon produced by carbonization and impregnation with Pt and Pd metals. Synthesized catalysts Pt/C and Pd/C were characterized by XRD, SEM, TEM, EDX, BET and XPS. The activity of the catalysts’ performance was evaluated by the hydrodeoxygenation of date pits oil for the production of second-generation biofuels, which includes jet fuel and green diesel fractions. Results indicate that the synthesized catalysts were highly active for the hydrodeoxygenation of date pits oil. Based on the elemental analysis, the degree of deoxygenation (DOD) of product oil was 97.5% and 89.4% for the Pd/C and Pt/C catalysts respectively. The high DOD was also confirmed by product analyses that mainly consist of paraffinic hydrocarbons. Results also showed that between the two catalysts, Pd/C showed a higher activity towards hydrodeoxygenation, a conclusion that was based on the high DOD of the product oil due to hydrocarbons formation. Based on the type of components in the product oil, the maximum fraction of hydrocarbons formed lay within the range of 72.03% and 72.78% green diesel, and 30.39% and 28.25% jet fuel using Pd/C and Pt/C catalysts respectively. It can be concluded that waste date pits can be a promising platform for the production of catalysts and biofuels.

Least tern and piping plover nesting at sand pits in Nebraska

Science.gov (United States)

Sidle, John G.; Kirsch, E.M.

1993-01-01

Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

Patent Foramen Ovale Closure in the Setting of Cryptogenic Stroke: A Meta-Analysis of Five Randomized Trials.

Science.gov (United States)

Garg, Lohit; Haleem, Affan; Varade, Shweta; Sivakumar, Keithan; Shah, Mahek; Patel, Brijesh; Agarwal, Manyoo; Agrawal, Sahil; Leary, Megan; Kluck, Bryan

2018-05-24

The clinical benefit of patent foramen ovale (PFO) closure after cryptogenic stroke has been a topic of debate for decades. Recently, 3 randomized controlled trials of PFO closure in patients with cryptogenic stroke demonstrated a significantly reduced risk of recurrent stroke compared with standard medical therapy alone. This meta-analysis was performed to clarify the efficacy of PFO closure for future stroke prevention in this population. A systematic literature search was undertaken. Published pooled data from 5 large randomized clinical trials (CLOSE, RESPECT, Gore REDUCE, CLOSURE I, and PC) were combined and then subsequently analyzed. Enrolled patients with cryptogenic stroke were assigned to receive standard medical care or to undergo endovascular PFO closure, with a primary outcome of reduction in stroke recurrence rate. Secondary outcomes included rates of transient ischemic attack (TIA), composite outcome of stroke, TIA, and death from all causes, and rates of atrial fibrillation events. We analyzed data for 3412 patients. Transcatheter PFO closure resulted in a statistically significant reduced rate of recurrent stroke, compared with medication alone. Patients undergoing closure were 58% less likely to have another stroke. The number needed to treat with PFO closure to reduce recurrent stroke for 1 patient was 40. Endovascular PFO closure was associated with a reduced risk of recurrent stroke in patients with a prior cryptogenic cerebral infarct. Although the absolute stroke reduction was small, these findings are clinically significant, given the young age of this patient population and the patients' lifetime risk of recurrent stroke. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Corrective Action Decision Document for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada: Revision No. 0

Energy Technology Data Exchange (ETDEWEB)

U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

2003-10-17

This Corrective Action Decision Document identifies and rationalizes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's selection of a recommended corrective action alternative appropriate to facilitate the closure of Corrective Action Unit (CAU) 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in Areas 5, 22, and 23 of the NTS, CAU 140 consists of nine corrective action sites (CASs). Investigation activities were performed from November 13 through December 11, 2002, with additional sampling to delineate the extent of contaminants of concern (COCs) conducted on February 4 and March 18 and 19, 2003. Results obtained from the investigation activities and sampling indicated that only 3 of the 9 CASs at CAU 140 had COCs identified. Following a review of existing data, future land use, and current operations at the NTS, the following preferred alternatives were developed for consideration: (1) No Further Action - six CASs (05-08-02, 05-17-01, 05-19-01, 05-35-01, 05-99-04, and 22-99-04); (2) Clean Closure - one CAS (05-08-01), and (3) Closure-in-Place - two CASs (05-23-01 and 23-17-01). These alternatives were judged to meet all requirements for the technical components evaluated. Additionally, the alternatives meet all applicable state and federal regulations for closure of the site and will eliminate potential future exposure pathways to the contaminated media at CAU 140.

Composição mineral e severidade de "bitter pit" em maçãs 'Catarina' Mineral composition and bitter pit severity in 'Catarina' apples

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2006-04-01

Full Text Available Maçãs 'Catarina', colhidas na maturação comercial em pomar no município de São Joaquim-SC, foram separadas em quatro lotes de 14 frutos, de acordo com a severidade de incidência de "bitter pit": nula (nenhuma lesão/fruto, baixa (1-2 lesões/fruto, moderada (3-5 lesões/fruto e alta (6-18 lesões/fruto. Foram determinadas as concentrações de Ca, Mg, K e N na casca e na polpa de cada fruto. Foram verificadas relação linear (P 'Catarina' apples were harvested at the commercial maturity in an orchard in São Joaquim-SC and segregated in four lots of 14 fruits with different levels of bitter pit severity: null (none pit/fruit, low (1-2 pits/fruit, moderate (3-5 pits/fruit, and high (6-18 pits/fruit. Nutritional analysis (Ca, Mg, K, and N in the skin and flesh tissues were performed on individual fruits of each severity level. The average number of pits/fruit (calculated for each lot of bitter pit severity showed a negative linear relationship (P < 0.05 with the skin Ca content, and a negative linear relationship (P < 0.05 with the ratios of Mg/Ca, (K+Mg/Ca, and (K+Mg+N/Ca in the skin. For the flesh, the increasing of bitter pit severity was accompanied by significant reduction of Ca and Mg contents. The multivariate analysis (canonical discriminant analysis showed that the Mg/Ca ratio in the skin provided the best discrimination between the lots of fruit with different levels of bitter pit severity. Therefore, for 'Catarina' apples, increasing values of the Mg/Ca ratio in the skin are indicative of fruits with increasing bitter pit susceptibility.

Systematic review and meta-analysis of published randomized controlled trials comparing purse-string vs conventional linear closure of the wound following ileostomy (stoma) closure.

Science.gov (United States)

Sajid, Muhammad Shafique; Bhatti, Muhammad I; Miles, William Fa

2015-05-01

The objective of this article is to systematically analyse the randomized, controlled trials comparing the effectiveness of purse-string closure (PSC) of an ileostomy wound with conventional linear closure (CLC). Randomized, controlled trials comparing the effectiveness of purse-string closure vs conventional linear closure (CLC) of ileostomy wound in patients undergoing ileostomy closure were analysed using RevMan®, and the combined outcomes were expressed as risk ratio (RR) and standardized mean difference (SMD). Three randomized, controlled trials, recruiting 206 patients, were retrieved from medical electronic databases. There were 105 patients in the PSC group and 101 patients in the CLC group. There was no heterogeneity among included trials. Duration of operation (SMD: -0.18; 95% CI: -0.45, 0.09; z = 1.28; P SMD: 0.01; 95% CI: -0.26, 0.28; z = 0.07; P infection (OR, 0.10; 95% CI: 0.03, 0.33; z = 3.78; P infection apparently without influencing the duration of operation and length of hospital stay. © The Author(s) 2014. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

Treatment of a mud pit by bioremediation.

Science.gov (United States)

Avdalović, Jelena; Đurić, Aleksandra; Miletić, Srdjan; Ilić, Mila; Milić, Jelena; Vrvić, Miroslav M

2016-08-01

The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg(-1) (95% degradation) during six months of treatment. © The Author(s) 2016.

Deterministic chaos in the pitting phenomena of passivable alloys

International Nuclear Information System (INIS)

Hoerle, Stephane

1998-01-01

It was shown that electrochemical noise recorded in stable pitting conditions exhibits deterministic (even chaotic) features. The occurrence of deterministic behaviors depend on the material/solution severity. Thus, electrolyte composition ([Cl - ]/[NO 3 - ] ratio, pH), passive film thickness or alloy composition can change the deterministic features. Only one pit is sufficient to observe deterministic behaviors. The electrochemical noise signals are non-stationary, which is a hint of a change with time in the pit behavior (propagation speed or mean). Modifications of electrolyte composition reveals transitions between random and deterministic behaviors. Spontaneous transitions between deterministic behaviors of different features (bifurcation) are also evidenced. Such bifurcations enlighten various routes to chaos. The routes to chaos and the features of chaotic signals allow to suggest the modeling (continuous and discontinuous models are proposed) of the electrochemical mechanisms inside a pit, that describe quite well the experimental behaviors and the effect of the various parameters. The analysis of the chaotic behaviors of a pit leads to a better understanding of propagation mechanisms and give tools for pit monitoring. (author) [fr

Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

DEFF Research Database (Denmark)

Søndergaard, Lars; Kasner, Scott E; Rhodes, John F

2017-01-01

BACKGROUND: The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new...... brain infarctions. METHODS: In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group......). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month...

ASSESSMENT OF LENS THICKNESS IN ANGLE CLOSURE DISEASE

Directory of Open Access Journals (Sweden)

Nishat Sultana Khayoom

2016-08-01

Full Text Available BACKGROUND Anterior chamber depth and lens thickness have been considered as important biometric determinants in primary angle-closure glaucoma. Patients with primary narrow angle may be classified as a primary angle closure suspect (PACS, or as having primary angle closure (PAC or primary angle closure glaucoma (PACG. 23.9% of patients with primary angle closure disease are in India, which highlights the importance of understanding the disease, its natural history, and its underlying pathophysiology, so that we may try to establish effective methods of treatment and preventative measures to delay, or even arrest, disease progression, thereby reducing visual morbidity. AIM To determine the lens thickness using A-scan biometry and its significance in various stages of angle closure disease. MATERIALS AND METHODS Patients attending outpatient department at Minto Ophthalmic Hospital between October 2013 to May 2015 were screened for angle closure disease and subsequently evaluated at glaucoma department. In our study, lens thickness showed a direct correlation with shallowing of the anterior chamber by determining the LT/ ACD ratio. A decrease in anterior chamber depth is proportional to the narrowing of the angle which contributes to the progression of the angle closure disease from just apposition to occlusion enhancing the risk for optic nerve damage and visual field loss. Hence, if the lens thickness values are assessed earlier in the disease process, appropriate intervention can be planned. CONCLUSION Determination of lens changes along with anterior chamber depth and axial length morphometrically can aid in early detection of angle closure. The role of lens extraction for PACG is a subject of increased interest. Lens extraction promotes the benefits of anatomical opening of the angle, IOP reduction and improved vision. This potential intervention may be one among the armamentarium of approaches for PACG. Among the current treatment modalities

Security option file - After closure (DOS-AF)

International Nuclear Information System (INIS)

2016-01-01

A first volume presents the context and scope of the Cigeo project, and the scope of this document. It proposes a general presentation of Cigeo, the regulatory framework and standards. It describes the different aspects and components of the security strategy: principles, security functions after closure, objectives of protection, global approach. It proposes a security assessment: objectives, consistency with international practices, assessment steps, scenarios, scenario quantitative assessment. The next part addresses security management. The second volume contains a description of the storage system: site characteristics, types of stored parcels, the future of the installation after its closure. The third volume proposes a security assessment. It addresses the management of risks and uncertainties, describes a scenario of normal evolution and also scenarios of altered evolutions, scenarios of unintentional human intrusion, and what-if type scenarios. The fourth volume reports lessons at the current stage of the project, and gives an overview of important activities from storage design to storage closure

Understanding of surface pit formation mechanism of GaN grown in MOCVD based on local thermodynamic equilibrium assumption

Science.gov (United States)

Zhi-Yuan, Gao; Xiao-Wei, Xue; Jiang-Jiang, Li; Xun, Wang; Yan-Hui, Xing; Bi-Feng, Cui; De-Shu, Zou

2016-06-01

Frank’s theory describes that a screw dislocation will produce a pit on the surface, and has been evidenced in many material systems including GaN. However, the size of the pit calculated from the theory deviates significantly from experimental result. Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN, we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same. If the kinetic process is too vigorous or too slow to reach a balance, the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state. When the curvature at the center of the dislocation core reaches the critical value 1/r 0, at the edge of the spiral, the accelerating rate of the curvature may not fall to zero, so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204009 and 61204011) and the Beijing Municipal Natural Science Foundation, China (Grant No. 4142005).

Spontaneous Resolution of Optic Disc Pit Maculopathy

Directory of Open Access Journals (Sweden)

Koushik Tripathy

2017-06-01

Full Text Available I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT does not clearly show typical intraretinal schisis (Figure 1B1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM cavity. Such cavities are known to occur following the resolution of sub-ILM bleed due to various cause including Valsalva retinopathy,2 Terson syndrome, and also in some retinitis3 cases.4 In fact, some of these cavities may simulate a neurosensory retinal detachment or central serous chorioretinopathy on cursory clinical examination.5 To confirm that the features of the current patient1 are indeed related to the optic disc pit, it is necessary for the authors to provide an OCT scan which shows a connection of the presented cavity with the optic disc pit. Also, clear OCT scans of the fovea, both at presentation and at final follow-up would help our understanding of the visual recovery of the patient. The interval between the presenting (28 June 2012 OCT and final OCT (30 Nov 2012 is 5 months and not 6 months as described in the manuscript. For an effective comparison, both the presenting and final OCT scans should have been taken using either horizontal or vertical orientation over the macula. Though the spontaneous resolution of optic disc pit maculopathy is possible, visual recovery in usually unlikely and in such cases an alternate diagnosis needs to be excluded.

Use of tracers to quantify subsurface flow through a mining pit.

Science.gov (United States)

Schladow, S Geoffrey; Clark, Jordan F

2008-12-01

Three independent tracer experiments were conducted to quantify the through-flow of water from Herman Pit, an abandoned mercury (Hg) mine pit adjacent to Clear Lake, California, USA. The tracers used were Rhodamine-WT, sulfur hexafluoride, and a mixture of sulfur hexafluoride and neon-22. The tracers were injected into Herman Pit, a generally well-mixed water body of approximately 81,000 m2, and the concentrations were monitored in the mine pit, observation wells, and the lake for 2-3 months following each injection. The results for all three experiments showed that the tracer arrived at certain observation wells within days of injection. Comparing all the well data showed a highly heterogeneous response, with a small number of wells showing this near-instantaneous response and others taking months before the tracer was detectable. Tracer was also found in the lake on four occasions over a one-month period, too few to infer any pattern but sufficient to confirm the connection of the two water bodies. Using a simple mass balance model it was possible to determine the effective loss rate through advection for each of the tracers and with this to estimate the through-flow rate. The through-flow rate for all three experiments was approximately 630 L/s, at least 1-2 orders of magnitude larger than previous estimates, all of which had been based on geochemical inferences or other indirect measures of the pit through-flow.

Lithium and sodium ion capacitors with high energy and power densities based on carbons from recycled olive pits

Science.gov (United States)

Ajuria, Jon; Redondo, Edurne; Arnaiz, Maria; Mysyk, Roman; Rojo, Teófilo; Goikolea, Eider

2017-08-01

In this work, we are presenting both lithium and sodium ion capacitors (LIC and NIC) entirely based on electrodes designed from recycled olive pit bio-waste derived carbon materials. On the one hand, olive pits were pyrolized to obtain a low specific surface area semigraphitic hard carbon to be used as the ion intercalation (battery-type) negative electrode. On the other hand, the same hard carbon was chemically activated with KOH to obtain a high specific surface area activated carbon that was further used as the ion-adsorption (capacitor-type) positive electrode. Both electrodes were custom-made to be assembled in a hybrid cell to either build a LIC or NIC in the corresponding Li- and Na-based electrolytes. For comparison purposes, a symmetric EDLC supercapacitor cell using the same activated carbon in 1.5 M Et4NBF4/acetonitrile electrolyte was also built. Both LIC and NIC systems demonstrate remarkable energy and power density enhancement over its EDLC counterpart while showing good cycle life. This breakthrough offers the possibility to easily fabricate versatile hybrid ion capacitors, covering a wide variety of applications where different requirements are demanded.

Defense Base Realignment and Closure Budget Data for the Realignment of the Bureau of Naval Personnel, Washington, D.C., to Naval Air Station Memphis, Tennessee

National Research Council Canada - National Science Library

Granetto, Paul

1995-01-01

... requested for each military construction project associated with Defense base realignment and closure does not exceed the original estimated cost provided to the Commission on Defense Base Closure and Realignment (the Commission...

Liquid waste processing from TRIGA spent fuel storage pits

International Nuclear Information System (INIS)

Buchtela, Karl

1988-01-01

At the Atominstitute of the Austrian Universities and also at other facilities running TRIGA reactors, storage pits for spent fuel elements are installed. During the last revision procedure, the reactor group of the Atominstitute decided to refill the storage pits and to get rid of any contaminated storage pit water. The liquid radioactive waste had been pumped to polyethylene vessels for intermediate storage before decontamination and release. The activity concentration of the storage pit water at the Aominstitute after a storage period of several years was about 40 kBq/l, the total amount of liquid in the storage pits was about 0.25 m 3 . It was attempted to find a simple and inexpensive method to remove especially the radioactive Cesium from the waste solution. Different methods for decontamination like distillation, precipitation and ion exchange are discussed

Factors associated with closures of emergency departments in the United States.

Science.gov (United States)

Hsia, Renee Y; Kellermann, Arthur L; Shen, Yu-Chu

2011-05-18

Between 1998 and 2008, the number of hospital-based emergency departments (EDs) in the United States declined, while the number of ED visits increased, particularly visits by patients who were publicly insured and uninsured. Little is known about the hospital, community, and market factors associated with ED closures. Federal law requiring EDs to treat all in need regardless of a patient's ability to pay may make EDs more vulnerable to the market forces that govern US health care. To determine hospital, community, and market factors associated with ED closures. Emergency department and hospital organizational information from 1990 through 2009 was acquired from the American Hospital Association (AHA) Annual Surveys (annual response rates ranging from 84%-92%) and merged with hospital financial and payer mix information available through 2007 from Medicare hospital cost reports. We evaluated 3 sets of risk factors: hospital characteristics (safety net [as defined by hospitals caring for more than double their Medicaid share of discharges compared with other hospitals within a 15-mile radius], ownership, teaching status, system membership, ED size, case mix), county population demographics (race, poverty, uninsurance, elderly), and market factors (ownership mix, profit margin, location in a competitive market, presence of other EDs). All general, acute, nonrural, short-stay hospitals in the United States with an operating ED anytime from 1990-2009. Closure of an ED during the study period. From 1990 to 2009, the number of hospitals with EDs in nonrural areas declined from 2446 to 1779, with 1041 EDs closing and 374 hospitals opening EDs. Based on analysis of 2814 urban acute-care hospitals, constituting 36,335 hospital-year observations over an 18-year study interval (1990-2007), for-profit hospitals and those with low profit margins were more likely to close than their counterparts (cumulative hazard rate based on bivariate model, 26% vs 16%; hazard ratio [HR], 1

Holistic Considerations in Optimizing a Sterile Product Package to Ensure Container Closure Integrity.

Science.gov (United States)

Degrazio, Fran L

2018-01-01

A new major chapter dealing with container closure integrity was released by the United States Pharmacopeial Convention. Chapter provides a significant amount of education and guidance concerning test methodologies to prove that a system is integral and safe for use. The test method used is only one of the major considerations in approaching the challenge of proving an integral system. This paper takes a holistic review of all the major considerations needed in qualifying a new vial system for container closure integrity. There is substantial interplay among many aspects in the process of sealing a vial. This review helps to define major risks that need to be considered and mitigated and reinforces the need to understand the maximum allowable leakage limit that is acceptable for a specific drug application. A typical risk-based approach considers materials, test methods, process, people, environment, and equipment. Each of these aspects is considered in some detail along with a recommended process flow for building a best practice, science-based approach. This approach will inform decision making for evaluating the correct combination of components and assuring they are assembled and tested in an appropriate manner. This work, once completed, can be the basis for a vial system platform or specific drug application qualification. LAY ABSTRACT: Container closure integrity is a fundamental requirement of every sterile drug package. With recent upgrading of compendia standards and guidance around this issue, there is an opportunity to better define a best practice approach to a complicated subject. It is important to recognize that there is substantial interplay among the components of the system, the process of assembly, and the test methods that are used. This paper takes a holistic approach to discussing these issues and identifying the risks that must be considered in assuring an integral container over the shelf life of a drug product. © PDA, Inc. 2018.

Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

Directory of Open Access Journals (Sweden)

Wei Yan

2016-01-01

Full Text Available Downhole casing and tubing are subjected to corrosion in many cases because of the exposure to corrosive environment. A more serious problem is that pitting corrosion occurs in the casing inner surface. Meanwhile, downhole strings are subjected to various forms of mechanical loads, for example, internal pressure load, external collapse load, or both. These loads acting on the corrosion pits will cause stress concentration and degrade the casing strength. Thus, it is essential to evaluate the stress concentration degree reasonably. The SCF (stress concentration factor is usually used to characterize the degree of stress concentration induced by corrosion pits. This paper presented a comparison on the SCFs regarding the analytical method for a single pit and experimental method for double pits. The results show that the SCF of a single pit depends mainly on the depth of the corrosion pit; however, the SCF of the double pits strongly depends on the pits distance. A correction factor of 1.3 was recommended in the double pits SCF prediction model.

Speed, Acceleration, Chameleons and Cherry Pit Projectiles

Science.gov (United States)

Planinsic, Gorazd; Likar, Andrej

2012-01-01

The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2008

International Nuclear Information System (INIS)

2009-01-01

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2008 and includes inspection and repair activities completed at the following ten CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 404: Roller Coaster Lagoons and Trench (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 426: Cactus Spring Waste Trenches (TTR) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) CAU 487: Thunderwell Site (TTR)

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2008

Energy Technology Data Exchange (ETDEWEB)

NSTec Environmental Restoration

2009-03-19

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2008 and includes inspection and repair activities completed at the following ten CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 404: Roller Coaster Lagoons and Trench (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 426: Cactus Spring Waste Trenches (TTR) CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 484: Surface Debris, Waste Sites, and Burn Area (TTR) CAU 487: Thunderwell Site (TTR)

Status of the pit disassembly and conversion facility

International Nuclear Information System (INIS)

Wood, Warren T.; Christensen, Lowell T.

2000-01-01

A planned new facility, the Pit Disassembly and Conversion Facility (PDCF), will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium from those pits into a form suitable for storage, international inspection, and final disposition. Sized to handle 35 metric tons of plutonium from pits and other sources over its 10-year operating life, the PDCF will apply the Advanced Recovery and Integrated Extraction System (ARIES) technology. ARIES process technology has been developed at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL), and an integrated system is being demonstrated at LANL. The Los Alamos National Laboratory is the lead for technical design oversight of the PDCF. Technical data gained from the ARIES demonstrations is integral for the proper design of the PDCF

Standard test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric Chloride solution

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 These test methods cover procedures for the determination of the resistance of stainless steels and related alloys to pitting and crevice corrosion (see Terminology G 15) when exposed to oxidizing chloride environments. Six procedures are described and identified as Methods A, B, C, D, E, and F. 1.1.1 Method A—Ferric chloride pitting test. 1.1.2 Method B—Ferric chloride crevice test. 1.1.3 Method C—Critical pitting temperature test for nickel-base and chromium-bearing alloys. 1.1.4 Method D—Critical crevice temperature test for nickel-base and chromium-bearing alloys. 1.1.5 Method E—Critical pitting temperature test for stainless steels. 1.1.6 Method F—Critical crevice temperature test for stainless steels. 1.2 Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium-bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys. Methods C, D, E and F allow for a rankin...

Biomechanics Strategies for Space Closure in Deep Overbite

Directory of Open Access Journals (Sweden)

Harryanto Wijaya

2013-07-01

Full Text Available Space closure is an interesting aspect of orthodontic treatment related to principles of biomechanics. It should be tailored individually based on patient’s diagnosis and treatment plan. Understanding the space closure biomechanics basis leads to achieve the desired treatment objective. Overbite deepening and losing posterior anchorage are the two most common unwanted side effects in space closure. Conventionally, correction of overbite must be done before space closure resulted in longer treatment. Application of proper space closure biomechanics strategies is necessary to achieve the desired treatment outcome. This cases report aimed to show the space closure biomechanics strategies that effectively control the overbite as well as posterior anchorage in deep overbite patients without increasing treatment time. Two patients who presented with class II division 1 malocclusion were treated with fixed orthodontic appliance. The primary strategies included extraction space closure on segmented arch that employed two-step space closure, namely single canine retraction simultaneously with incisors intrusion followed by enmasse retraction of four incisors by using differential moment concept. These strategies successfully closed the space, corrected deep overbite and controlled posterior anchorage simultaneously so that the treatment time was shortened. Biomechanics strategies that utilized were effective to achieve the desired treatment outcome.

Project transition to risk based corrective action

International Nuclear Information System (INIS)

Judge, J.M.; Cormier, S.L.

1996-01-01

Many states have adopted or are considering the adoption of the America Society for Testing and Materials (ASTM) Standard E 1739, Standard for Risk Based Corrective Action (RBCA) Applied to Petroleum Release Sites. This standard is being adopted to regulate leaking underground storage tank (LUST) sites. The case studies of two LUST sites in Michigan will be presented to demonstrate the decision making process and limiting factors involved in transitioning sites to the RBCA program. Both of these case studies had been previously investigated and one was actively remediated. The first case study involves a private petroleum facility where soil and ground water have been impacted. Remediation involved a ground water pump and treat system. Subsequent monitoring during system operation indicated that analytical data were still above the Tier 1 RBSLs but below the Tier 2 SSTLs. The closure strategy that was developed was based on the compounds of concern that were below the SSTLs. A deed restriction was also developed for the site as an institutional control. The second LUST site exhibited BTEX concentrations in soil and ground water above the Tier 1 RBSLs. Due to the exceedence of the Tier 1 RBSLs, the second site required a Tier 2 assessment to develop SSTLs as remedial objectives and remove hot spots in the soil and treat the ground water to achieve closure. Again, a deed restriction was instituted along with a performance monitoring plan

Pitted keratolysis – a frequently misdiagnosed, mild, infectious disorder of soles

Directory of Open Access Journals (Sweden)

Zuzanna Lewicka-Potocka

2016-05-01

Full Text Available Introduction . Pitted keratolysis (PK is a mild infectious skin disorder caused by Corynebacterium spp., Kytococcus sedentarius or Dermatophilus congolensis . These bacteria produce enzymes that digest keratin, causing superficial lesions in the plantar surface. The disease is predominantly observed in young men. Objective . Pitted keratolysis despite the characteristic presentation of skin lesions is often misdiagnosed. In this article we aimed to remind readers of its clinical aspects and treatment by presenting a typical PK case. Case report. A 35-year-old man was admitted to the dermatological clinic due to skin lesions on both soles. In the physical examination we found multiple crateriform pits, associated with hyperhidrosis and malodour diagnosed as PK. Remission of lesions was observed after treatment with oral erythromycin. Conclusions . The differential diagnosis of plantar skin lesions should include PK. Due to typical clinical manifestation the diagnosis is based on physical examination.

The role of inclusions in the pitting behaviour of maraging steel

International Nuclear Information System (INIS)

Ahmad, M.S.; Hussain, S.W.; Ashraf, H.

1999-01-01

The pitting characteristics of maraging steel in artificial seawater have been investigated electrochemically using the cyclic polarization technique. Pits were found to be associated with the inclusions present in steel. The hysteresis loop observed indicates that maraging steel has poor resistance to pitting in air saturated seawater. On examination of corroded surfaces under SEM, it is noted that the pits are always associated with inclusions, which are generally the carbonitrides of TiMo presents in maraging steel in varying quantities depending on the melting practice. In order to confirm that the pitting behavior is associated with inclusions, samples from clean maraging steel, having very low inclusion level, were tested. Such samples showed much less tendency for pitting. (author)

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester

Science.gov (United States)

Samuel L. Zelinka; Keith J. Bourne; John C. Hermanson; Samuel V. Glass; Adriana Costa; Alex C. Wiedenhoeft

2015-01-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force–displacement measurements for pit membranes of circular bordered pits, collected on a...

Investigating oiled birds from oil field waste pits

International Nuclear Information System (INIS)

Gregory, D.G.; Edwards, W.C.

1991-01-01

Procedures and results of investigations concerning the oiling of inland raptors, migratory water-fowl and other birds are presented. Freon washings from the oiled birds and oil from the pits were analyzed by gas chromatography. In most instances the source of the oil could be established by chromatographic procedures. The numbers of birds involved (including many on the endangered species list) suggested the need for netting or closing oil field waste pits and mud disposal pits. Maintaining a proper chain of custody was important

Spatial statistics of pitting corrosion patterning: Quadrat counts and the non-homogeneous Poisson process

International Nuclear Information System (INIS)

Lopez de la Cruz, J.; Gutierrez, M.A.

2008-01-01

This paper presents a stochastic analysis of spatial point patterns as effect of localized pitting corrosion. The Quadrat Counts method is studied with two empirical pit patterns. The results are dependent on the quadrat size and bias is introduced when empty quadrats are accounted for the analysis. The spatially inhomogeneous Poisson process is used to improve the performance of the Quadrat Counts method. The latter combines Quadrat Counts with distance-based statistics in the analysis of pit patterns. The Inter-Event and the Nearest-Neighbour statistics are here implemented in order to compare their results. Further, the treatment of patterns in irregular domains is discussed

Analysis of potential groundwater contamination in the vicinity of the Weldon Spring Raffinate Pits site, Weldon Spring, Missouri

International Nuclear Information System (INIS)

Tsai, S.Y.; Peterson, J.M.; Winters, M.C.B.

1984-08-01

Results of the analysis of contaminant migration beneath the raffinate pits at the Weldon Spring Raffinate Pits site indicate that during a 10,000-year time period, the maximum concentrations in the water immediately beneath the pit bottoms would be about 4600 pCi/L of radium-226 (Pit 3) and about 12,000 pCi/L of uranium-238 (Pit 1); these concentrations would occur at the centers of the pit bottoms. Based on the assumptions used in this study, the radioactive contaminants in the pits would migrate no more than 2 m (7 ft) below the pit bottoms. Because 6 to 12 m (20 to 40 ft) of silty clays underlie the raffinate pits, the radioactive contaminants would take several tens of thousands of years to reach nearby groundwater supplies. Although the results of these analyses indicate that a high degree of confinement is provided by the four raffinate pits, it should be noted that the validity of such analyses rests on the quality of the parameter values utilized. Due to a lack of current site-specific data for some physical parameters, it has been necessary to use historical and regional data for these values. The values cited are at times inconsistent and contradictory, e.g., the wide range of values indicated for the permeability of clays underlying the pits. However, these were the only data available. The analysis reported herein indicates that within the limitations of the available data, use of the Raffinate Pits site for long-term management of radioactive materials such as those currently being stored in the four pits appears to be feasible. 24 references, 14 figures, 7 tables

Proposed modifications to the RCRA post-closure permit for the Chestnut Ridge Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-05-01

This report presents proposed modifications to several conditions of the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit (PCP) for the Chestnut Ridge Hydrogeologic Regime (CRHR) (permit number TNHW-088, EPA ID No. TN3 89 009 0001). These permit conditions define the requirements for RCRA post-closure detection groundwater monitoring at the Chestnut Ridge Sediment Disposal Basin (CRSDB) and Kerr Hollow Quarry (KHQ), and RCRA post-closure corrective action groundwater monitoring at the Chestnut Ridge Security Pits (CRSPs). Modification of these PCP conditions is requested to: (1) clarify the planned integration of RCRA post-closure corrective action groundwater monitoring at the CRSPs with the monitoring program to be established in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) record of decision (ROD), (2) revise several of the current technical requirements for groundwater monitoring based on implementation of the RCRA monitoring programs during 1996, (3) replace several of the technical procedures included in the PCP with updated versions recently issued by the Y-12 Plant Groundwater Protection Program (GWPP), and (4) correct inaccurate regulatory citations and references to permit conditions and permit attachments. With these modifications, the Y- 12 Plant will continue to meet the full intent of all regulatory obligations for post-closure care of these facilities. Section 2 provides the technical justification for each proposed permit modification. Section 3.0 contains proposed changes to Section II of the PCP. Modifications to site-specific permit conditions are presented in Section 4.0 (CRSDB), Section 5.0 (CRSPs), and Section 6.0 (KHQ). Sections 7.0 and 8.0 reference updated and revised procedures for groundwater sampling, and monitoring well plugging and abandonment, respectively. Appendix A includes all proposed revisions to the permit attachments

Proposed modifications to the RCRA post-closure permit for the Chestnut Ridge Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-05-01

This report presents proposed modifications to several conditions of the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit (PCP) for the Chestnut Ridge Hydrogeologic Regime (CRHR) (permit number TNHW-088, EPA ID No. TN3 89 009 0001). These permit conditions define the requirements for RCRA post-closure detection groundwater monitoring at the Chestnut Ridge Sediment Disposal Basin (CRSDB) and Kerr Hollow Quarry (KHQ), and RCRA post-closure corrective action groundwater monitoring at the Chestnut Ridge Security Pits (CRSPs). Modification of these PCP conditions is requested to: (1) clarify the planned integration of RCRA post-closure corrective action groundwater monitoring at the CRSPs with the monitoring program to be established in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) record of decision (ROD), (2) revise several of the current technical requirements for groundwater monitoring based on implementation of the RCRA monitoring programs during 1996, (3) replace several of the technical procedures included in the PCP with updated versions recently issued by the Y-12 Plant Groundwater Protection Program (GWPP), and (4) correct inaccurate regulatory citations and references to permit conditions and permit attachments. With these modifications, the Y- 12 Plant will continue to meet the full intent of all regulatory obligations for post-closure care of these facilities. Section 2 provides the technical justification for each proposed permit modification. Section 3.0 contains proposed changes to Section II of the PCP. Modifications to site-specific permit conditions are presented in Section 4.0 (CRSDB), Section 5.0 (CRSPs), and Section 6.0 (KHQ). Sections 7.0 and 8.0 reference updated and revised procedures for groundwater sampling, and monitoring well plugging and abandonment, respectively. Appendix A includes all proposed revisions to the permit attachments.

Some questions on small uranium open-pit mines

International Nuclear Information System (INIS)

Li Junyi

1992-01-01

The experiences of the existing uranium open pits are summarized and the questions in design, erection and production are analyzed. It is important helpful to develop and to design such economical and reasonable small uranium open pits

Cleanups In My Community (CIMC) - RCRA and Base Realignment and Closure (BRAC) Federal Facilities, National Layer

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer provides access to Resource Conservation and Recovery Act (RCRA) Base Realignment and Closure (BRAC) sites as part of the CIMC web service. The...

Water and chemical budgets of gravel pit lakes : Case studies of fluvial gravel pit lakes along the Meuse River (The Netherlands) and coastal gravel pit lakes along the Adriatic Sea (Ravenna, Italy)

NARCIS (Netherlands)

Mollema, P.N.

2016-01-01

Gravel pit lakes form when gravel is excavated from below the water table of a phreatic or shallow confined aquifer. Typically many of these lakes are concentrated along naturally occurring sedimentary gravel deposits in areas where gravel is needed for construction. Most gravel pit lakes are

Closure The Definitive Guide

CERN Document Server

Bolin, Michael

2010-01-01

If you're ready to use Closure to build rich web applications with JavaScript, this hands-on guide has precisely what you need to learn this suite of tools in depth. Closure makes it easy for experienced JavaScript developers to write and maintain large and complex codebases -- as Google has demonstrated by using Closure with Gmail, Google Docs, and Google Maps. Author and Closure contributor Michael Bolin has included numerous code examples and best practices, as well as valuable information not available publicly until now. You'll learn all about Closure's Library, Compiler, Templates, tes

Special closures for steel drum shipping containers

International Nuclear Information System (INIS)

Bonzon, L.L.; Otts, J.V.

1976-01-01

The objective of this program was to develop special lid closures for typical, steel drum, radioactive material shipping containers. Previous experience and testing had shown that the existing container was adequate to withstand the required environmental tests for certification, but that the lid and closure were just marginally effective. Specifically, the lid closure failed to consistently maintain a tight seal between the container and the lid after drop tests, thus causing the package contents to be vulnerable in the subsequent fire test. Recognizing the deficiency, the United States Energy Research and Development Administration requested the development of new closure(s) which would: (1) be as strong and resistant to a drop as the bottom of the container; (2) have minimal economic impact on the overall container cost; (3) maximize the use of existing container designs; (4) consider crush loads; and (5) result in less dependence on personnel and loading procedures. Several techniques were evaluated and found to be more effective than the standard closure mechanism. Of these, three new closure techniques were designed, fabricated, and proven to be structurally adequate to provide containment when a 454-kg drum was drop tested from 9.14-m onto an unyielding surface. The three designs were: (1) a 152-mm long lid extension or skirt welded to the standard drum lid, (2) a separate inner lid, with 152-mm long skirt and (3) C-clamps used at the container-lid interface. Based upon structural integrity, economic impact, and minimal design change, the lid extension is the recommended special closure

Stochastic models for predicting pitting corrosion damage of HLRW containers

International Nuclear Information System (INIS)

Henshall, G.A.

1991-10-01

Stochastic models for predicting aqueous pitting corrosion damage of high-level radioactive-waste containers are described. These models could be used to predict the time required for the first pit to penetrate a container and the increase in the number of breaches at later times, both of which would be useful in the repository system performance analysis. Monte Carlo implementations of the stochastic models are described, and predictions of induction time, survival probability and pit depth distributions are presented. These results suggest that the pit nucleation probability decreases with exposure time and that pit growth may be a stochastic process. The advantages and disadvantages of the stochastic approach, methods for modeling the effects of environment, and plans for future work are discussed

Tale of two pit lakes: initial results of a three-year study of the Main Zone and Waterline pit lakes near Houston, British Columbia, Canada

Science.gov (United States)

Crusius, John; Pieters, R.; Leung, A.; Whittle, P.; Pedersen, T.; Lawrence, G.; McNee, J.J.

2003-01-01

Pit lakes are becoming increasingly common in North America as well as in the rest of the world. They are created as openpit mines fill passively with ground water and surface inflows on cessation of mining activity. In many instances, the water quality in these pit lakes does not meet regulatory requirements due to a number of influences. The most important are the oxidation of sulfide minerals and the associated release of acid and metals and the flushing of soluble metals during pit filling. Examples of pit lakes with severe water-quality problems include the Berkeley Pit lake (Butte, MT) and the Liberty Pit lake (Nevada), whose waters are characterized by a pH near 3 and Cu concentrations as high as ~150 mg/L (Miller et al., 1996; Davis and Eary, 1997). The importance of the problem can be seen in the fact that some of these sites in the United States are Superfund sites.

Defense Base Realignment and Closure Budget Data for Realignment of Construction Battalion Unit 416 from Naval Air Station Alameda, California, to Naval Air Station Fallon, Nevada

National Research Council Canada - National Science Library

1995-01-01

... requested for each military construction project associated with Defense base realignment and closure does not exceed the original estimated cost provided to the Commission on Defense Base Closure and Realignment (the Commission...

A risk-based approach to prioritize underground storage tanks

International Nuclear Information System (INIS)

Chidambariah, V.; Travis, C.C.; Trabalka, J.R.; Thomas, J.K.

1992-01-01

The purpose of this paper is to present a risk-based approach for rapid prioritization of low level liquid radioactive waste underground storage tanks (LLLW USTs) for possible interim corrective measures and/or ultimate closure. The ranking of LLLW USTs is needed to ensure that tanks with the greatest potential for adverse impact on the environment and human health receive top priority for further evaluation and remediation. Wastes from the LLLW USTs at the Oak Ridge National Laboratory (ORNL) were pumped out at the time the tanks were removed from service. The residual liquids and sludge contain a mixture of radionuclides and chemicals. Contaminants of concern that were identified in the liquid phase of the inactive LLLW USTs include, the radionuclides, 9O Sr, 137 Cs and 233 U and the chemicals, carbon tetrachloride, trichloroethene, tetrachloroethene, methyl ethyl ketone, mercury, lead and chromium. The risk-based approach for prioritization of the LLLW USTs is based upon three major criteria: (1) leaking characteristics of the tank; (2) location of the tanks; and (3) toxic potential of the tank contents

Fish assemblages in borrow-pit lakes of the Lower Mississippi River

Science.gov (United States)

Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

2013-01-01

Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

Modeling sludge accumulation rates in lined pit latrines in slum ...

African Journals Online (AJOL)

Yvonne

should include geo-physical characterization of soil and drainage of pit latrine sites so as ... Key words: Faecal, sludge accumulation rates, slum areas, lined pit latrines. .... Value and its unit Source .... overall quality of the models had to be assessed by validation on ..... Sanitation partnership series: Bringing pit emptying out.

The Rising Rate of Rural Hospital Closures.

Science.gov (United States)

Kaufman, Brystana G; Thomas, Sharita R; Randolph, Randy K; Perry, Julie R; Thompson, Kristie W; Holmes, George M; Pink, George H

2016-01-01

Since 2010, the rate of rural hospital closures has increased significantly. This study is a preliminary look at recent closures and a formative step in research to understand the causes and the impact on rural communities. The 2009 financial performance and market characteristics of rural hospitals that closed from 2010 through 2014 were compared to rural hospitals that remained open during the same period, stratified by critical access hospitals (CAHs) and other rural hospitals (ORHs). Differences were tested using Pearson's chi-square (categorical variables) and Wilcoxon rank test of medians. The relationships between negative operating margin and (1) market factors and (2) utilization/staffing factors were explored using logistic regression. In 2009, CAHs that subsequently closed from 2010 through 2014 had, in general, lower levels of profitability, liquidity, equity, patient volume, and staffing. In addition, ORHs that closed had smaller market shares and operated in markets with smaller populations compared to ORHs that remained open. Odds of unprofitability were associated with both market and utilization factors. Although half of the closed hospitals ceased providing health services altogether, the remainder have since converted to an alternative health care delivery model. Financial and market characteristics appear to be associated with closure of rural hospitals from 2010 through 2014, suggesting that it is possible to identify hospitals at risk of closure. As closure rates show no sign of abating, it is important to study the drivers of distress in rural hospitals, as well as the potential for alternative health care delivery models. © 2015 National Rural Health Association.

European Hernia Society guidelines on the closure of abdominal wall incisions

DEFF Research Database (Denmark)

Muysoms, F E; Antoniou, S A; Bury, K

2015-01-01

using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and methodological guidance was taken from Scottish Intercollegiate Guidelines Network (SIGN). The literature search included publications up to April 2014. The guidelines were written using the AGREE II...... of rapidly absorbable sutures. It is suggested using a slowly absorbable monofilament suture in a single layer aponeurotic closure technique without separate closure of the peritoneum. A small bites technique with a suture to wound length (SL/WL) ratio at least 4/1 is the current recommended method......, it is suggested using the smallest trocar size adequate for the procedure and closure of the fascial defect if trocars larger or equal to 10 mm are used. For single incision laparoscopic surgery, we suggest meticulous closure of the fascial incision to avoid an increased risk of incisional hernias....

Laboratory protocols for testing the efficacy of commercial pit latrine ...

African Journals Online (AJOL)

There is considerable national interest in the use of commercial microbially derived products for controlling the rate of accumulation of the contents of pit latrines. Manufacturers claim that some of these products can reduce accumulation rates, prevent the pit from ever filling up, or even result in decreases in pit contents ...

Contemporary Approach to the Diagnosis and Management of Primary Angle-Closure Disease.

Science.gov (United States)

Razeghinejad, M Reza; Myers, Jonathan S

2018-05-16

Primary angle closure disease spectrum varies from a narrow angle to advanced glaucoma. A variety of imaging technologies may assist the clinician in determining the pathophysiology and diagnosis of primary angle closure, but gonioscopy remains a mainstay of clinical evaluation. Laser iridotomy effectively eliminates the pupillary block component of angle closure; however, studies show that in many patients the iridocorneal angle remains narrow from underlying anatomic issues, and increasing lens size often leads to further narrowing over time. Recent studies have further characterized the role of the lens in angle closure disease, and cataract or clear lens extraction is increasingly used earlier in its management. As a first surgical step in angle closure glaucoma, lens extraction alone often effectively controls the pressure with less risk of complications than concurrent or stand alone glaucoma surgery, but may not be sufficient in more advanced or severe disease. We provide a comprehensive review on the primary angle-closure disease nomenclature, imaging, and current laser and surgical management. Copyright © 2018. Published by Elsevier Inc.

Appositional Closure Identified by Ultrasound Biomicroscopy in Population-Based Primary Angle-Closure Glaucoma Suspects: The Liwan Eye Study

Science.gov (United States)

Kong, Xiangbin; Foster, Paul J.; Huang, Qunxiao; Zheng, Yingfeng; Huang, Wenyong; Cai, Xiaoyu

2011-01-01

Purpose. To describe the characteristics of the iridocorneal angle using ultrasound biomicroscopy (UBM) in Chinese people classified gonioscopically as having suspected primary angle-closure (PACS) glaucoma. Methods. PACS were defined as not having visible posterior (usually pigmented) trabecular meshwork in two or more quadrants examined by static gonioscopy. The PACS and 1 of 10 those who did not meet this criterion were identified from a population-based survey. Iridotrabecular meshwork contact (ITC) was identified and further classified into low and high, according to standard UBM images. Those with high ITC were further classified according the configuration of ITC: B-type, with contiguous ITC from the base of the angle, and S-type, with ITC localized to the region of Schwalbe's line. Results. ITC was identified in 78.6% of the superior, 40.2% of the nasal, 59.8% of the inferior, and 25.6% of the temporal quadrants in the PACS (n = 117). These proportions were 43.9%, 15.8%, 29.8%, and 14.0% in the controls (n = 57), respectively. About two thirds of the eyes with ITC were classified as high. In those with high ITC, the number with B- and S-type ITC was very similar. The proportions of any high ITCs increased substantially from 15.4% in those with Shaffer angle grade 4 and 45.0% in grade 3, to 71.0% in grade 2, 70.2% in grade 1, and 86.4% in grade 0. Conclusions. More ITC is identified on UBM imaging than by gonioscopy. Careful consideration should be given to the assessment modality regarded as the reference standard in defining anatomic risk factors for glaucomatous visual loss and the need for treatment. PMID:21357394

105-KW Sandfilter Backwash Pit sludge volume calculation

International Nuclear Information System (INIS)

Dodd, E.N. Jr.

1995-01-01

The volume of sludge contained in the 100-KW Sandfilter Backwash Pit (SFBWP) was calculated from depth measurements of the sludge, pit dimension measurements and analysis of video tape recordings taken by an underwater camera. The term sludge as used in this report is any combination of sand, sediment, or corrosion products visible in the SFBWP area. This work was performed to determine baseline volume for use in determination of quantities of uranium and plutonium deposited in the pit from sandfilter backwashes. The SFBWP has three areas where sludge is deposited: (1) the main pit floor, (2) the transfer channel floor, and (3) the surfaces and structures in the SFBWP. The depths of sludge and the uniformity of deposition varies significantly between these three areas. As a result, each of the areas was evaluated separately. The total volume of sludge determined was 3.75 M 3 (132.2 ft 3 )

Closure Report for Corrective Action Unit 407: Roller Coaster RADSAFE Area, Tonopah Test Range, Nevada

International Nuclear Information System (INIS)

Fitzmaurice, T. M.

2001-01-01

This closure report (CR) provides documentation for the closure of the Roller Coaster RADSAFE Area (RCRSA) Corrective Action Unit (CAU) 407 identified in the Federal Facility Agreement and Consent Order (FFACO) (Nevada Division of Environmental Protection [NDEP] et al., 1996). CAU 407 is located at the Tonopah Test Range (TTR), Nevada. The TTR is approximately 225 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada (Figure 1). The RCRSA is located on the northeast comer of the intersection of Main Road and Browne's Lake Road, which is approximately 8 km (5 mi) south of Area 3 (Figure 1). The RCRSA was used during May and June of 1963 to decontaminate vehicles, equipment, and personnel from the Double Tracks and Clean Slate tests. Investigation of the RCRSA was conducted from June through November of 1998. A Corrective Action Decision Document (CADD) (U.S. Department of Energy, Nevada Operations Office [DOEN], 1999) was approved in October of 1999. The purpose of this CR is to: Document the closure activities as proposed in the Corrective Action Plan (CAP) (DOEM, 2000). Obtain a Notice of Completion from the NDEP. Recommend the movement of CAU 407 from Appendix III to Appendix IV of the FFACO. The following is the scope of the closure actions implemented for CAU 407: Removal and disposal of surface soils which were over three times background for the area. Soils identified for removal were disposed of at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS). Excavated areas were backfilled with clean borrow soil located near the site. A soil cover was constructed over the waste disposal pit area, where subsurface constituents of concern remain. The site was fenced and posted as an ''Underground Radioactive Material'' area

Management of Pit 9 - highlights of accomplishments and lessons learned to date

International Nuclear Information System (INIS)

Schwartz, F.G.

1995-01-01

The Pit 9 project is a U.S. Department of Energy prototype full scale demonstration to retrieve and treat buried mixed transuranic waste. The project is being managed by the DOE-Idaho Environmental Restoration Program, in conjunction with the Environmental Protection Agency Region 10 and the state of Idaho, under the Idaho National Engineering Laboratory Federal Facility Agreement and Consent Order. Pit 9 is located in the northeast corner of the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL). The Pit 9 project was conceived out of the need to determine capabilities to cost effectively retrieve and treat buried radioactive and radioactive mixed waste, and obtain characterization and contaminant migration data for buried waste at the INEL. Waste was disposed in Pit 9 from November 1967 to June 1969. Pit 9, at about 380 feet by 125 feet, represents approximately one acre of surface area of the 88 acre SDA. The pit contains approximately 350,000 ft 3 of soil beneath and between the buried waste and about 250,000 ft 3 of overburden soil. The average depth of the pit from soil surface to bedrock is approximately 17.5 feet. Approximately 110,000 ft 3 of transuranic (TRU) contaminated mixed wastes from Rocky Flats and approximately 40,000 ft 3 of low level and mixed wastes from the INEL were buried in Pit 9 during this period. Pit 9 is estimated to contain over 30,000 gallons of organics (over 30% of the total organic inventory in the SDA) and approximately 66 pounds of TRU radionuclides (between 3% and 4% of the total TRU inventory in the SDA). Pit 9 was selected as a demonstration site because it was one of the last disposal pits at the INEL to receive Rocky Flats waste, disposal records are better for Pit 9 than for disposal pits and trenches from earlier points in time, and the wastes in Pit 9 are representative of the wastes disposed in the SDA

Evaluation of water chemistry on the pitting susceptibility of aluminum

International Nuclear Information System (INIS)

Chandler, G.T.; Sindelar, R.L.; Lam, P.S.

1997-01-01

Aluminum-clad spent nuclear fuels are being stored in water in the Receiving Basin for Off-site Fuels (RBOF) and the reactor disassembly (cooling) basins at the Savannah River Site (SRS). Experience shows that fuels stored in water are subject to rapid pitting corrosion if the water quality is poor. Upgrade projects and actions, including those to improve water quality, were recently undertaken to upgrade the disassembly basins for extended storage. A technical strategy was developed for continued basin storage of aluminum-clad fuel assemblies. The strategy includes development and implementation of basin technical standards for water quality to minimize attack due to pitting corrosion over a desired storage period. In the absence of localized corrosion, only slow, general corrosion of the cladding would be expected. A laboratory corrosion program is being performed to provide the bases for technical standards by identifying the region of aggressive water qualities where existing oxide films would tend to break down and pits would initiate and remain active. Initial results from corrosion potential and cyclic polarization testing of aluminum alloys in various water chemistries have shown that low conductivity water (< 50 μS/cm) should not be aggressive to cause self-pitting corrosion. Initial results from tests of 8001 and 5052 aluminum and aluminium-10% uranium alloy indicate that a strong galvanic couple should not exist between the aluminum cladding materials and the aluminum-uranium fuel. Additional laboratory testing will include immersion testing to allow characterization of the growth rate of active pits to benchmark a kinetic model. This model will form the basis for a water quality technical standard and enable prediction of the life of aluminum-clad spent nuclear fuels in basin storage

Pit above the lesser tuberosity in axial view radiography.

Science.gov (United States)

Cho, Jae-Ho; Han, Kyeong-Jin; Lee, Doo-Hyung; Chung, Nam-Su; Park, Do Young

2015-02-01

This study examined the relationship between the presence of a pit above the lesser tuberosity on axial view radiographs and rotator cuff tears and compared the demographic data between groups according to the presence of a pit above the lesser tuberosity. The hypothesis of this study was that the radiographic finding of a pit above the lesser tuberosity is related to rotator cuff tears. For 112 patients with a symptomatic rotator cuff tear, plain radiographs of the symptomatic shoulder (tear side radiographs) and plain radiographs of the asymptomatic contralateral shoulder (no-tear side radiographs) were assessed. Seventeen radiological findings, including a pit above the lesser tuberosity, osteophytes, subchondral cysts, and sclerosis, were recorded by one blinded observer. Demographic data such as age, duration of symptoms, sex, arm dominance, smoking history, trauma history, American Shoulder and Elbow Surgeons score, Constant score, and involved tendon were collected. A pit above the lesser tuberosity was noted on tear side radiographs of 40 patients (35.7 %) and on the no-tear side radiographs of 27 patients (24.1 %), representing a significant difference (P = 0.040). A pit associated with a rotator cuff tear was observed more often in the dominant arm (P = 0.040) and more often in patients with less previous trauma (P = 0.024). A pit above the lesser tuberosity on axial view radiography was associated with a rotator cuff tear and occurred more often in the dominant arm of patients who had no trauma history. Prognostic study, Level III.

Acoustical measurements of sound fields between the stage and the orchestra pit inside an historical opera house

Science.gov (United States)

Sato, Shin-Ichi; Prodi, Nicola; Sakai, Hiroyuki

2004-05-01

To clarify the relationship of the sound fields between the stage and the orchestra pit, we conducted acoustical measurements in a typical historical opera house, the Teatro Comunale of Ferrara, Italy. Orthogonal factors based on the theory of subjective preference and other related factors were analyzed. First, the sound fields for a singer on the stage in relation to the musicians in the pit were analyzed. And then, the sound fields for performers in the pit in relation to the singers on the stage were considered. Because physical factors vary depending on the location of the sound source, performers can move on the stage or in the pit to find the preferred sound field.

Environmental assessments for the existing radioactive materials in the Weldon Spring raffinate pits

International Nuclear Information System (INIS)

Yang, J.Y.; Wang, J.

1985-01-01

Various radioactive residues (raffinates) and wastes from the processing of uranium and thorium between 1957 and 1966 are stored in four pits at Weldon Spring, Missouri. The US Department of Energy (DOE) plans to stabilize all the contaminated materials on a long-term (more than 1000-year) basis. The effectiveness of stabilization measures are evaluated by estimating radioactive releases under two options: (1) no action, and (2) improved containment using the existing raffinate pits. Two major pathways of radiation exposure are examined: (1) airborne radioactive gases and particulates, and (2) seepage into near-surface groundwater. The relative reductions of releases into the air and groundwater for a reference stabilization option (improved containment) are analyzed using mathematical models for radioactive and particulate gas fluxes and atmospheric dispersion, as well as groundwaterr transport and dispersion. The consequent health risks for nearby individuals and the general public are also evaluated. This study focuses on the migration of radionuclides under existing conditions and evaluates the effectiveness of proposed stabilization measures at the pits. Results indicate that the potential effects to the general public would be insignificant. 22 refs., 2 figs., 6 tabs

The differences of saliva pH before and after application of Bis-GMA resin based-pit and fissure sealant

Directory of Open Access Journals (Sweden)

Ayub Irmadani Anwar

2016-06-01

Full Text Available Pit and fissure sealant applications is one way to prevent caries. One of the effective ingredient as a pit and fissure sealant is a Bis-GMA resin. One of the active components  of  Bis-GMA  resin  is  sodium  fluoride,  which is capable  of releasing fluoride ions to the tooth surface and able to improve the repair and remineralization process through the replacement  of  calcium and phosphate ions found in saliva to increase the pH of saliva. This study was to determine the effect of pit and fissure sealant applications made from Bis-GMA resin to pH of saliva in children aged 6-12 years. The study design is pre and post test with control group design. Saliva samples were derived from 15 pediatric patients has met the criteria. The pH of saliva were taken before and after the application of pit and fissure sealant made from Bis-GMA and measured with pH meter. This study used a non-parametric test, the Wilcoxon Signed Rank test. The results of this study are also supported by the results of statistical tests showed p-: 0.005 (p<0.05 value, which means that there are significant differences in pH of saliva before and after the application of pit and fissure sealant made from Bis-GMA resin.

The phylogenetic significance of vestured pits in Boraginaceae

NARCIS (Netherlands)

Rabaey, D.; Lens, F.; Smets, E.; Jansen, S.

2010-01-01

The bordered pit structure in tracheary elements of 105 Boraginaceae species is studied using scanning electron microscopy to examine the systematic distribution of vestured pits. Forty-three species out of 16 genera show a uniform presence of this feature throughout their secondary xylem. Most

Structural evaluation of W-211 flexible receiver platforms and tank pit walls

International Nuclear Information System (INIS)

Shrivastava, H.P.

1997-01-01

This document is a structural analysis of the Flexible Receiver Platforms and the tank-pit wall during removal of equipment and during a accidental drop of that equipment. The platform and the pit walls must withstand a accidental drop of a mixer and transfer pumps in specific pits in tanks 102-AP and 104-AP. A mixer pump will be removed from riser 11 in pit 2A on tank 241-AP-102. A transfer pump will be removed from riser 13 in pit 2D on tank 241-AP-102 and another transfer pump will be removed from riser 3A in pit 4A on tank 241-AP-104

Consideration of early closure or continued operation of a nuclear power plant

International Nuclear Information System (INIS)

2006-07-01

This publication provides information to management and executives of electrical utilities responsible for the operation of nuclear power plants who are tasked with decision making related to early closures or continued operation. This information is based on the experiences of a number of countries in addressing a spectrum of issues broader than only the economics of the operation of the plant itself. Any major decision involving changes in direction for a major investment such as a nuclear power plant has the potential to incur considerable additional costs for stakeholders. Major economic risks can be unexpectedly encountered when decisions based on a simplified economic understanding of energy options are successfully challenged on the grounds that choices and decisions have been made without accounting for some environmental, social or economic issues which are considered of prime significance to important stakeholders. Such risks include not only changes in project scope and delays in project implementation due to re-evaluations necessitated by such challenges, but risks related to the effectiveness, efficiency and safety of ongoing operations or shutdown maintenance of the nuclear power plant. Additional risks encountered at this stage are the adequacy of the decommissioning fund and the need to establish a process whereby the availability of adequate funds will be assured at the time of the final plant shutdown. This publication provides information on several of these additional issues important to key stakeholders, and on methods that allow for their assessment and consideration when developing recommendations related to early closures or continued operations of a NPP. This publication consists of two parts: Part I: Includes a discussion of the main issues for consideration, with emphasis on issues important to stakeholders in addition to plant owners. Part II: Provides an example of a basic analytical approach to the assessment of plant life cycle

Emergent properties during dorsal closure in Drosophila morphogenesis

International Nuclear Information System (INIS)

Peralta, X G; Toyama, Y; Edwards, G S; Kiehart, D P

2008-01-01

Dorsal closure is an essential stage of Drosophila development that is a model system for research in morphogenesis and biological physics. Dorsal closure involves an orchestrated interplay between gene expression and cell activities that produce shape changes, exert forces and mediate tissue dynamics. We investigate the dynamics of dorsal closure based on confocal microscopic measurements of cell shortening in living embryos. During the mid-stages of dorsal closure we find that there are fluctuations in the width of the leading edge cells but the time-averaged analysis of measurements indicate that there is essentially no net shortening of cells in the bulk of the leading edge, that contraction predominantly occurs at the canthi as part of the process for zipping together the two leading edges of epidermis and that the rate constant for zipping correlates with the rate of movement of the leading edges. We characterize emergent properties that regulate dorsal closure, i.e., a velocity governor and the coordination and synchronization of tissue dynamics

Engineering sustainable ecosystems: using GIS-based habitat modeling for oil sands mine reclamation and closure planning

International Nuclear Information System (INIS)

Seel, K.

1997-01-01

A GIS model was built to predict the climax vegetation habitat types on reclaimed mine surfaces in the Fort McMurray region of the Mid-Boreal Mixedwood Ecoregion of northwestern Alberta. Regional vegetation habitat types were classified by digital remote sensing using Landsat Thematic Mapper satellite data. Terrain data was derived from a high-resolution digital elevation model. The validated model was applied to the GIS database of Syncrude Canada's Mildred Lake Mine to predict future vegetation patterns based on the final closure mine surface. The results were compared to revegetation and closure plans created by experts to analyze performance and sustainability of reclamation efforts

PITTING CORROSION OF STAINLESS STEEL AT THE VARIOUS SURFACE TREATMENT

Directory of Open Access Journals (Sweden)

Viera Zatkalíková

2011-09-01

Full Text Available The stainless steel surface treatment is very important with regard to its pitting corrosion susceptibility. An effect of various types surfacing on pitting corrosion resistance of AISI 304stainless steel is investigated in this work. The samples of the tested material are turned, blasted, peened, grinded and a half of them are pickled to achieve higher purity of surfaces and better quality of passive film. Eight types of different finished surfaces are tested by electrochemical and immersion tests to determine corrosion behaviour in conditions where pitting is evoked by controlled potential and second by solution with high redox potential. By this way the effect of mechanical and chemical surface treatment on the resistance to pitting corrosion, character, size and shape of pits are compared in the conditions of different mechanisms of corrosion process.

The Finishing Touch: Anatomy of Expert Lesson Closures

Science.gov (United States)

Webster, Collin A.; Connolly, Graeme; Schempp, Paul G.

2009-01-01

Background: Based on the idea that students remember best what is presented last, the lesson closure is commonly identified as an important component of effective teaching and has recently surfaced as a routine practice of expert teachers in sport. Despite its link to both effective and expert instruction, the lesson closure has seen scarce…

Tight closure and vanishing theorems

International Nuclear Information System (INIS)

Smith, K.E.

2001-01-01

Tight closure has become a thriving branch of commutative algebra since it was first introduced by Mel Hochster and Craig Huneke in 1986. Over the past few years, it has become increasingly clear that tight closure has deep connections with complex algebraic geometry as well, especially with those areas of algebraic geometry where vanishing theorems play a starring role. The purpose of these lectures is to introduce tight closure and to explain some of these connections with algebraic geometry. Tight closure is basically a technique for harnessing the power of the Frobenius map. The use of the Frobenius map to prove theorems about complex algebraic varieties is a familiar technique in algebraic geometry, so it should perhaps come as no surprise that tight closure is applicable to algebraic geometry. On the other hand, it seems that so far we are only seeing the tip of a large and very beautiful iceberg in terms of tight closure's interpretation and applications to algebraic geometry. Interestingly, although tight closure is a 'characteristic p' tool, many of the problems where tight closure has proved useful have also yielded to analytic (L2) techniques. Despite some striking parallels, there had been no specific result directly linking tight closure and L∼ techniques. Recently, however, the equivalence of an ideal central to the theory of tight closure was shown to be equivalent to a certain 'multiplier ideal' first defined using L2 methods. Presumably, deeper connections will continue to emerge. There are two main types of problems for which tight closure has been helpful: in identifying nice structure and in establishing uniform behavior. The original algebraic applications of tight closure include, for example, a quick proof of the Hochster-Roberts theorem on the Cohen-Macaulayness of rings of invariants, and also a refined version of the Brianqon-Skoda theorem on the uniform behaviour of integral closures of powers of ideals. More recent, geometric

40 CFR 264.228 - Closure and post-closure care.

Science.gov (United States)

2010-07-01

... remaining wastes to a bearing capacity sufficient to support final cover; and (iii) Cover the surface....112 must include both a plan for complying with paragraph (a)(1) of this section and a contingent plan... practicably removed at closure; and (ii) The owner or operator must prepare a contingent post-closure plan...

Geochemical evolution of a high arsenic, alkaline pit-lake in the Mother Lode Gold District, California

Science.gov (United States)

Savage, Kaye S.; Ashley, Roger P.; Bird, Dennis K.

2009-01-01

The Harvard orebody at the Jamestown gold mine, located along the Melones fault zone in the southern Mother Lode gold district, California, was mined in an open-pit operation from 1987 to 1994. Dewatering during mining produced a hydrologic cone of depression; recovery toward the premining ground-water configuration produced a monomictic pit lake with alkaline Ca-Mg-HCO3-SO4–type pit water, concentrations of As up to 1,200 μg/L, and total dissolved solids (TDS) up to 2,000 mg/L. In this study, pit-wall rocks were mapped and chemically analyzed to provide a context for evaluating observed variability in the composition of the pit-lake waters in relationship to seasonal weather patterns. An integrated hydrogeochemical model of pit-lake evolution based on observations of pit-lake volume, water composition (samples collected between 1998–2000, 2004), and processes occurring on pit walls was developed in three stages using the computer code PHREEQC. Stage 1 takes account of seasonally variable water fluxes from precipitation, evaporation, springs, and ground water, as well as lake stratification and mixing processes. Stage 2 adds CO2fluxes and wall-rock interactions, and stage 3 assesses the predictive capability of the model.Two major geologic units in fault contact comprise the pit walls. The hanging wall is composed of interlayered slate, metavolcanic and metavolcaniclastic rocks, and schists; the footwall rocks are chlorite-actinolite and talc-tremolite schists generated by metasomatism of greenschist-facies mafic and ultramafic igneous rocks. Alteration in the ore zone provides evidence for mineralizing fluids that introduced CO2, S, and K2O, and redistributed SiO2. Arsenian pyrite associated with the alteration weathers to produce goethite and jarosite on pit walls and in joints, as well as copiapite and hexahydrite efflorescences that accumulate on wall-rock faces during dry California summers. All of these pyrite weathering products incorporate arsenic at

The phenomenon of prehistoric ritual pits: Several examples from the central Balkans

Directory of Open Access Journals (Sweden)

Bulatović Aleksandar P.

2015-01-01

rituals. Many authors who concern themselves with this topic concur that the context of a pit and the objects within it, the choice of offerings and their symbolism, along with the pit’s stratigraphy and other patterns observed in it, are in fact the features that make it distinct, i.e. ritual. Similar pits are known throughout history and their descriptions can be found in ancient written sources, as well as identified in the field, with certain differences, stretching back all the way into deep prehistory. This paper presents several newly discovered ritual pits in the central Balkans from the Eneolithic, Bronze and Iron Age, and additionally mentions some of the previously published pits from the area and its near and more distant surroundings. In the course of recent investigations conducted at the site of Bubanj, two ritual pits were recorded in the Early Eneolithic horizon of the Bubanj-Hum I culture. Next to the first, shallower (up to 0.2 m, oval shaped pit, of around 2.5 m long and 1.7 m wide, an oven was noted, while the pit was filled with whole vessels, parts of grindstones, chipped and polished stone tools, baked clay, animal bones, etc. (Figs. 1, 2; Pl. I. Two smaller hollows were noted in the northern part of the pit, while several postholes, which might have supported some kind of roof or shelter construction, were detected somewhat deeper in the subsoil, around the oven and the pit. Below this pit, a smaller one was noted, around 0.7 m deep and with a base diameter of about 1.2 m, filled with yellow, sandy, refined soil. The bottom of the pit was dug to the level of the subsoil and levelled. The second ritual pit from Bubanj was considerably deeper (around 1.5 m and approximately 1.7 m in diameter, with baked walls and filled with red ashy soil. It contained fragmented or whole vessels, chipped stone tools, a part of an altar, an air nozzle (tuyиres, a polished stone axe, tools made of horn, a fragment of a grindstone, pebbles, house daub and animal

Post-Closure Inspection and Monitoring Report for Corrective Action Unit 417: Central Nevada Test Area Surface, Hot Creek Valley, Nevada, for Calendar Year 2007

Energy Technology Data Exchange (ETDEWEB)

None

2008-09-01

This report presents data collected during the annual post-closure site inspection conducted at the Central Nevada Test Area Surface Corrective Action Unit (CAU) 417 in May 2007. The annual post-closure site inspection included inspections of the UC-1, UC-3, and UC-4 sites in accordance with the Post-Closure Monitoring Plan provided in the CAU 417 Closure Report (NNSA/NV 2001). The annual inspection conducted at the UC-1 Central Mud Pit (CMP) indicated the site and soil cover were in good condition. No new cracks or fractures were observed in the soil cover during the annual inspection. A crack on the west portion of the cover was observed during the last quarterly inspection in December 2006. This crack was filled with bentonite as part of the maintenance activities conducted in February 2007 and will be monitored during subsequent annual inspections. The vegetation on the soil cover was adequate but showing signs of the area's ongoing drought. No issues were identified with the CMP fence, gate, or subsidence monuments. New DOE Office of Legacy Management signs with updated emergency phone numbers were installed as part of this annual inspection, no issues were identified with the warning signs and monuments at the other two UC-1 locations. The annual subsidence survey was conducted at UC-1 CMP and UC-4 Mud Pit C as part of the maintenance activities conducted in February 2007. The results of the subsidence surveys indicate that the covers are performing as expected, and no unusual subsidence was observed. A vegetation survey of the UC-1 CMP cover and adjacent areas was conducted as part of the annual inspection in May 2007. The vegetation survey indicated that revegetation continues to be successful, although stressed due to the area's prevailing drought conditions. The vegetation should continue to be monitored to document any changes in the plant community and to identify conditions that could potentially require remedial action to maintain a viable

RCRA corrective action and closure

International Nuclear Information System (INIS)

1995-02-01

This information brief explains how RCRA corrective action and closure processes affect one another. It examines the similarities and differences between corrective action and closure, regulators' interests in RCRA facilities undergoing closure, and how the need to perform corrective action affects the closure of DOE's permitted facilities and interim status facilities

The fabrication and application of patterned Si(001) substrates with ordered pits via nanosphere lithography

International Nuclear Information System (INIS)

Chen Peixuan; Fan Yongliang; Zhong Zhenyang

2009-01-01

A new scalable approach has been developed for fabricating large-scale pit patterns with controllable periodicity on Si(001) substrates. The fabrication processes start with self-assembling a monolayer of polystyrene (PS) spheres on hydrogenated Si(001) substrates. A novel net-like mask in combination of the Au pattern thermally evaporated in between the PS spheres and the Au-catalyzed SiO 2 around them is naturally formed. After selective etching of Si by KOH solution, two-dimensionally ordered pits with a periodicity equal to the diameter of the PS spheres in the range from micrometers to less than 100 nm can be obtained. The shape of the pits can be modulated by controlling the chemical etching time. Such pit-patterned Si substrates facilitate the formation of ordered Si-based nanostructures, such as ordered self-assembled GeSi quantum dots, by deposition of Ge using molecular beam epitaxy.

Effects of selected water chemistry variables on copper pitting propagation in potable water

International Nuclear Information System (INIS)

Ha Hung; Taxen, Claes; Williams, Keith; Scully, John

2011-01-01

Highlights: → The effects of water composition on pit propagation kinetics on Cu were separated from pit initiation and stabilization using the artificial pit method in a range of dilute HCO 3 - , SO 4 2- and Cl - -containing waters. → The effective polarization and Ohmic resistance of pits were lower in SO4 2- -containing solutions and greater in Cl - -containing solutions. → Relationship between the solution composition and the corrosion product identity and morphology were found. → These, in turn controlled the corrosion product Ohmic resistance and subsequently the pit growth rate. - Abstract: The pit propagation behavior of copper (UNS C11000) was investigated from an electrochemical perspective using the artificial pit method. Pit growth was studied systematically in a range of HCO 3 - , SO 4 2- and Cl - containing-waters at various concentrations. Pit propagation was mediated by the nature of the corrosion products formed both inside and over the pit mouth (i.e., cap). Certain water chemistry concentrations such as those high in sulfate were found to promote fast pitting that could be sustained over long times at a fixed applied potential but gradually stifled in all but the lowest concentration solutions. In contrast, Cl - containing waters without sulfate ions resulted in slower pit growth and eventual repassivation. These observations were interpreted through understanding of the identity, amount and porosity of corrosion products formed inside and over pits. These factors controlled their resistive nature as characterized using electrochemical impedance spectroscopy. A finite element model (FEM) was developed which included copper oxidation kinetics, transport by migration and diffusion, Cu(I) and Cu(II) solid corrosion product formation and porosity governed by equilibrium thermodynamics and a saturation index, as well as pit current and depth of penetration. The findings of the modeling were in good agreement with artificial pit experiments

Microstructural evolution and pitting resistance of annealed lean duplex stainless steel UNS S32304

International Nuclear Information System (INIS)

Zhang Ziying; Han Dong; Jiang Yiming; Shi Chong; Li Jin

2012-01-01

Highlights: ► The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. ► The specimens annealed at 1080 °C for 1 h, quenched in water exhibit the best pitting corrosion resistance. ► The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. ► The pitting corrosion resistance is consistent with pitting resistance equivalent number of weaker phase for UNS S32304 alloy. - Abstract: The effect of annealing temperature in the range from 1000 to 1200 °C on the pitting corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the pitting corrosion resistance firstly increased and then decreased. The highest pitting corrosion resistance was obtained at 1080 °C with the highest critical pitting temperature value and pitting nucleation resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.

Post-operative analgesic requirement in non-closure and closure of peritoneum during open appendectomy

International Nuclear Information System (INIS)

Khan, A.W.; Maqsood, R.; Saleem, M.M.

2017-01-01

To compare the mean post-operative analgesic requirement in non-closure and closure of peritoneum during open appendectomy. Study Design: Randomized controlled trial. Place and Duration of Study: Department of General Surgery Combined Military Hospital Quetta, from 1st August 2014 to 30th April 2015. Material and Methods: A total of 60 patients were included in this study and were divided into two groups of 30 each. Patients in group A underwent open appendectomy with closure of peritoneum while patients in group B had non-closure of peritoneum during the same procedure. Post-operatively, pain severity was assessed on visual analogue scale (VAS) numeric pain distress scale. On presence of VAS numeric pain distress scale between 5 to 7, intramuscular (IM) diclofenac sodium was given and on score >7, intravascular (IV) tramadol was given. The final outcome was measured at day 0 and day 1. Results: Pain score and analgesic requirements were significantly less in non-closure group than closure group on day 0 and day 1, showing statistically significant difference between the two groups. Conclusion: Mean post-operative analgesic requirement is significantly less in non-closure group as compared to closure group during open appendectomy. (author)

Percutaneous closure of the left atrial appendage in patients with diabetes mellitus.

Science.gov (United States)

Azizy, Obayda; Rammos, Christos; Lehmann, Nils; Rassaf, Tienush; Kälsch, Hagen

2017-09-01

Left atrial appendage closure is a preventive treatment of atrial fibrillation-related thrombo-embolism. Patients with diabetes mellitus have increased risk for a negative outcome in percutaneous cardiac interventions. We assessed whether percutaneous left atrial appendage closure is safe and effective in patients with diabetes mellitus. We included 78 patients (mean age of 74.4 ± 8.3 years) with indication for left atrial appendage closure in an open-label observational single-centre study. Patients with diabetes mellitus ( n = 31) were at higher thrombo-embolic and bleeding risk (CHA 2 DS 2 -VASc: 4.5 ± 0.9, HAS-BLED: 4.7 ± 0.7) compared to patients without diabetes mellitus ( n = 47, CHA 2 DS 2 -VASc: 3.5 ± 1.0, HAS-BLED: 4.1 ± 0.8; p diabetes mellitus (Euro II-Score: 6.6 ± 3.7 vs 3.9 ± 1.9, p diabetes mellitus had no events ( p = 0.672). Follow-up of 6 months revealed no bleeding complication in both groups. No stroke occurred in follow-up, and left atrial appendage flow velocity reduction (55.6 ± 38.6 vs 51.4 ± 19.1 cm/s, p = 0.474) and rate of postinterventional leakage in the left atrial appendage were comparable (0% vs 2.1%, p = 0.672). Despite patients with diabetes mellitus are high-risk patients, the outcome of percutaneous left atrial appendage closure is similar to patients without diabetes mellitus.

RCRA Facility Investigation/Remedial Investigation Report with Baseline Risk Assessment for the Central Shops Burning/Rubble Pit (631-6G), Volume 1 Final

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-04-01

The Burning/Rubble Pits at the Savannah River Site were usually shallow excavations approximately 3 to 4 meters in depth. Operations at the pits consisted of collecting waste on a continuous basis and burning on a monthly basis. The Central Shops Burning/Rubble Pit 631- 6G (BRP6G) was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal of paper, lumber, cans and empty galvanized steel drums. The unit may have received other materials such as plastics, rubber, rags, cardboard, oil, degreasers, or drummed solvents. The BRP6G was operated from 1951 until 1955. After disposal activities ceased, the area was covered with soil. Hazardous substances, if present, may have migrated into the surrounding soil and/or groundwater. Because of this possibility, the United States Environmental Protection Agency (EPA) has designated the BRP6G as a Solid Waste Management Unit (SWMU) subject to the Resource Conservation Recovery Act/Comprehensive Environmental Response, Compensation and Liability Act (RCRA/CERCLA) process.

Pitting growth rate in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1995-01-01

Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of below-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5% of the established limit) at a temperature of 50 C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured one each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

Body mass index affects time to definitive closure after damage control surgery.

Science.gov (United States)

Haricharan, Ramanath N; Dooley, Adam C; Weinberg, Jordan A; McGwin, Gerald; MacLennan, Paul A; Griffin, Russell L; Rue, Loring W; Reiff, Donald A

2009-06-01

A growing body of literature demonstrates that irrespective of the mechanism of injury, obesity is associated with significantly worse morbidity and mortality after trauma. Among patients requiring damage control laparotomy (DCL), clinical experience suggests that obesity affects time to definitive closure though this association has never been demonstrated quantitatively. All patients at an academic Level I trauma center requiring a DCL between January 2002 and December 2006 (N = 148) were included. Information pertaining to demographic, injury, and clinical characteristics was abstracted from patient medical records. The risk of specific complications including pneumonia, renal failure, and sepsis was compared between normal and overweight/obese patients, as measured by body mass index (BMI). The lengths of intensive care unit (ICU) stay and mechanical ventilation as well as time to abdominal closure were also compared. The risk of pneumonia, sepsis, and renal failure was 2.05-times, 1.77-times, and 2.84-times higher among overweight patients compared with patients with a normal BMI. The risk of pneumonia, sepsis, and renal failure was 2.01-times, 4.24-times, and 1.85-times higher among obese patients compared with those with a normal BMI. Obese patients also had a significantly longer ICU length of stay (28.7 days vs. 15.1 days; p < 0.0001), longer hospitalization (39.3 days vs. 27.0 days; p = 0.008), and time to definitive closure (8.4 days vs. 3.9 days; p = 0.03) compared with patients with a normal BMI. Among patients requiring DCL, those who are overweight or obese have a prolonged time to definitive closure. These patients also experience a significantly longer ICU course and a higher risk of pneumonia.

Newly reported lupus and rheumatoid arthritis in relation to deployment within proximity to a documented open-air burn pit in Iraq.

Science.gov (United States)

Jones, Kelly A; Smith, Besa; Granado, Nisara S; Boyko, Edward J; Gackstetter, Gary D; Ryan, Margaret A K; Phillips, Christopher J; Smith, Tyler C

2012-06-01

To assess the relationship between possible exposure to smoke from documented open-air burn pits and newly reported lupus and rheumatoid arthritis among Millennium Cohort participants who have deployed in support of operations in Iraq and Afghanistan. Prospectively assessed self-reported lupus and rheumatoid arthritis among deployers who completed both 2004-2006 and 2007-2008 questionnaires. After exclusions, more than 18,000 participants were deployed, including more than 3000 participants deployed within a 3-mile radius of a documented burn pit. After adjustment, proximity within 3 miles of a burn pit was not significantly associated with rheumatoid arthritis or lupus in general; however, one location was associated with lupus, although few cases were at this site (n = 2). Results indicate deployers potentially exposed to documented burn pits in the combined three-camp analysis were not at an elevated risk of lupus or rheumatoid arthritis.