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Sample records for adult dislocated workers

  1. 20 CFR 663.105 - When must adults and dislocated workers be registered?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false When must adults and dislocated workers be... LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.105 When must adults...

  2. 20 CFR 663.105 - When must adults and dislocated workers be registered?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false When must adults and dislocated workers be... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.105 When...

  3. 20 CFR 663.105 - When must adults and dislocated workers be registered?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false When must adults and dislocated workers be... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.105 When...

  4. 20 CFR 663.105 - When must adults and dislocated workers be registered?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false When must adults and dislocated workers be... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.105 When...

  5. 20 CFR 663.115 - What are the eligibility criteria for core services for dislocated workers in the adult and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... services for dislocated workers in the adult and dislocated worker programs? 663.115 Section 663.115 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker...

  6. 20 CFR 663.300 - What are training services for adults and dislocated workers?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What are training services for adults and..., DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Training Services § 663.300 What are training services for adults and dislocated workers? Training...

  7. 20 CFR 663.800 - What are supportive services for adults and dislocated workers?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are supportive services for adults and..., DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.800 What are supportive services for adults and dislocated workers?...

  8. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What core services must be provided to adults... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop...

  9. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What core services must be provided to adults... ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System §...

  10. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What core services must be provided to adults... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop...

  11. 20 CFR 663.800 - What are supportive services for adults and dislocated workers?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What are supportive services for adults and..., DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.800 What are supportive services for adults and dislocated workers?...

  12. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What core services must be provided to adults... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop...

  13. 20 CFR 663.300 - What are training services for adults and dislocated workers?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are training services for adults and dislocated workers? 663.300 Section 663.300 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... Training Services § 663.300 What are training services for adults and dislocated workers? Training...

  14. The Experiences of Older Adult Dislocated Workers in Community College Non-Credit Workforce Training Programs

    ERIC Educational Resources Information Center

    Williams, Stelfanie Sherrell

    2011-01-01

    The purpose of this qualitative study was to explore the experiences of older adult dislocated workers who participated in community college non-credit workforce training programs. The research questions guiding the study were: (a) what are the experiences of older adult dislocated workers who attend community college non-credit workforce…

  15. 20 CFR 663.115 - What are the eligibility criteria for core services for dislocated workers in the adult and...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... services for dislocated workers in the adult and dislocated worker programs? 663.115 Section 663.115 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and...

  16. 20 CFR 663.115 - What are the eligibility criteria for core services for dislocated workers in the adult and...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... services for dislocated workers in the adult and dislocated worker programs? 663.115 Section 663.115 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and...

  17. 20 CFR 663.115 - What are the eligibility criteria for core services for dislocated workers in the adult and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... services for dislocated workers in the adult and dislocated worker programs? 663.115 Section 663.115 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and...

  18. 20 CFR 663.300 - What are training services for adults and dislocated workers?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What are training services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Training Services § 663.300 What are training services for adults and dislocated...

  19. 20 CFR 663.300 - What are training services for adults and dislocated workers?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What are training services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Training Services § 663.300 What are training services for adults and dislocated...

  20. 20 CFR 663.800 - What are supportive services for adults and dislocated workers?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What are supportive services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.800 What are supportive services for adults and dislocated...

  1. 20 CFR 663.800 - What are supportive services for adults and dislocated workers?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What are supportive services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.800 What are supportive services for adults and dislocated...

  2. 20 CFR 663.300 - What are training services for adults and dislocated workers?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What are training services for adults and dislocated workers? 663.300 Section 663.300 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... INVESTMENT ACT Training Services § 663.300 What are training services for adults and dislocated...

  3. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663... through the One-Stop delivery system. (b) Followup services must be made available, as appropriate, for...

  4. 20 CFR 663.110 - What are the eligibility criteria for core services for adults in the adult and dislocated worker...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... services for adults in the adult and dislocated worker programs? 663.110 Section 663.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  5. 20 CFR 663.610 - Does the statutory priority for use of adult funds also apply to dislocated worker funds?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Does the statutory priority for use of adult... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE... adult funds also apply to dislocated worker funds? No, the statutory priority applies to adult funds...

  6. 20 CFR 663.610 - Does the statutory priority for use of adult funds also apply to dislocated worker funds?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Does the statutory priority for use of adult... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE... adult funds also apply to dislocated worker funds? No, the statutory priority applies to adult funds...

  7. 20 CFR 663.110 - What are the eligibility criteria for core services for adults in the adult and dislocated worker...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... services for adults in the adult and dislocated worker programs? 663.110 Section 663.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated...

  8. 20 CFR 663.110 - What are the eligibility criteria for core services for adults in the adult and dislocated worker...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... services for adults in the adult and dislocated worker programs? 663.110 Section 663.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated...

  9. 20 CFR 663.110 - What are the eligibility criteria for core services for adults in the adult and dislocated worker...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... services for adults in the adult and dislocated worker programs? 663.110 Section 663.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated...

  10. 20 CFR 663.610 - Does the statutory priority for use of adult funds also apply to dislocated worker funds?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Does the statutory priority for use of adult... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... priority for use of adult funds also apply to dislocated worker funds? No, the statutory priority...

  11. 20 CFR 663.610 - Does the statutory priority for use of adult funds also apply to dislocated worker funds?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Does the statutory priority for use of adult... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... priority for use of adult funds also apply to dislocated worker funds? No, the statutory priority...

  12. 20 CFR 663.145 - What services are WIA title I adult and dislocated workers formula funds used to provide?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What services are WIA title I adult and... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the...

  13. 20 CFR 663.145 - What services are WIA title I adult and dislocated workers formula funds used to provide?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What services are WIA title I adult and... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop...

  14. 20 CFR 663.145 - What services are WIA title I adult and dislocated workers formula funds used to provide?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What services are WIA title I adult and... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the...

  15. 20 CFR 663.145 - What services are WIA title I adult and dislocated workers formula funds used to provide?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What services are WIA title I adult and... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the...

  16. 20 CFR 663.610 - Does the statutory priority for use of adult funds also apply to dislocated worker funds?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Does the statutory priority for use of adult... TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... priority for use of adult funds also apply to dislocated worker funds? No, the statutory priority...

  17. 20 CFR 663.800 - What are supportive services for adults and dislocated workers?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What are supportive services for adults and dislocated workers? 663.800 Section 663.800 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... providers, must develop a policy on supportive services that ensures resource and service coordination...

  18. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the...

  19. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  20. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  1. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services...

  2. 20 CFR 664.500 - May youth participate in both youth and adult/dislocated worker programs concurrently?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false May youth participate in both youth and adult... Concurrent Enrollment § 664.500 May youth participate in both youth and adult/dislocated worker programs concurrently? (a) Yes, under the Act, eligible youth are 14 through 21 years of age. Adults are defined in...

  3. 20 CFR 664.500 - May youth participate in both youth and adult/dislocated worker programs concurrently?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false May youth participate in both youth and adult... Concurrent Enrollment § 664.500 May youth participate in both youth and adult/dislocated worker programs concurrently? (a) Yes, under the Act, eligible youth are 14 through 21 years of age. Adults are defined in...

  4. 20 CFR 664.500 - May youth participate in both youth and adult/dislocated worker programs concurrently?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false May youth participate in both youth and adult... Enrollment § 664.500 May youth participate in both youth and adult/dislocated worker programs concurrently? (a) Yes, under the Act, eligible youth are 14 through 21 years of age. Adults are defined in the...

  5. 20 CFR 664.500 - May youth participate in both youth and adult/dislocated worker programs concurrently?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false May youth participate in both youth and adult... Enrollment § 664.500 May youth participate in both youth and adult/dislocated worker programs concurrently? (a) Yes, under the Act, eligible youth are 14 through 21 years of age. Adults are defined in the...

  6. 20 CFR 664.500 - May youth participate in both youth and adult/dislocated worker programs concurrently?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false May youth participate in both youth and adult... Concurrent Enrollment § 664.500 May youth participate in both youth and adult/dislocated worker programs concurrently? (a) Yes, under the Act, eligible youth are 14 through 21 years of age. Adults are defined in...

  7. 20 CFR 663.100 - What is the role of the adult and dislocated worker programs in the One-Stop delivery system?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs in the...

  8. Dislocated Worker Project.

    ERIC Educational Resources Information Center

    1988

    Due to the severe economic decline in the automobile manufacturing industry in southeastern Michigan, a Dislocated Workers Program has been developed through the partnership of the Flint Area Chamber of Commerce, three community colleges, the National Center for Research in Vocational Education, the Michigan State Department of Education, the…

  9. 20 CFR 663.145 - What services are WIA title I adult and dislocated workers formula funds used to provide?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery... to provide core, intensive and training services through the One-Stop delivery system. Local Boards... to provide the other services described in WIA section 134(e): (1) Discretionary One-Stop...

  10. 20 CFR 663.110 - What are the eligibility criteria for core services for adults in the adult and dislocated worker...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are the eligibility criteria for core... the One-Stop Delivery System § 663.110 What are the eligibility criteria for core services for adults in the adult and dislocated worker programs? To be eligible to receive core services as an adult...

  11. 20 CFR 663.105 - When must adults and dislocated workers be registered?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... dislocated workers be registered? (a) Registration is the process for collecting information to support a determination of eligibility. This information may be collected through methods that include electronic data... determined eligible. (c) EO data must be collected on every individual who is interested in being...

  12. 20 CFR 663.120 - Are displaced homemakers eligible for dislocated worker activities under WIA?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery... the adult program....

  13. 20 CFR 663.120 - Are displaced homemakers eligible for dislocated worker activities under WIA?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker Services Through the One-Stop Delivery... the adult program....

  14. The Perceptions of Dislocated Workers under the Workforce Investment Act

    ERIC Educational Resources Information Center

    Wilson, Michael S.; Brown, James M.

    2012-01-01

    This descriptive qualitative case study investigated the perceptions of dislocated workers offered program services through the Workforce Investment Act's (WIA) Dislocated Worker program in Minnesota. This research focused on recently dislocated workers who lost their jobs through no fault of their own and hence were eligible for unemployment…

  15. 20 CFR 663.115 - What are the eligibility criteria for core services for dislocated workers in the adult and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Through the One-Stop Delivery System § 663.115 What are the eligibility criteria for core services for... procedures for One-Stop operators to use in determining an individual's eligibility as a dislocated...

  16. The Dislocated Worker: When Training Is Not Enough.

    ERIC Educational Resources Information Center

    Blong, John T.; Shultz, Rose M.

    1990-01-01

    Discusses the socioeconomic effects of plant closings, focusing on the problems faced by dislocated workers who lack the financial resources to complete a retraining program. Describes the Eastern Iowa Community College District's efforts to train and counsel dislocated workers through its Caterpillar Worker Assistance Center. (DMM)

  17. A Comparison of Starting Wages and Job Satisfaction for Reemployed Dislocated Workers Participating in the Rock County Dislocated Worker Program.

    ERIC Educational Resources Information Center

    Borremans, Robert T.

    Following the economic recession of the early 1980's and the consequent high levels of unemployment in Rock County, a program was created at the Blackhawk Technical Institute (BTI) to assist dislocated workers reentering the labor force. The Rock County Dislocated Worker Program was intended as a comprehensive program with two principal activities…

  18. Worker Dislocation: A Policy Study and Selected References on Worker Dislocation and the Unemployment Process. An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Clark, Marilyn; And Others

    Dislocated workers are distinguished from chronically unemployed individuals in that the former have a stable work history and are generally unaware of the community's social services programs and how to use them. Dislocated workers frequently lack job search skills and do not see the transferability of their work skills. Often, they have heavy…

  19. Dislocated Workers and Midcareer Retraining in Other Industrial Nations.

    ERIC Educational Resources Information Center

    Bendick, Marc, Jr.

    Market-oriented industrial nations other than the United States have experienced rapid structural changes in their economies and reemployment problems among dislocated midcareer workers. The Swedish active labor market approach is a socialized one. This system has been criticized for excessive reliance on microeconomic labor market programs to…

  20. Ipsilateral open anterior hip dislocation and open posterior elbow dislocation in an adult.

    PubMed

    Kumar, Sunil; Rathi, Akhilesh; Sehrawat, Sunil; Gupta, Vikas; Talwar, Jatin; Arora, Sumit

    2014-01-01

    Open anterior dislocation of the hip is a very rare injury, especially in adults. It is a hyperabduction, external rotation and extension injury. Its combination with open posterior dislocation of the elbow has not been described in English language-based medical literature. Primary resuscitation, debridement, urgent reduction of dislocation, and adequate antibiotic support resulted in good clinical outcome in our patient. At 18 months follow-up, no signs of avascular necrosis of the femoral head or infection were observed.

  1. New Economy Work (NEW) Scholarships: Universal Access to Training for Dislocated Workers. Policy Report.

    ERIC Educational Resources Information Center

    Weinstein, Paul, Jr.

    The New Economy Work (NEW) Scholarship is a proposed scholarship designed to reform federal training programs and to make them universally accessible to dislocated or disadvantaged workers. NEW Scholarships would accomplish the following things: (1) make access to training for dislocated workers as universally available as access to college; (2)…

  2. Factors Related to Predicting Grade Point Averages of Dislocated Workers at a Rural Community College

    ERIC Educational Resources Information Center

    Gregory, James Brent

    2010-01-01

    The purpose of the study was to examine relationships which existed between selected demographics and college grade point averages "GPAs" for dislocated workers and non dislocated workers enrolled in career-technical courses at a rural community college. The variables included in the study are age, gender, and marital status. The study…

  3. Dislocation

    MedlinePlus

    Joint dislocation ... It may be hard to tell a dislocated joint from a broken bone . Both are emergencies that ... to repair a ligament that tears when the joint is dislocated is needed. Injuries to nerves and ...

  4. Plant Closings. Limited Advance Notice and Assistance Provided Dislocated Workers. Report to Congressional Committees.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Div. of Human Resources.

    This is the final report in a series issued to assist Congress in assessing the problems of worker dislocation and employer practices related to advance notice and assistance provided to workers. A national survey of 2,600 business establishments was conducted to determine: (1) the extent of business closures and permanent layoffs between January…

  5. Dislocated Worker Human Capital Depreciation and Recovery. Upjohn Institute Staff Working Paper 90-04.

    ERIC Educational Resources Information Center

    Hollenbeck, Kevin

    This study examined the characteristics of dislocated workers' wage profiles upon reemployment. In particular, it related these profiles to the model developed by Mincer and Ofek (1982). An inference from this model was that workers recovered wage losses relatively rapidly. Explanations for a steeply sloped reentry wage profile were as follows:…

  6. Surgical treatment for permanent dislocation of the patella in adults.

    PubMed

    Noda, Mitsuaki; Saegusa, Yasuhiro; Kashiwagi, Naoya; Seto, Yoichi

    2011-12-06

    Permanent dislocation of the patella in adults is a rare condition that presents with complete irreducible lateral dislocation of the patella, combined with secondary changes, such as valgus deformity and leg-length discrepancy. Because these secondary changes cannot heal spontaneously after skeletal maturation if left untreated, the patients frequently possess pathology not limited to the knee joint and extending to the whole lower extremity, such as malalignment or leg-length discrepancy, that can develop into osteoarthritis of the knee. However, to our knowledge, few surgeons advocate the significance of correcting the malalignment in treating adult patients. We treated a 34-year-old woman with permanent dislocation of the patella in a 2-stage surgery, consisting of first-stage correction of valgus deformity and limb shortening using a Ilizarov external fixator and second-stage realignment of the dislocated patella over the trochlea. A follow-up examination conducted 3 years after the second operation revealed plantigrade gait with normal alignment of the lower extremity without limping and medial thrust. The patella was tracking centrally in the patellofemoral groove. Radiographs showed a neutral mechanical axis of the lower extremity, no evidence of patellar subluxation, and no deteriorating osteoarthritic changes at the tibiofemoral joint. This case highlights the importance of correcting secondary changes, such as valgus deformity and leg-length discrepancy, to reduce the risk of future osteoarthrosis and postoperative dislocation, especially when these deformities are substantial.

  7. Upward Mobility Programs in the Service Sector for Disadvantaged and Dislocated Workers. Volume I: Final Report.

    ERIC Educational Resources Information Center

    Tao, Fumiyo; And Others

    Upward mobility programs in the service sector for low-skilled, economically disadvantaged, and dislocated or displaced workers promote employment security, career development, and productivity. Two basic types of upward mobility programs are basic and job-specific skills training. Although 60-80 percent of all employer-sponsored formal training…

  8. Customer Satisfaction Perceptions of Dislocated Workers Served by WIN Job Centers in the Mississippi Corridor Consortium

    ERIC Educational Resources Information Center

    Washburn, Dava Michelle

    2009-01-01

    The purpose of this study was to determine the perceptions of satisfaction of dislocated workers served by WIN Job Centers in the Mississippi Corridor Consortium. Four WIN Job Centers participated in this study: Northeast Mississippi Community College WIN Job Center in Corinth, Northwest Mississippi Community College WIN Job Center in Oxford,…

  9. Upward Mobility Programs in the Service Sector for Disadvantaged and Dislocated Workers. Volume II: Technical Appendices.

    ERIC Educational Resources Information Center

    Tao, Fumiyo; And Others

    This volume contains technical and supporting materials that supplement Volume I, which describes upward mobility programs for disadvantaged and dislocated workers in the service sector. Appendix A is a detailed description of the project methodology, including data collection methods and information on data compilation, processing, and analysis.…

  10. Dislocations

    MedlinePlus

    ... Attempting to move or jam a dislocated bone back in can damage blood vessels, muscles, ligaments, and nerves. Apply an ice pack. Ice can ease swelling and pain in and around the joint. Use ibuprofen or ...

  11. The Effect of New Technological Training, Employability Skills Training, and Individual Counseling on the Self-Esteem and Anxiety of Dislocated Workers.

    ERIC Educational Resources Information Center

    Rosenberg, Jeffrey A.

    An attempt was made to increase dislocated worker's self-esteem and decrease their anxiety through implementation of a technical retraining program that included teaching employability skills and counseling. The program was offered by a community college to 23 dislocated workers. Self-esteem and anxiety were measured three times during the program…

  12. 20 CFR 631.30 - Designation or creation and functions of a State dislocated worker unit or office, and rapid...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Provide technical assistance and advice to substate grantees; (5) Exchange information and coordinate...) Technical advice as well as information on sources of assistance, and liaison with other public and private... State dislocated worker unit or office, and rapid response assistance. 631.30 Section 631.30...

  13. A prevalence study of recurrent shoulder dislocations in young adults.

    PubMed

    Milgrom, C; Mann, G; Finestone, A

    1998-01-01

    The computerized database of the Israeli Defence Forces Medical Corps monitors recurrent shoulder dislocations before citizens are eligible for military induction, during the years of regular military service, and during the time of eligibility for reserve army service. With the computerized database of the Israeli Defence Forces Medical Corps, between the years of 1978 to 1995 the prevalence rate of subjects with recurrent shoulder dislocations less than or equal to 21 years of age was found to be 19.7 of 10,000 for men and 5.01 of 10,000 for women. The prevalence rate of subjects with a history of shoulder dislocations in the male population between the ages of 22 and 33 years was 42.4 of 10,000. Forty-four percent were judged to be sufficiently unstable to warrant surgery, but only 55% of these actually underwent surgery. These epidemiologic data may be important if arthroscopic shoulder surgery is being considered after a first shoulder dislocation.

  14. Adult Monteggia and Olecranon Fracture Dislocations of the Elbow.

    PubMed

    Wong, Justin C; Getz, Charles L; Abboud, Joseph A

    2015-11-01

    Monteggia fractures and olecranon fracture dislocations represent complex injuries with distinct patterns of bony and soft tissue involvement. Fractures of the proximal ulna and olecranon process may lead to disruption of the proximal radioulnar joint and/or ulnohumeral joint. The keys to treatment are recognition of the pattern of injury and formation of an algorithmic surgical plan to address all components of the injury process. Complications are common and may be related to the injury spectrum itself and/or inadequate fracture alignment or fixation.

  15. 20 CFR 663.705 - What are the requirements for OJT contracts for employed workers?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE... production or service procedures, upgrading to new jobs that require additional skills, workplace...

  16. Notch signalling mediates reproductive constraint in the adult worker honeybee

    PubMed Central

    Duncan, Elizabeth J.; Hyink, Otto; Dearden, Peter K.

    2016-01-01

    The hallmark of eusociality is the reproductive division of labour, in which one female caste reproduces, while reproduction is constrained in the subordinate caste. In adult worker honeybees (Apis mellifera) reproductive constraint is conditional: in the absence of the queen and brood, adult worker honeybees activate their ovaries and lay haploid male eggs. Here, we demonstrate that chemical inhibition of Notch signalling can overcome the repressive effect of queen pheromone and promote ovary activity in adult worker honeybees. We show that Notch signalling acts on the earliest stages of oogenesis and that the removal of the queen corresponds with a loss of Notch protein in the germarium. We conclude that the ancient and pleiotropic Notch signalling pathway has been co-opted into constraining reproduction in worker honeybees and we provide the first molecular mechanism directly linking ovary activity in adult worker bees with the presence of the queen. PMID:27485026

  17. Finding the Worker: Adult Education and Workers' Education

    ERIC Educational Resources Information Center

    Rose, Amy D.; Jeris, Laurel H.

    2011-01-01

    This article looks at how administrators and teachers who consider themselves adult educators but who find themselves in a union environment come to think about their role and their context. This article is based on research conducted with administrators and teachers working in a joint union-employer sponsored program. Joint programs were…

  18. Credential Attainment by Older Workers: The Role of Community Colleges and the Dislocated Worker Program in Successful Employment Outcomes

    ERIC Educational Resources Information Center

    Cummins, Phyllis Ann

    2013-01-01

    Workers are remaining in the labor force at older ages and despite their desire to work, those without jobs face unprecedented durations of unemployment. Many of the unemployed lack current skills for jobs in demand and need to either upgrade their skills or be trained for a new occupation to become reemployed. An aging workforce combined with…

  19. Marketing Strategies Preferred by South Carolina One-Stop Career Center Area Directors to Attract Dislocated Workers under the Workforce Investment Act of 1998: Policy Implications

    ERIC Educational Resources Information Center

    Ratliff, Eugene F.

    2011-01-01

    The purpose of this study was to determine the marketing strategies South Carolina One-Stop Career Centers Area Directors felt provided the best opportunity for dislocated workers to learn about their services. Two theories emerged: the Service Marketing Theory and the Word-of-Mouth Marketing Theory. Of the 36 area directors cited for this study,…

  20. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult – A Rare Association

    PubMed Central

    James, Boblee

    2016-01-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado’s fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  1. Fracture-dislocation of the humeral condyles in adults: results of surgical treatment.

    PubMed

    Bentounsi, Abdelhakim

    2015-09-01

    Fracture-dislocation of the humeral condyle is exceptional in adults. The purpose was to analyze the results of surgical treatment by open reduction and internal fixation without ligamentous repair. There were six men with an average age of 31 years. According to the AO classification, five fractures were classified as AO type B1 and one as B2. Dislocation was reduced in emergency before osteosynthesis. Postoperatively, the joint was held immobile with a brace for 25.40 days. Five patients were reviewed after a mean follow-up of 52.96 months. The median arc of flexion/extension was 104.80° and 157.8° for pronation-supination. All elbows were stable and all fractures were consolidated. Two elbows were painful. The results were satisfactory in five patients. The elbow stability can be ensured only by the synthesis of bone structures. Surgical treatment should restore exact anatomy between the condyle and trochlea. This protocol may provide a joint stability and satisfactory results.

  2. Effectiveness of Dysphagia Training for Adult Learning Disabilities Support Workers

    ERIC Educational Resources Information Center

    Tredinnick, Gerlind; Cocks, Naomi

    2014-01-01

    This study investigated the effectiveness of a 1-day dysphagia training package delivered to support workers who work with adults with a learning disability. Thirty-eight support staff took part in this study. Twenty-five support staff received training, and 13 did not receive training and therefore acted as a control group. Three questionnaires…

  3. Atlanto Axial Rotatory Dislocation in Adults: A Rare Complication of an Epileptic Seizure—Case Report

    PubMed Central

    TARANTINO, Roberto; DONNARUMMA, Pasquale; MAROTTA, Nicola; MISSORI, Paolo; VIOZZI, Ilaria; LANDI, Alessandro; DELFINI, Roberto

    2014-01-01

    Atlanto Axial Rotatory Dislocations (AARDs) are a heterogeneous group of post-traumatic pathologies typical of the pediatric age, and rare in adults. We describe the case of a 34-year-old woman, developing Atlanto Axial Rotatory Fixation (AARF) after a generalized tonic-clonic epileptic seizure, an extremely rare traumatic cause never described in literature. AARF was detected only 1 month after the accident and nonsurgical treatment was attempted at the beginning. The patient underwent surgery only 2 months after the accident. The best treatment should be conservative reduction within 1 month; when it is not possible, it is advisable to perform surgery as soon as possible. C1–C2 fixation with Harm's technique is the gold standard for fixed luxations. Delay of treatment makes intraoperative reduction more difficult and increase the establishment of the chronic permanent change of neck muscles and ligaments. PMID:24201098

  4. [Anterior dislocation of the elbow joint without peri-articular fracture in an adult].

    PubMed

    Chbani, B; Lahrach, K; Amar, M-F; Ibnlkadi, K; Elmoubaker, S; Bennani, A; Marzouki, A; Boutayeb, F

    2012-12-01

    In view of the comparative frequency of posterior dislocations of the elbow, it is rather remarkable that anterior dislocations of that joint should be among the rarest of injuries [1]. Our case is one of the first cases of anterior dislocation of the elbow without any periarticular fracture or pre-existing deformities around the elbow [2].

  5. Seat Belt Use Among Adult Workers - 21 States, 2013.

    PubMed

    Boal, Winifred L; Li, Jia; Rodriguez-Acosta, Rosa L

    2016-06-17

    Roadway incidents involving motorized vehicles accounted for 24% of fatal occupational injuries in the United States during 2013 and were the leading cause of fatal injuries among workers.* In 2013, workers' compensation costs for serious, nonfatal injuries among work-related roadway incidents involving motorized land vehicles were estimated at $2.96 billion.(†) Seat belt use is a proven method to reduce injuries to motor vehicle occupants (1). Use of lap/shoulder seat belts reduces the risk for fatal injuries to front seat occupants of cars by 45% and the risk to light truck occupants by 60%.(§) To characterize seat belt use among adult workers by occupational group, CDC analyzed data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS) and found that not always using a seat belt was significantly associated with occupational group after controlling for factors known to influence seat belt use. Occupational groups with the highest prevalences of not always using a seat belt included construction and extraction; farming, fishing, and forestry; and installation, maintenance, and repair. To increase seat belt use among persons currently employed, states can enact and enforce primary seat belt laws, employers can set and enforce safety policies requiring seat belt use by all vehicle occupants, and seat belt safety advocates can target interventions to workers in occupational groups with lower reported seat belt use.

  6. A Rare Combination of Complex Elbow Dislocation and Distal Radial Fracture in Adults

    PubMed Central

    Vaishya, Raju; Krishnan, Midhun; Agarwal, Amit Kumar

    2016-01-01

    Although it is common for separate elbow joint dislocation and fracture of forearm bones to occur, it is a rare sighting for both elbow dislocation and ipsilateral fracture of the distal radius. We report a case of an anterior dislocation of the elbow with ipsilateral fracture of the distal radius. The case was treated operatively. We describe two possible mechanisms of injury for these rare injury types. The case underlines the importance of assessing the wrist in the case of an elbow fracture and vice versa. PMID:28003939

  7. A Rare Combination of Complex Elbow Dislocation and Distal Radial Fracture in Adults.

    PubMed

    Vaishya, Raju; Krishnan, Midhun; Vijay, Vipul; Agarwal, Amit Kumar

    2016-11-08

    Although it is common for separate elbow joint dislocation and fracture of forearm bones to occur, it is a rare sighting for both elbow dislocation and ipsilateral fracture of the distal radius. We report a case of an anterior dislocation of the elbow with ipsilateral fracture of the distal radius. The case was treated operatively. We describe two possible mechanisms of injury for these rare injury types. The case underlines the importance of assessing the wrist in the case of an elbow fracture and vice versa.

  8. Social Workers' Attitudes toward Older Adults: A Review of the Literature

    ERIC Educational Resources Information Center

    Wang, Donna; Chonody, Jill

    2013-01-01

    Ageist attitudes toward older adults have been recognized as barriers to recruiting and training competent social workers. This article provides a systematic review of the literature that focused on social workers' and social work students' attitudes toward older adults and working with older adults. The authors sought empirical studies…

  9. Environmental Education through Adult Education. A Manual for Adult Educators, Instructors, Teachers and Social Extension Workers.

    ERIC Educational Resources Information Center

    Rugumayo, Edward B., Comp.; Ibikunle-Johnson, Victor O., Comp.

    The purpose of this manual is to make available to adult educators and field extension workers in Kenya resource material that may be used in formal and nonformal training programs for the environmental education of a wide range of target groups. The document begins with a 26-item glossary, an introduction, a section on the document's use,…

  10. [Work values and goal consciousness in young adult workers].

    PubMed

    Sakai, Keiko; Hanzawa, Reino

    2008-04-01

    This study aimed to examine the goal consciousness scale as lifespan developmental index in young adult workers, and the relationship between work values and the goal consciousness. Survey data from 240 young adult workers were used, two subscales in work values scale and five subscales in goal consciousness scale were confirmed by factor analyses. Analysis of variance (ANOVAs) showed that goal-confidence and time-management were high with high expert-orientation or low work-as-devise-orientation. Thirst for goal was low with low expert-orientation and low work-as-devise-orientation. Anxiety about the future was high with high work-as-devise-orientation in the case of males who have high expert-orientation. Planning was high with low work-as-devise-orientation in the case of male. These results indicated that expert-orientation promotes goal-consciousness, work-as-devise-orientation disturbs it, especially, expert-as-devise-orientation raises anxiety for the future.

  11. 20 CFR 631.30 - Designation or creation and functions of a State dislocated worker unit or office, and rapid...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-management cooperation to achieve the goals of this part; (3) Operate a monitoring, reporting, and management... workers under the NAFTA Worker Security Act for which the Governor has made a finding under §...

  12. Examining Self-Protection Measures Guarding Adult Protective Services Social Workers against Compassion Fatigue

    ERIC Educational Resources Information Center

    Bourassa, Dara

    2012-01-01

    Little research has focused on the risk factors, effects, and experiences of compassion fatigue among gerontological social workers. This qualitative study explores the experiences and perspectives of nine Adult Protective Services (APS) social workers in relation to compassion fatigue. Results show that the APS social workers combined personal…

  13. Open anterior dislocation of the hip in an adult: a case report and review of literature.

    PubMed

    de Oliveira, Anderson Luiz; Machado, Eduardo Gomes

    2014-01-01

    Open anterior hip dislocation is a rare condition and results from high-energy trauma. Ten cases of open anterior dislocation have been described in the literature so far. Its rarity is due to the inherent stability of the joint, its deep position in the pelvis, with strong ligaments and bulky muscles around the articulation. Several factors influence the prognosis, such as the degree of compounding, the associated soft tissue injuries, the age of the patient and, mainly, the delay in reduction. The main complications are: arthrosis of the hip, with incidence of 50% of cases, when associated with fractures of the femoral head; and osteonecrosis of the femoral head, with incidence between 1.7 and 40% (in closed anterior dislocation). Because of the rarity and the potential disability of this lesion, we report a case in a 46-year-old man, involved in an automobile accident. The hip was reduced (anterior superior dislocation) in the first three hours of the trauma. The patient was kept non-weight bearing until sixth week, with complete weight bearing after 10th week. After one year follow-up, the functional result was poor (Harris Hip Score: 52), probably because of the associated labral tear, but without signs of osteonecrosis of the femoral head in magnetic resonance imaging.

  14. Elbow fracture-dislocation combined with Galeazzi fracture in adult: A case report and literature review

    PubMed Central

    Asadollahi, Saeed; Shepherd, David; Hau, Raphael C.

    2013-01-01

    INTRODUCTION Galeazzi fracture associated with ipsilateral posterior elbow dislocation and radial head fracture is a rare pattern of injury. Few reports exist that describes this injury pattern and its treatment. We describe a case report of simultaneous occurrence of Galeazzi fracture and ipsilateral dislocation of elbow. PRESENTATION OF CASE A 58 year-old female presented with Galeazzi fracture and posterior elbow dislocation associated with radial head fracture of left upper extremity. This was managed with closed reduction of the elbow, open reduction and internal fixation of the radial shaft fracture and K-wire stabilisation of the unstable distal radioulnar joint. Prophylactic fasciotomy was performed. At 10 months follow-up, the outcome was favourable with the American shoulder and elbow surgeon score of 92 and the disabilities of the arm, shoulder and hand score of 18. DISCUSSION The presumed mechanism of the injury was a forceful axial loading of a hyperpronated forearm and extended elbow. Our literature review shows that this pattern of injury occurs as a result of high energy trauma in young individuals, and successful outcome can be achieved by addressing each component of this complex injury individually. CONCLUSION Simultaneous occurrence of elbow dislocation and Galeazzi fracture seems to be the result of extreme axial force and unique position of upper extremity at the time of impact. Individualised approach to each component of this injury can result in favourable outcome. PMID:23726112

  15. [Elbow dislocation].

    PubMed

    de Pablo Márquez, B; Castillón Bernal, P; Bernaus Johnson, M C; Ibañez Aparicio, N M

    2017-03-09

    Elbow dislocation is the most frequent dislocation in the upper limb after shoulder dislocation. Closed reduction is feasible in outpatient care when there is no associated fracture. A review is presented of the different reduction procedures.

  16. 20 CFR 663.200 - What are intensive services for adults and dislocated workers?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of time. Work experience may be paid or unpaid, as appropriate. A work experience workplace may be in... workforce readiness, relocation assistance, internships, and work experience may be provided, based on an assessment or individual employment plan. (b) For the purposes of paragraph (a) of this section,...

  17. 20 CFR 663.200 - What are intensive services for adults and dislocated workers?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of time. Work experience may be paid or unpaid, as appropriate. A work experience workplace may be in... workforce readiness, relocation assistance, internships, and work experience may be provided, based on an assessment or individual employment plan. (b) For the purposes of paragraph (a) of this section,...

  18. 20 CFR 663.200 - What are intensive services for adults and dislocated workers?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... section, work experience is a planned, structured learning experience that takes place in a workplace for a limited period of time. Work experience may be paid or unpaid, as appropriate. A work experience... basic workforce readiness, relocation assistance, internships, and work experience may be...

  19. 20 CFR 663.200 - What are intensive services for adults and dislocated workers?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... section, work experience is a planned, structured learning experience that takes place in a workplace for a limited period of time. Work experience may be paid or unpaid, as appropriate. A work experience... basic workforce readiness, relocation assistance, internships, and work experience may be...

  20. 20 CFR 663.200 - What are intensive services for adults and dislocated workers?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... section, work experience is a planned, structured learning experience that takes place in a workplace for a limited period of time. Work experience may be paid or unpaid, as appropriate. A work experience... basic workforce readiness, relocation assistance, internships, and work experience may be...

  1. 20 CFR 663.825 - What are the eligibility requirements for dislocated workers to receive needs-related payments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... services under WIA section 134(d)(4) by the end of the 13th week after the most recent layoff that resulted... the 8th week after the worker is informed that a short-term layoff will exceed 6 months; or (b)...

  2. Linguistic Problems of Adult Migrant Workers and Socio-linguistic Problems of Migrant Workers' Children Being Educated in the Host Country.

    ERIC Educational Resources Information Center

    Verdoodt, Albert

    This article examines the linguistic problems of adult migrant workers and sociolinguistic problems of their children. The introduction states provisions for migrant workers' ethnic and linguistic rights. An examination of the actual situation leads to the general statement that linguistic rights of migrant workers are passively tolerated and not…

  3. 76 FR 43729 - Notice of Random Assignment Study To Evaluate Workforce Investment Act Adult and Dislocated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... Employment and Training Administration Notice of Random Assignment Study To Evaluate Workforce Investment Act... conduct an evaluation to provide rigorous, nationally representative estimates of the net impacts of intensive services and training provided under the Workforce Investment Act (WIA) Adult and...

  4. Rescue of newborn ants by older Cataglyphis cursor adult workers.

    PubMed

    Nowbahari, Elise; Amirault, Céline; Hollis, Karen L

    2016-05-01

    Cataglyphis cursor worker ants are capable of highly sophisticated rescue behaviour in which individuals are able to identify what has trapped a nestmate and to direct their behaviour towards that obstacle. Nonetheless, rescue behaviour is constrained by workers' subcaste: whereas foragers, the oldest workers, are able both to give and to receive the most help, the youngest workers, inactives, neither give nor receive any help whatsoever; nurses give and receive intermediate levels of aid, reflecting their intermediate age. Such differences in rescue behaviour across subcastes suggest that age and experience play a critical role. In this species, as in many others in which a sensitive period for nestmate recognition exists, newly enclosed ants, called callows, are adopted by ants belonging not only to different colonies but also to different species; foreign callows receive nearly the same special care provided to resident newborns. Because callows are younger than inactives, which are incapable of soliciting rescue, we wondered whether entrapped callows would receive such aid. In the present study, we artificially ensnared individual callows from their own colony (homocolonial), from a different colony (heterocolonial), and from a different species (heterospecific), and tested each one with groups of five potential C. cursor rescuers, either all foragers or all nurses. Our results show that all three types of callows are able to elicit rescue behaviour from both foragers and nurses. Nonetheless, nurse rescuers are better able to discriminate between the three types of callow victims than are foragers.

  5. Examining self-protection measures guarding Adult Protective Services social workers against compassion fatigue.

    PubMed

    Bourassa, Dara

    2012-06-01

    Little research has focused on the risk factors, effects, and experiences of compassion fatigue among gerontological social workers. This qualitative study explores the experiences and perspectives of nine Adult Protective Services (APS) social workers in relation to compassion fatigue. Results show that the APS social workers combined personal characteristics and professional factors to develop boundary-setting mechanisms that protected them from experiencing the deleterious symptoms and effects of compassion fatigue. Implications center around the elements needed to implement boundaries in order to maintain a separation between the work and home environment. Suggestions for future research are provided.

  6. Keeping the Doors of Learning Open for Adult Student-Workers within Higher Education?

    ERIC Educational Resources Information Center

    Walters, Shirley; Abrahams, Mark; Witbooi, Sally

    2015-01-01

    The Freedom Charter of the African National Congress (ANC), the triumphant South African liberation movement, proclaims that "the doors of learning shall be open" for all. Twenty years since coming to power, the doors of the universities are struggling to stay open for adult student-workers. An action research project into implementation…

  7. Relationships between Adult Workers' Spiritual Well-Being and Job Satisfaction: A Preliminary Study

    ERIC Educational Resources Information Center

    Robert, Tracey E.; Young, J. Scott; Kelly, Virginia A.

    2006-01-01

    The authors studied the relationships between adult workers' spiritual well-being and job satisfaction. Two hundred participants completed 2 instruments: the Spiritual Well-Being Scale (C. W. Ellison & R. F. Paloutzian, 1982) and the Minnesota Satisfaction Questionnaire Short Form (D. J. Weiss, R. V. Dawis, G. W. England, & L. H. Lofquist,…

  8. Unravelling the Lifelong Learning Process for Canadian Workers and Adult Learners Acquiring Higher Skills

    ERIC Educational Resources Information Center

    Taylor, Maurice; Trumpower, David; Pavic, Ivana

    2013-01-01

    This article reports on a mixed methods study that investigated aspects of formal, non-formal and informal learning for workers and adult high school learners seeking literacy and essential skills. Three key themes emerged from the qualitative data: motivations for participation in various forms of learning; seeking out informal learning…

  9. Support Systems for Injured Workers. Tierra de Oportunidad Module 5. LAES: Latino Adult Education Services Project.

    ERIC Educational Resources Information Center

    Kissam, Ed; Dorsey, Holda

    This module, which may be used as the basis for a workshop or as a special topic unit in an adult basic education or English-as-a-Second-Language (ESL) course, focuses on support systems for injured workers. The following items are included: module overview; list of basic, thinking, interpersonal, information utilization, and other skills…

  10. 20 CFR 663.600 - What priority must be given to low-income adults and public assistance recipients served with...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... adults and public assistance recipients served with adult funds under title I? 663.600 Section 663.600 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER... priority must be given to low-income adults and public assistance recipients served with adult funds...

  11. Policy Implications of Gallup Data on Adult Employed Workers.

    ERIC Educational Resources Information Center

    Hoyt, Kenneth B.

    1989-01-01

    Discusses results of a survey of 735 working adults concerning their perceptions of the relevance of their education to their work. Policy implications drawn from this survey include (1) rethink reform; (2) strengthen ties between education and work; (3) college is not for everyone; (4) motivate with recognition; and (5) begin planning early. (CH)

  12. WORKERS IN ADULT EDUCATION, THEIR STATUS, RECRUITMENT, AND PROFESSIONAL TRAINING.

    ERIC Educational Resources Information Center

    JESSUP, F.W.

    A PILOT STUDY PREPARED FOR THE COUNCIL OF EUROPE COMPARES ADULT EDUCATOR STATUS, RECRUITMENT, AND PROFESSIONAL TRAINING IN FRANCE, FLANDERS (BELGIUM), WEST GERMANY, THE NETHERLANDS, NORWAY, AND THE UNITED KINGDOM. MAJOR CONCERNS INCLUDE SALARIES AND BENEFITS, QUALIFICATIONS, INSERVICE TRAINING, SPONSORING BODIES, ATTITUDES TOWARD FORMAL STAFF…

  13. 20 CFR 663.820 - What are the eligibility requirements for adults to receive needs-related payments?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... adults to receive needs-related payments? 663.820 Section 663.820 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... requirements for adults to receive needs-related payments? Adults must: (a) Be unemployed, (b) Not qualify...

  14. 20 CFR 663.820 - What are the eligibility requirements for adults to receive needs-related payments?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... adults to receive needs-related payments? 663.820 Section 663.820 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... requirements for adults to receive needs-related payments? Adults must: (a) Be unemployed, (b) Not qualify...

  15. 20 CFR 663.820 - What are the eligibility requirements for adults to receive needs-related payments?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... adults to receive needs-related payments? 663.820 Section 663.820 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE... requirements for adults to receive needs-related payments? Adults must: (a) Be unemployed, (b) Not qualify...

  16. [Traumatic bilateral rotatory C1-C2 dislocation in an adult: case report and review of the literature].

    PubMed

    Lefebvre, Y; Babin, S R; Clavert, P; Dosch, J C; Jobard, D; Bonnomet, F; Simon, P

    2002-10-01

    Trauma led to bilateral rotatory atlantoaxial dislocation in a 23-year-old woman. Clinical diagnosis of this uncommon dislocation of the cervical spin is generally difficult and often made late. Typical signs include pain in the upper cervical spine and a fixed rotated position of the head. Integrity of the transverse ligament of the atlas is a determining factor for atlantoaxial stability and allows orthopedic treatment after reduction using moderate traction on the head. As for most authors, orthopedic was successful in our patient who totally recovered cervical spine mobility without pain.

  17. First-time traumatic anterior dislocation of the shoulder in young adults: the position of the arm during immobilisation revisited.

    PubMed

    De Baere, Tom; Delloye, Christian

    2005-10-01

    In contrast to the surgical treatment of chronic shoulder instability, there are only scarce publications about the management after a first episode of anterior shoulder dislocation and how to prevent the evolution towards chronic instability. We present here a review of the literature on this subject. Particular attention is paid to recent studies about the position of the arm during immobilisation. According to recent views, it may be preferable to immobilise the arm in external rather than internal rotation, but this has to be confirmed by further clinical studies. The issue of early arthroscopic stabilisation after a first dislocation event in young athletic patients is also discussed.

  18. Zinc protoporphyrin IX concentrations between normal adults and the lead-exposed workers measured by HPLC, spectrofluorometer, and hematofluorometer.

    PubMed

    Roh, Y M; Kim, K; Kim, H

    2000-10-01

    To establish the relationship between Zinc protoporphyrin (ZPP) concentrations and blood lead (PbB) levels and to identify reliable analytical methods of ZPP and Protoporhyrin (PP), blood samples were obtained from 263 office workers without the history of occupational lead exposure and 49 lead-acid battery workers. The mean concentrations of PbB for the normal adults and the battery workers were 9.26 microg/dl and 42.60 microg/dl, respectively. The geometric mean concentrations of ZPP and PP by HPLC were 18.73 microg/dl and 2.27 microg/dl for normal adults and were 46.99 microg/dl and 5.53 microg/dl for the exposed workers, respectively. The geometric mean concentrations of ZPP and PP by a spectrofluorometer (SF) were 30.27 microg/dl and 5.16 microg/dl for normal adults and were 50.91 microg/dl and 6.69 +/- 1.39 microg/dl for the exposed workers. The geometric mean ZPP concentration measured by a hematofluorometer (HF) was 30.88 microg/dl for normal adults. The results showed that ZPP concentrations measured by HF were consistently higher than those by HPLC and SF for normal adults, and lower for the exposed workers. ZPP concentrations were not correlated with PbB levels for normal adults but a statistically significant correlation was found among the exposed workers.

  19. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  20. The Prevalence of Childhood Adversity among Healthcare Workers and Its Relationship to Adult Life Events, Distress and Impairment

    ERIC Educational Resources Information Center

    Maunder, Robert G.; Peladeau, Nathalie; Savage, Diane; Lancee, William J.

    2010-01-01

    Objective: We investigated the prevalence of childhood adversity among healthcare workers and if such experiences affect responses to adult life stress. Methods: A secondary analysis was conducted of a 2003 study of 176 hospital-based healthcare workers, which surveyed lifetime traumatic events, recent life events, psychological distress, coping,…

  1. Simple Elbow Dislocation.

    PubMed

    Armstrong, April

    2015-11-01

    Simple elbow dislocation refers to those elbow dislocations that do not involve an osseous injury. A complex elbow dislocation refers to an elbow that has dislocated with an osseous injury. Most simple elbow dislocations are treated nonoperatively. Understanding the importance of the soft tissue injury following a simple elbow dislocation is a key to being successful with treatment.

  2. Estimation of maximal oxygen uptake without exercise testing in Korean healthy adult workers.

    PubMed

    Jang, Tae-Won; Park, Shin-Goo; Kim, Hyoung-Ryoul; Kim, Jung-Man; Hong, Young-Seoub; Kim, Byoung-Gwon

    2012-01-01

    Maximal oxygen uptake is generally accepted as the most valid and reliable index of cardiorespiratory fitness and functional aerobic capacity. The exercise test for measuring maximal oxygen uptake is unsuitable for screening tests in public heath examinations, because of the potential risks of exercise exertion and time demands. We designed this study to determine whether work-related physical activity is a potential predictor of maximal oxygen uptake, and to develop a maximal oxygen uptake equation using a non-exercise regression model for the cardiorespiratory fitness test in Korean adult workers. Study subjects were adult workers of small-sized companies in Korea. Subjects with history of disease such as hypertension, diabetes, asthma and angina were excluded. In total, 217 adult subjects (113 men of 21-55 years old and 104 women of 20-64 years old) were included. Self-report questionnaire survey was conducted on study subjects, and maximal oxygen uptake of each subject was measured with the exercise test. The statistical analysis was carried out to develop an equation for estimating maximal oxygen uptake. The predictors for estimating maximal oxygen uptake included age, gender, body mass index, smoking, leisure-time physical activity and the factors representing work-related physical activity. The work-related physical activity was identified to be a predictor of maximal oxygen uptake. Moreover, the equation showed high validity according to the statistical analysis. The equation for estimating maximal oxygen uptake developed in the present study could be used as a screening test for assessing cardiorespiratory fitness in Korean adult workers.

  3. 20 CFR 663.820 - What are the eligibility requirements for adults to receive needs-related payments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... adults to receive needs-related payments? 663.820 Section 663.820 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.820 What are the eligibility requirements for adults...

  4. 20 CFR 663.820 - What are the eligibility requirements for adults to receive needs-related payments?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... adults to receive needs-related payments? 663.820 Section 663.820 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Supportive Services § 663.820 What are the eligibility requirements for adults...

  5. Honey Bee Workers That Are Pollen Stressed as Larvae Become Poor Foragers and Waggle Dancers as Adults

    PubMed Central

    Scofield, Hailey N.; Mattila, Heather R.

    2015-01-01

    The negative effects on adult behavior of juvenile undernourishment are well documented in vertebrates, but relatively poorly understood in invertebrates. We examined the effects of larval nutritional stress on the foraging and recruitment behavior of an economically important model invertebrate, the honey bee (Apis mellifera). Pollen, which supplies essential nutrients to developing workers, can become limited in colonies because of seasonal dearths, loss of foraging habitat, or intensive management. However, the functional consequences of being reared by pollen-stressed nestmates remain unclear, despite growing concern that poor nutrition interacts with other stressors to exacerbate colony decline. We manipulated nurse bees’ access to pollen and then assessed differences in weight, longevity, foraging activity, and waggle-dance behavior of the workers that they reared (who were co-fostered as adults). Pollen stress during larval development had far-reaching physical and behavioral effects on adult workers. Workers reared in pollen-stressed colonies were lighter and shorter lived than nestmates reared with adequate access to pollen. Proportionally fewer stressed workers were observed foraging and those who did forage started foraging sooner, foraged for fewer days, and were more likely to die after only a single day of foraging. Pollen-stressed workers were also less likely to waggle dance than their unstressed counterparts and, if they danced, the information they conveyed about the location of food was less precise. These performance deficits may escalate if long-term pollen limitation prevents stressed foragers from providing sufficiently for developing workers. Furthermore, the effects of brief pollen shortages reported here mirror the effects of other environmental stressors that limit worker access to nutrients, suggesting the likelihood of their synergistic interaction. Honey bees often experience the level of stress that we created, thus our findings

  6. Trade Adjustment Assistance: Trends, Outcomes, and Management Issues in Dislocated Worker Programs. Report to the Chairman and Ranking Minority Member, Committee on Finance, U.S. Senate.

    ERIC Educational Resources Information Center

    Westin, Susan S.

    To assess the effectiveness of the Trade Adjustment Assistance and North American Free Trade Agreement (NAFTA) Transitional Adjustment Assistance programs, the General Accounting Office (GAO) reviewed available Department of Labor program data and surveyed 20 states representing about 76% of all workers certified under the two programs in fiscal…

  7. Starvation stress during larval development facilitates an adaptive response in adult worker honey bees (Apis mellifera L.).

    PubMed

    Wang, Ying; Kaftanoglu, Osman; Brent, Colin S; Page, Robert E; Amdam, Gro V

    2016-04-01

    Most organisms are constantly faced with environmental changes and stressors. In diverse organisms, there is an anticipatory mechanism during development that can program adult phenotypes. The adult phenotype would be adapted to the predicted environment that occurred during organism maturation. However, whether this anticipatory mechanism is present in eusocial species is questionable because eusocial organisms are largely shielded from exogenous conditions by their stable nest environment. In this study, we tested whether food deprivation during development of the honey bee (Apis mellifera), a eusocial insect model, can shift adult phenotypes to better cope with nutritional stress. After subjecting fifth instar worker larvae to short-term starvation, we measured nutrition-related morphology, starvation resistance, physiology, endocrinology and behavior in the adults. We found that the larval starvation caused adult honey bees to become more resilient toward starvation. Moreover, the adult bees were characterized by reduced ovary size, elevated glycogen stores and juvenile hormone (JH) titers, and decreased sugar sensitivity. These changes, in general, can help adult insects survive and reproduce in food-poor environments. Overall, we found for the first time support for an anticipatory mechanism in a eusocial species, the honey bee. Our results suggest that this mechanism may play a role in honey bee queen-worker differentiation and worker division of labor, both of which are related to the responses to nutritional stress.

  8. Neurologic effects of solvents in older adults. (UW retired worker study). Final performance report

    SciTech Connect

    Daniell, W.E.

    1993-11-12

    The possibility that previous occupational exposure to solvents might be associated with clinically significant neurological dysfunction in older adults was investigated in a cross-sectional study. Subjects included 67 painters, 22 aerospace painters and fuel cell sealers, and a comparison group of 126 carpenters. All subjects had retired from regular employment at least 1 year prior to the study. As measured by semiquantitative exposure index, the cumulative histories of lifetime occupational solvent exposure were on the average comparable in the two exposed study groups, painters and aerospace workers. The carpenters differed from the other groups in solvent exposure by several orders of magnitude. The painters had a significantly higher history of consuming alcoholic beverages than did the other two study groups. The painters had a significantly higher score on the Beck Depression Inventory, a measure of current depressive symptoms. The painters reported significantly more general neurologic symptoms than did the other two groups. The aerospace workers showed much greater evidence of possible adverse effects from former solvent exposure on current neuropsychological function than did the painters when determined by reasoning and memory tests, memory visual motor speed and motor tests. No evidence of persistent effects on liver or renal excretory function was seen in solvent exposed subjects.

  9. Nurses' and care workers' attitudes toward death and caring for dying older adults in Japan.

    PubMed

    Matsui, Miho; Braun, Kathryn

    2010-12-01

    Registered nurses (RNs) and care workers (CWs) have important roles in providing end-of-life care to older adults, but little is known about the attitudes of RNs and CWs in Japan. In this study, 464 RNs and CWs working in facilities in Japan were asked to complete a self-administered questionnaire that included the Frommelt Attitude Toward Care of the Dying Scale, Form B, Japanese version (FATCOD-Form B-J) and the Death Attitude Profile (DAP), Japanese version. A total of 388 (83.6%) questionnaires were returned, and 367 (79.1%) were fully completed. The final sample included 190 RNs and 177 CWs. Multiple regression analysis showed that better attitudes toward caring for the dying were positively associated with seminar attendance and negatively associated with fear of death.

  10. The Workforce Paradox for Adults with Limited Literacy or English Language Proficiency: A Report from the Field.

    ERIC Educational Resources Information Center

    Pinkey, Diane; Hofer, Judy

    Under the 1998 Workforce Investment Act (WIA), One Stop Career Centers were developed to provide training and employment related services to adults, youths, and dislocated workers. This study investigated the extent to which adults with limited literacy and/or English language skills were being served at One Stop Career Centers in New Mexico. Data…

  11. What adult worker model? A critical look at recent social policy reform in Europe from a gender and family perspective.

    PubMed

    Daly, Mary

    2011-01-01

    Analyses regularly feature claims that European welfare states are in the process of creating an adult worker model. The theoretical and empirical basis of this argument is examined here by looking first at the conceptual foundations of the adult worker model formulation and then at the extent to which social policy reform in western Europe fits with the argument. It is suggested that the adult worker formulation is under-specified. A framework incorporating four dimensions—the treatment of individuals vis-à-vis their family role and status for the purposes of social rights, the treatment of care, the treatment of the family as a social institution, and the extent to which gender inequality is problematized—is developed and then applied. The empirical analysis reveals a strong move towards individualization as social policy promotes and valorizes individual agency and self-sufficiency and shifts some childcare from the family. Yet evidence is also found of continued (albeit changed) familism. Rather than an unequivocal move to an individualized worker model then, a dual earner, gender-specialized, family arrangement is being promoted. The latter is the middle way between the old dependencies and the new “independence.” This makes for complexity and even ambiguity in policy, a manifestation of which is that reform within countries involves concurrent moves in several directions.

  12. Dislocation motion and instability

    NASA Astrophysics Data System (ADS)

    Zhu, Yichao; Chapman, Stephen Jonathan; Acharya, Amit

    2013-08-01

    The Peach-Koehler expression for the stress generated by a single (non-planar) curvilinear dislocation is evaluated to calculate the dislocation self stress. This is combined with a law of motion to give the self-induced motion of a general dislocation curve. A stability analysis of a rectilinear, uniformly translating dislocation is then performed. The dislocation is found to be susceptible to a helical instability, with the maximum growth rate occurring when the dislocation is almost, but not exactly, pure screw. The non-linear evolution of the instability is determined numerically, and implications for slip band formation and non-Schmid behavior in yielding are discussed.

  13. Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms

    NASA Astrophysics Data System (ADS)

    Hum Na, Yong; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F.; Xu, X. George

    2010-07-01

    Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte

  14. Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms.

    PubMed

    Na, Yong Hum; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F; Xu, X George

    2010-07-07

    Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms--modeled entirely in mesh surfaces--of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo

  15. Isolated Carpo-Metacarpal Dislocation of the Thumb

    PubMed Central

    Suresh, SS; Zaki, Hosam; Ahmed, Aamir

    2012-01-01

    Introduction: Isolated dislocations of the trapezio metacarpal joint without associated fracture has been reported very rarely in the literature. There are reports of associated injuries like fracture of the trapezium, dislocation of the metacarpophalangeal joint and fractures of the base of the thumb metacarpal. Case Report: Authors report a case of isolated carpometacarpal dislocation of the right thumb, in an adult, successfully managed conservatively. At 15 months follow up the patient had full function of the hand without any clinical or radiological evidence of instability or posttraumatic arthritis. Conclusion: Isolated dislocations can be successfully managed by closed reduction and immobilization in a back slab, with unstable dislocations requiring surgical intervention. PMID:27298846

  16. Breaking New Ground: The Development of Adult and Workers' Education in North America. Proceedings from the Syracuse University Kellogg Project's Visiting Scholar Conference in the History of Adult Education (1st, Syracuse, New York, March 1989).

    ERIC Educational Resources Information Center

    Rohfield, Rae Wahl, Ed.

    The 19 papers in this conference report examine the formative period of the field of adult education, the development of workers' education, and the interrelationships of the two fields. The four papers in Section I, on defining adult education are: "Challenging the System: The Adult Education Movement and the Educational Bureaucracy of the…

  17. Adult Education in a Workplace Context: Recognising Production Workers' Responses and Partnership Challenges

    ERIC Educational Resources Information Center

    Wärvik, Gun-Britt

    2016-01-01

    This article is about a larger regional Swedish partnership programme that was established to develop site-based education for production workers. A partnership is seen as composed of different practice architectures. The actors involved represented larger transnational as well as smaller manufacturing companies, employers, the metal workers'…

  18. Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis

    PubMed Central

    Olds, M; Ellis, R; Donaldson, K; Parmar, P; Kersten, P

    2015-01-01

    Background Recurrent instability following a first-time anterior traumatic shoulder dislocation may exceed 26%. We systematically reviewed risk factors which predispose this population to events of recurrence. Methods A systematic review of studies published before 1 July 2014. Risk factors which predispose recurrence following a first-time traumatic anterior shoulder dislocation were documented and rates of recurrence were compared. Pooled ORs were analysed using random-effects meta-analysis. Results Ten studies comprising 1324 participants met the criteria for inclusion. Recurrent instability following a first-time traumatic anterior shoulder dislocation was 39%. Increased risk of recurrent instability was reported in people aged 40 years and under (OR=13.46), in men (OR=3.18) and in people with hyperlaxity (OR=2.68). Decreased risk of recurrent instability was reported in people with a greater tuberosity fracture (OR=0.13). The rate of recurrent instability decreased as time from the initial dislocation increased. Other factors such as a bony Bankart lesion, nerve palsy and occupation influenced rates of recurrent instability. Conclusions Sex, age at initial dislocation, time from initial dislocation, hyperlaxity and greater tuberosity fractures were key risk factors in at least two good quality cohort studies resulting in strong evidence as concluded in the GRADE criteria. Although bony Bankart lesions, Hill Sachs lesions, occupation, physiotherapy treatment and nerve palsy were risk factors for recurrent instability, the evidence was weak using the GRADE criteria—these findings relied on poorer quality studies or were inconsistent among studies. PMID:25900943

  19. Differential antennal proteome comparison of adult honeybee drone, worker and queen (Apis mellifera L.).

    PubMed

    Fang, Yu; Song, Feifei; Zhang, Lan; Aleku, Dereje Woltedji; Han, Bin; Feng, Mao; Li, Jianke

    2012-01-04

    To understand the olfactory mechanism of honeybee antennae in detecting specific volatile compounds in the atmosphere, antennal proteome differences of drone, worker and queen were compared using 2-DE, mass spectrometry and bioinformatics. Therefore, 107 proteins were altered their expressions in the antennae of drone, worker and queen bees. There were 54, 21 and 32 up-regulated proteins in the antennae of drone, worker and queen, respectively. Proteins upregulated in the drone antennae were involved in fatty acid metabolism, antioxidation, carbohydrate metabolism and energy production, protein folding and cytoskeleton. Proteins upregulated in the antennae of worker and queen bees were related to carbohydrate metabolism and energy production while molecular transporters were upregulated in the queen antennae. Our results explain the role played by the antennae of drone is to aid in perceiving the queen sexual pheromones, in the worker antennae to assist for food search and social communication and in the queen antennae to help pheromone communication with the worker and the drone during the mating flight. This first proteomic study significantly extends our understanding of honeybee olfactory activities and the possible mechanisms played by the antennae in response to various environmental, social, biological and biochemical signals.

  20. Irreducible posterolateral elbow dislocation.

    PubMed

    Atkinson, Cameron T; Pappas, Nick D; Lee, Donald H

    2014-02-01

    Elbow dislocations are a high-energy traumatic event resulting in loss of congruence of a stable joint. The majority of elbow dislocations can be reduced by closed means and treated conservatively. We present a case of an irreducible elbow dislocation with reduction blocked by the radial head buttonholed through the lateral ligamentous complex. We performed open reduction with release followed by repair of the lateral ligamentous complex. Clinicians need to understand this unique variant of an elbow dislocation to appropriately treat this operative injury.

  1. Discrete dislocations in graphene

    NASA Astrophysics Data System (ADS)

    Ariza, M. P.; Ortiz, M.

    2010-05-01

    In this work, we present an application of the theory of discrete dislocations of Ariza and Ortiz (2005) to the analysis of dislocations in graphene. Specifically, we discuss the specialization of the theory to graphene and its further specialization to the force-constant model of Aizawa et al. (1990). The ability of the discrete-dislocation theory to predict dislocation core structures and energies is critically assessed for periodic arrangements of dislocation dipoles and quadrupoles. We show that, with the aid of the discrete Fourier transform, those problems are amenable to exact solution within the discrete-dislocation theory, which confers the theory a distinct advantage over conventional atomistic models. The discrete dislocations exhibit 5-7 ring core structures that are consistent with observation and result in dislocation energies that fall within the range of prediction of other models. The asymptotic behavior of dilute distributions of dislocations is characterized analytically in terms of a discrete prelogarithmic energy tensor. Explicit expressions for this discrete prelogarithmic energy tensor are provided up to quadratures.

  2. Dislocated shoulder - aftercare

    MedlinePlus

    ... aftercare; Shoulder subluxation - aftercare; Shoulder reduction - aftercare; Glenohumeral joint dislocation ... that connect bone to bone) of the shoulder joint. All of these tissues help keep your arm ...

  3. Economic Competition, Restructuring and Worker Dislocation.

    ERIC Educational Resources Information Center

    Blalock, Ann Bonar, Ed.

    1995-01-01

    In this issue various concepts of economic change are examined. Part I looks at economic change as a context for focusing on workforce issues. Parts II and III discuss what is being done to address this contemporary problem. This issue contains the following papers: "Presidential Perspectives on Economic Change and Restructuring: An…

  4. Metallurgy: Starting and stopping dislocations

    NASA Astrophysics Data System (ADS)

    Minor, Andrew M.

    2015-09-01

    A comparison of dislocation dynamics in two hexagonal close-packed metals has revealed that dislocation movement can vary substantially in materials with the same crystal structure, associated with how the dislocations relax when stationary.

  5. Starvation stress during larval development reveals predictive adaptive response in adult worker honey bees (Apis mellifera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of organisms exhibit developmental plasticity that results in differences in adult morphology, physiology or behavior. This variation in the phenotype, called “Predictive Adaptive Response (PAR),” gives a selective advantage in an adult's environment if the adult experiences environments s...

  6. ADULT EDUCATION FOR MIGRANT AND SEASONAL FARM WORKERS. PROJECT REPORT, JUNE 12 - SEPTEMBER 1, 1967.

    ERIC Educational Resources Information Center

    MAURER, WAYNE F.

    THE CHIEF PURPOSE OF ADULT MIGRANT EDUCATION, AS DISCUSSED IN THIS REPORT, IS TO ELIMINATE POVERTY BY PREPARING THE MIGRANT FOR PROFITABLE PARTICIPATION IN SOCIETY. THE FLORIDA STATE DEPARTMENT OF EDUCATION STATES THAT THE PURPOSE OF THE IMMOKALEE MIGRANT ADULT EDUCATION PROJECT IS TO PROVIDE ADULT BASIC EDUCATION AND PRE-VOCATIONAL EXPERIENCES…

  7. Parallel Dislocation Simulator

    SciTech Connect

    2006-10-30

    ParaDiS is software capable of simulating the motion, evolution, and interaction of dislocation networks in single crystals using massively parallel computer architectures. The software is capable of outputting the stress-strain response of a single crystal whose plastic deformation is controlled by the dislocation processes.

  8. Traumatic proximal tibiofibular dislocation.

    PubMed

    Burgos, J; Alvarez-Montero, R; Gonzalez-Herranz, P; Rapariz, J M

    1997-01-01

    Proximal tibiofibular dislocation is an exceptional lesion. Rarer still is its presentation in childhood. We describe the clinical case of a 6-year-old boy, the victim of a road accident. He had a tibiofibular dislocation associated with a metaphyseal fracture of the tibia.

  9. Electromechanical simulations of dislocations

    NASA Astrophysics Data System (ADS)

    Skiba, Oxana; Gracie, Robert; Potapenko, Stanislav

    2013-04-01

    Improving the reliability of micro-electronic devices depends in part on developing a more in-depth understanding of dislocations because dislocations are barriers to charge carriers. To this end, the quasi-static simulation of discrete dislocations dynamics in materials under mechanical and electrical loads is presented. The simulations are based on the extended finite element method, where dislocations are modelled as internal discontinuities. The strong and weak forms of the boundary value problem for the coupled system are presented. The computation of the Peach-Koehler force using the J-integral is discussed. Examples to illustrate the accuracy of the simulations are presented. The motion of the network of the dislocations under different electrical and mechanical loads is simulated. It was shown that even in weak piezoelectric materials the effect of the electric field on plastic behaviour is significant.

  10. Examining a Proposed Job Retention Model for Adult Workers with Mental Retardation

    ERIC Educational Resources Information Center

    Fornes, Sandra L.

    2008-01-01

    This research provides an analysis of factors predicting job retention (JR), job satisfaction (JS), and job performance (JP) of workers with mental retardation (MR). The findings highlight self-determination as a critical skill in influencing three important employee's outcomes, JR, JS, and JP. The intent of the study was to develop job retention…

  11. Reframing the Public in Public Education: The Landless Workers Movement (MST) and Adult Education in Brazil

    ERIC Educational Resources Information Center

    Thapliyal, Nisha

    2013-01-01

    Education for rural Brazilians has historically been dominated by two imperatives: human capital and political patronage. For the last four decades, the Landless Workers Movement (MST) have maintained a struggle to democratise public education and democracy itself. In this article, I make a situated analysis of the educational politics of the MST…

  12. Bilateral traumatic hip dislocation associated with sacro-iliac dislocation.

    PubMed

    Galois, L; Meuley, E; Pfeffer, F; Mainard, D; Delagoutte, J P

    We report a rare injury in an 18-year-old woman who sustained posterior bilateral hip dislocation with sacro-iliac dislocation after a high energy motor vehicle accident. She was treated by closed reduction and skeletal traction. Bilateral traumatic hip dislocation is an uncommon occurrence. Rarer still is bilateral traumatic hip dislocation associated with sacro-iliac dislocation because it combines two different mechanisms of trauma. (Hip International 2002; 1: 47-9).

  13. Elbow dislocation with complete triceps avulsion.

    PubMed

    Karuppiah, S V; Knox, D

    2014-01-01

    Radio-ulnar Fracture dislocation of the elbow is a high-energy trauma which can be associated with significant ligamentous injury in adults. We report an unusual triad of injury in a patient with avulsion injury of the triceps. This injury can be thought of as a variant of "terrible triad" with dislocation of radio-ulnar joint, radial head fracture, and medial collateral ligament injury with avulsion of the triceps. Elbow has to be stabilized with early repair of the ligaments for a successful outcome.

  14. Elbow Dislocation with Complete Triceps Avulsion

    PubMed Central

    Karuppiah, S. V.; Knox, D.

    2014-01-01

    Radio-ulnar Fracture dislocation of the elbow is a high-energy trauma which can be associated with significant ligamentous injury in adults. We report an unusual triad of injury in a patient with avulsion injury of the triceps. This injury can be thought of as a variant of “terrible triad” with dislocation of radio-ulnar joint, radial head fracture, and medial collateral ligament injury with avulsion of the triceps. Elbow has to be stabilized with early repair of the ligaments for a successful outcome. PMID:24876982

  15. Where Are the Adults? The Attitudes of Parents, Teachers, Clergy, Coaches, and Youth Workers on Teen Pregnancy. A Focus Group Report.

    ERIC Educational Resources Information Center

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    In 1997, the National Campaign To Prevent Teen Pregnancy convened nine focus groups of parents of teens and other adults who work with teens such as teachers, clergy, coaches, youth recreation specialists, youth-serving organization staff, and community outreach workers. This report publishes the results of these focus groups, which involved 57…

  16. Promoting reproductive health practices among working adolescents and young adults (industrial workers). RAS/88/P11.

    PubMed

    1999-06-01

    In Cambodia, Care (Deutschland), through the Cambodia Health Education Development (CHED) and the Reproductive Health Association of Cambodia, is working towards the promotion of reproductive health (RH) practices among working adolescents and young adults. The project seeks to reach a minimum target group of 10,000 out-of-school, single, working adolescents and young adults aged 12-29 years, and at least 50 trained RH providers and educators in selected project sites. It also aims to provide specialist RH services to at least 200 single adolescents and young adults per month and per newly operational RH facility in project areas; and to build the capacity of at least two partner nongovernmental organizations in adolescent RH services. As its two-part strategy, the project is sharing information, education, and communication (IEC) expertise and using CHED as an informal IEC clearing house. The main activities of the project are outlined.

  17. The Making of Vulnerable Workers: Uncredentialed Young Adults in Postindustrial, Urban America

    ERIC Educational Resources Information Center

    Brown, Tara M.

    2016-01-01

    Common explanations for the employment difficulties facing young adults without a secondary credential center on skill deficits, with little attention given to policies and practices that shape the nature of work. Using interview data from a participatory action research project, this article examines the employment experiences of 43…

  18. Farm Activities and Agricultural Injuries in Youth and Young Adult Workers.

    PubMed

    DeWit, Yvonne; Pickett, William; Lawson, Joshua; Dosman, James

    2015-01-01

    Youth and young adults who work in the agricultural sector experience high rates of injury. This study aimed to investigate relations between high-risk farm activities and the occurrence of agricultural injuries in these vulnerable groups. A cross-sectional analysis was conducted using written questionnaire data from 1135 youth and young adults from the Saskatchewan Farm Injury Cohort. The prevalence of agricultural injury was estimated at 4.9%/year (95% confidence interval [CI]: 3.7, 6.2). After adjustment for important covariates, duration of farm work was strongly associated with the occurrence of injury (risk ratio [RR] = 8.0 [95% CI: 1.7, 36.7] for 10-34 vs. <10 hours/week; RR = 10.3 [95% CI: 2.2, 47.5] for those working 35+ hours/week). Tractor maintenance, tractor operation, chores with large animals, herd maintenance activities, and veterinary activities were identified as risk factors for agricultural injury. Risks for agricultural injury among youth and young adults on farms relate directly to the amounts and types of farm work exposures that young people engage in.

  19. Dislocation climb models from atomistic scheme to dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Niu, Xiaohua; Luo, Tao; Lu, Jianfeng; Xiang, Yang

    2017-02-01

    We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment kinetics at jogs leading to the motion of jogs. Our mesoscopic model consists of the vacancy bulk diffusion equation and a dislocation climb velocity formula. The effects of these microscopic mechanisms are incorporated by a Robin boundary condition near the dislocations for the bulk diffusion equation and a new contribution in the dislocation climb velocity due to vacancy pipe diffusion driven by the stress variation along the dislocation. Our climb formulation is able to quantitatively describe the translation of prismatic loops at low temperatures when the bulk diffusion is negligible. Using this new formulation, we derive analytical formulas for the climb velocity of a straight edge dislocation and a prismatic circular loop. Our dislocation climb formulation can be implemented in dislocation dynamics simulations to incorporate all the above four microscopic mechanisms of dislocation climb.

  20. Nutrient balancing of the adult worker bumblebee (Bombus terrestris) depends on the dietary source of essential amino acids

    PubMed Central

    Stabler, Daniel; Paoli, Pier P.; Nicolson, Susan W.; Wright, Geraldine A.

    2015-01-01

    ABSTRACT Animals carefully regulate the amount of protein that they consume. The quantity of individual essential amino acids (EAAs) obtained from dietary protein depends on the protein source, but how the proportion of EAAs in the diet affects nutrient balancing has rarely been studied. Recent research using the Geometric Framework for Nutrition has revealed that forager honeybees who receive much of their dietary EAAs from floral nectar and not from solid protein have relatively low requirements for dietary EAAs. Here, we examined the nutritional requirements for protein and carbohydrates of foragers of the buff-tailed bumblebee Bombus terrestris. By using protein (sodium caseinate) or an equimolar mixture of the 10 EAAs, we found that the intake target (nutritional optimum) of adult workers depended on the source and proportion of dietary EAAs. When bees consumed caseinate-containing diets in a range of ratios between 1:250 and 1:25 (protein to carbohydrate), they achieved an intake target (IT) of 1:149 (w/w). In contrast to those fed protein, bees fed the EAA diets had an IT more biased towards carbohydrates (1:560 w/w) but also had a greater risk of death than those fed caseinate. We also tested how the dietary source of EAAs affected free AAs in bee haemolymph. Bees fed diets near their IT had similar haemolymph AA profiles, whereas bees fed diets high in caseinate had elevated levels of leucine, threonine, valine and alanine in the haemolymph. We found that like honeybees, bumblebee workers prioritize carbohydrate intake and have a relatively low requirement for protein. The dietary source of EAAs influenced both the ratio of protein/EAA to carbohydrate and the overall amount of carbohydrate eaten. Our data support the idea that EAAs and carbohydrates in haemolymph are important determinants of nutritional state in insects. PMID:25617453

  1. Storytelling by community-dwelling older adults: perspectives of home care workers.

    PubMed

    Mastel-Smith, Beth; Binder, Brenda; Hersch, Gayle; Davidson, Harriett A; Walsh, Teresa

    2011-04-01

    The purpose of this exploratory, qualitative study was to investigate storytelling by home care clients to their home care workers (HCWs). Specific research questions were: (a) When does storytelling by a care recipient occur during usual care?; (b) How do HCWs engage older clients in storytelling?; (c) How do HCWs respond to the stories told by clients?; and (d) What is the perceived effect of storytelling by older clients on the relationship between the client and the HCW? Two focus groups consisting of 10 HCWs each were conducted. Verbatim transcripts of both focus groups were analyzed using the constant comparative analysis method. Categories and concepts were identified. Characteristics of the HCW and client set the stage for storytelling. The process of storytelling included context, triggers, and temporal aspects. HCWs also shared the content of stories, the impact on their relationship with the client, and the perceived effect on each individual. A visual model depicting the nature of storytelling in association with the care of older clients is presented.

  2. Exposure to neonicotinoids influences the motor function of adult worker honeybees.

    PubMed

    Williamson, Sally M; Willis, Sarah J; Wright, Geraldine A

    2014-10-01

    Systemic pesticides such as neonicotinoids are commonly used on flowering crops visited by pollinators, and their use has been implicated in the decline of insect pollinator populations in Europe and North America. Several studies show that neonicotinoids affect navigation and learning in bees but few studies have examined whether these substances influence their basic motor function. Here, we investigated how prolonged exposure to sublethal doses of four neonicotinoid pesticides (imidacloprid, thiamethoxam, clothianidin, dinotefuran) and the plant toxin, nicotine, affect basic motor function and postural control in foraging-age worker honeybees. We used doses of 10 nM for each neonicotinoid: field-relevant doses that we determined to be sublethal and willingly consumed by bees. The neonicotinoids were placed in food solutions given to bees for 24 h. After the exposure period, bees were more likely to lose postural control during the motor function assay and fail to right themselves if exposed to imidacloprid, thiamethoxam, clothianidin. Bees exposed to thiamethoxam and nicotine also spent more time grooming. Other behaviours (walking, sitting and flying) were not significantly affected. Expression of changes in motor function after exposure to imidacloprid was dose-dependent and affected all measured behaviours. Our data illustrate that 24 h exposure to sublethal doses of neonicotinoid pesticides has a subtle influence on bee behaviour that is likely to affect normal function in a field setting.

  3. Supersonic Dislocation Bursts in Silicon

    DOE PAGES

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; ...

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolutionmore » we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.« less

  4. Supersonic Dislocation Bursts in Silicon

    SciTech Connect

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.

  5. Elbow Dislocations in Contact Sports.

    PubMed

    Morris, Mark S; Ozer, Kagan

    2017-02-01

    Elbow dislocations are more common in athletes than in the general population. Simple elbow dislocations should be managed with early range of motion and early return to sport, even with high-level contact athletes. Patients with instability on examination or with complex elbow dislocations may require surgical intervention. Overall, the outcomes after simple elbow dislocations are excellent and athletes should be able to return to play without significant limitations.

  6. Elbow fractures and dislocations.

    PubMed

    Little, Kevin J

    2014-07-01

    Elbow fractures are common in pediatric patients. Most injuries to the pediatric elbow are stable and require simple immobilization; however, more severe fractures can occur, often requiring operative stabilization and/or close monitoring. This article highlights the common fractures and dislocations about the pediatric elbow and discusses the history, evaluation, and treatment options for specific injuries.

  7. Behavior of dislocations in silicon

    SciTech Connect

    Sumino, Koji

    1995-08-01

    A review is given of dynamic behavior of dislocations in silicon on the basis of works of the author`s group. Topics taken up are generation, motion and multiplication of dislocations as affected by oxygen impurities and immobilization of dislocations due to impurity reaction.

  8. Prevalence of Premorbid Metabolic Syndrome in Spanish Adult Workers Using IDF and ATPIII Diagnostic Criteria: Relationship with Cardiovascular Risk Factors

    PubMed Central

    Tauler, Pedro; Bennasar-Veny, Miquel; Morales-Asencio, Jose M.; Lopez-Gonzalez, Angel A.; Vicente-Herrero, Teofila; De Pedro-Gomez, Joan; Royo, Vanessa; Pericas-Beltran, Jordi; Aguilo, Antoni

    2014-01-01

    Background Metabolic Syndrome (MetS) is a complex disorder defined as a cluster of interconnected risk factors such as hypertension, dyslipidemia, obesity and high blood glucose levels. Premorbid metabolic syndrome (PMetS) is defined by excluding patients with previously diagnosed cardiovascular disease or diabetes mellitus from those suffering MetS. We aimed to determine the prevalence of PMetS in a working population, and to analyse the relationship between the diagnostic criteria of the International Diabetes Federation (IDF) and of the National Cholesterol Education Program Adult Treatment Panel III (ATPIII). The relationship between the presence of PMetS and cardiovascular risk factors was also analysed. Research Methodology/Findings A cross-sectional study was conducted in 24,529 male and 18,736 female Spanish (white western European) adult workers (20–65 years) randomly selected during their work health periodic examinations. Anthropometrics, blood pressure and serum parameters were measured. The presence of MetS and PMetS was ascertained using ATPIII and IDF criteria. Cardiovascular risk was determined using the Framingham-REGICOR equation. The results showed MetS had an adjusted global prevalence of 12.39% using ATPIII criteria and 16.46% using IDF criteria. The prevalence of PMetS was slightly lower (11.21% using ATPIII criteria and 14.72% using IDF criteria). Prevalence in males was always higher than in females. Participants with PMetS displayed higher values of BMI, waist circumference, blood pressure, glucose and triglycerides, and lower HDL-cholesterol levels. Logistic regression models reported lower PMetS risk for females, non-obese subjects, non-smokers and younger participants. Cardiovascular risk determined with Framingham-REGICOR was higher in participants with PMetS. Conclusions PMetS could be a reliable tool for the early identification of apparently healthy individuals who have a significant risk for developing cardiovascular events and

  9. Effects of restrictive clothing on lumbar range of motion and trunk muscle activity in young adult worker manual material handling.

    PubMed

    Eungpinichpong, Wichai; Buttagat, Vitsarut; Areeudomwong, Pattanasin; Pramodhyakul, Noppol; Swangnetr, Manida; Kaber, David; Puntumetakul, Rungthip

    2013-11-01

    The objective of this study was to examine the effect of wearing restrictive trousers on lumbar spine movement, trunk muscle activity and low back discomfort (LBD) in simulations of manual material handling (MMH) tasks. Twenty-eight young adults participated in the study performing box lifting, liquid container handling while squatting, and forward reaching while sitting on a task chair when wearing tight pants (sizes too small for the wearer) vs. fit pants (correct size according to anthropometry). Each task was repeated three times and video recordings were used as a basis for measuring lumbar range of motion (LRoM). The response was normalized in terms on baseline hip mobility. Trunk muscle activity of rectus abdominis (RA) and erector spinae (ES) muscles were also measured in each trial and normalized. At the close of each trial, participants rated LBD using a visual analog scale. Results revealed significant effects of both pants and task types on the normalized LRoM, trunk muscle activity and subjective ratings of LBD. The LRoM was higher and trunk muscle (ES) activity was lower for participants when wearing tight pants, as compared to fit pants. Discomfort ratings were significantly higher for tight pants than fit. These results provide guidance for recommendations on work clothing fit in specific types of MMH activities in order to reduce the potential of low-back pain among younger workers in industrial companies.

  10. Xenobiotic effects on intestinal stem cell proliferation in adult honey bee (Apis mellifera L) workers.

    PubMed

    Forkpah, Cordelia; Dixon, Luke R; Fahrbach, Susan E; Rueppell, Olav

    2014-01-01

    The causes of the current global decline in honey bee health are unknown. One major group of hypotheses invokes the pesticides and other xenobiotics to which this important pollinator species is often exposed. Most studies have focused on mortality or behavioral deficiencies in exposed honey bees while neglecting other biological functions and target organs. The midgut epithelium of honey bees presents an important interface between the insect and its environment. It is maintained by proliferation of intestinal stem cells throughout the adult life of honey bees. We used caged honey bees to test multiple xenobiotics for effects on the replicative activity of the intestinal stem cells under laboratory conditions. Most of the tested compounds did not alter the replicative activity of intestinal stem cells. However, colchicine, methoxyfenozide, tetracycline, and a combination of coumaphos and tau-fluvalinate significantly affected proliferation rate. All substances except methoxyfenozide decreased proliferation rate. Thus, the results indicate that some xenobiotics frequently used in apiculture and known to accumulate in honey bee hives may have hitherto unknown physiological effects. The nutritional status and the susceptibility to pathogens of honey bees could be compromised by the impacts of xenobiotics on the maintenance of the midgut epithelium. This study contributes to a growing body of evidence that more comprehensive testing of xenobiotics may be required before novel or existing compounds can be considered safe for honey bees and other non-target species.

  11. Xenobiotic Effects on Intestinal Stem Cell Proliferation in Adult Honey Bee (Apis mellifera L) Workers

    PubMed Central

    Forkpah, Cordelia; Dixon, Luke R.; Fahrbach, Susan E.; Rueppell, Olav

    2014-01-01

    The causes of the current global decline in honey bee health are unknown. One major group of hypotheses invokes the pesticides and other xenobiotics to which this important pollinator species is often exposed. Most studies have focused on mortality or behavioral deficiencies in exposed honey bees while neglecting other biological functions and target organs. The midgut epithelium of honey bees presents an important interface between the insect and its environment. It is maintained by proliferation of intestinal stem cells throughout the adult life of honey bees. We used caged honey bees to test multiple xenobiotics for effects on the replicative activity of the intestinal stem cells under laboratory conditions. Most of the tested compounds did not alter the replicative activity of intestinal stem cells. However, colchicine, methoxyfenozide, tetracycline, and a combination of coumaphos and tau-fluvalinate significantly affected proliferation rate. All substances except methoxyfenozide decreased proliferation rate. Thus, the results indicate that some xenobiotics frequently used in apiculture and known to accumulate in honey bee hives may have hitherto unknown physiological effects. The nutritional status and the susceptibility to pathogens of honey bees could be compromised by the impacts of xenobiotics on the maintenance of the midgut epithelium. This study contributes to a growing body of evidence that more comprehensive testing of xenobiotics may be required before novel or existing compounds can be considered safe for honey bees and other non-target species. PMID:24608542

  12. Participation in the Women, Infants, and Children (WIC) Program as Reported by Documented and Undocumented Farm Worker Adults in the Households.

    PubMed

    Leigh, J Paul; Medel-Herrero, Alvaro

    2015-01-01

    Debate surrounds the provision of Women, Infants, and Children (WIC) benefits to undocumented immigrants. Few studies are available to estimate use of WIC services by documented and undocumented households using nationally representative data. The authors analyzed data from the National Agricultural Workers Survey (NAWS) annual cross-sections from 1993 through 2009 (N = 40,896 person-years). Household documentation status is defined by the status of the adults in the household, not children. Simple mean differences, logistic regressions, and time charts described household participation in WIC over 2-year intervals. Without adjustments for covariates, 10.7% of undocumented farm workers' households and 12.4% of documented households received WIC benefits, yielding an odds ratio of 0.84 (95% confidence interval [CI]: 0.76-0.94). Logistic regressions revealed that for the same number of children in the household, participation by undocumented persons was higher than participation by documented persons. Time charts and logistic regressions with interaction terms showed a stronger correspondence between participation in WIC and number of children <6 years old in undocumented households than documented households. Undocumented farm workers' households were only a little less likely to participate in WIC than documented farm workers' households, and undocumented households' participation was especially responsive to the presence of children. These results are consistent with the legal requirements for WIC participation, which do not distinguish between documented and undocumented households. These results may be helpful in the debate surrounding the effects of undocumented workers on WIC participation and costs.

  13. Neglected isolated scaphoid dislocation

    PubMed Central

    Baek, Jong-Ryoon; Cho, Seung Hyun; Lee, Yong Seuk; Roh, Young Hak

    2016-01-01

    The authors present a case of isolated scaphoid dislocation in a 40-year-old male that was undiagnosed for 2 months. The patient was treated by open reduction, Kirschner wire fixation, interosseous ligament repair using a suture anchor and Blatt's dorsal capsulodesis. At 6 years followup, his radiographs of wrist showed a normal carpal alignment with a scapholunate gap of 3 mm and no evidence of avascular necrosis (AVN) of the scaphoid. PMID:27904228

  14. Labor Market Conditions and the Reemployment of Displaced Workers.

    ERIC Educational Resources Information Center

    Howland, Marie; Peterson, George E.

    1988-01-01

    This study examined the impact of local labor market conditions on the financial losses of dislocated manufacturing workers. It found that strong overall growth in the local economy reduced economic losses of white collar workers but not of blue collar workers. (JOW)

  15. 20 CFR 671.110 - What are major economic dislocations or other events which may qualify for a national emergency...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... events which may qualify for a national emergency grant? 671.110 Section 671.110 Employees' Benefits... DISLOCATED WORKERS § 671.110 What are major economic dislocations or other events which may qualify for a... at a single site of employment; (c) Closures and realignments of military installations; (d)...

  16. Vanishing honey bees: Is the dying of adult worker bees a consequence of short telomeres and premature aging?

    PubMed

    Stindl, Reinhard; Stindl, Wolfgang

    2010-10-01

    Einstein is often quoted to have said that without the bee, mankind would have but 4years to live. It is highly unlikely that he made this comment, which was even mentioned in a Lancet article on honey bees. However, the current vanishing of the bees can have serious consequences for human health, because 35% of the human diet is thought to benefit from pollination. Colony collapse disorder (CCD) in honey bees is characterized by the rapid decline of the adult bee population, leaving the brood and the queen poorly or completely unattended, with no dead bodies in or around the hive. A large study found no evidence that the presence or amount of any individual pesticide or infectious agent occurred more frequently or abundantly in CCD-affected colonies. The growing consensus is that honey bees are suffering from comprised immune systems, which allow various infectious pathogens to invade. The question remains, what causes immunosuppression in many colonies of Apis mellifera in North America and Europe? Telomeres are protective DNA structures located at eukaryotic chromosome tips that shorten in the somatic tissues of animals with age. Lifelong tissue regeneration takes place in Apis mellifera, and worker bees have been shown to senesce. In humans, a vast amount of literature has accumulated on exhausted telomere reserves causing impaired tissue regeneration and age-associated diseases, specifically cancer and immunosuppression. Therefore, we propose a new causative mechanism for the vanishing of the bees: critically short telomeres in long-lived winter bees. We term this the telomere premature aging syndrome.

  17. [Congenital knee dislocation: case report].

    PubMed

    Arvinius, C; Luque, R; Díaz-Ceacero, C; Marco, F

    2016-01-01

    Congenital knee dislocation is an infrequent condition with unknown etiology. In some cases it occurs as an isolated condition, while in others it coexists with associated conditions or syndromes. The treatment of congenital knee dislocation is driven by the severity and flexibility of the deformity. The literature includes from serial casting or the Pavlik harness to quadriceps tendon plasty or femoral osteotomies. We report herein the case of a congenital dislocation treated with serial casting with a good outcome.

  18. Dislocation Diffusion in Metallic Materials

    DTIC Science & Technology

    2011-09-08

    DATES COVERED (From - To) April 1,2007-March 31, 2010 4. TITLE AND SUBTITLE Dislocation Diffusion in Metallic Materials 5a. CONTRACT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT The goals of this project were: (1) perform a fundamental study of atomic diffusion along dislocation cores in metals and...alloys, (2) develop new methods for the calculation of dislocation diffusion coefficients as functions of temperature and chemical composition and (3

  19. Pathologic dislocation of the shoulder secondary to septic arthritis: a case report

    PubMed Central

    2009-01-01

    Septic arthritis of the shoulder is uncommon in adults, and complete dislocation of the glenohumeral joint following septic arthritis is extremely rare. We report a case of pathologic shoulder dislocation secondary to septic arthritis in an intravenous drug abuser. PMID:20062648

  20. Misfit dislocations in epitaxy

    NASA Astrophysics Data System (ADS)

    van der Merwe, Jan H.

    2002-08-01

    This article on epitaxy highlights the following: the definition and some historical milestones; the introduction by Frenkel and Kontorowa (FK) of a truncated Fourier series to model the periodic interaction at crystalline interfaces; the invention by Frank and van der Merwe (FvdM)—using the FK model—of (interfacial) misfit dislocations as an important mechanism in accommodating misfit at epilayer-substrate interfaces; the generalization of the FvdM theory to multilayers; the application of the parabolic model by Jesser and van der Merwe to describe, for growing multilayers and superlattices, the impact of Fourier coefficients in the realization of epitaxial orientations and the stability of modes of misfit accommodation; the involvement of intralayer interaction in the latter—all features that impact on the attainment of perfection in crystallinity of thin films, a property that is so vital in the fabrication of useful uniformly thick epilayers (uniformity being another technological requirement), which also depends on misfit accommodation through the interfacial energy that function strongly in the criterion for growth modes, proposed by Bauer; and the ingenious application of the Volterra model by Matthews and others to describe misfit accommodation by dislocations in growing epilayers.

  1. Dislocation-Based Si-Nanodevices

    NASA Astrophysics Data System (ADS)

    Reiche, Manfred; Kittler, Martin; Buca, Dan; Hähnel, Angelika; Zhao, Qing-Tai; Mantl, Siegfried; Gösele, Ulrich

    2010-04-01

    The realization of defined dislocation networks by hydrophobic wafer bonding allows the electrical characterization of individual dislocations. The present paper investigates the properties of such dislocations in samples containing high dislocations densities down to only six dislocations. The current induced by a single dislocation is determined by extrapolation of the current measured for various dislocation densities. Based on our present and previously reported analyses the electronic properties of individual dislocations can be inferred. The investigations show that dislocations in the channel of metal-oxide-semiconductor field-effect transistors (MOSFETs) result in increasing drain currents even at low drain and gate voltages. Because a maximum increase of the current is obtained if a single dislocation is present in the channel, arrays of MOSFETs each containing only one dislocation could be realized on the nanometer scale. The distance of the dislocations can be well controlled by wafer bonding techniques.

  2. Using My Vocational Situation with Workers Facing a Plant Closing.

    ERIC Educational Resources Information Center

    Mosley-Howard, G. Susan; Andersen, Patricia

    1993-01-01

    Data from 199 respondents among 2,000 dislocated auto workers showed My Vocational Situation to be a reliable instrument. Differences between high and low scorers on the Vocational Identity subscale suggest that different counseling interventions may be appropriate. (SK)

  3. Inferior hip dislocation after falling from height: A case report

    PubMed Central

    Tekin, Ali Çağrı; Çabuk, Haluk; Büyükkurt, Cem Dinçay; Dedeoğlu, Süleyman Semih; İmren, Yunus; Gürbüz, Hakan

    2016-01-01

    Introduction Traumatic inferior hip dislocation is the least common of all hip dislocations. Adult inferior hip dislocations usually occur after high-energy trauma, very few cases are reported without fracture. Presentation of case A 26-year-old female was brought to the emergency department with severe pain in the left hip, impaired posture and restricted movement following a fall from 15 m height. The hip joint was fixed in 90° flexion, 15° abduction, and 20° external rotation. No neurovascular impairment was determined. On radiologic examination, a left ischial type inferior hip dislocation was detected. Hemorrhagic shock which developed due to acute blood loss to thoracic and abdominal cavity and patient died at third hour after she was brought to the hospital. Discussion Traumatic hip dislocations have high morbidity and mortality rates due to multiple organ damage, primarily of the extremities, chest and abdomen. In the treatment of traumatic hip dislocation, closed reduction is recommended through muscle relaxation under general anesthesia or sedation. This procedure should be applied before any intervention for concomitant extremity injuries. A detailed evaluation on emergency presentation, a multi-disciplinary approach and early diagnosis with the rapid application of imaging methods could be life-saving for such patients. PMID:27058153

  4. 20 CFR 663.165 - How long must an individual be in core services in order to be eligible for intensive services?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker...

  5. 20 CFR 663.165 - How long must an individual be in core services in order to be eligible for intensive services?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult and Dislocated Worker...

  6. Reliability of the Non-Communicating Adult Pain Checklist (NCAPC), Assessed by Different Groups of Health Workers

    ERIC Educational Resources Information Center

    Lotan, M.; Moe-Nilssen, R.; Ljunggren, A. E.; Strand, L. I.

    2009-01-01

    Evaluating pain in adults with intellectual and developmental disability (IDD) is a challenge. The Non-Communicating Adults Pain Checklist (NCAPC) was recently developed from the Non-Communicating Children's Pain Checklist (NCCPC) and examined in a group of adults with IDD (N = 228) and found to hold satisfactory construct validity, internal…

  7. Patellar Dislocations and Reduction Procedure.

    PubMed

    Ramponi, Denise

    2016-01-01

    Acute patellar dislocations are a common injury occurring in adolescents involved in sports and dancing activities. This injury usually occurs when the knee is in full extension and sustains a valgus stress on the knee. The medial patellofemoral ligament is the medial restraint that assists in stabilizing the patella from lateral dislocations. The patella usually dislocates laterally and is usually not difficult to reduce after patient evaluation and prereduction radiographs. After postreduction radiographs confirm proper position of the patella postreduction and the absence of fractures, the patient is usually treated conservatively with initial immobilization, orthopedic referral, and physical therapy.

  8. Buckling of dislocation in graphene

    NASA Astrophysics Data System (ADS)

    Yao, Yin; Wang, Shaofeng; Bai, Jianhui; Wang, Rui

    2016-10-01

    The buckling of dislocation in graphene is discussed through the lattice theory of dislocation and elastic theory. The approximate solution of the buckling is obtained based on the inner stress distribution caused by different structure of dislocations and is proved to be suitable by the simulation. The position of the highest buckling is predicted to be at the vertex of the pentagon far away from the heptagon. The buckling is strongly influenced by the internal stress and the distance between the extrusive area and stretching area, as well as the critical stress σc. The SW defect is proved to be unbuckled due to its strong interaction between extrusion and stretching.

  9. Quenched dislocation enhanced supersolid ordering.

    PubMed

    Toner, John

    2008-01-25

    I show using Landau theory that quenched dislocations can facilitate the supersolid to normal solid transition, making it possible for the transition to occur even if it does not in a dislocation-free crystal. I make detailed predictions for the dependence of the supersolid to normal solid transition temperature T_{c}(L), superfluid density rho_{S}(T,L), and specific heat C(T,L) on temperature T and dislocation spacing L, all of which can be tested against experiments. The results should also be applicable to an enormous variety of other systems, including, e.g., ferromagnets.

  10. Antioxidant enzymes status and reproductive health of adult male workers exposed to brick kiln pollutants in Pakistan.

    PubMed

    Jahan, Sarwat; Falah, Samreen; Ullah, Hizb; Ullah, Asad; Rauf, Naveed

    2016-07-01

    The present study was designed to study the effect of brick kilns emissions on the reproductive health and biochemical status of brick kiln workers and people living in the area near brick kilns. Body mass index (BMI) was significantly reduced in brick makers, carriers, and bakers compared to the control. Red blood cells count and hematocrit (%) were significantly high in brick bakers while MCH was significantly reduced in brick makers and brick bakers. Heavy metals (lead, cadmium, and chromium) concentration in whole blood of the brick kiln workers were significantly higher as compared to the control. Antioxidant enzymes (CAT, SOD, POD, GSH, and GR) were significantly reduced in brick kiln workers as compared to the control while TBARS level were significantly high in brick bakers as compared to the control. Plasma leutinizing hormone (LH) was significantly high in brick bakers while testosterone concentrations were significantly reduced in brick makers, carriers, and bakers. The present study shows that brick kiln workers and people living in the brick kiln vicinity are exposed to heavy metals and other pollutants that is a serious threat to their health. Alternate technology is needed to be developed and brick kilns should be replaced.

  11. Lateral patellar dislocation: mechanism of disease, radiographic presentation, and management.

    PubMed

    Abramov, Michael; Stock, Harlan

    2013-04-01

    Lateral patellar dislocation is a common injury occurring in young active adults. The mechanism is that of twisting injury to the knee on a planted foot with valgus stress. Several predisposing factors, including femoral trochlear dysplasia, patella alta, and lateralization of the tibial tuberosity, contribute to patellar instability and lateral patellar dislocation. Magnetic resonance (MR) imaging of the knee is the modality of choice to evaluate underlying bone contusion patterns, associated soft-tissue injuries, and additional complex ligamentous and osteochondral injuries, many of which are not apparent on conventional radiographs.

  12. Pediatric complex divergent elbow dislocation.

    PubMed

    van Wagenberg, Jan-Maarten F; van Huijstee, Pieter J; Verhofstad, Michiel H J

    2011-01-01

    A divergent dislocation of the elbow is a very rare injury, and only a few cases have been described in the literature. It is characterized as a dorsal dislocation of the ulnohumeral joint combined with a lateral dislocation of the proximal radius. All three articulations of the elbow joint are involved. Like in our case, it can be accompanied by an avulsion fracture of the coronoid and a distal radius fracture. For correct understanding of the injury, proper radiographic studies are imperative. In contrast to some earlier reports that advise a conservative approach, we performed a very aggressive operative treatment. To ensure anatomic reconstruction of the elbow, surgical exposure of the various injuries was performed first. After gross reduction of the joint dislocation, definitive osteosynthesis of the distal radius fracture was performed. Subsequently, the coronoid process and lateral collateral ligament could be repaired anatomically, improving the stability of the elbow. An uneventful recovery with excellent elbow motion and stability was achieved.

  13. Dislocation sources in ordered intermetallics

    SciTech Connect

    Yoo, M.H.; Appel, F.; Wagner, R.; Mecking, H.

    1996-09-01

    An overview on the current understanding of dislocation sources and multiplication mechanisms is made for ordered intermetallic alloys of the L1{sub 2}, B2, and D0{sub 19} structures. In L1{sub 2} alloys, a large disparity of edge/screw segments in their relative mobility reduces the efficiency of a Frank-Read Type multiplication mechanism. In Fe-40%Al of the B2 structure, a variety of dislocation sources are available for <111> slip, including ones resulting from condensation of thermal vacancies. In NiAl with the relatively high APB energy, <100> dislocations may result from the dislocation decomposition reactions, the prismatic punching out from inclusion particles, and/or steps and coated layers of the surface. Internal interfaces often provide sites for dislocation multiplication, e.g., grain boundaries, sub-boundaries in Ni{sub 3}Ga, NiAl and Ti{sub 3}Al, and antiphase domain boundaries in Ti{sub 3}Al. As for the crack tip as a dislocation source, extended SISFs trailed by super-Shockley partials emanating form the cracks in Ni{sub 3}Al and Co{sub 3}Ti are discussed in view of a possible toughening mechanism.

  14. On the hierarchy of interfacial dislocation structure

    NASA Astrophysics Data System (ADS)

    Balluffi, R. W.; Olson, G. B.

    1985-04-01

    Many different types of dislocations have been defined in dislocation models for grain boundaries and interphase boundaries. It is emphasized that there is no unique dislocation model for a boundary, and that the formal dislocation content depends upon the choice of the lattice correspondence relating the adjoining lattices. However, it is concluded that no problems of real physical significance arise from this lack of uniqueness. “Best≓, or most useful, descriptions often exist, and these are discussed. A hierarchy consisting of four different types of interfacial dislocations may be distinguished, which is useful in describing the dislocation content of interfaces. These entities are termed: (1) primary interfacial dislocations; (2) secondary interfacial dislocations; (3) coherency interfacial dislocations; and (4) translational interfacial dislocations. While there may be a lack of agreement on terminology in the literature, it is believed that these dislocation types are distinguishable and play unique roles in useful dislocation models for interfaces. Detailed descriptions of these dislocation types are given, and actual examples in real interfaces are presented. It is concluded that dislocation descriptions of interface structures become of purely formal significance in the limit of fully incoherent interfaces since the cores are then delocalized. The utility of various dislocation descriptions therefore depends on the degree to which various types of local coherency exist.

  15. Negative correlation between Nosema ceranae spore loads and deformed wing virus infection levels in adult honey bee workers.

    PubMed

    Costa, Cecilia; Tanner, Gina; Lodesani, Marco; Maistrello, Lara; Neumann, Peter

    2011-11-01

    Interactions between pathogens might contribute to honey bee colony losses. Here we investigated if there is an association between the microsporidian Nosema ceranae and the deformed wing virus (DWV) in different body sections of individual honey bee workers (Apis mellifera ligustica) under exclusion of the vector Varroa destructor. Our data provide correlational evidence for antagonistic interactions between the two pathogens in the midgut of the bees.

  16. A simple model for dislocation emission mediated dynamic nanovoid growth

    NASA Astrophysics Data System (ADS)

    Wilkerson, Justin; Ramesh, K. T.

    2015-06-01

    Failure of ductile metals has long been attributed to the microscopic processes of void nucleation, growth, and finally coalescence leading to fracture. Our traditional view of void nucleation is associated with interface debonding at second-phase particles. However, much of this understanding has been gleaned from observations of quasi-static fracture surfaces. Under more extreme dynamic loading conditions second-phase particles may not necessarily be the dominant source of void nucleating material defects, and a few key experimental observations of laser spall surfaces seem to support this assertion. Here, we motivate an alternative mechanism to the traditional view, namely shock-induced vacancy generation and clustering followed by nanovoid growth mediated by dislocation emission. This mechanism only becomes active at very large stresses, and thus it is desirable to establish a closed-form criterion for the macroscopic stress required to activate dislocation emission in porous materials. Following an approach similar to Lubarda and co-workers, we make use of stability arguments applied to the analytic solutions of the elastic interactions of dislocations and voids to derive the desired criterion. We then propose a dynamic nanovoid growth law that is motivated by the kinetics of dislocation emission. The resulting failure model is validated against a number of molecular dynamics simulations with favorable agreement. Lastly, we make use of our simple model to predict some interesting anomalous behaviors associated with high surface energies and nonlinear elasticity.

  17. Bilateral hip dislocation in a 79 years patient.

    PubMed

    Alexa, O; Cozma, T; Puha, B; Alexa, I D

    2012-01-01

    Bilateral simultaneous dislocation of the hip is an unusual occurrence, especially if there is no previous history of hip abnormality or ligamentous laxity. Most of the reports published until now most frequently describe this type of injury in adults. The majority of case reports present patients with ages ranging between 20 and 30 years old, because at this age the bone is strong enough not to suffer a fracture but a dislocation. The oldest patient with bilateral simultaneous dislocation of the hip described in literature (to our knowledge) is 65 years old. We present the case of a 79 year old man that was involved in an agricultural accident in which a heavy load fell on both his feet while he was laying on the ground. Anteroposterior pelvic radiograph reveal bilateral posterior hip dislocation with an associated left-side acetabular fracture and also a minimum displaced anterior left pelvic ring fracture. Both hips were reduced within three hours of presentation by closed manipulation under spinal anaesthesia. Literature search revealed no case presentation that reported a bilateral simultaneous dislocation of the hip in elderly--to our knowledge, this is the first.

  18. Early sex work initiation independently elevates odds of HIV infection and police arrest among adult sex workers in a Canadian setting

    PubMed Central

    GOLDENBERG, Shira M.; CHETTIAR, Jill; SIMO, Annick; SILVERMAN, Jay G.; STRATHDEE, Steffanie A.; MONTANER, Julio; SHANNON, Kate

    2014-01-01

    Objectives To explore factors associated with early sex work initiation, and model the independent effect of early initiation on HIV infection and prostitution arrests among adult sex workers (SWs). Design Baseline data (2010–2011) were drawn from a cohort of SWs who exchanged sex for money within the last month and were recruited through time-location sampling in Vancouver, Canada. Analyses were restricted to adults ≥18 years old. Methods SWs completed a questionnaire and HIV/STI testing. Using multivariate logistic regression, we identified associations with early sex work initiation (<18 years old) and constructed confounder models examining the independent effect of early initiation on HIV and prostitution arrests among adult SWs. Results Of 508 SWs, 193 (38.0%) reported early sex work initiation, with 78.53% primarily street-involved SWs and 21.46% off-street SWs. HIV prevalence was 11.22%, which was 19.69% among early initiates. Early initiates were more likely to be Canadian-born (Adjusted Odds Ratio (AOR): 6.8, 95% Confidence Interval (CI): 2.42–19.02), inject drugs (AOR: 1.6, 95%CI: 1.0–2.5), and to have worked for a manager (AOR: 2.22, 95%CI: 1.3–3.6) or been coerced into sex work (AOR: 2.3, 95%CI: 1.14–4.44). Early initiation retained an independent effect on increased risk of HIV infection (AOR: 2.5, 95% CI: 1.3–3.2) and prostitution arrests (AOR: 2.0, 95%CI: 1.3–3.2). Conclusions Adolescent sex work initiation is concentrated among marginalized, drug and street-involved SWs. Early initiation holds an independent increased effect on HIV infection and criminalization of adult SWs. Findings suggest the need for evidence-based approaches to reduce harm among adult and youth SWs. PMID:23982660

  19. Blueprint Reading for Sheet Metal Workers. Training Guide.

    ERIC Educational Resources Information Center

    Anoka-Hennepin Technical Coll., Minneapolis, MN.

    This training guide, developed during a project to retrain defense industry workers at risk of job loss or dislocation because of conversion of the defense industry, is designed for a course in blueprint reading for sheet metal workers. The following are among the topics covered in the course: orthographic projection; isometric and oblique…

  20. Dislocation Multi-junctions and Strain Hardening

    SciTech Connect

    Bulatov, V; Hsiung, L; Tang, M; Arsenlis, A; Bartelt, M; Cai, W; Florando, J; Hiratani, M; Rhee, M; Hommes, G; Pierce, T; Diaz de la Rubia, T

    2006-06-20

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects--dislocations. First theorized in 1934 to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed only two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening: a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions tying dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed hereafter multi-junctions. The existence of multi-junctions is first predicted by Dislocation Dynamics (DD) and atomistic simulations and then confirmed by the transmission electron microscopy (TEM) experiments in single crystal molybdenum. In large-scale Dislocation Dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in BCC crystals.

  1. Dislocation multi-junctions and strain hardening.

    PubMed

    Bulatov, Vasily V; Hsiung, Luke L; Tang, Meijie; Arsenlis, Athanasios; Bartelt, Maria C; Cai, Wei; Florando, Jeff N; Hiratani, Masato; Rhee, Moon; Hommes, Gregg; Pierce, Tim G; de la Rubia, Tomas Diaz

    2006-04-27

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects called dislocations. First proposed theoretically in 1934 (refs 1-3) to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening, a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions that tie the dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed 'multi-junctions'. We first predict the existence of multi-junctions using dislocation dynamics and atomistic simulations and then confirm their existence by transmission electron microscopy experiments in single-crystal molybdenum. In large-scale dislocation dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication, thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in body-centred cubic crystals.

  2. Bacterial diversity in worker adults of Apis mellifera capensis and Apis mellifera scutellata (Insecta: Hymenoptera) assessed using 16S rRNA sequences.

    PubMed

    Jeyaprakash, Ayyamperumal; Hoy, Marjorie A; Allsopp, Michael H

    2003-10-01

    High-fidelity PCR of 16S rRNA sequences was used to identify bacteria associated with worker adults of the honeybee subspecies Apis mellifera capensis and Apis mellifera scutellata. An expected approximately 1.5-kb DNA band, representing almost the entire length of the 16S rRNA gene, was amplified from both subspecies and cloned. Ten unique sequences were obtained: one sequence each clustered with Bifidobacterium (Gram-positive eubacteria), Lactobacillus (Gram-positive eubacteria), and Gluconacetobacter (Gram-negative alpha-proteobacteria); two sequences each clustered with Simonsiella (beta-proteobacteria) and Serratia (gamma-proteobacteria); and three sequences each clustered with Bartonella (alpha-proteobacteria). Although the sequences relating to these six bacterial genera initially were obtained from either A. m. capensis or A. m. scutellata or both, newly designed honeybee-specific 16S rRNA primers subsequently amplified all sequences from all individual workers of both subspecies. Attempts to amplify these sequences from eggs have failed. However, the wsp primers designed to amplify Wolbachia DNA from arthropods, including these bees, consistently produced a 0.6-kb DNA band from individual eggs, indicating that amplifiable bacterial DNA was present. Hence, the 10 bacteria could have been acquired orally from workers or from other substrates. This screening of 16S rRNA sequences from A. m. capensis and A. m. scutellata found sequences related to Lactobacillus and Bifidobacterium which previously had been identified from other honeybee subspecies, as well as sequences related to Bartonella, Gluconacetobacter, Simonsiella/Neisseria, and Serratia, which have not been identified previously from honeybees.

  3. Dislocations and other topological oddities

    NASA Astrophysics Data System (ADS)

    Pieranski, Pawel

    2016-03-01

    We will show that the book Dislocations by Jacques Friedel, published half a century ago, can still be recommended, in agreement with the author's intention, as a textbook ;for research students at University and for students at engineering schools as well as for research engineers;. Indeed, today dislocations are known to occur not only in solid crystals but also in many other systems discovered more recently such as colloidal crystals or liquid crystals having periodic structures. Moreover, the concept of dislocations is an excellent starting point for lectures on topological defects occurring in systems equipped with order parameters resulting from broken symmetries: disclinations in nematic or hexatic liquid crystals, dispirations in chiral smectics or disorientations in lyotropic liquid crystals. The discussion of dislocations in Blue Phases will give us an opportunity to call on mind Sir Charles Frank, friend of Jacques Friedel since his Bristol years, who called these ephemeral mesophases ;topological oddities;. Being made of networks of disclinations, Blue Phases are similar to Twist Grain Boundary (TGB) smectic phases, which are made of networks of screw dislocations and whose existence was predicted by de Gennes in 1972 on the basis of the analogy between smectics and superconductors. We will stress that the book by Jacques Friedel contains seeds of this analogy.

  4. Measurement of probability distributions for internal stresses in dislocated crystals

    SciTech Connect

    Wilkinson, Angus J.; Tarleton, Edmund; Vilalta-Clemente, Arantxa; Collins, David M.; Jiang, Jun; Britton, T. Benjamin

    2014-11-03

    Here, we analyse residual stress distributions obtained from various crystal systems using high resolution electron backscatter diffraction (EBSD) measurements. Histograms showing stress probability distributions exhibit tails extending to very high stress levels. We demonstrate that these extreme stress values are consistent with the functional form that should be expected for dislocated crystals. Analysis initially developed by Groma and co-workers for X-ray line profile analysis and based on the so-called “restricted second moment of the probability distribution” can be used to estimate the total dislocation density. The generality of the results are illustrated by application to three quite different systems, namely, face centred cubic Cu deformed in uniaxial tension, a body centred cubic steel deformed to larger strain by cold rolling, and hexagonal InAlN layers grown on misfitting sapphire and silicon carbide substrates.

  5. Responding to Economic Dislocation. Assistance Programs for Unemployed Steelworkers and a Directory of District Programs.

    ERIC Educational Resources Information Center

    United Steelworkers of America (AFL-CIO), Pittsburgh, PA.

    This report describes job training and placement programs offered by the United Steelworkers of America (USWA) for members dislocated by plant closings and job reductions. The first part of the booklet provides general information about the Steelworkers' worker assistance programs, including program summary, program principles, the comprehensive…

  6. Responses to Defense Cutbacks: The Dislocation Aversion Approach. Research and Evaluation Report Series 97-C.

    ERIC Educational Resources Information Center

    Social Policy Research Associates, Menlo Park, CA.

    Of the 19 projects conducted as part of the Defense Conversion Adjustment (DCA) Demonstration administered by the U.S. Department of Labor's Office of Work-Based Learning, 9 tested the dislocation aversion approach. The projects attempted to alleviate the negative impacts of defense cutbacks on communities, firms, and workers. Six projects…

  7. The Prevalence of Melasma and Its Association with Quality of Life among Adult Male Migrant Latino Workers

    PubMed Central

    Pichardo, Rita; Vallejos, Quirina; Feldman, Steven R.; Schulz, Mark R.; Verma, Amit; Quandt, Sara A.; Arcury, Thomas A.

    2008-01-01

    Background Melasma is a common condition of Latina women that detracts from their quality of life. The prevalence and impact of melasma in Latino men is not well characterized. Purpose We assess the prevalence of melasma and its association with quality of life among Latino men from Mexico and Central America working in the U.S. Methods The prevalence of melasma was assessed in three studies of Latino men; by direct examination in a study of 25 Latino poultry workers, by direct examination in a study of 54 Latino farmworkers, and by examination of store-and-forward teledermatology images in a study of 300 Latino farmworkers. Quality of life (QOL) was assessed with a Spanish version of the Dermatology Life Quality Index (DLQI). Results The prevalence of melasma was 36.0%, 7.4%, and 14.0% in the three studies. Prevalence of melasma was greatest among those aged 31 years and older, who were from Guatemala, and who spoke an indigenous language. Presence of melasma was associated with higher DLQI scores, indicating worse life quality, in the poultry worker population. Conclusions Melasma is a common condition in Latino men associated with poor quality of life in some affected individuals. Clinicians should be aware that melasma may be a concern for their male Latino patients. Research on the association of skin conditions with quality of life among minority men is needed. PMID:19126046

  8. Thermal effects in dislocation theory

    NASA Astrophysics Data System (ADS)

    Langer, J. S.

    2016-12-01

    The mechanical behaviors of polycrystalline solids are determined by the interplay between phenomena governed by two different thermodynamic temperatures: the configurational effective temperature that controls the density of dislocations, and the ordinary kinetic-vibrational temperature that controls activated depinning mechanisms and thus deformation rates. This paper contains a review of the effective-temperature theory and its relation to conventional dislocation theories. It includes a simple illustration of how these two thermal effects can combine to produce a predictive theory of spatial heterogeneities such as shear-banding instabilities. Its main message is a plea that conventional dislocation theories be reformulated in a thermodynamically consistent way so that the vast array of observed behaviors can be understood systematically.

  9. Multiscale Theory of Dislocation Climb.

    PubMed

    Geslin, Pierre-Antoine; Appolaire, Benoît; Finel, Alphonse

    2015-12-31

    Dislocation climb is a ubiquitous mechanism playing a major role in the plastic deformation of crystals at high temperature. We propose a multiscale approach to model quantitatively this mechanism at mesoscopic length and time scales. First, we analyze climb at a nanoscopic scale and derive an analytical expression of the climb rate of a jogged dislocation. Next, we deduce from this expression the activation energy of the process, bringing valuable insights to experimental studies. Finally, we show how to rigorously upscale the climb rate to a mesoscopic phase-field model of dislocation climb. This upscaling procedure opens the way to large scale simulations where climb processes are quantitatively reproduced even though the mesoscopic length scale of the simulation is orders of magnitude larger than the atomic one.

  10. SOME FACTORS IN WORKERS' DECISIONS TO FOREGO RETRAINING, PROGRESS REPORT OF A STUDY IN METROPOLITAN TORONTO. PAPER PRESENTED AT THE NATIONAL SEMINAR ON ADULT EDUCATION RESEARCH (CHICAGO, FEBRUARY 11-13, 1968).

    ERIC Educational Resources Information Center

    ABBEY, DAVID S.

    TO DETERMINE HOW TO MOTIVATE ADULTS TO TAKE ADVANTAGE OF THE ACADEMIC AND TECHNICAL TRAINING AVAILABLE TO THEM IN METROPOLITAN TORONTO, TWO GROUPS OF WORKERS WERE INTERVIEWED--27 APPLICANTS TO CANADIAN MANPOWER CENTRES WHO HAD REJECTED RETRAINING ("REFUSER" SAMPLE), AND 46 WHO HAD ACCEPTED BUT FAILED TO APPEAR AFTER THEY RECEIVED THEIR…

  11. The blue man: burn from muriatic acid combined with chlorinated paint in an adult pool construction worker.

    PubMed

    O'Cleireachain, Marc R; Macias, Luis H; Richey, Karen J; Pressman, Melissa A; Shirah, Gina R; Caruso, Daniel M; Foster, Kevin N; Matthews, Marc R

    2014-01-01

    Muriatic acid (hydrochloric acid), a common cleaning and resurfacing agent for concrete pools, can cause significant burn injuries. When coating a pool with chlorinated rubber-based paint, the pool surface is initially cleansed using 31.45% muriatic acid. Here we report a 50-year-old Hispanic male pool worker who, during the process of a pool resurfacing, experienced significant contact exposure to a combination of muriatic acid and blue chlorinated rubber-based paint. Confounding the clinical situation was the inability to efficiently remove the chemical secondary to the rubber-based nature of the paint. Additionally, vigorous attempts were made to remove the rubber paint using a variety of agents, including bacitracin, chlorhexidine soap, GOOP adhesive, and Johnson's baby oil. Resultant injuries were devastating fourth-degree burns requiring an immediate operative excision and amputation. Despite aggressive operative intervention and resuscitation, he continued to have severe metabolic derangements and ultimately succumbed to his injuries. We present our attempts at debridement and the system in place to manage patients with complex chemical burns.

  12. Evolution of geometrically necessary dislocation density from computational dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Guruprasad, P. J.; Benzerga, A. A.

    2009-07-01

    This paper presents a method for calculating GND densities in dislocation dynamics simulations. Evolution of suitably defined averages of GND density as well as maps showing the spatial nonuniform distribution of GNDs are analyzed under uniaxial loading. Focus is laid on the resolution dependence of the very notion of GND density, its dependence upon physical dimensions of plastically deformed specimens and its sensitivity to initial conditions. Acknowledgments Support from the National Science Foundation (CMMI-0748187) is gratefully acknowledged.

  13. Solute drag on perfect and extended dislocations

    NASA Astrophysics Data System (ADS)

    Sills, R. B.; Cai, W.

    2016-04-01

    The drag force exerted on a moving dislocation by a field of mobile solutes is studied in the steady state. The drag force is numerically calculated as a function of the dislocation velocity for both perfect and extended dislocations. The sensitivity of the non-dimensionalized force-velocity curve to the various controlling parameters is assessed, and an approximate analytical force-velocity expression is given. A non-dimensional parameter S characterizing the strength of the solute-dislocation interaction, the background solute fraction ?, and the dislocation character angle ?, are found to have the strongest influence on the force-velocity curve. Within the model considered here, a perfect screw dislocation experiences no solute drag, but an extended screw dislocation experiences a non-zero drag force that is about 10 to 30% of the drag on an extended edge dislocation. The solutes can change the spacing between the Shockley partials in both stationary and moving extended dislocations, even when the stacking fault energy remains unaltered. Under certain conditions, the solutes destabilize an extended dislocation by either collapsing it into a perfect dislocation or causing the partials to separate unboundedly. It is proposed that the latter instability may lead to the formation of large faulted areas and deformation twins in low stacking fault energy materials containing solutes, consistent with experimental observations of copper and stainless steel containing hydrogen.

  14. Theory of interacting dislocations on cylinders

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Paulose, Jayson; Nelson, David R.

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  15. Migrant Workers.

    ERIC Educational Resources Information Center

    Social and Labour Bulletin, 1983

    1983-01-01

    Discusses a new German law to encourage foreign workers to return to their home countries, employment exchanges for young foreigners in Germany, and a training program for migrant workers in India. (SK)

  16. An Unusual Traumatic Presentation: Luxatio Erecta Humeri and Concomitant Hip Dislocation

    PubMed Central

    Anarat, Berkan; Ersin, Mehmet; Erşen, Ali; Şen, Cengiz

    2016-01-01

    Introduction. Inferior dislocation of the glenohumeral joint, known as luxatio erecta humeri, and posterior hip dislocation are both rare presentations in the emergency department. The most common aetiology is falling for luxatio erecta humeri. The aim of this manuscript was to present a unique case in terms of luxatio erecta humeri, which has a different aetiology, treatment method, and concomitant injury. Presentation of Case. We report a construction worker who was rescued from a collapsed building who presented with both luxatio erecta humeri and complex posterior hip dislocation. An orthopaedic surgeon reducted luxatio erecta humeri with a one-step reduction technique under procedural anaesthesia as soon as the patient's vital signs were stable. Discussion. Different concomitant injuries and various injury mechanisms have been described in regard to inferior shoulder dislocation in the literature. However, posterior dislocation of the hip as a concomitant distant region injury and trapping as an injury mechanism for luxatio erecta humeri are being described for the first time in this case report. Two reduction manoeuvers, one-step and two-step, have been used for this dislocation. Some authors suggested that a two-step manoeuver can be more easy to apply. In our specific case, luxatio erecta was easily reducted by a single operator in a single attempt. Conclusion. Luxatio erecta humeri may occur from trapping and complex injuries can accompany luxatio erecta humeri in patients with multiple trauma. A one-step closed reduction can be easily applied by a single operator under procedural anaesthesia. PMID:28078152

  17. Simultaneous shoulder and elbow dislocation.

    PubMed

    Cobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-05-23

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice.

  18. Simultaneous shoulder and elbow dislocation

    PubMed Central

    Çobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-01-01

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice. PMID:24859563

  19. [Arthrography in congenital hip dislocation].

    PubMed

    Sipukhin, Ia M; Bazlova, E S; Cheberiak, N V

    1992-01-01

    The paper is concerned with the results of contrast arthrography in 73 children with hip joint dysplasia, among which true dislocations prevailed (70 patients). In addition to bone alterations, arthrography revealed various soft tissue changes like hypertrophy and deformity of limbus, soft tissue interposition, separation of the articular sac with the presence of an isthmus, disintegration of articular cartilages. These findings are used to define indications for surgical intervention as well as for planning the area of operation.

  20. Results of the northern Manhattan diabetes community outreach project: a randomized trial studying a community health worker intervention to improve diabetes care in Hispanic adults.

    PubMed

    Palmas, Walter; Findley, Sally E; Mejia, Miriam; Batista, Milagros; Teresi, Jeanne; Kong, Jian; Silver, Stephanie; Fleck, Elaine M; Luchsinger, Jose A; Carrasquillo, Olveen

    2014-04-01

    OBJECTIVE The Northern Manhattan Diabetes Community Outreach Project evaluated whether a community health worker (CHW) intervention improved clinically relevant markers of diabetes care in adult Hispanics. RESEARCH DESIGN AND METHODS Participants were adult Hispanics, ages 35-70 years, with recent hemoglobin A1c (A1C) ≥8% (≥64 mmol/mol), from a university-affiliated network of primary care practices in northern Manhattan (New York City, NY). They were randomized to a 12-month CHW intervention (n = 181), or enhanced usual care (educational materials mailed at 4-month intervals, preceded by phone calls, n = 179). The primary outcome was A1C at 12 months; the secondary outcomes were systolic blood pressure (SBP), diastolic blood pressure, and LDL-cholesterol levels. RESULTS There was a nonsignificant trend toward improvement in A1C levels in the intervention group (from unadjusted mean A1C of 8.77 to 8.40%), as compared with usual care (from 8.58 to 8.53%) (P = 0.131). There was also a nonsignificant trend toward an increase in SBP and LDL cholesterol in the intervention arm. Intervention fidelity, measured as the number of contacts in the intervention arm (visits, phone contacts, group support, and nutritional education), showed a borderline association with greater A1C reduction (P = 0.054). When assessed separately, phone contacts were associated with greater A1C reduction (P = 0.04). CONCLUSIONS The trend toward A1C reduction with the CHW intervention failed to achieve statistical significance. Greater intervention fidelity may achieve better glycemic control, and more accessible treatment models, such as phone-based interventions, may be more efficacious in socioeconomically disadvantaged populations.

  1. Does Racial/Ethnic Identity Influence the Effectiveness of a Community Health Worker Intervention for African American and Latino Adults With Type 2 Diabetes?

    PubMed

    Murayama, Hiroshi; Spencer, Michael S; Sinco, Brandy R; Palmisano, Gloria; Kieffer, Edith C

    2016-12-08

    Background Community health worker (CHW) interventions are known to be an effective strategy to improve health behaviors and outcomes in relation to diabetes, particularly for racial/ethnic communities. Although understanding the function of identity with same race/ethnicity among clients of CHW interventions could contribute to more effective program design, few studies have explored whether levels of racial/ethnic identity among participants can influence the effectiveness of CHW interventions. Aims We tested the relationship between level of racial/ethnic identity and changes in hemoglobin A1c and diabetes self-efficacy among low-income African American and Latino adults with type 2 diabetes who participated in a CHW intervention. Methods Data came from a randomized controlled trial of the CHW intervention with a 6-month delayed control group design for 164 African American and Latino adults in Detroit, Michigan. Racial/ethnic identity was created from two items and classified into high, moderate, and low. We combined the two arms (immediate and delayed) into one because there was no significant difference in baseline characteristics, other than age and postintervention self-efficacy, and multivariable linear regression models were applied in the analysis. Results Possession of high racial/ethnic identity was associated with greater improvement both in hemoglobin A1c and diabetes self-efficacy at 6 months. Moreover, among those with high hemoglobin A1c at preintervention, higher racial/ethnic identity had a greater impact on hemoglobin A1c improvement, compared with those with lower identity. Conclusions This study suggests the importance of considering racial/ethnic identity of the participants in designing and operating the CHW intervention for racial/ethnic minority population.

  2. Epidemiology of traumatic hip dislocation in patients treated in Ceará, Brazil

    PubMed Central

    Lima, Luciana Cascão; do Nascimento, Robson Alves; de Almeida, Victor Monte Tenório; Façanha, Fernando Antônio Mendes

    2014-01-01

    OBJECTIVE: To describe the epidemiological profile of patients with traumatic hip dislocation treated in our Institute from November/2012 to July/2013. METHODS: A descriptive cross-sectional study based on interviews and involving 43 patients who suffered traumatic hip dislocation was conducted. RESULTS: The mean age of patients was 34.4 years old and 90.7% were male. Regarding the mechanism of injury, 95% involved traffic accidents. The posterior dislocation of the hip was the most common injury (93%). Associated lesions were observed in 74.4% of patients, hip fractures being the most frequent. The time span between accident and dislocation reduction was less than 6 hours in 37.2% of patients, between 6 and 12 hours in 32.5% and over 12 hours in 30.3%, ranging from 1 hour to 15 days. A fraction of 90.7% of patients was submitted to closed reduction. CONCLUSION: Traumatic hip dislocation affected mostly young adults, victims of traffic accidents. The posterior dislocation of the hip was the most frequent injury and closed reduction was performed in 90.7% of patients. The time span between accident and dislocation reduction was less than 12 hours in most patients. Level of Evidence III, Study of Nonconsecutive Patients. PMID:25061422

  3. Three-dimensional formulation of dislocation climb

    NASA Astrophysics Data System (ADS)

    Gu, Yejun; Xiang, Yang; Quek, Siu Sin; Srolovitz, David J.

    2015-10-01

    We derive a Green's function formulation for the climb of curved dislocations and multiple dislocations in three-dimensions. In this new dislocation climb formulation, the dislocation climb velocity is determined from the Peach-Koehler force on dislocations through vacancy diffusion in a non-local manner. The long-range contribution to the dislocation climb velocity is associated with vacancy diffusion rather than from the climb component of the well-known, long-range elastic effects captured in the Peach-Koehler force. Both long-range effects are important in determining the climb velocity of dislocations. Analytical and numerical examples show that the widely used local climb formula, based on straight infinite dislocations, is not generally applicable, except for a small set of special cases. We also present a numerical discretization method of this Green's function formulation appropriate for implementation in discrete dislocation dynamics (DDD) simulations. In DDD implementations, the long-range Peach-Koehler force is calculated as is commonly done, then a linear system is solved for the climb velocity using these forces. This is also done within the same order of computational cost as existing discrete dislocation dynamics methods.

  4. Evaluation of Worker Profiling and Reemployment Services Systems: Interim Report. Unemployment Insurance Occasional Paper 96-1.

    ERIC Educational Resources Information Center

    Hawkins, Evelyn K.; And Others

    The Evaluation of Worker Profiling and Reemployment Services (WPRS) systems was designed to provide the U.S. Department of Labor information on how states are designing, implementing, and operating their worker profiling and reemployment services systems for dislocated workers and to compare the effectiveness of different state approaches to…

  5. Factors predisposing to dislocation of the Thompson hemiarthroplasty: 22 dislocations in 338 patients.

    PubMed

    Pajarinen, Jarkko; Savolainen, Vesa; Tulikoura, Ilkka; Lindahl, Jan; Hirvensalo, Eero

    2003-02-01

    In a series of 338 patients, we have retrospectively analyzed technical and anatomical factors, which may predispose to a dislocation of the Thompson hemiprosthesis. 22 patients (7%) had at least 1 dislocation during the 6-month follow-up. The most significant independent factor predisposing to dislocation was the use of a posterior approach (dislocation rate 16%). We examined the radiographs and data on operations in the 22 patients, using 79 random patients without dislocation as controls. Factors correlating with an increase in the incidence of dislocation were the length of the residual femoral neck > 0.5 cm in short patients (< 165 cm), and considerable change in the postoperative offset of the hip. Acetabular measurements showed no correlation to the dislocation. Our findings suggest that the main factors predicting dislocation are technical and not related to anatomical measurements.

  6. The epidemiology of shoulder dislocation in a state-hospital: a review of 106 cases.

    PubMed

    Hazmy, C H Wan; Parwathi, A

    2005-07-01

    This retrospective study was conducted in a state hospital set-up and aimed at identifying the magnitude of shoulder dislocations and their demographic data, characteristics of the injury, mechanism and predisposing factors, and the instituted treatment. Patients with radiographic evidence of shoulder dislocation admitted to the hospital from January 1999 to December 2002 were included. Data were recorded from the case notes. There were 105 shoulder dislocations with male predomination in 77% cases and age ranged between 11 and 90 years (average 30.9 years). The right shoulder was affected in 68% of the cases. The contributing events were fall in 37% of cases, road traffic accident 23%, sports 17% and pathological conditions 13%. Anterior dislocation occurred in 96.2% of the cases. Posterior and inferior dislocations encountered in two patients for each type. Twelve dislocations were associated fracture of the greater tuberosity, two each with humeral neck fracture and cerebral injuries. First time dislocation occurred in 73.6% of the cases. The recurrences ranged between 2 to 6 times (average 3.4 times). Closed manipulative reduction and strapping was the definitive treatment in 92.4% of the cases and the remaining needed surgical reconstruction. Four patients had open reduction and internal fixation of the associated fractures while another four had arthroscopic Bankart's repair. In conclusion, shoulder dislocation represents the most common shoulder problems. It afflicted young adults of reproductive age (21-40 years) and participation in sports was a risk factor in men. Women over 40 years and fall were at risk to develop shoulder dislocation.

  7. Massively-Parallel Dislocation Dynamics Simulations

    SciTech Connect

    Cai, W; Bulatov, V V; Pierce, T G; Hiratani, M; Rhee, M; Bartelt, M; Tang, M

    2003-06-18

    Prediction of the plastic strength of single crystals based on the collective dynamics of dislocations has been a challenge for computational materials science for a number of years. The difficulty lies in the inability of the existing dislocation dynamics (DD) codes to handle a sufficiently large number of dislocation lines, in order to be statistically representative and to reproduce experimentally observed microstructures. A new massively-parallel DD code is developed that is capable of modeling million-dislocation systems by employing thousands of processors. We discuss the general aspects of this code that make such large scale simulations possible, as well as a few initial simulation results.

  8. Enabling Strain Hardening Simulations with Dislocation Dynamics

    SciTech Connect

    Arsenlis, A; Cai, W

    2006-12-20

    Numerical algorithms for discrete dislocation dynamics simulations are investigated for the purpose of enabling strain hardening simulations of single crystals on massively parallel computers. The algorithms investigated include the /(N) calculation of forces, the equations of motion, time integration, adaptive mesh refinement, the treatment of dislocation core reactions, and the dynamic distribution of work on parallel computers. A simulation integrating all of these algorithmic elements using the Parallel Dislocation Simulator (ParaDiS) code is performed to understand their behavior in concert, and evaluate the overall numerical performance of dislocation dynamics simulations and their ability to accumulate percents of plastic strain.

  9. Elbow dislocation with ipsilateral distal radius fracture

    PubMed Central

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-01-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer. PMID:24082758

  10. Elbow dislocation with ipsilateral distal radius fracture.

    PubMed

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-07-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer.

  11. Microdiffraction Analysis of Hierarchical Dislocation Organization

    SciTech Connect

    Barabash, R.I.; Ice, G.E.

    2007-12-19

    This article describes how x-ray microdiffraction is influenced by the number, kind, and organization of dislocations. Particular attention is placed on micro-Laue diffraction, where polychromatic x-rays are diffracted into characteristic Laue patterns that are sensitive to the dislocation content and arrangement. Diffraction is considered for various stages of plastic deformation. For early stages of plastic deformation with random dislocation spacing, the intensity in reciprocal space is redistributed about Laue spots with a length scale proportional to the number of dislocations within the sample volume and with a characteristic shape that depends on the kinds of dislocations and the momentum transfer vector. Unpaired dislocations that contribute to lattice rotations cause the largest redistribution of scattered intensity. In later stages of plastic deformation, strong interactions between individual dislocations cause them to organize into correlated arrangements. Here again, xray diffraction Laue spots are broadened in proportion to the number of excess (unpaired) dislocations inside the wall and to the total number of unpaired walls, but the broadening can be discontinuous. With microdiffraction it is possible to quantitatively test models of dislocation organization.

  12. Congenital dislocation of the patella - clinical case.

    PubMed

    Miguel Sá, Pedro; Raposo, Filipa; Santos Carvalho, Manuel; Alegrete, Nuno; Coutinho, Jorge; Costa, Gilberto

    2016-01-01

    Congenital patellar dislocation is a rare condition in which the patella is permanently dislocated and cannot be reduced manually. The patella develops normally as a sesamoid bone of the femur. This congenital dislocation results from failure of the internal rotation of the myotome that forms the femur, quadriceps muscle and extensor apparatus. It usually manifests immediately after birth, although in some rare cases, the diagnosis may be delayed until adolescence or adulthood. Early diagnosis is important, thereby allowing surgical correction and avoiding late sequelae, including early degenerative changes in the knee. A case of permanent dislocation of the patella is presented here, in a female child aged seven years.

  13. Multiscale modeling of dislocation-precipitate interactions in Fe: From molecular dynamics to discrete dislocations.

    PubMed

    Lehtinen, Arttu; Granberg, Fredric; Laurson, Lasse; Nordlund, Kai; Alava, Mikko J

    2016-01-01

    The stress-driven motion of dislocations in crystalline solids, and thus the ensuing plastic deformation process, is greatly influenced by the presence or absence of various pointlike defects such as precipitates or solute atoms. These defects act as obstacles for dislocation motion and hence affect the mechanical properties of the material. Here we combine molecular dynamics studies with three-dimensional discrete dislocation dynamics simulations in order to model the interaction between different kinds of precipitates and a 1/2〈111〉{110} edge dislocation in BCC iron. We have implemented immobile spherical precipitates into the ParaDis discrete dislocation dynamics code, with the dislocations interacting with the precipitates via a Gaussian potential, generating a normal force acting on the dislocation segments. The parameters used in the discrete dislocation dynamics simulations for the precipitate potential, the dislocation mobility, shear modulus, and dislocation core energy are obtained from molecular dynamics simulations. We compare the critical stresses needed to unpin the dislocation from the precipitate in molecular dynamics and discrete dislocation dynamics simulations in order to fit the two methods together and discuss the variety of the relevant pinning and depinning mechanisms.

  14. Contingent workers.

    PubMed

    Guerrina, Ryan T; Burns, Candace M; Conlon, Helen

    2011-03-01

    Contingent workers compose a large portion of the U.S. work force. Contingent workers include temporary employees, contracted employees, day laborers, and freelancers. The skill level and educational requirements for their jobs vary from basic to highly advanced. Construction, housekeeping, engineering, and nursing have such positions. U.S. contingent workers are more likely to engage in occupations associated with increased risk of injury, and a variety of factors increase their risk of work injuries, particularly those leading to death. This article focuses on select occupational health and safety issues affecting contingent workers and their implications for occupational health nurses.

  15. Education and Today's Older Worker.

    ERIC Educational Resources Information Center

    Roberson, Donald N.

    New perspectives need to be gained on the roles of older adults and older workers in the new millenium. Because today's adult is healthier, policies concerning social security, retirement, and work need to be changed. There is a need for acceptance of various types of aging. Rather than mandating specific retirement, the individual should have…

  16. Randomized Controlled Trial of a Community Health Worker Self-Management Support Intervention Among Low-Income Adults With Diabetes, Seattle, Washington, 2010–2014

    PubMed Central

    Taylor, Leslie; Silverman, Julie; Kiefer, Meghan; Hebert, Paul; Lessler, Dan; Krieger, James

    2017-01-01

    Introduction Community health workers (CHWs) can improve diabetes outcomes; however, questions remain about translating research findings into practical low-intensity models for safety-net providers. We tested the effectiveness of a home-based low-intensity CHW intervention for improving health outcomes among low-income adults with diabetes. Methods Low-income patients with glycated hemoglobin A1c (HbA1c) of 8.0% or higher in the 12 months before enrollment from 3 safety-net providers were randomized to a 12-month CHW-delivered diabetes self-management intervention or usual care. CHWs were based at a local health department. The primary outcome was change in HbA1c from baseline enrollment to 12 months; secondary outcomes included blood pressure and lipid levels, quality of life, and health care use. Results The change in HbA1c in the intervention group (n = 145) (unadjusted mean of 9.09% to 8.58%, change of −0.51) compared with the control group (n = 142) (9.04% to 8.71%, change of −0.33) was not significant (P = .54). In an analysis of participants with poor glycemic control (HbA1c >10%), the intervention group had a 1.23-point greater decrease in HbA1c compared with controls (P = .046). For the entire study population, we found a decrease in reported physician visits (P < .001) and no improvement in health-related quality of life (P = .07) in the intervention group compared with the control group. Conclusion A low-intensity CHW-delivered intervention to support diabetes self-management did not significantly improve HbA1c relative to usual care. Among the subgroup of participants with poor glycemic control (HbA1c >10% at baseline), the intervention was effective. PMID:28182863

  17. Promoting smoking cessation in Bangladeshi and Pakistani male adults: design of a pilot cluster randomised controlled trial of trained community smoking cessation workers

    PubMed Central

    2009-01-01

    Background The prevalence of smoking is higher among Pakistani and Bangladeshi males than among the general population. Smokers who receive behavioural support and medication quadruple their chances of stopping smoking, but evidence suggests that these populations do not use National Health Service run stop smoking clinics as frequently as would be expected given their high prevalence of smoking. This study aims to tackle some of the main barriers to use of stop smoking services and adherence to treatment programmes by redesigning service delivery to be more acceptable to these adult male populations. The study compares the effectiveness of trained Pakistani and Bangladeshi smoking cessation workers operating in an outreach capacity ('clinic + outreach') with standard care ('clinic only') to improve access to and success of National Health Service smoking cessation services. Methods/design This is a pilot cluster randomised controlled trial based in Birmingham, UK. Super output areas of Birmingham will be identified in which more than 10% of the population are of Pakistani and/or Bangladeshi origin. From these areas, 'natural geographical communities' will be identified. Sixteen aggregated agglomerations of super output areas will be identified, separating areas from each other using buffer regions in order to reduce potential contamination. These natural communities will be randomised to 'clinic + outreach' (intervention) or 'clinic only' (control) arms. The use of stop smoking services and the numbers of people quitting smoking (defined as prolonged self-reported abstinence at four weeks, three months and six months) will be assessed in each area. In addition, we will assess the impact of the intervention on adherence to smoking cessation treatments and patient satisfaction. Trial registration Current Controlled Trials ISRCTN 82127540. PMID:19682374

  18. Quantum dislocations in solid Helium-4

    NASA Astrophysics Data System (ADS)

    Aleinikava, Darya

    In this thesis the following problems on properties of solid 4He are considered: (i) the role of long-range interactions in suppression of dislocation roughening at T = 0; (ii) the combined effect of 3He impurities and Peierls potential on shear modulus softening; (iii) the dislocation superclimb and its connection to the phenomenon of "giant isochoric compressibility"; (iv) non-linear dislocation response to the applied stress and stress-induces dislocation roughening as a I-order phase transition in 1D at finite temperature. First we investigate the effect of long-range interactions on the state of edge dislocation at T = 0. Such interactions are induced by elastic forces of the solid. We found that quantum roughening transition of a dislocation at T = 0 is completely suppressed by arbitrarily small long-range interactions between kinks. A heuristic argument is presented and the result has been verified by numerical Monte-Carlo simulations using Worm Algorithm in J-current model. It was shown that the Peierls potential plays a crucial role in explaining the elastic properties of dislocations, namely shear modulus softening phenomenon. The crossover from T = 0 to finite temperatures leads to intrinsic softening of the shear modulus and is solely controlled by kink typical energy. It was demonstrated that the mechanism, involving only the binding of 3He impurities to the dislocations, requires an unrealistically high concentrations of defects (or impurities) in order to explain the shear modulus phenomenon and therefore an inclusion of Peierls potential in consideration is required. Superclimbing dislocations, that is the edge dislocations with the superfluidity along the core, were investigated. The theoretical prediction that superclimb is responsible for the phenomenon of "giant isochoric compressibility" was confirmed by Monte-Carlo simulations. It was demonstrated that the isochoric compressibility is suppressed at low temperatures. The dependence of

  19. Technology Everywhere: A Campus Agenda for Educating and Managing Workers in the Digital Age. EDUCAUSE Leadership Strategies. The Jossey-Bass Higher and Adult Education Series.

    ERIC Educational Resources Information Center

    Hawkins, Brian L., Ed.; Rudy, Julia A., Ed.; Wallace, William H., Jr, Ed.

    This book addresses the dual role played by colleges and universities that must recruit, hire, and train knowledge worker professionals and education information technology (IT) learners to manage the flow of information. Part 1, The Context, contains these chapters: (1) The Supply of IT Workers in the United States (William Aspray and Peter A.…

  20. Dislocated interests and climate change

    NASA Astrophysics Data System (ADS)

    Davis, Steven J.; Diffenbaugh, Noah

    2016-06-01

    The predicted effects of climate change on surface temperatures are now emergent and quantifiable. The recent letter by Hansen and Sato (2016 Environ. Res. Lett. 11 034009) adds to a growing number of studies showing that warming over the past four decades has shifted the distribution of temperatures higher almost everywhere, with the largest relative effects on summer temperatures in developing regions such as Africa, South America, southeast Asia, and the Middle East (e.g., Diffenbaugh and Scherer 2011 Clim. Change 107 615-24 Anderson 2011 Clim. Change 108 581; Mahlstein et al 2012 Geophys. Res. Lett. 39 L21711). Hansen and Sato emphasize that although these regions are warming disproportionately, their role in causing climate change—measured by cumulative historical CO2 emissions produced—is small compared to the US and Europe, where the relative change in temperatures has been less. This spatial and temporal mismatch of climate change impacts and the burning of fossil fuels is a critical dislocation of interests that, as the authors note, has ‘substantial implications for global energy and climate policies.’ Here, we place Hansen and Sato’s ‘national responsibilities’ into a broader conceptual framework of problematically dislocated interests, and briefly discuss the related challenges for global climate mitigation efforts.

  1. Palmar dislocation of scaphoid and lunate.

    PubMed

    Idrissi, Khalid Koulali; Galiua, Farid

    2011-09-28

    A palmar dislocation of scaphoid and lunate is uncommon. We have found only 19 reported cases in the literature. We reported a simultaneous, divergent dislocation. The closed reduction followed by percutaneous pinning has given a good result without avascular necrosis of any carpal bone.

  2. Statistics of dislocation pinning at localized obstacles

    SciTech Connect

    Dutta, A.; Bhattacharya, M. Barat, P.

    2014-10-14

    Pinning of dislocations at nanosized obstacles like precipitates, voids, and bubbles is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often studied at fundamental level by means of analytical tools, atomistic simulations, and finite element methods. Nevertheless, the information extracted from such studies cannot be utilized to its maximum extent on account of insufficient information about the underlying statistics of this process comprising a large number of dislocations and obstacles in a system. Here, we propose a new statistical approach, where the statistics of pinning of dislocations by idealized spherical obstacles is explored by taking into account the generalized size-distribution of the obstacles along with the dislocation density within a three-dimensional framework. Starting with a minimal set of material parameters, the framework employs the method of geometrical statistics with a few simple assumptions compatible with the real physical scenario. The application of this approach, in combination with the knowledge of fundamental dislocation-obstacle interactions, has successfully been demonstrated for dislocation pinning at nanovoids in neutron irradiated type 316-stainless steel in regard to the non-conservative motion of dislocations. An interesting phenomenon of transition from rare pinning to multiple pinning regimes with increasing irradiation temperature is revealed.

  3. Fast Fourier transform discrete dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Graham, J. T.; Rollett, A. D.; LeSar, R.

    2016-12-01

    Discrete dislocation dynamics simulations have been generally limited to modeling systems described by isotropic elasticity. Effects of anisotropy on dislocation interactions, which can be quite large, have generally been ignored because of the computational expense involved when including anisotropic elasticity. We present a different formalism of dislocation dynamics in which the dislocations are represented by the deformation tensor, which is a direct measure of the slip in the lattice caused by the dislocations and can be considered as an eigenstrain. The stresses arising from the dislocations are calculated with a fast Fourier transform (FFT) method, from which the forces are determined and the equations of motion are solved. Use of the FFTs means that the stress field is only available at the grid points, which requires some adjustments/regularizations to be made to the representation of the dislocations and the calculation of the force on individual segments, as is discussed hereinafter. A notable advantage of this approach is that there is no computational penalty for including anisotropic elasticity. We review the method and apply it in a simple dislocation dynamics calculation.

  4. Dislocation generation during early stage sintering.

    NASA Technical Reports Server (NTRS)

    Sheehan, J. E.; Lenel, F. V.; Ansell, G. S.

    1973-01-01

    Discussion of the effects of capillarity-induced stresses on dislocations during early stage sintering. A special version of Hirth's (1963) theoretical calculation procedures modified to describe dislocation nucleation on planes meeting the sintering body's neck surface obliquely is shown to predict plastic flow at stress levels know to exist between micron size metal particles in the early stages of sintering.

  5. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  6. Characterization of Geometrically Necessary Dislocation Content with EBSD-Based Continuum Dislocation Microscopy

    NASA Astrophysics Data System (ADS)

    Ruggles, Timothy J.

    Modeling of plasticity is often hampered by the difficulty in accurately characterizing dislocation density on the microscale for real samples. It is particularly difficult to resolve measured dislocation content onto individual dislocation systems at the length scales most commonly of interest in plasticity studies. Traditionally, dislocation content is analyzed at the continuum level using the Nye tensor and the fundamental relation of continuum dislocation theory to interpret information measured by diffraction techniques, typically EBSD or High Resolution EBSD. In this work the established Nye-Kroner method for resolving measured geometrically necessary dislocation content onto individual slip systems is assessed and extended. Two new methods are also presented to relieve the ambiguity of the Nye-Kroner method. One of these methods uses modified classical dislocation equations to bypass the Nye-Kroner relation, and the other estimates the bulk dislocation density via the entry-wise one-norm of the Nye tensor. These methods are validated via a novel simulation of distortion fields around continuum fields of dislocation density based on classical lattice mechanics and then applied to actual HR-EBSD scans of a micro-indented single crystals of nickel and tantalum. Finally, a detailed analysis of the effect of the spacing between points in an EBSD scan (which is related to the step size of the numerical derivatives used in EBSD dislocation microscopy) on geometrically necessary dislocation measurements is conducted.

  7. Glide dislocation nucleation from dislocation nodes at semi-coherent {111} Cu–Ni interfaces

    SciTech Connect

    Shao, Shuai; Wang, Jian; Beyerlein, Irene J.; Misra, Amit

    2015-07-23

    Using atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, we show that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. We identified four distinctive node structures: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu–Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces. Finally, under biaxial tension/compression applied parallel to the interface, we show that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.

  8. Glide dislocation nucleation from dislocation nodes at semi-coherent {111} Cu–Ni interfaces

    DOE PAGES

    Shao, Shuai; Wang, Jian; Beyerlein, Irene J.; ...

    2015-07-23

    Using atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, we show that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. We identified four distinctive node structures: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu–Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces.more » Finally, under biaxial tension/compression applied parallel to the interface, we show that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.« less

  9. Dislocation core radii near elastic stability limits

    NASA Astrophysics Data System (ADS)

    Sawyer, C. A.; Morris, J. W., Jr.; Chrzan, D. C.

    2013-04-01

    Recent studies of transition metal alloys with compositions that place them near their limits of elastic stability [e.g., near the body-centered-cubic (BCC) to hexagonal-close-packed (HCP) transition] suggest interesting behavior for the dislocation cores. Specifically, the dislocation core size is predicted to diverge as the stability limit is approached. Here a simple analysis rooted in elasticity theory and the computation of ideal strength is used to analyze this divergence. This analysis indicates that dislocation core radii should diverge as the elastic limits of stability are approached in the BCC, HCP, and face-centered-cubic (FCC) structures. Moreover, external stresses and dislocation-induced stresses also increase the core radii. Density functional theory based total-energy calculations are combined with anisotropic elasticity theory to compute numerical estimates of dislocation core radii.

  10. Acute traumatic posterior elbow dislocation in children.

    PubMed

    Lieber, Justus; Zundel, Sabine M; Luithle, Tobias; Fuchs, Jörg; Kirschner, Hans-Joachim

    2012-09-01

    Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

  11. Bipolar dislocation of the forearm (floating forearm).

    PubMed

    Aşkar, Hüseyin; Ertürk, Cemil; Altay, Mehmet Akif; Akif Altay, Mehmet; Bilge, Ali

    2014-01-01

    Bipolar dislocation of the forearm (floating forearm) is an unusual injury and is therefore often overlooked. We report a 28-year-old male patient who presented at another center with a history of a fall while climbing a tree. The patient's left elbow was treated with closed reduction and immobilization with a long-arm cast brace due to elbow dislocation. However, the patient was admitted with pain and swelling of the wrist to our emergency department the following day. Physical and radiological examination revealed dorsal trans-scaphoid perilunate dislocation. A dorsal incision was performed for open reduction and internal fixation to provide wide surgical exposure. Concomitant occurrence of elbow dislocation and fracture-dislocation of the perilunate is infrequent. Therefore, physicians should be aware of possible additional injuries and current recommended treatment methods.

  12. Internal stresses, dislocation mobility and ductility

    NASA Astrophysics Data System (ADS)

    Saada, G.

    1991-06-01

    The description of plastic deformation must take into account individual mechanisms and heterogeneity of plastic strain. Influence of dislocation interaction with forest dislocations and of cross slip are connected with the organization of dipole walls. The latter are described and their development is explained as a consequence of edge effects. Applications are discussed. La description de la déformation plastique doit prendre en compte les interactions individuelles des dislocations et l'hétérogénéité à grande échelle de la déformation plastique. Les interactions des dislocations mobiles avec la forêt de dislocations, le glissement dévié, ont pour effet la création de parois dipolaires. Celles-ci sont décrites et leur développement est appliqué à partir des effets de bord.

  13. Responses to Defense Cutbacks: The Worker Mobility Approach. Research and Evaluation Report Series 97-D.

    ERIC Educational Resources Information Center

    Social Policy Research Associates, Menlo Park, CA.

    Of the 19 projects conducted as part of the Defense Conversion Adjustment (DCA) Demonstration administered by the U.S. Department of Labor's Office of Work-Based Learning, 8 tested the worker mobility approach. The projects, which shared the common goal of helping dislocated defense workers find high-quality jobs, tested one or more of the…

  14. A novel method of reduction for first-time acute lateral patellar dislocations in children and adolescents.

    PubMed

    Ong, Gene Yong-Kwang

    2016-03-01

    Five pediatric patients with acute traumatic "first-time" lateral patellar dislocations were successfully reduced using a novel, atraumatic, and simple technique. Uniquely, unlike the traditional method of patellar reduction, the patellar dislocations were reduced without any direct manipulation of the patella. In co-operative patients, no analgesia was required. Further validation of the reproducibility of the effectiveness of this method for successful patellar reduction in pediatric and adult populations are required.

  15. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    SciTech Connect

    Chen, Qian

    2008-01-01

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  16. Increasing preoperative dislocations and total time of dislocation affect surgical management of anterior shoulder instability

    PubMed Central

    Denard, Patrick J.; Dai, Xuesong; Burkhart, Stephen S.

    2015-01-01

    Purpose: Our purpose was to determine the relationship between number of preoperative shoulder dislocations and total dislocation time and the need to perform bone deficiency procedures at the time of primary anterior instability surgery. Our hypothesis was that need for bone deficiency procedures would increase with the total number and hours of dislocation. Materials and Methods: A retrospective review was performed of primary instability surgeries performed by a single surgeon. Patients with <25% glenoid bone loss were treated with an isolated arthroscopic Bankart repair. Those who also had an engaging Hill-Sachs lesion underwent arthroscopic Bankart repair with remplissage. Patients with >25% glenoid bone loss were treated with Latarjet reconstruction. Number of dislocations and total dislocation time were examined for their relationship with the treatment method. Results: Ten arthroscopic Bankart repairs, 13 arthroscopic Bankart plus remplissage procedures, and 9 Latarjet reconstructions were available for review. Total dislocations (P = 0.012) and total hours of dislocation (P = 0.019) increased from the Bankart, to the remplissage, to the Latarjet groups. Patients with a total dislocation time of 5 h or more were more likely to require a Latarjet reconstruction (P = 0.039). Patients with only 1 preoperative dislocation were treated with an isolated Bankart repair in 64% (7 of 11) of cases, whereas those with 2 or more dislocations required a bone loss procedure in 86% (18 of 21) of cases (P = 0.013). Conclusion: Increasing number of dislocations and total dislocation time are associated with the development of glenoid and humeral head bony lesions that alter surgical management of anterior shoulder instability. The necessity for the addition of a remplissage to an arthroscopic Bankart repair or the use of a Latarjet reconstruction increases with only 1 recurrent dislocation. Level of evidence: Level III, retrospective comparative study. PMID:25709237

  17. On Dislocation Glide in Planetary Interiors

    NASA Astrophysics Data System (ADS)

    Cordier, P.; Carrez, P.; Gouriet, K.; Kraych, A.; Ritterbex, S.

    2015-12-01

    The dynamics of hot planets depends strongly on how heat is transported to their surfaces through large scale convection flows. This is ultimately controlled by the rheology of high-pressure phases under extreme conditions. Whenever solid rocks are concerned, plastic flow results from the propagation of crystal defects (point defects, dislocations, grain boundaries). In this presentation we focus on the role of pressure on dislocation glide which is usually the most efficient strain-producing mechanism. Dislocation glide is assessed through multiscale numerical modeling. First, dislocations are modeled at the atomic scale based on first-principles calculations to incorporate the influence of pressure. Then the mobility law of dislocation at finite temperature is modeled by describing thermally-activated mechanisms for dislocation glide based on the kink-pair model. Then the flow stress at the grain scale is deduced either from application of the Orowan equation or by dislocation dynamics modeling. This approach is applied to wadsleyite, ringwoodite, bridgmanite and post-perovskite. Mechanical properties are either calculated at laboratory strain-rates to be compared with experiments when available or at mantle strain-rate to assess their efficiency under natural conditions.

  18. Thermodynamic forces in single crystals with dislocations

    NASA Astrophysics Data System (ADS)

    Van Goethem, Nicolas

    2014-06-01

    A simple model for the evolution of macroscopic dislocation regions in a single crystal is presented. This model relies on maximal dissipation principle within Kröner's geometric description of the dislocated crystal. Mathematical methods and tools from shape optimization theory provide equilibrium relations at the dislocation front, similarly to previous work achieved on damage modelling (J Comput Phys 33(16):5010-5044, 2011). The deformation state variable is the incompatible strain as related to the dislocation density tensor by a relation involving the Ricci curvature of the crystal underlying elastic metric. The time evolution of the model variables follows from a novel interpretation of the Einstein-Hilbert flow in terms of dislocation microstructure energy. This flow is interpreted as the dissipation of non-conservative dislocations, due to the climb mechanism, modelled by an average effect of mesoscopic dislocations moving normal to their glide planes by adding or removing points defects. The model equations are a fourth-order tensor parabolic equation involving the operator "incompatibility," here appearing as a tensorial counterpart of the scalar Laplacian. This work encompasses and generalizes results previously announced (C R Acad Sci Paris Ser I 349:923-927, 2011), with in addition a series of physical interpretations to give a meaning to the newly introduced concepts.

  19. Chronic bilateral dislocation of temporomandibular joint.

    PubMed

    Shakya, S; Ongole, R; Sumanth, K N; Denny, C E

    2010-01-01

    Dislocation of the condyle of the mandible is a common condition that may occur in an acute or chronic form. It is characterised by inability to close the mouth with or without pain. Dislocation has to be differentiated from subluxation which is a self reducible condition. Dislocation can occur in any direction with anterior dislocation being the commonest one. Various predisposing factors have been associated with dislocation like muscle fatigue and spasm, the defect in the bony surface like shallow articular eminence, and laxity of the capsular ligament. People with defect in collagen synthesis like Ehler Danlos syndrome, Marfan syndrome are said to be genetically predisposed to this condition. Various treatment modalities have been used ranging from conservative techniques to surgical methods. Acute dislocations can be reduced manually or with conservative approach and recurrent and chronic cases can be reduced by surgical intervention. Though the dislocation in our case was 4 months a simple manual reduction proved to be successful. We believe that manual reduction can be attempted as first line of treatment prior to surgical intervention.

  20. Distribution of distances between dislocations in different types of dislocation substructures in deformed Cu-Al alloys

    SciTech Connect

    Trishkina, L. Zboykova, N.; Koneva, N. Kozlov, E.; Cherkasova, T.

    2016-01-15

    The aim of the investigation was the determination of the statistic description of dislocation distribution in each dislocation substructures component forming after different deformation degrees in the Cu-Al alloys. The dislocation structures were investigated by the transmission diffraction electron microscopy method. In the work the statistic description of distance distribution between the dislocations, dislocation barriers and dislocation tangles in the deformed Cu-Al alloys with different concentration of Al and test temperature at the grain size of 100 µm was carried out. It was established that the above parameters influence the dislocation distribution in different types of the dislocation substructures (DSS): dislocation chaos, dislocation networks without disorientation, nondisoriented and disoriented cells, in the walls and inside the cells. The distributions of the distances between dislocations in the investigated alloys for each DSS type formed at certain deformation degrees and various test temperatures were plotted.

  1. Monteggia fracture-dislocations: A Historical Review

    PubMed Central

    Rehim, Shady A.; Maynard, Mallory A.; Sebastin, Sandeep J.; Chung, Kevin C.

    2014-01-01

    The eponym Monteggia fracture-dislocation originally referred to a fracture of the shaft of the ulna accompanied by anterior dislocation of the radial head that was described by Giovanni Battista Monteggia of Italy in 1814. Subsequently, a further classification system based on the direction of the radial head dislocation and associated fractures of the radius and ulna was proposed by Jose Luis Bado of Uruguay in 1958. This article investigates the evolution of treatment, classification, and outcomes of the Monteggia injury and sheds light on the lives and contributions of Monteggia and Bado. PMID:24792923

  2. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  3. [Conservative treatment of congenital patellar dislocation].

    PubMed

    Zajonz, D; Schumann, E; Wojan, M; Moche, M; Heyde, C-E

    2017-02-01

    This article presents the rare case of a boy who was born in our hospital with valgus deformity and external rotation of the right lower leg because of congenital patellar dislocation. In the case presented a stable repositioning of the patella could be achieved by redressment with a plaster cast and leg brace. During a 4-year follow-up there were no tendencies towards dislocation during the clinical examination and no dislocation events were documented. In selected cases an attempt at conservative repositioning and retention treatment appears to be worthwhile before surgical treatment is indicated.

  4. Intrauterine Temporomandibular Joint Dislocation: Prenatal Sonographic Evaluation

    PubMed Central

    Çil, Ahmet Said; Bozkurt, Murat; Bozkurt, Duygu Kara

    2014-01-01

    Congenital temporomandibular joint (TMJ) diseases are very rare disorders and are usually diagnosed in childhood. Developmental disorders of the TMJ such as hypoplasia, hyperplasia, and aplasia of the TMJ compartments are characterized by TMJ dysfunction. In childhood, these patients experience recurrent dislocation, pain, and malocclusion. We present the case of a 25-week fetus with unilateral TMJ dislocation with fluid retention in the joint diagnosed by ultrasonography. To the best of our knowledge, this is the first case of TMJ dislocation diagnosed by ultrasonographic evaluation during the prenatal period. PMID:23669613

  5. A Report on the use of Weak-Shock Wave Profiles and 3-D Dislocation Dynamics Simulations for Validation of Dislocation Multiplication and Mobility in the Phonon Drag Regime

    SciTech Connect

    Cazamias, J; Lassila, D; Shehadeh, M; Zbib, H

    2004-02-19

    Dynamically loaded gas gun experiments were performed to validate the predictive capabilities of 3-D dislocation dynamics (DD) code simulations at very high strain rates and dislocation velocities where the phonon drag mechanism will be dominant. Experiments were performed in the weak-shock regime on high-purity Mo single crystals with [001] compression axes. We have also performed shock-recovery experiments and are in the process of analyzing the dislocation structure generated by the weak-shock using transmission electron microscopy (TEM), which will also be used to validate the dislocation structure predicted by the DD simulations. The DD simulations being performed at Washington State University by Prof. H. Zbib and co-workers will be compared to the experimentally measured wave profiles, thereby validating mechanisms of dislocation generation and motion. Some DD simulation results are presented to demonstrate the feasibility of using a combined experimental/simulation effort for the validation of dislocation generation and mobility physics issues in the phonon drag regime.

  6. "Conjugate channeling" effect in dislocation core diffusion: carbon transport in dislocated BCC iron.

    PubMed

    Ishii, Akio; Li, Ju; Ogata, Shigenobu

    2013-01-01

    Dislocation pipe diffusion seems to be a well-established phenomenon. Here we demonstrate an unexpected effect, that the migration of interstitials such as carbon in iron may be accelerated not in the dislocation line direction ξ, but in a conjugate diffusion direction. This accelerated random walk arises from a simple crystallographic channeling effect. c is a function of the Burgers vector b, but not ξ, thus a dislocation loop possesses the same everywhere. Using molecular dynamics and accelerated dynamics simulations, we further show that such dislocation-core-coupled carbon diffusion in iron has temperature-dependent activation enthalpy like a fragile glass. The 71° mixed dislocation is the only case in which we see straightforward pipe diffusion that does not depend on dislocation mobility.

  7. Traumatic bilateral knee dislocations, unilateral hip dislocation, and contralateral humeral amputation: a case report.

    PubMed

    Voos, James E; Heyworth, Benton E; Piasecki, Dana P; Henn, R Frank; MacGillivray, John D

    2009-02-01

    Bilateral traumatic knee dislocations are a rarity. We report a case of bilateral traumatic knee dislocations with concomitant right hip dislocation and complete traumatic amputation of the left, nondominant upper extremity at the level of the proximal one-third of the humerus. Angiograms revealed no evidence of popliteal artery injury. Orthopedic treatment consisted of immediate reduction of the dislocations and urgent revision amputation of the upper extremity. Staged, bilateral knee ligamentous reconstructions were performed on hospital days 24 and 29, respectively. Despite this constellation of devastating injuries, the patient had a satisfactory outcome. In patients with high-energy hip or knee dislocations, the bilateral hips and knees should be carefully examined to check for associated fractures and/or dislocations.

  8. “Conjugate Channeling” Effect in Dislocation Core Diffusion: Carbon Transport in Dislocated BCC Iron

    PubMed Central

    Ishii, Akio; Li, Ju; Ogata, Shigenobu

    2013-01-01

    Dislocation pipe diffusion seems to be a well-established phenomenon. Here we demonstrate an unexpected effect, that the migration of interstitials such as carbon in iron may be accelerated not in the dislocation line direction , but in a conjugate diffusion direction. This accelerated random walk arises from a simple crystallographic channeling effect. is a function of the Burgers vector b, but not , thus a dislocation loop possesses the same everywhere. Using molecular dynamics and accelerated dynamics simulations, we further show that such dislocation-core-coupled carbon diffusion in iron has temperature-dependent activation enthalpy like a fragile glass. The 71° mixed dislocation is the only case in which we see straightforward pipe diffusion that does not depend on dislocation mobility. PMID:23593255

  9. Fundamentals in generalized elasticity and dislocation theory of quasicrystals: Green tensor, dislocation key-formulas and dislocation loops

    NASA Astrophysics Data System (ADS)

    Lazar, Markus; Agiasofitou, Eleni

    2014-12-01

    The present work provides fundamental quantities in generalized elasticity and dislocation theory of quasicrystals. In a clear and straightforward manner, the three-dimensional Green tensor of generalized elasticity theory and the extended displacement vector for an arbitrary extended force are derived. Next, in the framework of dislocation theory of quasicrystals, the solutions of the field equations for the extended displacement vector and the extended elastic distortion tensor are given; that is, the generalized Burgers equation for arbitrary sources and the generalized Mura-Willis formula, respectively. Moreover, important quantities of the theory of dislocations as the Eshelby stress tensor, Peach-Koehler force, stress function tensor and the interaction energy are derived for general dislocations. The application to dislocation loops gives rise to the generalized Burgers equation, where the displacement vector can be written as a sum of a line integral plus a purely geometric part. Finally, using the Green tensor, all other dislocation key-formulas for loops, known from the theory of anisotropic elasticity, like the Peach-Koehler stress formula, Mura-Willis equation, Volterra equation, stress function tensor and the interaction energy are derived for quasicrystals.

  10. Superolateral dislocation of the condyle: report of a rare case.

    PubMed

    Papadopoulos, H; Edwards, R S

    2010-05-01

    Anterior dislocation of the mandibular condyle is commonly seen in patients with chronic dislocation of their temporomandibular joints. Posterior, superior and lateral dislocation is rare. Superolateral dislocation of an intact condyle, let alone intact mandible is uncommon, usually occurring after a traumatic insult to the mandible. The authors report on such a case, and its management.

  11. Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in (alpha)RDX

    DTIC Science & Technology

    2013-11-01

    November 2013 Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in αRDX Lynn B. Munday and Jaroslaw Knap Computational ...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This work reports on the algorithms used to determine the...anisotropic and isotropic elastic properties of dislocations and their nucleation from a crack tip. The appendix contains a numerical implementation of these

  12. Automated identification and indexing of dislocations in crystal interfaces

    DOE PAGES

    Stukowski, Alexander; Bulatov, Vasily V.; Arsenlis, Athanasios

    2012-10-31

    Here, we present a computational method for identifying partial and interfacial dislocations in atomistic models of crystals with defects. Our automated algorithm is based on a discrete Burgers circuit integral over the elastic displacement field and is not limited to specific lattices or dislocation types. Dislocations in grain boundaries and other interfaces are identified by mapping atomic bonds from the dislocated interface to an ideal template configuration of the coherent interface to reveal incompatible displacements induced by dislocations and to determine their Burgers vectors. Additionally, the algorithm generates a continuous line representation of each dislocation segment in the crystal andmore » also identifies dislocation junctions.« less

  13. Automated identification and indexing of dislocations in crystal interfaces

    SciTech Connect

    Stukowski, Alexander; Bulatov, Vasily V.; Arsenlis, Athanasios

    2012-10-31

    Here, we present a computational method for identifying partial and interfacial dislocations in atomistic models of crystals with defects. Our automated algorithm is based on a discrete Burgers circuit integral over the elastic displacement field and is not limited to specific lattices or dislocation types. Dislocations in grain boundaries and other interfaces are identified by mapping atomic bonds from the dislocated interface to an ideal template configuration of the coherent interface to reveal incompatible displacements induced by dislocations and to determine their Burgers vectors. Additionally, the algorithm generates a continuous line representation of each dislocation segment in the crystal and also identifies dislocation junctions.

  14. Quenched pinning and collective dislocation dynamics

    PubMed Central

    Ovaska, Markus; Laurson, Lasse; Alava, Mikko J.

    2015-01-01

    Several experiments show that crystalline solids deform in a bursty and intermittent fashion. Power-law distributed strain bursts in compression experiments of micron-sized samples, and acoustic emission energies from larger-scale specimens, are the key signatures of the underlying critical-like collective dislocation dynamics - a phenomenon that has also been seen in discrete dislocation dynamics (DDD) simulations. Here we show, by performing large-scale two-dimensional DDD simulations, that the character of the dislocation avalanche dynamics changes upon addition of sufficiently strong randomly distributed quenched pinning centres, present e.g. in many alloys as immobile solute atoms. For intermediate pinning strength, our results adhere to the scaling picture of depinning transitions, in contrast to pure systems where dislocation jamming dominates the avalanche dynamics. Still stronger disorder quenches the critical behaviour entirely. PMID:26024505

  15. Hydrogenated vacancies lock dislocations in aluminium

    PubMed Central

    Xie, Degang; Li, Suzhi; Li, Meng; Wang, Zhangjie; Gumbsch, Peter; Sun, Jun; Ma, Evan; Li, Ju; Shan, Zhiwei

    2016-01-01

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ∼103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. Vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment. PMID:27808099

  16. Dislocation Glasses: Aging during Relaxation and Coarsening

    SciTech Connect

    Bako, B.; Groma, I.; Gyoergyi, G.; Zimanyi, G. T.

    2007-02-16

    The dynamics of dislocations is reported to exhibit a range of glassy properties. We study numerically various versions of 2D edge dislocation systems, in the absence of externally applied stress. Two types of glassy behavior are identified (i) dislocations gliding along randomly placed, but fixed, axes exhibit relaxation to their spatially disordered stable state; (ii) if both climb and annihilation are allowed, irregular cellular structures can form on a growing length scale before all dislocations annihilate. In all cases both the correlation function and the diffusion coefficient are found to exhibit aging. Relaxation in case (i) is a slow power law, furthermore, in the transient process (ii) the dynamical exponent z{approx_equal}6, i.e., the cellular structure coarsens relatively slowly.

  17. Hydrogenated vacancies lock dislocations in aluminium

    NASA Astrophysics Data System (ADS)

    Xie, Degang; Li, Suzhi; Li, Meng; Wang, Zhangjie; Gumbsch, Peter; Sun, Jun; Ma, Evan; Li, Ju; Shan, Zhiwei

    2016-11-01

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ~103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. Vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment.

  18. Developmental Dislocation (Dysplasia) of the Hip (DDH)

    MedlinePlus

    ... developmental dysplasia (dislocation) of the hip (DDH), the hip joint has not formed normally. The ball is loose ... be taken to provide detailed pictures of the hip joint. Treatment When DDH is detected at birth, it ...

  19. Complete dorsal dislocation of the carpal scaphoid with perilunate dorsal dislocation

    PubMed Central

    Kang, Jong Woo; Park, Jong Hoon; Suh, Dong Hun; Park, Jong Woong

    2016-01-01

    Complete dorsal dislocation of the carpal scaphoid combined with dorsal perilunate dislocation is an extremely rare carpal injury. We describe the case of a 23-year-old man who presented with a complete dorsal dislocation of the carpal scaphoid, combined with a perilunate dislocation. Surgical treatment was performed with open reduction and interosseus ligament repair. At 4 years follow up, the patient's wrist pain had completely resolved without limitations of wrist joint motion and without evidence of avascular necrosis of the carpal scaphoid. PMID:27512229

  20. Incidence of Posttraumatic Shoulder Dislocation in Poland

    PubMed Central

    Szyluk, Karol J.; Jasiński, Andrzej; Mielnik, Michał; Koczy, Bogdan

    2016-01-01

    Background The incidence of shoulder joint dislocation has been estimated at 11–26 per 100 000 population per year. In our opinion, basic epidemiological data need to be continually updated in studies of large populations. To study the incidence of posttraumatic dislocation of the shoulder joint in the Polish population. Material/Methods We retrospectively investigated the entire Polish population between 1 January 2010 and 1 January 2015. To identify the study group, data collected in the electronic database of the National Health Fund were used. The study group was divided into subgroups to detect possible differences in the incidence of shoulder dislocation with regard to age, sex, and season of the year (month) when the dislocation occurred. Results The cumulative size of the study sample was 192.72 million over the 5 years of the study. We identified 51 409 patients with first posttraumatic shoulder dislocation, at a mean age of 50.83 years (SD 21.12), from 0 to 104 years. The incidence of traumatic shoulder dislocations for the entire study group ranged from 24.75/100 000/year (number of posttraumatic shoulder dislocations per 100 000 persons per year) to 29.09/100 000/year, for a mean of 26.69/100 000/year. Conclusions In this study, the overall incidence of first-time posttraumatic shoulder dislocations in the Polish general population was 26.69 per 100 000 persons per year. These results are higher than estimates presented by other authors. It is necessary to study, regularly update, and monitor this problem in the general population. PMID:27777396

  1. Traumatic posterior dislocation of hip in children.

    PubMed

    Kutty, S; Thornes, B; Curtin, W A; Gilmore, M F

    2001-02-01

    Traumatic posterior dislocation of the hip joint in children is an uncommon injury. It constitutes a true orthopedic emergency. It makes up over 80% of pediatric hip dislocations. In children, it can occur as a result of minimal trauma, which is attributed to a soft pliable acetabulum and ligamentous laxity. In skeletally mature adolescents, a greater force is required to dislocate the hip joint. Delay in reduction is associated with long-term complications such as avascular necrosis and degenerative arthritis. Avascular necrosis is related to the duration of dislocation. A poorer prognosis is associated with delay in reduction beyond 6 hours, advanced skeletal maturity, or multiple traumas. Prompt reduction minimizes complications. We report two cases of traumatic posterior dislocation of hip in children aged 3 and 14 years. Both were reduced within 6 hours of dislocation, and review at 6 months revealed normal examination and no evidence of any post-traumatic changes. Post-reduction treatment remains without a consensus. This review highlights the clinical presentation, management, and time-sensitive complications of the injury.

  2. Investigation of the Dynamics of a Screw Dislocation in Copper

    NASA Astrophysics Data System (ADS)

    Kolupaeva, S. N.; Petelina, Yu. P.; Polosukhin, K. A.; Petelin, A. E.

    2015-08-01

    A modification of the mathematical model of forming the crystallographic shear band is proposed in which the strength of elastic interaction between all dislocations of the forming dislocation pileups is taken into account in addition to the Peach-Keller force; lattice, impurity, and dislocation friction; linear tension; viscous braking; and intensity of generation of point defects behind kinks. The model is used to investigate the influence of the dislocation density on the time characteristics of the formation of dislocation loops in copper.

  3. Rehabilitation After Posterolateral Dislocation of the Elbow in a Collegiate Football Player: A Case Report

    PubMed Central

    Uhl, Tim L.; Gould, Michelle; Gieck, Joe H.

    2000-01-01

    Objective: To describe a functional rehabilitation program for a football player with a grade 2 posterolateral elbow dislocation to facilitate early return to competition. Background: Conservative management of a posterior dislocation of the elbow is common. The elbow is the second most frequently dislocated large joint in adults. Two common mechanisms of dislocation are hyperextension and posterolateral rotation. Prolonged immobilization can be detrimental to regaining full range of motion and function of the elbow, whereas early directed rehabilitation may lead to early return to normal function. Differential Diagnosis: Elbow dislocation with medial collateral ligament rupture, elbow subluxation, elbow dislocation with neurovascular compromise, or supracondylar fracture. Treatment: The athlete received immediate care of reduction and immobilization in a 90° posterior splint followed by a radiologic evaluation. Postreduction treatment included a short immobilization period and early initiation of protected active and resistive range-of-motion exercises. The athlete was able to return to full football activities in 3 weeks. He competed for the rest of the season with the elbow braced and taped, with no recurring incidents of instability. Uniqueness: The time to return to full participation was rapid. The medial collateral ligament was intact, as determined by magnetic resonance imaging. The athlete has since been followed for 2 football seasons and has not demonstrated any detrimental effects due to his early return. Conclusions: Early determination of the status of the medial collateral ligament through physical examination or imaging combined with early directed rehabilitation of a posterolateral elbow instability enabled this athlete to respond well. He regained pain-free full range of motion, strength, and function, allowing full participation in football at the Division I level with no recurring incidence of dislocation. Imagesp109-a PMID:16558601

  4. TRAINING METHODS FOR OLDER WORKERS. EMPLOYMENT OF OLDER WORKERS, 2.

    ERIC Educational Resources Information Center

    BELBIN, R.M.

    A SURVEY WAS PRESENTED OF SCIENTIFIC KNOWLEDGE ON AGE CHANGES IN HUMAN CAPACITIES, ESPECIALLY IN LEARNING ABILITY AND ADAPTABILITY, AND DESCRIBED VARIOUS METHODS USED TO TRAIN WORKERS OVER 40. THE ROLE OF MEMORY, MOTIVATION, RIGIDITY, AND INTELLIGENCE IN DETERMINING THE LEARNING EFFICIENCY OF MATURE ADULTS WAS ASSESSED, ALSO DIFFICULTIES CAUSED BY…

  5. Quantum dynamics of a single dislocation

    NASA Astrophysics Data System (ADS)

    de Gennes, Pierre-Gilles

    We discuss the zero temperature motions of an edge dislocation in a quantum solid (e.g., He4). If the dislocation has one kink (equal in length to its Burgers vector b) the kink has a creation energy U and can move along the line with a certain transfer integral t. When t and U are of comparable magnitude, two opposite kinks can form an extended bound state, with a size l. The overall shape of the dislocation in the ground state is then associated with a random walk of persistence length l (along the line) and hop sizes b. We also discuss the motions of kinks under an applied shear stress σ: the glide velocity is proportional to exp(-σ*/σ), where σ* is a characteristic stress, controlled by tunneling processes. Mouvements quantiques d'une dislocation. On analyse le mouvement à température nulle d'une dislocation coin dans un solide quantique (He4). La dislocation peut avoir un cran (d'énergie U) dans son plan de glissement. Le cran peut avancer ou reculer le long de la dislocation par effet tunnel, avec une certaine intégrale de transfert t. Deux crans de signe opposé peuvent former un état lié. En présence d'une contrainte extérieure σ, la ligne doit avancer avec une vitesse ~exp(-σ*/σ) où σ* est une contrainte seuil, contrôlée par l'effet tunnel.

  6. Gatekeeper Training for Youth Workers

    ERIC Educational Resources Information Center

    Cartmill, Tania; Deane, Frank; Wilson, Coralie

    2009-01-01

    Adults who act as gatekeepers for young people may have the same barriers to help-seeking for mental health issues as young people. This study investigated the personal help-seeking practices of 47 Australian youth workers prior to and after a training workshop on youth mental health issues. Pre-post workshop evaluation revealed some increases in…

  7. Recurrent elbow dislocation--an uncommon presentation.

    PubMed

    Sunderamoorthy, D; Smith, A; Woods, D A

    2005-09-01

    A 58 year old female attended our A&E department following a fall in the garden with swelling and bruising of the right arm and the elbow. Anteroposterior and lateral radiographs were interpreted as showing a normal elbow joint. A diagnosis of soft tissue injury to the elbow was made and the patient was discharged with advice. She returned 2 days later, did not have an x ray, and again given advice. Three weeks later she was referred back to A&E by the general practitioner with persistent swelling of the elbow. Further radiographs showed a posterolateral dislocation of the elbow. The elbow was reduced under sedation but was subsequently dislocated at follow up, and was treated by external fixator and transolecranon pin. The fixator was removed at 4 weeks and the elbow was then stable. This case highlights that recurrent elbow dislocations due to significant ligament injuries can present in joint and subsequently dislocate. A high index of suspicion is necessary and appropriate referral to the specialist must be made to avoid the morbidity associated with recurrent dislocation. It also emphasises the need to always assess the patient on his or her own merits despite previously normal investigations.

  8. Use of cervical collar in temporomandibular dislocation.

    PubMed

    Jaisani, Mehul R; Pradhan, Leeza; Sagtani, Alok

    2015-06-01

    Dislocation of the temporomandibular joint represents 3 % of all reported dislocated joints. In the last 3 decades many cases of TMJ dislocation have been reported with a wide variety of treatment options ranging from non-surgical conservative approaches to open joint procedures. The question remains whether one method is superior to the others. Conservative treatments are still the option in this part of the continent due to financial constraints and as well as due to availability of skilled manpower. A variety of conservative techniques have been described for reducing dislocations, all of which require 10-14 days of immobilization of the jaw post reduction so as to prevent further episodes of dislocation. Immobilization of the jaw can be done in the form of barrel bandage, barton bandage, head chin cap or maxillomandibular fixation using arch bars. We suggest the use of a cervical collar as a form of post reduction immobilization technique to overcome the inherent disadvantages of conventional forms of immobilization techniques.

  9. Continuum Theory of Dislocations: Cell Structure Formation

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; Sethna, James P.

    2005-03-01

    Line-like topological defects inside metals are called dislocations. These dislocations in late stages of hardening form patterns called cell structures. We are developing a mesoscale theory for the formation of cell structures that systematically derives the order parameter fields and evolution laws from the conserved topological Burgers vector density or the Nye dislocation tensor. (In classical plasticity theories, describing scales large compared to these cells, one normally bypasses the complicated motions of the dislocations by supplying yield surface and plastic hardening function in order to determine the evolution of state variables.) Using Landau approach and a closure approximation, an evolution equation for the dislocation density tensor is obtained by employing simple symmetry arguments and the constraint that the elastic energy must decrease with time at fixed stress. The evolution laws lead to singularity formation at finite times, which we expect will be related to the formation of cell walls. Implementation of finite difference simulations using the upwind scheme and the results in one and higher dimensions will be discussed.

  10. Chiral anomaly in Dirac semimetals due to dislocations

    NASA Astrophysics Data System (ADS)

    Chernodub, M. N.; Zubkov, M. A.

    2017-03-01

    The dislocation in Dirac semimetal carries an emergent magnetic flux parallel to the dislocation axis. We show that due to the emergent magnetic field, the dislocation accommodates a single fermion massless mode of the corresponding low-energy one-particle Hamiltonian. The mode is propagating along the dislocation with its spin directed parallel to the dislocation axis. In agreement with the chiral anomaly observed in Dirac semimetals, an external electric field results in the spectral flow of the one-particle Hamiltonian, in pumping of the fermionic quasiparticles out from vacuum, and in creating a nonzero axial (chiral) charge in the vicinity of the dislocation.

  11. High dislocation density of tin induced by electric current

    SciTech Connect

    Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung; Wu, Albert T.

    2015-12-15

    A dislocation density of as high as 10{sup 17} /m{sup 2} in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10{sup 3} A/ cm{sup 2}. The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining.

  12. Successful Conservative Management of a Dislocated IUD

    PubMed Central

    Inal, Hasan Ali; Ozturk Inal, Zeynep; Alkan, Ender

    2015-01-01

    Background. Intrauterine contraceptive devices (IUDs) are widely utilized all over the world owing to their low cost and high efficacy. Uterine perforation is a rare complication that may occur at IUD insertion resulting in extrauterine location of the IUD. Traditionally, surgical removal of dislocated IUDs has been recommended. Case. A 68-year-old patient who had an IUD (Lippes loop) inserted 32 years ago and whose routine examination incidentally revealed a dislocated IUD in the abdominal cavity. The patient remained asymptomatic during three years of follow-up and the IUD was left in place. Conclusion. Asymptomatic patients, whose vaginal examinations and ultrasonography or X-ray results reveal a dislocated IUD, may benefit from conservative management. PMID:25861494

  13. Crack Tip Dislocation Nucleation in FCC Solids

    NASA Astrophysics Data System (ADS)

    Knap, J.; Sieradzki, K.

    1999-02-01

    We present results of molecular dynamic simulations aimed at examining crack tip dislocation emission in fcc solids. The results are analyzed in terms of recent continuum formulations of this problem. In mode II, Au, Pd, and Pt displayed a new unanticipated mechanism of crack tip dislocation emission involving the creation of a pair of Shockley partials on a slip plane one plane below the crack plane. In mode I, for all the materials examined, Rice's continuum formulation [J. Mech. Phys. Solids 40, 239 (1992)] underestimated the stress intensity for dislocation emission by almost a factor of 2. Surface stress corrections to the emission criterion brought the agreement between continuum predictions and simulations to within 20%.

  14. Chronic Elbow Dislocation: Evaluation and Management.

    PubMed

    Donohue, Kenneth W; Mehlhoff, Thomas L

    2016-07-01

    Chronic elbow dislocation is defined as a dislocation that has remained unreduced for >2 weeks. The soft-tissue and skeletal changes that develop during this time usually prevent successful closed reduction. These changes include the development of extensive intra-articular fibrotic tissue, as well as contracture of the triceps, collateral ligaments, and elbow capsule. Ulnar nerve involvement and associated fractures may also be present. Because treatment of chronic elbow dislocation is challenging, a stepwise approach is used in the evaluation and management of this condition. No large series of data are available to guide treatment. Most patients are treated on the basis of the surgeon's anecdotal experience. Treatment typically involves open reduction, often with the use of hinged external fixators. The role of triceps lengthening or primary collateral ligament reconstruction remains a topic of debate.

  15. High-temperature discrete dislocation plasticity

    NASA Astrophysics Data System (ADS)

    Keralavarma, S. M.; Benzerga, A. A.

    2015-09-01

    A framework for solving problems of dislocation-mediated plasticity coupled with point-defect diffusion is presented. The dislocations are modeled as line singularities embedded in a linear elastic medium while the point defects are represented by a concentration field as in continuum diffusion theory. Plastic flow arises due to the collective motion of a large number of dislocations. Both conservative (glide) and nonconservative (diffusion-mediated climb) motions are accounted for. Time scale separation is contingent upon the existence of quasi-equilibrium dislocation configurations. A variational principle is used to derive the coupled governing equations for point-defect diffusion and dislocation climb. Superposition is used to obtain the mechanical fields in terms of the infinite-medium discrete dislocation fields and an image field that enforces the boundary conditions while the point-defect concentration is obtained by solving the stress-dependent diffusion equations on the same finite-element grid. Core-level boundary conditions for the concentration field are avoided by invoking an approximate, yet robust kinetic law. Aspects of the formulation are general but its implementation in a simple plane strain model enables the modeling of high-temperature phenomena such as creep, recovery and relaxation in crystalline materials. With emphasis laid on lattice vacancies, the creep response of planar single crystals in simple tension emerges as a natural outcome in the simulations. A large number of boundary-value problem solutions are obtained which depict transitions from diffusional to power-law creep, in keeping with long-standing phenomenological theories of creep. In addition, some unique experimental aspects of creep in small scale specimens are also reproduced in the simulations.

  16. Interaction of dislocations with carbon-decorated dislocation loops in bcc Fe: an atomistic study.

    PubMed

    Terentyev, Dmitry; Anento, Napoleón; Serra, Anna

    2012-11-14

    Properties of ferritic Fe-based alloys are highly sensitive to the carbon content dissolved in the matrix because interstitial carbon is known to strongly interact with lattice point defects and dislocations. As a result, the accumulation of radiation defects and its impact on the change of mechanical properties is also affected by the presence of dissolved interstitial carbon. This work contributes to an understanding of how interstitial carbon atoms influence the properties of small dislocation loops, which form directly in collision cascades upon neutron or ion irradiation and are 'invisible' to (i.e. undetectable by) standard experimental techniques applied to reveal nano-structural damage in metals. We have carried out MD simulations to investigate how the trapping of 1/2 inner product 111 dislocation loops at thermally stable carbon-vacancy complexes, known to form under irradiation, affects the interaction of these dislocation loops with dislocations in bcc Fe. We have considered loops of size 1 and 3.5 nm, which represent experimentally invisible and visible defects, respectively. The obtained results point at the strong suppression of the drag of carbon-decorated loops by dislocations. In the case of direct interaction between dislocation and carbon-decorated loops, invisible loops are found to act as obstacles whose strength is at least twice as high compared to that of undecorated ones. Additional strengthening due to the carbon decoration on the visible loops was also regularly registered. The reasons for the additional strengthening have been rationalized and discussed. It is demonstrated that carbon decoration/segregation at dislocation loops affects not only accumulation of radiation damage under prolonged irradiation but also alters the post-irradiation plastic deformation mechanisms. For the first time, we provide evidence that undetectable dislocation loops decorated by carbon do contribute to the radiation hardening.

  17. Geometry of dislocated de Broglie waves

    SciTech Connect

    Holland, P.R.

    1987-04-01

    The geometrical structures implicit in the de Broglie waves associated with a relativistic charged scalar quantum mechanical particle in an external field are analyzed by employing the ray concept of the causal interpretation. It is shown how an osculating Finslerian metric tensor, a torsion tensor, and a tetrad field define respectively the strain, the dislocation density, and the Burgers vector in the natural state of the wave, which is a non-Riemannian space of distant parallelism. A quantum torque determined by the quantum potential is introduced and the example of a screw dislocated wave is discussed.

  18. Mesoscale modeling of dislocations in molecular crystals

    NASA Astrophysics Data System (ADS)

    Lei, Lei; Koslowski, Marisol

    2011-02-01

    Understanding the inelastic deformation of molecular crystals is of fundamental importance to the modeling of the processing of drugs in the pharmaceutical industry as well as to the initiation of detonation in high energy density materials. In this work, we present dislocation dynamics simulations of the deformation of two molecular crystals of interest in the pharmaceutical industry, sucrose and paracetamol. The simulations calculate the yield stress of sucrose and paracetamol in good agreement with experimental observation and predict the anisotropy in the mechanical response observed in these materials. Our results show that dislocation dynamics is an effective tool to study plastic deformation in molecular crystals.

  19. Irreducible posterolateral elbow dislocation: a rare injury.

    PubMed

    Fenelon, Christopher; Zafar, Muhammed M; Sheridan, Gerard Anthony; Kearns, Stephen

    2016-12-30

    Posterolateral dislocation of the elbow is an injury commonly treated in the emergency department by closed reduction. Very rarely it can be irreducible and require open reduction. Only four cases of irreducible posterolateral elbow dislocation have been described in the literature over the past 50 years. We report the case of a 20-year-old man who sustained such an injury. Open reduction was performed and revealed the radial head protruding or 'buttonholing' through the lateral collateral ligament complex. This case highlights that continued closed reduction of the elbow should not be attempted, as a mechanical block to reduction can occur making reduction impossible.

  20. Rotator Cuff Tear Consequent to Glenohumeral Dislocation.

    PubMed

    Gilotra, Mohit N; Christian, Matthew W; Lovering, Richard M

    2016-08-01

    The patient was a 21-year-old collegiate running back who was tackled during a football game and sustained a posterior glenohumeral dislocation. He was referred to an orthopaedist and presented 3 weeks after the injury, and, following examination, further imaging was ordered by the orthopaedist due to rotator cuff weakness. Magnetic resonance imaging showed a complete tear of the supraspinatus and infraspinatus, as well as a posterior Bankart lesion, a subscapularis tear, and a dislocation of the biceps long head tendon into the reverse Hill-Sachs lesion. J Orthop Sports Phys Ther 2016;46(8):708. doi:10.2519/jospt.2016.0413.

  1. Changes in the Burgers Vector of Perfect Dislocation Loops without Contact with the External Dislocations

    SciTech Connect

    Arakawa, K.; Hatanaka, M.; Mori, H.; Kuramoto, E.; Ono, K.

    2006-03-31

    We report the observations of a new type of changing process in the Burgers vector of dislocations by in situ transmission electron microscopy. Small interstitial-type perfect dislocation loops in bcc iron with diameters less than approximately 50 nm are transformed from a 1/2<111> loop to another 1/2<111> one or an energetically unfavorable <100> one; furthermore, a <100> loop is transformed to a 1/2<111> one. These transformations occurred on high-energy electron irradiation or simple heating without contact with external dislocations. The origin of these phenomena is discussed.

  2. Effect of dislocations on helium retention in deformed pure iron

    NASA Astrophysics Data System (ADS)

    Gong, Y. H.; Cao, X. Z.; Jin, S. X.; Lu, E. Y.; Hu, Y. C.; Zhu, T.; Kuang, P.; Xu, Q.; Wang, B. Y.

    2016-12-01

    The effects of dislocations created by deformation on helium retention in pure iron, including the helium atoms diffusion along the dislocation line and desorption from dislocation trapping sites, were investigated. The dislocation defect was introduced in specimens by cold-rolling, and then 5 keV helium ions were implanted into the deformed specimens. Slow positron beam technology and thermal desorption spectroscopy were used to investigate the evolution of dislocation defects and the desorption behavior of helium atoms under influence of dislocation. The behaviors of S-E, W-E and S-W plots indicate clearly that lots of helium atoms remain in the deformed specimen and helium atoms combining with dislocation change the distribution of electron density. The helium desorption plot indicates that dislocation accelerates helium desorption at 293 K-600 K and facilitates helium dissociation from HenVm (n/m = 1.8) cluster.

  3. Dislocation of the lens: a complication after cyclocryotherapy.

    PubMed

    Sony, Parul; Sharma, Namrata; Pangtey, Mayank S

    2002-12-01

    An unusual complication is reported of a case of complete dislocation of the lens after cyclocryotherapy in a patient with neovascular glaucoma. To the best of the authors' knowledge, no case of lens dislocation following cyclocryotherapy has previously been reported.

  4. 20 CFR 663.500 - What is the purpose of this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Eligible Training... train adults and dislocated workers. In order to maximize customer choice and assure that...

  5. 20 CFR 663.410 - What is an Individual Training Account (ITA)?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT... on behalf of a participant. WIA title I adult and dislocated workers purchase training services...

  6. 20 CFR 663.410 - What is an Individual Training Account (ITA)?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT... on behalf of a participant. WIA title I adult and dislocated workers purchase training services...

  7. 20 CFR 663.515 - What is the process for initial determination of provider eligibility?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE... of provider eligibility? (a) To be eligible to receive adult or dislocated worker training...

  8. 20 CFR 663.440 - What are the requirements for consumer choice?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT... individual with an ITA to a training provider is paid by the applicable adult or dislocated worker...

  9. 20 CFR 663.440 - What are the requirements for consumer choice?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT... individual with an ITA to a training provider is paid by the applicable adult or dislocated worker...

  10. 20 CFR 663.500 - What is the purpose of this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Eligible Training... train adults and dislocated workers. In order to maximize customer choice and assure that...

  11. A dislocation density based constitutive model for cyclic deformation

    SciTech Connect

    Estrin, Y.; Braasch, H.; Brechet, Y.

    1996-10-01

    A new constitutive model describing material response to cyclic loading is presented. The model includes dislocation densities as internal variables characterizing the microstructural state of the material. In the formulation of the constitutive equations, the dislocation density evolution resulting from interactions between dislocations in channel-like dislocation patterns is considered. The capabilities of the model are demonstrated for INCONEL 738 LC and Alloy 800H.

  12. Dislocations in magnetohydrodynamic waves in a stellar atmosphere.

    PubMed

    López Ariste, A; Collados, M; Khomenko, E

    2013-08-23

    We describe the presence of wave front dislocations in magnetohydrodynamic waves in stratified stellar atmospheres. Scalar dislocations such as edges and vortices can appear in Alfvén waves, as well as in general magnetoacoustic waves. We detect those dislocations in observations of magnetohydrodynamic waves in sunspots in the solar chromosphere. Through the measured charge of all the dislocations observed, we can give for the first time estimates of the modal contribution in the waves propagating along magnetic fields in solar sunspots.

  13. Skill Level as a Factor in the Relationship Between Worker Satisfaction and Worker Performance.

    ERIC Educational Resources Information Center

    Warner, Dennis A.; Warner, Stephen J.

    Thirty-three adult male employees at a chemical plant completed a Worker Opinion Questionnaire (WOQ) designed to yield a measure of worker satisfaction. The quality of their job performance was obtained by means of supervisor ratings. Eighteen of the subjects were involved in "skilled labor and fifteen in "unskilled" labor. It was hypothesized…

  14. Dislocation substructure in fatigued duplex stainless steel

    SciTech Connect

    Polak, J. . Lab. de Mecanique de Lille Inst. of Physical Metallurgy, Brno . Academy of Sciences); Degallaix, S. . Lab. de Mecanique de Lille); Kruml, T. . Academy of Sciences)

    1993-12-15

    Cyclic plastic straining of crystalline materials results in the formation of specific dislocation structures. Considerable progress in mapping and understanding internal dislocation structures has been achieved by studying single crystal behavior: however, most structural materials have a polycrystalline structure and investigations of polycrystals in comparison to single crystal behavior of simple metals prove to be very useful in understanding more complex materials. There are some classes of materials, however, with complicated structure which do not have a direct equivalent in single crystalline form. Moreover, the specific dimensions and shapes of individual crystallites play an important role both in the cyclic stress-strain response of these materials and in the formation of their interior structure in cyclic straining. Austenitic-ferritic duplex stainless steel, which is a kind of a natural composite, is a material of this type. The widespread interest in the application of duplex steels is caused by approximately doubled mechanical properties and equal corrosion properties, when compared with classical austenitic stainless steels. Fatigue resistance of these steels as well as the surface damage evolution in cyclic straining have been studied; however, much less is known about the internal substructure development in cyclic straining. In this study the dislocation arrangement in ferritic and austenitic grains of the austenitic-ferritic duplex steel alloyed with nitrogen and cyclically strained with two strain amplitudes, is reported and compared to the dislocation arrangement found in single and polycrystals of austenitic and ferritic materials of a similar composition and with the surface relief produced in cyclic plastic straining.

  15. Tailoring noncollinear magnetism by misfit dislocation lines

    NASA Astrophysics Data System (ADS)

    Finco, Aurore; Hsu, Pin-Jui; Kubetzka, André; von Bergmann, Kirsten; Wiesendanger, Roland

    2016-12-01

    The large epitaxial stress induced by the misfit between a triple atomic layer Fe film and an Ir(111) substrate is relieved by the formation of a dense dislocation line network. Spin-polarized scanning tunneling microscopy investigations show that the strain is locally varying within the Fe film and that this variation affects the magnetic state of the system. Two types of dislocation line regions can be distinguished and both exhibit spin spirals with strain-dependent periods (ranging from 3 to 10 nm ). Using a simple micromagnetic model, we attribute the changes of the period of the spin spirals to variations of the effective exchange coupling in the magnetic film. This assumption is supported by the observed dependence of the saturation magnetic field on the period of the zero-field spin spiral. Moreover, magnetic skyrmions appear in an external magnetic field only in one type of dislocation line area, which we impute to the different pinning properties of the dislocation lines.

  16. Left Dislocation in Near-Native French

    ERIC Educational Resources Information Center

    Donaldson, Bryan

    2011-01-01

    The present study is concerned with the upper limits of SLA--specifically, mastery of the syntax-discourse interface in successful endstate learners of second-language (L2) French (near-native speakers). Left dislocation (LD) is a syntactic means of structuring spoken French discourse by marking topic. Its use requires speakers to coordinate…

  17. Dislocations - Multiple Languages: MedlinePlus

    MedlinePlus

    ... XYZ List of All Topics All Dislocations - Multiple Languages To use the sharing features on this page, please enable JavaScript. Arabic (العربية) French (français) Russian (Русский) Somali (af Soomaali) Spanish (español) Arabic (العربية) ...

  18. [Habitual dislocation of the temporomandibular joint].

    PubMed

    Hjortdal, O

    1975-02-01

    A case of recurrent dislocation of the left temporamandibular joint is reported. Different methods of treatment are reviewed. The present case was successfully treated with a combination of two methods: 1. Restriction of excessive condylar movement by means of continuous loop wiring and intermaxillary monofilament fishing line. 2. Intra-articular injections of autologous blood.

  19. An Acoustic Profile of Right-Dislocations in French.

    ERIC Educational Resources Information Center

    Ashby, William J.

    1994-01-01

    Provides an acoustic profile of the prosody of right-dislocations in French, using the CECIL computer hardware and software package to analyze 28 right-dislocations occurring in a corpus of natural French discourse. It was found that, although right-dislocations appear to fulfill various functional roles in discourse, no correlation appears…

  20. Metatarsal Shaft Fracture with Associated Metatarsophalangeal Joint Dislocation

    PubMed Central

    2016-01-01

    Metatarsophalangeal joint dislocations of lesser toes are often seen in the setting of severe claw toes. Traumatic irreducible dislocations have been reported in rare cases following both low-energy and high-energy injuries to the forefoot. In this case report, I present a previously unreported association of a metatarsal shaft fracture with metatarsophalangeal joint dislocation of a lesser toe. PMID:27597914

  1. Enhanced annealing of the dislocation network under irradiation

    SciTech Connect

    Mordehai, Dan; Martin, Georges

    2011-07-01

    In crystalline metals, the dislocation network is the main source of internal strain, while irradiation steadily injects new sources of internal strain (point defects, defect clusters). As a consequence, the evolution of the dislocation network is driven by irradiation. While the atomistic mechanisms by which the forcing proceeds have long been suggested, namely the partitioning of defect elimination between dislocations and other defect sinks, both in stationary or transient regimes, some of the macroscopic consequences, such as irradiation enhanced dislocation annealing and irradiation driven recrystallization, are left unexplained. In this work we show that dislocation sink strengths for point defects are altered in the presence of neighboring dislocations and their climb motion is coordinated with the dislocation microstructure. A climb model, which takes into account the dislocation network, provides the mechanism for coordinated climb, which is shown to ease dislocation annealing. In particular, we demonstrate that coordinated dislocation climb accelerates the annihilation of dislocation pairs with the opposite sign and the repulsion of dislocations of the same sign, thereby, among other things, promoting the annealing of small-angle tilt boundaries by subgrain rotation.

  2. Dislocation core fields and forces in FCC metals

    SciTech Connect

    Henager, Charles H.; Hoagland, Richard G.

    2004-04-01

    Atomistic models were used to obtain dislocation core fields for edge, screw, and mixed dislocations in Al and Cu using EAM. Core fields are analyzed using a line force dipole representation, with dilatant and dipole terms. The core field contribution to the force between dislocations is shown to be significant for interactions within 50b.

  3. Hydrogen diffusion in the elastic fields of dislocations in iron

    NASA Astrophysics Data System (ADS)

    Sivak, A. B.; Sivak, P. A.; Romanov, V. A.; Chernov, V. M.

    2016-12-01

    The effect of dislocation stress fields on the sink efficiency thereof is studied for hydrogen interstitial atoms at temperatures of 293 and 600 K and at a dislocation density of 3 × 1014 m-2 in bcc iron crystal. Rectilinear full screw and edge dislocations in basic slip systems <111>{110}, <111>{112}, <100>{100}, and <100>{110} are considered. Diffusion of defects is simulated by means of the object kinetic Monte Carlo method. The energy of interaction between defects and dislocations is calculated using the anisotropic theory of elasticity. The elastic fields of dislocations result in a less than 25% change of the sink efficiency as compared to the noninteracting linear sink efficiency at a room temperature. The elastic fields of edge dislocations increase the dislocation sink efficiency, whereas the elastic fields of screw dislocations either decrease this parameter (in the case of dislocations with the Burgers vector being 1/2<111>) or do not affect it (in the case of dislocations with the Burgers vector being <100>). At temperatures above 600 K, the dislocations affect the behavior of hydrogen in bcc iron mainly owing to a high binding energy between the hydrogen atom and dislocation cores.

  4. Assessment of hardening due to dislocation loops in bcc iron: Overview and analysis of atomistic simulations for edge dislocations

    NASA Astrophysics Data System (ADS)

    Bonny, G.; Terentyev, D.; Elena, J.; Zinovev, A.; Minov, B.; Zhurkin, E. E.

    2016-05-01

    Upon irradiation, iron based steels used for nuclear applications contain dislocation loops of both < 100 > and ½ < 111 > type. Both types of loops are known to contribute to the radiation hardening and embrittlement of steels. In the literature many molecular dynamics works studying the interaction of dislocations with dislocation loops are available. Recently, based on such studies, a thermo-mechanical model to threat the dislocation - dislocation loop (DL) interaction within a discrete dislocation dynamics framework was developed for ½ < 111 > loops. In this work, we make a literature review of the dislocation - DL interaction in bcc iron. We also perform molecular dynamics simulations to derive the stress-energy function for < 100 > loops. As a result we deliver the function of the activation energy versus activation stress for < 100 > loops that can be applied in a discrete dislocation dynamics framework.

  5. Dislocation Processes and Frictional Stability of Faults

    NASA Astrophysics Data System (ADS)

    Toy, V. G.; Mitchell, T. M.; Druiventak, A.

    2011-12-01

    The rate dependence of frictional processes in faults in quartzofeldspathic crust is proposed to change at c. 300°C, because above this temperature asperity deformation can be accommodated by crystal plastic processes. As a consequence, the real fault contact area increases and the fault velocity strengthens. Conversely, faults at lower temperatures are velocity weakening and therefore prone to earthquake slip. We have investigated whether dislocation processes are important around faults in quartzites on seismic timescales, by inducing fault slip on a saw cut surface in novaculite blocks. Deformation was carried out at 450°C and 600°C in a Griggs apparatus. Slip rates of 8.3 x 10-7s-1 allowed total slip, u, of 0.5mm to be achieved in c. 10 minutes. Failure occurred at peak differential stresses of ~1.7 GPa and 1.4 GPa respectively, followed by significant weakening. Structures of the novaculite within and surrounding the fault surface were examined using EBSD, FIB-SEM and TEM to elucidate changes to their dislocation substructure. In the sample deformed at 450°C, a ~50μm thick layer of amorphous / non-crystalline silica was developed on the saw-cut surface during deformation. Rare clasts of the wall rock are preserved within this material. The surrounding sample is mostly composed of equant quartz grains of 5-10μm diameter that lack a preferred orientation, contain very few intercrystalline dislocations, and are divided by organised high angle grain boundaries. After deformation, most quartz grains within the sample retain their starting microstructure. However, within ~10μm of the sliding surface, dislocations are more common, and these are arranged into elongated, tangled zones (subgrain boundaries?). Microfractures are also observed. These microstructures are characteristic of deformation accommodated by low temperature plasticity. Our preliminary observations suggest that dislocation processes may be able to accommodate some deformation around fault

  6. Subacute dislocation of the elbow following Galeazzi fracture-dislocation of the radius: A case report

    PubMed Central

    2011-01-01

    Introduction The Galeazzi fracture-dislocation was originally described by Sir Astley Cooper in 1822 but was named after Italian surgeon Ricardo Galeazzi in 1934. It is an injury classified as a radial shaft fracture with associated dislocation of the distal radioulnar joint and disruption of the forearm axis joint. The associated distal radioulnar joint injury may be purely ligamentous in nature, tearing the triangular fibrocartilaginous complex, or involve bony tissue (that is, ulnar styloid avulsions) or both. We report this case because of the rare association of posterior dislocation of the elbow along with Galeazzi fracture-dislocation. To the best of our knowledge, this has not been previously reported in the English literature. Case presentation A 26-year-old Caucasian man presented to our department after a fall from a motorbike. He sustained a closed, isolated Galeazzi fracture-dislocation of the right forearm and no associated elbow injuries, and this necessitated open reduction and internal fixation of the radius. Post-operative radiographs films were satisfactory. However, clinical and radiological evidence of ipsilateral elbow dislocation was noted at a five-week follow-up, subsequently requiring open reduction of the joint and collateral ligament repair. Our patient was noted to have full elbow and forearm function at three months. Conclusions Although the Galeazzi fracture-dislocation has been classically described as involving only the distal radioulnar joint, traumatic forces can be transmitted to the elbow via the interosseous membrane of the forearm. This can lead to instability of the elbow joint. Therefore, we recommend that, in every case of forearm fracture, both elbow and wrist joints be assessed clinically as well as radiologically for subluxation or dislocation. PMID:22185342

  7. [Modern ideas on the treatment of dislocations and fracture-dislocations in the elbow joint].

    PubMed

    Dul'tsev, I A; Zhabin, G I; Neverov, V A

    2005-01-01

    The authors describe the causes and surgical methods of treatment of fresh and long-standing dislocations and fracture-dislocations in the elbow joint. The indications to using different operative methods and technical-surgical interventions are described in details as well as long-term results of treatment by the literature data. The current methods and the authors' methods of prophylactics and treatment of postoperative complications are analyzed. The methods of rehabilitation of such patients are also described.

  8. Elbow dislocation with irreparable fracture radial head

    PubMed Central

    Tanna, Dilip

    2013-01-01

    Background: Treatment of elbow dislocation with irreparable radial head fracture needs replacement of radial head to achieve stability of elbow. An alternate method in cases of elbow dislocation with radial head fracture can be resection of radial head with repair of medial collateral ligament. We report a retrospective analysis of cases of elbow dislocation with irreparable radial head treated by excision head of radius and repair of MCL. Materials and Methods: Nine patients of elbow dislocation with associated irreparable fractures of the head of the radius were included in this analysis (6 F:3 M, Age: 35-47 years). Radial head excision was done through the lateral approach and MCL was sutured using no 3 Ethibond using medial approach. Above elbow plaster was given for 6 weeks and gradual mobilization was done thereafter. All patients were assessed at final followup using Mayo elbow performance score (MEPS). Results: Mean followup was 19.55 ± 7.12 months (range 14-36 months). There was no extension deficit when compared to opposite side with mean range of flexion of 138.8° ± 6.97° (range 130 -145°). Mean pronation was 87.7° ± 4.4° (range 80-90°) and mean supination was 87.7 ± 4.62° (range 80-90°). The mean MEPS was 98.8 ± 3.33 (range 90-100). No patient had pain, sensory complaints, subluxation or redislocation. All were able to carry out their daily activities without disability. Conclusion: Radial head excision with MCL repair is an acceptable option for treatment of patients with elbow dislocation and irreparable radial head fracture. PMID:23798760

  9. Re-dislocation after corrective osteotomy for chronic dislocation of the radial head in children.

    PubMed

    Suzuki, T; Seki, A; Nakamura, T; Ikegami, H; Takayama, S; Nakamura, M; Matsumoto, M; Sato, K

    2015-11-01

    This retrospective study was designed to evaluate the outcomes of re-dislocation of the radial head after corrective osteotomy for chronic dislocation. A total of 12 children with a mean age of 11 years (5 to 16), with further dislocation of the radial head after corrective osteotomy of the forearm, were followed for a mean of five years (2 to 10). Re-operations were performed for radial head re-dislocation in six children, while the other six did not undergo re-operation ('non-re-operation group'). The active range of movement (ROM) of their elbows was evaluated before and after the first operation, and at the most recent follow-up. In the re-operation group, there were significant decreases in extension, pronation, and supination when comparing the ROM following the corrective osteotomy and following re-operation (p < 0.05). The children who had not undergone re-operation achieved a better ROM than those who had undergone re-operation. There was a significant difference in mean pronation (76° vs 0°) between the non- re-operation and the re-operation group (p = 0.002), and a trend towards increases in mean flexion (133° vs 111°), extension (0° vs 23°), and supination (62° vs 29°). We did not find a clear benefit for re-operation in children with a re-dislocation following corrective osteotomy for chronic dislocation of the radial head.

  10. "Our Success Is Our Graduates" Case Study of Year Up: A Career Advancement Model for Low-Income Young Adults. Advancement for Low-Wage Workers Report Series

    ERIC Educational Resources Information Center

    Biswas, Radha Roy

    2005-01-01

    This report describes the "Year Up" program, an innovative technology training program, that prepares and places low-income, urban young adults in entry-level IT jobs while also preparing them for college. The program targets recent high school graduates and GED recipients between the ages of 18 and 24 who are either unemployed or…

  11. The dynamics of an edge dislocation in a ferromagnetic crystals

    NASA Astrophysics Data System (ADS)

    Dezhin, V. V.; Nechaev, V. N.

    2016-08-01

    The system of equations describing the bending vibrations of the dislocation in the ferromagnetic crystal is written. Elastic and magnetostrictive properties of the ferromagnetic crystals are considered isotropic. The linearization of the resulting system produced a relatively small contribution to the magnetization from the influence of dislocation. In the linear approximation of the dislocation displacement system of equation describing vibrations of a ferromagnetic crystal with an edge dislocation is obtained. The equation of motion of an edge dislocation in a ferromagnetic crystal is found.

  12. Radiation enhanced basal plane dislocation glide in GaN

    NASA Astrophysics Data System (ADS)

    Yakimov, Eugene B.; Vergeles, Pavel S.; Polyakov, Alexander Y.; Lee, In-Hwan; Pearton, Stephen J.

    2016-05-01

    A movement of basal plane segments of dislocations in GaN films grown by epitaxial lateral overgrowth under low energy electron beam irradiation (LEEBI) was studied by the electron beam induced current (EBIC) method. Only a small fraction of the basal plane dislocation segments were susceptible to irradiation and the movement was limited to relatively short distances. The effect is explained by the radiation enhanced dislocation glide (REDG) in the structure with strong pinning. A dislocation velocity under LEEBI with a beam current lower than 1 nA was estimated as about 10 nm/s. The results assuming the REDG for prismatic plane dislocations were presented.

  13. Ulnopalmar dislocation of the fifth carpometacarpal joint. A rare injury.

    PubMed

    Fischer, J W; Waseem, M; Gambhir, A; Creedon, R J

    2002-04-01

    Volar dislocation of the carpometacarpal joint of the little finger is an uncommon injury. It is subdivided in ulnopalmar and radiopalmar dislocations. The injury can easily be missed on standard x-rays. Closed reduction and K-wire fixation has commonly been used in the treatment, although closed reduction and casting has been reported. Only 10 cases of an ulnopalmar dislocation were published previously. We report a case of a simultaneous dislocation of the 4th metacarpophalangeal joint and an ulnopalmar dislocation of the 5th carpometacarpal joint. The combination of these injuries has not been reported yet. We review the available literature and discuss the methods of treatment.

  14. Dislocation kinematics: a molecular dynamics study in Cu

    NASA Astrophysics Data System (ADS)

    Oren, E.; Yahel, E.; Makov, G.

    2017-02-01

    The kinematics and kinetics of edge and screw dislocations in FCC materials were studied by molecular dynamics, with Cu as a case study. It was found that with increasing stress screw dislocations enter into the transonic regime continuously and that they remain stable up to a velocity of about 2.2 km s-1. Edge dislocations are limited by the transverse sound velocity at low stresses and discontinuously cross into the transonic regime at higher stresses. For sufficiently long edge dislocations, the subsonic-transonic transition is initiated by an athermal nucleation process. Finally, an expression for the velocity dependence of the dislocation mobility was derived.

  15. Empirical potential simulations of interstitial dislocation loops in uranium dioxide

    NASA Astrophysics Data System (ADS)

    Le Prioux, Arno; Fossati, Paul; Maillard, Serge; Jourdan, Thomas; Maugis, Philippe

    2016-10-01

    Stoichiometric circular shaped interstitial dislocation loop energies are calculated in stoichiometric UO2 by empirical potential simulation. The Burgers vector directions studied are <110> and <111>. The main structural properties of each type of interstitial dislocation loop are determined, including stacking fault energy. Defect energies are compared and a maximum size for stable <111> dislocation loops before transition to <110> dislocation loops is given. A model of dislocation loop energy based on elasticity theory is then fitted on the basis of these simulation results.

  16. Dislocation mechanisms in stressed crystals with surface effects

    NASA Astrophysics Data System (ADS)

    Wu, Chi-Chin; Crone, Joshua; Munday, Lynn; Discrete Dislocation Dynamics Team

    2014-03-01

    Understanding dislocation properties in stressed crystals is the key for important processes in materials science, including the strengthening of metals and the stress relaxation during the growth of hetero-epitaxial structures. Despite existing experimental approaches and theories, many dislocation mechanisms with surface effects still remain elusive in experiments. Even though discrete dislocation dynamics (DDD) simulations are commonly employed to study dislocations, few demonstrate sufficient computational capabilities for massive dislocations with the combined effects of surfaces and stresses. Utilizing the Army's newly developed FED3 code, a DDD computation code coupled with finite elements, this work presents several dislocation mechanisms near different types of surfaces in finite domains. Our simulation models include dislocations in a bended metallic cantilever beam, near voids in stressed metals, as well as threading and misfit dislocations in as-grown semiconductor epitaxial layers and their quantitative inter-correlations to stress relaxation and surface instability. Our studies provide not only detailed physics of individual dislocation mechanisms, but also important collective dislocation properties such as dislocation densities and strain-stress profiles and their interactions with surfaces.

  17. 20 CFR 663.220 - Who may receive intensive services?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.220 Who may receive intensive services? There are two categories of adults and dislocated workers who may receive intensive services: (a) Adults and dislocated workers who are unemployed,...

  18. 20 CFR 663.220 - Who may receive intensive services?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.220 Who may receive intensive services? There are two categories of adults and dislocated workers who may receive intensive services: (a) Adults and dislocated workers who are unemployed,...

  19. Electron energy can oscillate near a crystal dislocation

    NASA Astrophysics Data System (ADS)

    Li, Mingda; Cui, Wenping; Dresselhaus, Mildred S.; Chen, Gang

    2017-01-01

    Crystal dislocations govern the plastic mechanical properties of materials but also affect the electrical and optical properties. However, a fundamental and quantitative quantum field theory of a dislocation has remained undiscovered for decades. Here we present an exactly-solvable one-dimensional quantum field theory of a dislocation, for both edge and screw dislocations in an isotropic medium, by introducing a new quasiparticle which we have called the ‘dislon’. The electron-dislocation relaxation time can then be studied directly from the electron self-energy calculation, which is reducible to classical results. In addition, we predict that the electron energy will experience an oscillation pattern near a dislocation. Compared with the electron density’s Friedel oscillation, such an oscillation is intrinsically different since it exists even with only single electron is present. With our approach, the effect of dislocations on materials’ non-mechanical properties can be studied at a full quantum field theoretical level.

  20. Dislocation dynamics in hexagonal close-packed crystals

    DOE PAGES

    Aubry, S.; Rhee, M.; Hommes, G.; ...

    2016-04-14

    Extensions of the dislocation dynamics methodology necessary to enable accurate simulations of crystal plasticity in hexagonal close-packed (HCP) metals are presented. They concern the introduction of dislocation motion in HCP crystals through linear and non-linear mobility laws, as well as the treatment of composite dislocation physics. Formation, stability and dissociation of and other dislocations with large Burgers vectors defined as composite dislocations are examined and a new topological operation is proposed to enable their dissociation. Furthermore, the results of our simulations suggest that composite dislocations are omnipresent and may play important roles both in specific dislocation mechanisms and in bulkmore » crystal plasticity in HCP materials. While fully microscopic, our bulk DD simulations provide wealth of data that can be used to develop and parameterize constitutive models of crystal plasticity at the mesoscale.« less

  1. Elastic Stiffness of Grain Boundary Scars and Dislocation Dynamics

    NASA Astrophysics Data System (ADS)

    Shin, Homin; Bowick, Mark

    2006-03-01

    We analytically calculate the stiffness of finite-length grain boundaries (scars) on a spherical crystal within the continuum elasticity theory. The scar is composed of an isolated disclination with +1 topological charge together with a finite number of dislocations. We determine the elastic free energy of a single finite-grain boundary scar by considering interacting defects, such as Disclination-Disclination (D-D), Disclination-dislocation (D-d), and dislocation-dislocation (d-d). The harmonic potential binding dislocations to the scar is obtained by determining the free energy of a single dislocation perturbed away from its equilibrium position. The elastic spring constants so obtained are compared to experimental data on dislocation dynamics [1]. We conclude with some comments on interstitial dynamics. [1] Lipowsky, P., Bowick, M. J., Meinke, J. H., Nelson, D. R. and Bausch, A. R. Nature Mater. 4, 407-411 (2005).

  2. Dislocation dynamics in hexagonal close-packed crystals

    SciTech Connect

    Aubry, S.; Rhee, M.; Hommes, G.; Bulatov, V. V.; Arsenlis, A.

    2016-04-14

    Extensions of the dislocation dynamics methodology necessary to enable accurate simulations of crystal plasticity in hexagonal close-packed (HCP) metals are presented. They concern the introduction of dislocation motion in HCP crystals through linear and non-linear mobility laws, as well as the treatment of composite dislocation physics. Formation, stability and dissociation of and other dislocations with large Burgers vectors defined as composite dislocations are examined and a new topological operation is proposed to enable their dissociation. Furthermore, the results of our simulations suggest that composite dislocations are omnipresent and may play important roles both in specific dislocation mechanisms and in bulk crystal plasticity in HCP materials. While fully microscopic, our bulk DD simulations provide wealth of data that can be used to develop and parameterize constitutive models of crystal plasticity at the mesoscale.

  3. Adult Education in Australia: The Council of Adult Education.

    ERIC Educational Resources Information Center

    Randell, Shirley

    Liberal adult education in Victoria, Australia, takes its ideals, if not its form, from the pre-war university and Workers Education Association (WEA) partnerships: the university providing tutors and content, the WEA providing contact with unions and workers. Unique to Victoria is the level to which community-based adult education has been…

  4. Low energy dislocation structures in epitaxy

    NASA Technical Reports Server (NTRS)

    Van Der Merwe, Jan H.; Woltersdorf, J.; Jesser, W. A.

    1986-01-01

    The principle of minimum energy was applied to epitaxial interfaces to show the interrelationship beteen misfit, overgrowth thickness and misfit dislocation spacing. The low energy dislocation configurations were presented for selected interfacial geometries. A review of the interfacial energy calculations was made and a critical assessment of the agreement between theory and experiment was presented. Modes of misfit accommodation were presented with emphasis on the distinction between kinetic effects and equilibrium conditions. Two-dimensional and three-dimensional overgrowths were treated together with interdiffusion-modified interfaces, and several models of interfacial structure were treated including the classical and the current models. The paper is concluded by indicating areas of needed investigation into interfacial structure.

  5. Transtriquetral perihamate fracture-dislocation: case report.

    PubMed

    Moraes, Frederico Barra de; Ferreira, Rodrigo Cunha; Geraldino, Stéphanie Zago; Farias, Renato Silva; Silva, Ricardo Pereira da; Kuwae, Mário Yoshihide

    2016-01-01

    The wrist is a region that is very vulnerable to injuries of the extremities. Among these injuries, fractures of the pyramidal bone (or triquetrum) in association with dislocation of the hamate and carpal instability are uncommon. They are generally correlated with high-energy trauma and may be associated with neurovascular deficits, muscle-tendon disorders, skin lesions or injuries to other carpal bones. Thus, in this report, one of these rare cases of transtriquetral perihamate fracture-dislocation with carpal instability is presented, diagnosed by means of radiography on the right wrist of the patient who presented pain, edema and limitation of flexion-extension of the carpus after trauma to the region. The stages of attending to the case are described, from the initial consultation to the surgical treatment and physiotherapy, which culminated in restoration of the strength and range of motion of the wrist.

  6. Dislocations: 75 years of Deformation Mechanisms

    NASA Technical Reports Server (NTRS)

    Schneider, Judy

    2009-01-01

    The selection of papers presented in this section reflect on themes to be explored at the "Dislocations: 75 years of Deformation Mechanisms" Symposium to be held at the Annual 2009 TMS meeting. The symposium was sponsored by the Mechanical Behavior of Materials Committee to give tribute to the evolution of a concept that has formed the basis of our mechanistic understanding of how crystalline solids plastically deform and how they fail.

  7. Dislocation Etching Solutions for Mercury Cadmium Selenide

    DTIC Science & Technology

    2014-09-01

    Dislocation Etching Solutions for Mercury Cadmium Selenide by Kevin Doyle and Sudhir Trivedi ARL-CR-0744 September 2014...Etching Solutions for Mercury Cadmium Selenide Kevin Doyle and Sudhir Trivedi Sensors and Electron Devices Directorate, ARL prepared by...Solutions for Mercury Cadmium Selenide 5a. CONTRACT NUMBER W811NF-12-2-0019 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kevin Doyle and

  8. Dislocation movement and hysteresis in Maraging blades

    NASA Astrophysics Data System (ADS)

    Di Cintio, Arianna; Marchesoni, Fabio; Ascione, Maria; Bhawal, Abhik; De Salvo, Riccardo

    2009-10-01

    All seismic isolation systems developed for gravitational-wave interferometric detectors, such as LIGO, Virgo and TAMA, make use of Maraging steel blades. The dissipation properties of these blades have been studied at low frequencies, by using a geometric anti-spring (GAS) filter, which allowed the exploration of resonant frequencies below 100 mHz. At this frequency an anomalous transfer function was observed in the GAS filter: this is one of several motivations for this work. The many unexpected effects observed and measured are explainable by the collective movement of dislocations inside the material described with the statistic of self-organised criticality. At low frequencies, below 200 mHz, the dissipation mechanism can subtract elasticity from the system even leading to sudden collapse. While Young's modulus is weaker, excess dissipation is observed. At higher frequencies the applied stress is probably too fast to allow the full growth of dislocation avalanches, and less losses are observed, thus explaining the higher Q-factor in this frequency range. The domino effect that leads to the release of entangled dislocations allows the understanding of the random walk of the Virgo and TAMA inverted pendula, the anomalous GAS filter transfer function as well as the loss of predictability of the ring-down decay in the LIGO seismic attenuation system inverted pendula.

  9. Congenital subtalar dislocation--a case report.

    PubMed

    Saini, Raghav; Dhillon, M S; Gill, S S

    2009-09-01

    Congenital dislocation of the subtalar joint is one of the rarest forms of presentation of a calcaneo-valgus foot. We report the second case of this type published; an 18-month female child aged was seen with calcaneo-valgus deformity of left foot since birth. She was walking over the medial malleolus and medial border of foot. Radiographs and 3D CT scan of the left foot confirmed the diagnosis of a congenital subtalar dislocation. Surgical correction was achieved through a posterolateral incision, and the reduced joint was fixed with a k-wires for 6 weeks; the foot was immobilized in below knee cast for another 6 weeks, and an ankle foot orthosis was used for another 3 years. At 3 years post-surgical follow up, the child has a plantigrade foot with no functional impairment. Follow up radiographs and 3D CT scan confirmed the maintenance of well aligned talo-calcaneal joint. This type of dislocation should be considered in the differential diagnosis of calcaneo-valgus foot; a clear understanding of the pathology, a precise operative reduction, and long-term use of orthosis results in a favourable outcome.

  10. Dislocation Theory of the Fatigue of Metals

    NASA Technical Reports Server (NTRS)

    Machlin, E S

    1949-01-01

    A dislocation theory of fatigue failure for annealed solid solutions is presented. On the basis of this theory, an equation giving the dependence of the number of cycles for failure on the stress, the temperature, the material parameters, and the frequency is derived for uniformly stressed specimens. The equation is in quantitative agreement with the data. Inasmuch as one material parameter is indicated to be temperature-dependent and its temperature dependence is unknown, it is impossible to predict the temperature dependence of the number of cycles for failure. A predicted quantitative correlation between fatigue and creep was found to exist, which suggests the practical possibility of obtaining fatigue data for annealed solid solutions and elements from steady-state creep-rate data for these materials. As a result of this investigation, a modification of the equation for the steady-state creep rate previously developed on the basis of the dislocation theory is suggested. Additional data are required to verify completely the dislocation theory of fatigue.

  11. Management of an Uncomplicated Posterior Elbow Dislocation

    PubMed Central

    Blackard, Douglas; Sampson, Jo-Ann

    1997-01-01

    Objective: To present a case of an uncomplicated posterior elbow dislocation in a US World Cup athlete and discuss her rehabilitation. Background: Traditional protocol for management of this injury has been splint immobilization for several weeks, but research suggests a shortened duration of immobilization and early active motion. Differential Diagnosis: Elbow dislocation with possible fracture. Treatment: The dislocation was reduced and a compression bandage and sling were applied. The sports medicine staff and athlete determined that rehabilitation would involve limited immobilization with a posterior splint. Also, active range-of- motion exercises were to be incorporated early in the range-of- motion program to decrease pain at the articulation. Uniqueness: The athlete was not immobilized and her aggressive five-phase rehabilitation program progressed according to decrease in inflammation and increase in range of motion and strength. Conclusions: Shortened immobilization and return to World Championship competition 6 weeks postinjury had no longterm adverse effects on the athlete. ImagesFig 1.Fig 2.Fig 3.Fig 4.Fig. 5. PMID:16558436

  12. Open Galeazzi fracture with ipsilateral elbow dislocation.

    PubMed

    Adanır, Oktay; Yüksel, Serdar; Beytemur, Ozan; Güleç, M Akif

    2016-08-01

    Combination of the Galeazzi fracture and dislocation of the elbow joint in same extremity is very rare. In this article, we report a 26-year-old male patient with a posterolateral dislocation of the elbow and ipsilateral volar type Galeazzi fracture. We performed closed reduction for the elbow dislocation during admission to the emergency department. Patient was taken to the operating room in the sixth hour of his application to emergency department and open wound on the ulnovolar region of the wrist was closed primarily after irrigation and debridement. We performed open reduction and internal fixation of the radial fracture with a dynamic compression plate. After fixation, we evaluated the stability of the elbow joint and distal radioulnar joint. Distal radioulnar joint was unstable under fluoroscopic examination and fixed with one 1.8 mm Kirschner wire in a pronated position. Then, elbow joint was stable. One year after surgery, patient had no pain or sings of instability. At the last follow-up, range of motion of the elbow was 10°-135° and forearm pronation and supination were 70°.

  13. [Bilateral Asymmetric Traumatic Dislocation of Hip Joints].

    PubMed

    Paša, L; Veselý, R; Kelbl, M

    2017-01-01

    The authors present a rare case of bilateral asymmetric traumatic dislocation of hip joints, where the left joint was treated conservatively after the reduction, while the right joint, with an acetabular fragment interposition, was treated surgically - by arthroscopically assisted reduction and fixation of an osteochondral fragment of posterior wall of the acetabulum. The female patient healed with no complications, showing an excellent clinical outcome with no signs of instability or limited mobility of hip joints, and also with no signs of para-articular calcification or necrosis of the hip at 1 year after the injury and treatment. Bilateral asymmetric dislocation of hip joint is a rare injury with the total incidence of 150 cases as reported by the literature. Recently, its incidence is higher due to the increased traffic and the associated accident rate. A precise and prompt reduction of the injured hip joint is always necessary, if possible under general anesthesia. Also, it is always necessary to carry out a complete examination of the patient since this type of injury is always caused by a strong force and is often accompanied by injuries of other parts of the body. Key words: bilateral asymmetric dislocation of hip joints, hip arthroscopy, acetabular fracture.

  14. Does Gender Influence Participation? Predictors of Participation in a Community Health Worker Diabetes Management Intervention with African-American and Latino Adults

    PubMed Central

    Hawkins, Jaclynn; Kieffer, Edith; Sinco, Brandy; Spencer, Michael; Anderson, Michael; Rosland, Ann-Marie

    2014-01-01

    Purpose The purpose of the study was to determine the effects of gender on participation in a community-based, culturally tailored diabetes lifestyle intervention, led by trained community health workers (CHW), and conducted with African Americans and Latinos with type 2 diabetes. Methods This study utilized data collected from 180 participants. Multivariable binary and cumulative logistic regression models were used to analyze associations between gender and race/ethnicity with study completion and participation in three aspects of the intervention: group classes, CHW home visits, and CHW-accompanied doctor visits. Results Among Latinos, men were less likely than women to complete the study, attend >x classes, and complete # CHW home visits. There were no gender differences in participation seen among African-Americans. Conclusions Diabetes management interventions may need to adapt their designs to optimize retention and participation of Latino men. Among African American men, the CHW model may be promising. Reasons for low participation among Latino men should receive more study. Future studies should assess whether similar findings apply in other communities and populations. PMID:23859885

  15. Making Experience Work: Generic Skills Through the Eyes of Displaced Workers. Volume 1 [and] Volume 2.

    ERIC Educational Resources Information Center

    Virgona, Crina; Waterhouse, Peter; Sefton, Robin; Sansuinetti, Jill

    The role of generic skills in the lives, work, and employment of 127 dislocated workers in a broad cross-section of job categories in five areas of Australia were examined through individual interviews, focus groups, and a survey questionnaire. Selected findings are as follows: (1) generic skills are developed in all areas of human endeavor,…

  16. Probing the character of ultra-fast dislocations

    SciTech Connect

    Rudd, R. E.; Ruestes, C. J.; Bringa, E. M.; Remington, B. A.; Remington, T. P.; Meyers, M. A.

    2015-11-23

    Plasticity is often controlled by dislocation motion, which was first measured for low pressure, low strain rate conditions decades ago. However, many applications require knowledge of dislocation motion at high stress conditions where the data are sparse, and come from indirect measurements dominated by the effect of dislocation density rather than velocity. Here we make predictions based on atomistic simulations that form the basis for a new approach to measure dislocation velocities directly at extreme conditions using three steps: create prismatic dislocation loops in a near-surface region using nanoindentation, drive the dislocations with a shockwave, and use electron microscopy to determine how far the dislocations moved and thus their velocity at extreme stress and strain rate conditions. We report on atomistic simulations of tantalum that make detailed predictions of dislocation flow, and find that the approach is feasible and can uncover an exciting range of phenomena, such as transonic dislocations and a novel form of loop stretching. Furthermore, the simulated configuration enables a new class of experiments to probe average dislocation velocity at very high applied shear stress.

  17. Probing the character of ultra-fast dislocations

    DOE PAGES

    Rudd, R. E.; Ruestes, C. J.; Bringa, E. M.; ...

    2015-11-23

    Plasticity is often controlled by dislocation motion, which was first measured for low pressure, low strain rate conditions decades ago. However, many applications require knowledge of dislocation motion at high stress conditions where the data are sparse, and come from indirect measurements dominated by the effect of dislocation density rather than velocity. Here we make predictions based on atomistic simulations that form the basis for a new approach to measure dislocation velocities directly at extreme conditions using three steps: create prismatic dislocation loops in a near-surface region using nanoindentation, drive the dislocations with a shockwave, and use electron microscopy tomore » determine how far the dislocations moved and thus their velocity at extreme stress and strain rate conditions. We report on atomistic simulations of tantalum that make detailed predictions of dislocation flow, and find that the approach is feasible and can uncover an exciting range of phenomena, such as transonic dislocations and a novel form of loop stretching. Furthermore, the simulated configuration enables a new class of experiments to probe average dislocation velocity at very high applied shear stress.« less

  18. BBilateral Neglected Anterior Shoulder Dislocation with Greater Tuberosity Fractures

    PubMed Central

    Upasani, Tejas; Bhatnagar, Abhinav; Mehta, Sonu

    2016-01-01

    Introduction: Shoulder dislocations are a very common entity in routine orthopaedic practice. Chronic unreduced anterior dislocations of the shoulder are not very common. Neurological and vascular complications may occur as a result of an acute anterior dislocation of the shoulder or after a while in chronic unreduced shoulder dislocation. Open reduction is indicated for most chronic shoulder dislocations. We report a case of neglected bilateral anterior shoulder dislocation with bilateral displaced greater tuberosity fracture. To the best of our knowledge, only a handful cases have been reported in literature with bilateral anterior shoulder dislocation with bilateral fractures. Delayed diagnosis/reporting is a scenario which makes the list even slimmer and management all the more challenging. Case Report: We report a case of a 35-year-old male who had bilateral anterior shoulder dislocation and bilateral greater tuberosity fracture post seizure and failed to report it for a period of 30 days. One side was managed conservatively with closed reduction and immobilization and the other side with open reduction. No neurovascular complications pre or post reduction of shoulder were seen. Conclusion: Shoulder dislocations should always be suspected post seizures and if found should be treated promptly. Treatment becomes difficult for any shoulder dislocation that goes untreated for considerable period of time PMID:27703939

  19. Probing the character of ultra-fast dislocations

    PubMed Central

    Ruestes, C. J.; Bringa, E. M.; Rudd, R. E.; Remington, B. A.; Remington, T. P.; Meyers, M. A.

    2015-01-01

    Plasticity is often controlled by dislocation motion, which was first measured for low pressure, low strain rate conditions decades ago. However, many applications require knowledge of dislocation motion at high stress conditions where the data are sparse, and come from indirect measurements dominated by the effect of dislocation density rather than velocity. Here we make predictions based on atomistic simulations that form the basis for a new approach to measure dislocation velocities directly at extreme conditions using three steps: create prismatic dislocation loops in a near-surface region using nanoindentation, drive the dislocations with a shockwave, and use electron microscopy to determine how far the dislocations moved and thus their velocity at extreme stress and strain rate conditions. We report on atomistic simulations of tantalum that make detailed predictions of dislocation flow, and find that the approach is feasible and can uncover an exciting range of phenomena, such as transonic dislocations and a novel form of loop stretching. The simulated configuration enables a new class of experiments to probe average dislocation velocity at very high applied shear stress. PMID:26592764

  20. Modal analysis of dislocation vibration and reaction attempt frequency

    DOE PAGES

    Sobie, Cameron; Capolungo, Laurent; McDowell, David L.; ...

    2017-02-04

    Transition state theory is a fundamental approach for temporal coarse-graining. It estimates the reaction rate for a transition processes by quantifying the activation free energy and attempt frequency for the unit process. To calculate the transition rate of a gliding dislocation, the attempt frequency is often obtained from line tension estimates of dislocation vibrations, a highly simplified model of dislocation behavior. This work revisits the calculation of attempt frequency for a dislocation bypassing an obstacle, in this case a self-interstitial atom (SIA) loop. First, a direct calculation of the vibrational characteristics of a finite pinned dislocation segment is compared tomore » line tension estimates before moving to the more complex case of dislocation-obstacle bypass. The entropic factor associated with the attempt frequency is calculated for a finite dislocation segment and for an infinite glide dislocation interacting with an SIA loop. Lastly, it is found to be dislocation length independent for three cases of dislocation-self interstitial atom (SIA) loop interactions.« less

  1. Atomistic calculations of dislocation core energy in aluminium

    NASA Astrophysics Data System (ADS)

    Zhou, X. W.; Sills, R. B.; Ward, D. K.; Karnesky, R. A.

    2017-02-01

    A robust molecular-dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: It does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield converged results regardless of the atomistic system size. Utilizing a high-fidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and the Burgers vector. These calculations show that, for the face-centered-cubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elastic energy: Ec=A sin2β +B cos2β , and this dependence is independent of temperature between 100 and 300 K. By further analyzing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and the core radius of a perfect versus an extended dislocation. With our methodology, the dislocation core energy can accurately be accounted for in models of dislocation-mediated plasticity.

  2. Analogies between continuum dislocation theory, continuum mechanics and fluid mechanics

    NASA Astrophysics Data System (ADS)

    Silbermann, C. B.; Ihlemann, J.

    2017-03-01

    Continuum Dislocation Theory (CDT) relates gradients of plastic deformation in crystals with the presence of geometrically necessary dislocations. Interestingly, CDT shows striking analogies to other branches of continuum mechanics. The present contribution demonstrates this on two essential kinematical quantities which reflect tensorial dislocation properties: the (resultant) Burgers vector and the dislocation density tensor. First, the limiting process for the (resultant) Burgers vector from an integral to a local quantity is performed analogously to the limiting process from the force vector to the traction vector. By evaluating the balance of forces on a tetrahedral volume element, Cauchy found his famous formula relating traction vector and stress tensor. It is shown how this procedure may be adopted to a continuously dislocated tetrahedron. Here, the conservation of Burger’s vector implicates the introduction of the dislocation density tensor. Second, analogies between the plastic flow of a continuously dislocated solid and the liquid flow of a fluid are highlighted: the resultant Burgers vector of a dislocation ensemble plays a similar role as the (resultant) circulation of a vortex tube. Moreover, both vortices within flowing fluids and dislocations within deforming solids induce discontinuities in the velocity field and the plastic distortion field, respectively. Beyond the analogies, some peculiar properties of the dislocation density tensor are presented as well.

  3. Sternoclavicular dislocation: case report and surgical technique.

    PubMed

    Terra, Bernardo Barcellos; Rodrigues, Leandro Marano; Pádua, David Victoria Hoffmann; Martins, Marcelo Giovanini; Teixeira, João Carlos de Medeiros; De Nadai, Anderson

    2015-01-01

    Sternoclavicular dislocations account for less than 5% of all dislocations of the scapular belt. Most cases of anterior dislocation of the sternoclavicular joint do not present symptoms. However, some patients may develop chronic anterior instability and remain symptomatic, and surgical treatment is indicated in these cases. There is a scarcity of reports in the literature relating to reconstruction using the long palmar tendon in cases of traumatic anterior instability. Although rare, these injuries deserve rapid diagnosis and efficient treatment in order to avoid future complications. The aim of this report was to report on a case of a motocross competitor who developed chronic traumatic anterior instability of the sternoclavicular joint and underwent surgical reconstruction using the autogenous long palmar tendon. The patient was a 33-year-old man with a history of anterior dislocation of the sternoclavicular subsequent to a fall during a maneuver in a motocross competition. Conservative treatment was instituted initially, consisting of use of a functional sling to treat the symptoms for 3 weeks, along with physiotherapeutic rehabilitation for 3 months. We chose to use a modification of the "figure of eight" technique based on the studies by Spencer and Kuhn. A longitudinal incision of approximately 10 cm was made at the level of the sternoclavicular joint. The graft from the ipsilateral long palmar tendon was passed through the orifices in the form of a modified "figure of eight" and its ends were sutured together. The patient was immobilized using an American sling for 4 weeks. After 6 months of follow-up, the patient no longer presented pain or instability when movement of the sternoclavicular joint was required. Minor discomfort and slight prominence of the sternoclavicular joint continued to be present but did not affect the patient's activities. Thus, the patient was able to return to racing 6 months after the operation. Our study presented a case of

  4. Acute patellar dislocation with multiple ligament injuries after knee dislocation and single session reconstruction.

    PubMed

    Gormeli, Gokay; Gormeli, Cemile Ayse; Karakaplan, Mustafa; Gurbuz, Sukru; Ozdemir, Zeynep; Ozer, Mustafa

    2016-06-01

    Knee dislocation is a relatively rare condition of all orthopaedic injuries. Accompanying multiple ligament injuries are common after knee dislocations. A 41-year-old male presented to the emergency department suffering from right knee dislocation in June 2013. The patient had anterior cruciate ligament, medial collateral ligament (MCL), medial patellofemoral ligament (MPFL) rupture, and lateral meniscal tear. A single-bundle anatomic reconstruction, medial collateral ligament reconstruction, medial patellofemoral ligament reconstruction and meniscus repair were performed in single session. At twelve months follow-up; there was 160º flexion and 10° extension knee range of motion. Lysholm knee score was 90. Extensive forces can cause both MCL and MPFL injury due to overload and the anatomical relationship between these two structures. Therefore, patients with valgus instability should be evaluated for both MPFL and MCL tears to facilitate successful treatment.

  5. Community Health Worker Handbook.

    ERIC Educational Resources Information Center

    Perales, Aurora Rodriguez

    An experienced community health worker describes her experiences in the field as a basis for recommended guidelines for the role, philosophy, aims, and goals of community health workers. The role of the community health worker as a member of the health care team is explored, and the problem of recognition for community health workers is considered…

  6. [Elbow dislocation with ipsilateral proximal radial shaft fracture and radial head dislocation].

    PubMed

    Köhn, N; Mendel, T; Ullrich, B W

    2015-11-01

    Elbow dislocation with ipsilateral proximal radial shaft fracture and dislocated radial head is a rarely described injury. In this article we present the case of a 23-year-old man with this injury. After the initial diagnostics, the radial shaft fracture was osteosynthetically fixed, whereby the anatomical positions of all parts of the elbow joint were correctly aligned and the medial collateral ligament was reconstructed. After 4.5 months the radial shaft fracture was healed with nearly complete functional recovery of the upper extremity. Thus, a good outcome can be expected when all aspects of bony and ligamentous injuries are accurately addressed.

  7. Concurrent palmar lunate dislocation and posterior elbow dislocation: a case report.

    PubMed

    Papanna, Madhavan Chikkapapanna; Al-Hadithy, Nawfal; Sarkar, J S

    2011-12-01

    We report a rare case of concurrent palmar lunate dislocation of the left wrist combined with a posterior dislocation of the left elbow joint in a 40-year-old man. He sustained both injuries after falling onto his outstretched left hand. The elbow was reduced by the closed method. The wrist was treated with open reduction with carpal tunnel decompression and fixation with a Kirschner wire through the volar approach. Both the scapholunate and radioscaphocapitate ligaments were also repaired. At month 3, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a porter.

  8. Dislocation-related plasticity of ceria-stabilized zirconia polycrystals

    SciTech Connect

    Zhe, X.; Hendry, A.; Wang, C.

    1996-06-01

    Much higher plastic strain of 4% in Ce-TZP ceramics was produced by a novel thermal-mechanical process below 450 C. Observation by TEM showed that there were abundant dislocation pile-ups associated with a few martensitic laths in the deformed samples. The density of dislocations increased with thermal-mechanical cycles. These suggested that dislocation multiplication was caused by the high local stress concentration in front of a martensitic lath during the thermal-mechanical deformation. The generation and movement of dislocations introduced extra plasticity beside the transformation plasticity caused by martensite. Meanwhile, movement of dislocations relaxes the interface stress at martensitic laths to prevent reverse martensitic transformation and early cracking of the specimens. The results are discussed in terms of thermal-mechanical action and dislocation multiplication.

  9. Simultaneous Bilateral Fracture Dislocation of the Talus: A Case Report

    PubMed Central

    Taraz-Jamshidi, Mohammad Hosein; Shapari, Omid; Shiravani, Reza; Moalemi, Saeed; Birjandinejad, Ali

    2013-01-01

    Introduction Fracture - dislocations of the talus are typically due to high energy injuries. Displaced fracture - dislocations of the talus have poor outcomes in general and complications are common. Although talar fracture is common and comprises the second most common tarsal fracture, bilateral fracture - dislocations of the talus are rare. Not many reports regarding the subject can be found in the literature. Case Presentation We report a patient with bilateral fracture - dislocations of the talus treated by open reduction and internal fixation. This patient was a 25 year-old man who sustained bilateral fracture - dislocation of the talus due to a motor vehicle accident. Conclusions Bilateral talar fracture - dislocation is rare. The surgical approach discussed together with the pathomechanics of this injury can yield good short term results. PMID:24350160

  10. Atomistic simulations of dislocation pileup: Grain boundaries interaction

    DOE PAGES

    Wang, Jian

    2015-05-27

    Here, using molecular dynamics (MD) simulations, we studied the dislocation pileup–grain boundary (GB) interactions. Two Σ11 asymmetrical tilt grain boundaries in Al are studied to explore the influence of orientation relationship and interface structure on dislocation activities at grain boundaries. To mimic the reality of a dislocation pileup in a coarse-grained polycrystalline, we optimized the dislocation population in MD simulations and developed a predict-correct method to create a dislocation pileup in MD simulations. MD simulations explored several kinetic processes of dislocations–GB reactions: grain boundary sliding, grain boundary migration, slip transmission, dislocation reflection, reconstruction of grain boundary, and the correlation ofmore » these kinetic processes with the available slip systems across the GB and atomic structures of the GB.« less

  11. Atomistic simulations of dislocation pileup: Grain boundaries interaction

    SciTech Connect

    Wang, Jian

    2015-05-27

    Here, using molecular dynamics (MD) simulations, we studied the dislocation pileup–grain boundary (GB) interactions. Two Σ11 asymmetrical tilt grain boundaries in Al are studied to explore the influence of orientation relationship and interface structure on dislocation activities at grain boundaries. To mimic the reality of a dislocation pileup in a coarse-grained polycrystalline, we optimized the dislocation population in MD simulations and developed a predict-correct method to create a dislocation pileup in MD simulations. MD simulations explored several kinetic processes of dislocations–GB reactions: grain boundary sliding, grain boundary migration, slip transmission, dislocation reflection, reconstruction of grain boundary, and the correlation of these kinetic processes with the available slip systems across the GB and atomic structures of the GB.

  12. Isolated volar carpometacarpal dislocation of the fifth digit.

    PubMed

    Lintner, S A; Rettig, A C

    1995-12-01

    McWharter first described volar carpometacarpal dislocations of the fifth digit in 1918. Since then, 14 cases have been reported in the medical literature. Berg and Murphy were first to report a case of ulnopalmar dislocation that was successfully treated with closed reduction and immobilization. Previously reported cases required internal fixation with or without open reduction. We report a fifth carpometacarpal ulnopalmar dislocation, treated with closed reduction and casting.

  13. Jaw Dislocation as an Unusual Complication of Upper Endoscopy

    PubMed Central

    Dellon, Evan S.; Steele, David

    2016-01-01

    This case report presents an unusual complication of upper endoscopy, resulting in jaw dislocation. Temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation, but it is not widely recognized as a complication of gastrointestinal endoscopy. This report also reviews the current literature regarding this complication and discusses the potential causes of dislocation, differential diagnoses for jaw pain following endoscopy, and recommendations for prevention. PMID:27403117

  14. The equivalence between dislocation pile-ups and cracks

    NASA Technical Reports Server (NTRS)

    Liu, H. W.; Gao, Q.

    1990-01-01

    Cracks and dislocation pile-ups are equivalent to each other. In this paper, the physical equivalence between cracks and pile-ups is delineated, and the relationshps between crack-extension force, force on the leading dislocation, stress-intensity factor, and dislocation density are reviewed and summarized. These relations make it possible to extend quantitatively the recent advances in the concepts and practices of fracture mechanics to the studies of microfractures and microplastic deformations.

  15. Dislocations: do you want them moving or in 3D ?

    NASA Astrophysics Data System (ADS)

    Cordier, Patrick; Boioli, Francesca; Bollinger, Caroline; Idrissi, Hosni; Mussi, Alexandre; Clitton Nzogang, Billy; Schryvers, Dominique

    2016-04-01

    Plastic deformation of minerals and rocks can be explained in most cases by the presence of crystal defects. Among those, dislocations represent the most efficient strain-producing actors of deformation. The physics of deformation by dislocations is complex since it is intrinsically multiscale. At the atomic scale, the dislocation core structure controls a fundamental property: their mobility. However, the plastic strain results from the collective behavior of dislocations which can be understood only at the mesoscopic scale. Multiscale numerical modeling has provided a lot of insights on these aspects in the recent years, also in mineral physics. These progress were calling for parallel developments in experiments and characterization. Here we present two studies on dislocations in olivine deformed under lithospheric conditions based in recent developments in transmission electron microscopy. We present plastic deformation experiments performed on olivine in situ, in the transmission electron microscope, at room temperature. The ductile behavior is made possible thanks to the very small size of the specimens (maximum dimension < 5μm) which are prepared by focused ion beam and strained in a special Micro-Electro-Mechanical-System (MEMS) device called push-to-pull (PI 95 TEM PicoIndenter from Hysitron). By performing experiments under constant load, the velocity of [001] screw dislocations has been measured as a function of stress. This mobility law has then been introduced in a Dislocation Dynamics model to determine the stress strain curves. We present also some recent developments on electron tomography of dislocations performed on olivine. The difficulty is here to keep diffraction conditions strictly constant over a wide range of tilt acquisitions. We present some examples obtained by imaging dislocations in weak-beam dark-field using precession electron diffraction. The analysis of dislocation microstructures in 3D is used to characterize dislocations glide

  16. Dislocation structure of the magnesium nanocrystal in uniaxial loading

    NASA Astrophysics Data System (ADS)

    Vlasova, A. M.; Nikonov, A. Yu.; Zhuravlev, A. K.; Kesarev, A. G.

    2016-11-01

    We report on molecular-dynamics (MD) simulations of compression loading of nanocrystalline magnesium modeled by the embedded-atom method (EAM) potential. It is shown that plastic deformation is by basal slip and (102) twinning. The formation of stable configurations of dislocation grids is observed. Some dislocation reactions are suggested to explain the occurrence of grids. The structure of the dislocation core is shown with the Burgers vector 1 /18 [0 4 ¯43 ] .

  17. Congenital knee dislocation in a 49,XXXXY boy.

    PubMed Central

    Sijmons, R H; van Essen, A J; Visser, J D; Iprenburg, M; Nelck, G F; Vos-Bender, M L; de Jong, B

    1995-01-01

    We report on a 12 year old mentally retarded boy who presented at birth with bilateral knee dislocations, dislocation of the right hip, and general joint laxity. Cytogenetic studies showed a 49,XXXXY karyotype. Hyperlaxity of joints is known to occur in 49,XXXXY patients, but congenital knee dislocation has not been reported. Rarely in 49,XXXXY and 49,XXXXX syndromes Larsen-like features may be seen. Patients with congenital joint dislocation or laxity, combined with other malformations, especially if psychomotor development is delayed, should be karyotyped to exclude chromosomal abnormalities. Images PMID:7643364

  18. Interfacial dislocation motion and interactions in single-crystal superalloys

    SciTech Connect

    Liu, B.; Raabe, D.; Roters, F.; Arsenlis, A.

    2014-10-01

    The early stage of high-temperature low-stress creep in single-crystal superalloys is characterized by the rapid development of interfacial dislocation networks. Although interfacial motion and dynamic recovery of these dislocation networks have long been expected to control the subsequent creep behavior, direct observation and hence in-depth understanding of such processes has not been achieved. Incorporating recent developments of discrete dislocation dynamics models, we simulate interfacial dislocation motion in the channel structures of single-crystal superalloys, and investigate how interfacial dislocation motion and dynamic recovery are affected by interfacial dislocation interactions and lattice misfit. Different types of dislocation interactions are considered: self, collinear, coplanar, Lomer junction, glissile junction, and Hirth junction. The simulation results show that strong dynamic recovery occurs due to the short-range reactions of collinear annihilation and Lomer junction formation. The misfit stress is found to induce and accelerate dynamic recovery of interfacial dislocation networks involving self-interaction and Hirth junction formation, but slow down the steady interfacial motion of coplanar and glissile junction forming dislocation networks. The insights gained from these simulations on high-temperature low-stress creep of single-crystal superalloys are also discussed.

  19. Dislocation luminescence in GaN single crystals under nanoindentation

    PubMed Central

    2014-01-01

    This work presents an experimental study on the dislocation luminescence in GaN by nanoindentation, cathodoluminescence, and Raman. The dislocation luminescence peaking at 3.12 eV exhibits a series of special properties in the cathodoluminescence measurements, and it completely disappears after annealing at 500°C. Raman spectroscopy shows evidence for existence of vacancies in the indented region. A comprehensive investigation encompassing cathodoluminescence, Raman, and annealing experiments allow the assignment of dislocation luminescence to conduction-band-acceptor transition involving Ga vacancies. The nanoscale plasticity of GaN can be better understood by considering the dislocation luminescence mechanism. PMID:25593548

  20. Fractal analysis of deformation-induced dislocation patterns

    SciTech Connect

    Zaiser, M. ); Bay, K. . Inst. fuer Theoretische und Angewandte Physik); Haehner, P. . Joint Research Centre TU Braunschweig . Inst. fuer Metallphysik und Nukleare Festkoerperphysik)

    1999-06-22

    The paper reports extensive analyses of the fractal geometry of cellular dislocation structures observed in Cu deformed in multiple-slip orientation. Several methods presented for the determination of fractal dimensions are shown to give consistent results. Criteria are formulated which allow the distinguishing of fractal from non-fractal patterns, and implications of fractal dislocation patterning for quantitative metallography are discussed in detail. For an interpretation of the findings a theoretical model is outlined according to which dislocation cell formation is associated to a noise-induced structural transition far from equilibrium. This allows relating the observed fractal dimensions to the stochastic properties of deformation by collective dislocation glide.

  1. Lateral subtalar dislocation: Case report and review of the literature

    PubMed Central

    Veltman, Ewout S; Steller, Ernst JA; Wittich, Philippe; Keizer, Jort

    2016-01-01

    A case of complicated lateral subtalar dislocation is presented and the literature concerning this injury is reviewed. Subtalar joint dislocations are rare and often the result of a high-energy trauma. Complications include avascular necrosis of the talus, infection, posttraumatic osteoarthritis requiring arthrodesis and chronic subtalar instability. Negative prognostic factors include lateral and complicated dislocations, total talar extrusions, and associated fractures. A literature search was performed to identify studies describing outcome after lateral subtalar joint dislocation. Eight studies including fifty patients could be included, thirty out of 50 patients suffered a complicated injury. Mean follow-up was fifty-five months. Ankle function was reported as good in all patients with closed lateral subtalar dislocation. Thirteen out of thirty patients with complicated lateral subtalar joint dislocation developed a complication. Avascular necrosis was present in nine patients with complicated injury. Four patients with complicated lateral subtalar dislocation suffered deep infection requiring treatment with antibiotics. In case of uncomplicated lateral subtalar joint dislocation, excellent functional outcome after closed reduction and immobilization can be expected. In case of complicated lateral subtalar joint dislocation immediate reduction, wound debridement and if necessary (external) stabilisation are critical. Up to fifty percent of patients suffering complicated injury are at risk of developing complications such as avascular talar necrosis and infection. PMID:27672576

  2. [Bilateral elbow dislocation related to Essex-Lopresti injury].

    PubMed

    Romero Pérez, B; Marcos García, A; Medina Henríquez, J A; Muratore Moreno, G

    2012-01-01

    Elbow dislocation is second in frequency, after the shoulder, whereas bilateral dislocation is uncommon, even less than dislocations with concurrent associated fractures. One of the least frequent associations is the Essex-Lopresti injury which consists of a fracture of the radial head affecting the distal radioulnar joint with injury to the interosseous membrane. This is a case of bilateral elbow dislocation, one of the elbows associated with the Essex-Lopresti injury. During treatment, the premature closed reduction prevails, previously making sure the elbow is stable, the premise which will determine the orthopedic or surgical treatment of the injury.

  3. Surface dislocation nucleation controlled deformation of Au nanowires

    SciTech Connect

    Roos, B.; Kapelle, B.; Volkert, C. A.; Richter, G.

    2014-11-17

    We investigate deformation in high quality Au nanowires under both tension and bending using in-situ transmission electron microscopy. Defect evolution is investigated during: (1) tensile deformation of 〈110〉 oriented, initially defect-free, single crystal nanowires with cross-sectional widths between 30 and 300 nm, (2) bending deformation of the same wires, and (3) tensile deformation of wires containing coherent twin boundaries along their lengths. We observe the formation of twins and stacking faults in the single crystal wires under tension, and storage of full dislocations after bending of single crystal wires and after tension of twinned wires. The stress state dependence of the deformation morphology and the formation of stacking faults and twins are not features of bulk Au, where deformation is controlled by dislocation interactions. Instead, we attribute the deformation morphologies to the surface nucleation of either leading or trailing partial dislocations, depending on the Schmid factors, which move through and exit the wires producing stacking faults or full dislocation slip. The presence of obstacles such as neutral planes or twin boundaries hinder the egress of the freshly nucleated dislocations and allow trailing and leading partial dislocations to combine and to be stored as full dislocations in the wires. We infer that the twins and stacking faults often observed in nanoscale Au specimens are not a direct size effect but the result of a size and obstacle dependent transition from dislocation interaction controlled to dislocation nucleation controlled deformation.

  4. Predicting High Temperature Dislocation Physics in HCP Crystal Structures

    SciTech Connect

    Hunter, Abigail; Carpenter, John S.; Martinez Saez, Enrique

    2016-05-09

    This report applies models and experiments to answer key questions about the way materials deform; specifics regarding phase field dislocations dynamics; as well as high temperature rolling experiments.

  5. Atomistic calculations of dislocation core energy in aluminium

    DOE PAGES

    Zhou, X. W.; Sills, R. B.; Ward, D. K.; ...

    2017-02-16

    A robust molecular dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: it does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield highly converged results regardless of the atomistic system size. Utilizing a high-fidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and Burgers vector. These calculations show that, for the face-centred-cubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elasticmore » energy: Ec = A·sin2β + B·cos2β, and this dependence is independent of temperature between 100 and 300 K. By further analysing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and radius of a perfect versus extended dislocation. With our methodology, the dislocation core energy can be accurately accounted for in models of plastic deformation.« less

  6. Mobility of edge dislocations in stressed iron crystals during irradiation

    SciTech Connect

    Korchuganov, A. V. Zolnikov, K. P.; Kryzhevich, D. S.; Chernov, V. M.; Psakhie, S. G.

    2015-10-27

    The behavior of a/2(111)(110) edge dislocations in iron in shear loading and irradiation conditions was studied by means of molecular dynamics simulation. Edge dislocations were exposed to shock waves formed by atomic displacement cascades of different energies. It was shown that starting from a certain threshold amplitude shock waves cause displacement of edge dislocations in the loaded samples. Calculations showed that the larger the shear load and the amplitude of the shock wave, the greater the displacement of dislocations in the crystallite.

  7. Dislocation conduction in Bi-Sb topological insulators

    NASA Astrophysics Data System (ADS)

    Hamasaki, Hiromu; Tokumoto, Yuki; Edagawa, Keiichi

    2017-02-01

    Previous theoretical works have predicted that when a specific condition is satisfied, dislocations in three-dimensional topological insulators form one-dimensional gapless states, which are topologically protected against disorder scattering. Here, the predicted dislocation conduction is experimentally investigated in Bi-Sb topological insulators. High-density dislocations with the Burgers vector satisfying the conductivity condition are introduced into Bi-Sb single crystals by plastic deformation. Conductivity measurements for deformed and undeformed samples and those for the deformed samples in different orientations show excess conductivity due to dislocation conduction.

  8. Dislocation mediated alignment during metal nanoparticle coalescence

    SciTech Connect

    Lange, A. P.; Samanta, A.; Majidi, H.; Mahajan, S.; Ging, J.; Olson, T. Y.; van Benthem, K.; Elhadj, S.

    2016-09-13

    Dislocation mediated alignment processes during gold nanoparticle coalescence were studied at low and high temperatures using molecular dynamics simulations and transmission electron microscopy. Particles underwent rigid body rotations immediately following attachment in both low temperature (500 K) simulated coalescence events and low temperature (~315 K) transmission electron microscopy beam heating experiments. In many low temperature simulations, some degree of misorientation between particles remained after rigid body rotations, which was accommodated by grain boundary dislocation nodes. These dislocations were either sessile and remained at the interface for the duration of the simulation or dissociated and cross-slipped through the adjacent particles, leading to improved co-alignment. Minimal rigid body rotations were observed during or immediately following attachment in high temperature (1100 K) simulations, which is attributed to enhanced diffusion at the particles' interface. However, rotation was eventually induced by {111} slip on planes parallel to the neck groove. These deformation modes led to the formation of single and multi-fold twins whose structures depended on the initial orientation of the particles. The driving force for {111} slip is attributed to high surface stresses near the intersection of low energy {111} facets in the neck region. The details of this twinning process were examined in detail using simulated trajectories, and the results reveal possible mechanisms for the nucleation and propagation of Shockley partials on consecutive planes. Deformation twinning was also observed in-situ using transmission electron microscopy, which resulted in the co-alignment of a set of the particles' {111} planes across their grain boundary and an increase in their dihedral angle. As a result, this constitutes the first detailed experimental observation of deformation twinning during nanoparticle coalescence, validating simulation results

  9. Nonrigid image registration with crystal dislocation energy.

    PubMed

    Luo, Yishan; Chung, Albert C S

    2013-01-01

    The goal of nonrigid image registration is to find a suitable transformation such that the transformed moving image becomes similar to the reference image. The image registration problem can also be treated as an optimization problem, which tries to minimize an objective energy function that measures the differences between two involved images. In this paper, we consider image matching as the process of aligning object boundaries in two different images. The registration energy function can be defined based on the total energy associated with the object boundaries. The optimal transformation is obtained by finding the equilibrium state when the total energy is minimized, which indicates the object boundaries find their correspondences and stop deforming. We make an analogy between the above processes with the dislocation system in physics. The object boundaries are viewed as dislocations (line defects) in crystal. Then the well-developed dislocation energy is used to derive the energy assigned to object boundaries in images. The newly derived registration energy function takes the global gradient information of the entire image into consideration, and produces an orientation-dependent and long-range interaction between two images to drive the registration process. This property of interaction endows the new registration framework with both fast convergence rate and high registration accuracy. Moreover, the new energy function can be adapted to realize symmetric diffeomorphic transformation so as to ensure one-to-one matching between subjects. In this paper, the superiority of the new method is theoretically proven, experimentally tested and compared with the state-of-the-art SyN method. Experimental results with 3-D magnetic resonance brain images demonstrate that the proposed method outperforms the compared methods in terms of both registration accuracy and computation time.

  10. Dislocation mediated alignment during metal nanoparticle coalescence

    DOE PAGES

    Lange, A. P.; Samanta, A.; Majidi, H.; ...

    2016-09-13

    Dislocation mediated alignment processes during gold nanoparticle coalescence were studied at low and high temperatures using molecular dynamics simulations and transmission electron microscopy. Particles underwent rigid body rotations immediately following attachment in both low temperature (500 K) simulated coalescence events and low temperature (~315 K) transmission electron microscopy beam heating experiments. In many low temperature simulations, some degree of misorientation between particles remained after rigid body rotations, which was accommodated by grain boundary dislocation nodes. These dislocations were either sessile and remained at the interface for the duration of the simulation or dissociated and cross-slipped through the adjacent particles, leadingmore » to improved co-alignment. Minimal rigid body rotations were observed during or immediately following attachment in high temperature (1100 K) simulations, which is attributed to enhanced diffusion at the particles' interface. However, rotation was eventually induced by {111} slip on planes parallel to the neck groove. These deformation modes led to the formation of single and multi-fold twins whose structures depended on the initial orientation of the particles. The driving force for {111} slip is attributed to high surface stresses near the intersection of low energy {111} facets in the neck region. The details of this twinning process were examined in detail using simulated trajectories, and the results reveal possible mechanisms for the nucleation and propagation of Shockley partials on consecutive planes. Deformation twinning was also observed in-situ using transmission electron microscopy, which resulted in the co-alignment of a set of the particles' {111} planes across their grain boundary and an increase in their dihedral angle. As a result, this constitutes the first detailed experimental observation of deformation twinning during nanoparticle coalescence, validating simulation results

  11. Palmar divergent dislocation of scaphoid and lunate.

    PubMed

    Kang, Ho-Jung; Shim, Dong-Joon; Hahn, Soo-Bong; Kang, Eung-Shick

    2003-12-30

    A 28-year-old man presented with a palmar divergent dislocation of the scaphoid and lunate. He was treated with an open reduction and an internal fixation with two Kirschner's wires after the 25th day of trauma due to a neurological injury. The results were satisfactory after 18 months follow up without any evidence of avascular necrosis and traumatic arthritis of the scaphoid and lunate. The patient had no limitation in motion or intermittent wrist pain. We reported this case with a brief review of relevant literatures.

  12. Mechanical of Cracks Screened by Dislocations

    DTIC Science & Technology

    1982-01-01

    En principe, on peut obtenir un crittre de rupture totale en prbcisant )a condition locale de clivage sur Ia fissure et la r6sistance du r ~ seau sur...DislocationsRerit G. PERFORMING ORG. REPORT NUMBER ____ ___ ___ ___ _ ___ ___ ___ ____ ___ ___ ___ N/A V. AUT04ORWs CONRAC OR GRANT’ NUMBER(s) R . Ii...Thomson, J. E. Sinclair ARO 36-82 9. PERFORMING ORZANIZATIOha NAME AND ADDRESS r 0. PRPQ;RAM ELEMENT. PROjECT. TASK National Bureau of Standards AE OKUI

  13. A Guide to Functional Literacy for Literacy Administrators and Workers.

    ERIC Educational Resources Information Center

    Tripathi, Virenda

    This guide provides an overview and practical suggestions for the literacy administrator and worker. Chapters deal with: an overview of the problem of illiteracy; adult learner characteristics; methods of teaching languages to illiterate adults; the organization, administration, and supervision of literacy classes; patterns of adult education;…

  14. 77 FR 61789 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Workforce...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ...; Workforce Investment Act Adult and Dislocated Worker Programs Gold Standard Evaluation Follow-Up Surveys..., ``Workforce Investment Act Adult and Dislocated Worker Programs Gold Standard Evaluation Follow-Up Surveys... Dislocated Worker Programs Gold Standard Evaluation Follow-Up Surveys, Veterans Study, and Cost Data. OMB...

  15. Concept of healing of recurrent shoulder dislocation.

    PubMed

    D'Angelo, Donato

    2014-01-01

    This paper presents the main surgical techniques applied in the treatment of anterior recurrent shoulder dislocation, aiming the achievement of the normality of articulate movements. This was obtained by combining distinct surgical procedures, which allowed the recovery of a complete functional capacity of the shoulder, without jeopardizing the normality of movement, something that has not been recorded in the case of the tense sutures of the surgical procedures of Putti-Platt, Bankart, Latarjet, Dickson-O'Dell and others. The careful review of the methods applied supports the conclusion that recurrent shoulder dislocation can be cured, since cure has been obtained in 97% of the treated cases. However, some degree of limitation in the shoulder movement has been observed in most of the treated cases. Our main goal was to achieve a complete shoulder functional recovery, by treating simultaneously all of the anatomical-pathological lesions, without considering the so-called essential lesions. The period of post-operatory immobilization only last for the healing of soft parts; this takes place in a position of neutral shoulder rotation, since the use of vascular bone graft eliminates the need for long time immobilization, due to the shoulder stabilization provided by rigid fixation of the coracoid at the glenoid edge, as in the Latarjet's technique. Our procedure, used since 1959, comprises the association of several techniques, which has permitted shoulder healing without movement limitation. That was because of the tension reduction in the sutures of the subescapularis, capsule, and coracobraquialis muscles.

  16. Implicit integration methods for dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; Hommes, G.; Aubry, S.; Arsenlis, A.

    2015-03-01

    In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. This paper investigates the viability of high-order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a way of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.

  17. Implicit integration methods for dislocation dynamics

    DOE PAGES

    Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; ...

    2015-01-20

    In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events, and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. Here, this paper investigates the viability of high order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a waymore » of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.« less

  18. Implicit integration methods for dislocation dynamics

    SciTech Connect

    Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; Hommes, G.; Aubry, S.; Arsenlis, A.

    2015-01-20

    In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events, and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. Here, this paper investigates the viability of high order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a way of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.

  19. Training and Qualifications (Teachers and Workers for the Deaf).

    ERIC Educational Resources Information Center

    World Federation of the Deaf, Rome (Italy).

    Three papers consider the training and qualifications of teachers and workers for the deaf. H. Okopinski describes "Training Teachers for Deaf Children's Schools in Poland" and A. F. Mackenzie defines "The Qualifications of Workers for the Adult Deaf" in the United Kingdom. E. S. Levine reports on New York University's…

  20. Reprint of: Dynamics of discrete screw dislocations on glide directions

    NASA Astrophysics Data System (ADS)

    Alicandro, R.; De Luca, L.; Garroni, A.; Ponsiglione, M.

    2016-12-01

    We consider a simple discrete model for screw dislocations in crystals. Using a variational discrete scheme we study the motion of a configuration of dislocations toward low energy configurations. We deduce an effective fully overdamped dynamics that follows the maximal dissipation criterion introduced in Cermelli and Gurtin (1999) and predicts motion along the glide directions of the crystal.

  1. Effective mobility of dislocations from systematic coarse-graining

    NASA Astrophysics Data System (ADS)

    Kooiman, M.; Hütter, M.; Geers, MGD

    2015-06-01

    The dynamics of large amounts of dislocations governs the plastic response of crystalline materials. In this contribution we discuss the relation between the mobility of discrete dislocations and the resulting flow rule for coarse-grained dislocation densities. The mobilities used in literature on these levels are quite different, for example in terms of their intrinsic the stress dependence. To establish the relation across the scales, we have derived the macroscopic evolution equations of dislocation densities from the equations of motion of individual dislocations by means of systematic coarse-graining. From this, we can identify a memory kernel relating the driving force and the flux of dislocations. This kernel can be considered as an effective macroscopic mobility with two contributions; a direct contribution related to the overdamped motion of individual dislocations, and an emergent contribution that arises from time correlations of fluctuations in the Peach-Koehler force. Scaling analysis shows that the latter contribution is dominant for dislocations in metals at room temperature. We also discuss several concerns related to the separation of timescales.

  2. A field theory of piezoelectric media containing dislocations

    SciTech Connect

    Taupin, V. Fressengeas, C.; Ventura, P.; Lebyodkin, M.

    2014-04-14

    A field theory is proposed to extend the standard piezoelectric framework for linear elastic solids by accounting for the presence and motion of dislocation fields and assessing their impact on the piezoelectric properties. The proposed theory describes the incompatible lattice distortion and residual piezoelectric polarization fields induced by dislocation ensembles, as well as the dynamic evolution of these fields through dislocation motion driven by coupled electro-mechanical loading. It is suggested that (i) dislocation mobility may be enhanced or inhibited by the electric field, depending on the polarity of the latter, (ii) plasticity mediated by dislocation motion allows capturing long-term time-dependent properties of piezoelectric polarization. Due to the continuity of the proposed electro-mechanical framework, the stress/strain and polarization fields are smooth even in the dislocation core regions. The theory is applied to gallium nitride layers for validation. The piezoelectric polarization fields associated with bulk screw/edge dislocations are retrieved and surface potential modulations are predicted. The results are extended to dislocation loops.

  3. Non-reducible palmar dislocation of the distal radioulnar joint

    PubMed Central

    Zannou, Rupestre S.; Rezzouk, Joel; Ruijs, Aleid C.J.

    2015-01-01

    Abstract A rare case of an isolated traumatic palmar dislocation of the distal radioulnar joint is presented. Clinically, there is a loss of pronation and supination. The dislocation was treated using an open reduction, reinsertion of the capsule-ligamentous complex and temporary stabilization using K-wires. PMID:26158121

  4. Dynamics of discrete screw dislocations on glide directions

    NASA Astrophysics Data System (ADS)

    Alicandro, R.; De Luca, L.; Garroni, A.; Ponsiglione, M.

    2016-07-01

    We consider a simple discrete model for screw dislocations in crystals. Using a variational discrete scheme we study the motion of a configuration of dislocations toward low energy configurations. We deduce an effective fully overdamped dynamics that follows the maximal dissipation criterion introduced in Cermelli and Gurtin (1999) and predicts motion along the glide directions of the crystal.

  5. Multiscale characterization of dislocation processes in Al 5754

    NASA Astrophysics Data System (ADS)

    Kacher, Josh; Mishra, Raja K.; Minor, Andrew M.

    2015-07-01

    Multiscale characterization was performed on an Al-Mg alloy, Al 5754 O-temper, including in situ mechanical deformation in both the scanning electron microscope and the transmission electron microscope. Scanning electron microscopy characterization showed corresponding inhomogeneity in the dislocation and Mg distribution, with higher levels of Mg correlating with elevated levels of dislocation density. At the nanoscale, in situ transmission electron microscopy straining experiments showed that dislocation propagation through the Al matrix is characterized by frequent interactions with obstacles smaller than the imaging resolution that resulted in the formation of dislocation debris in the form of dislocation loops. Post-mortem chemical characterization and comparison to dislocation loop behaviour in an Al-Cr alloy suggests that these obstacles are small Mg clusters. Previous theoretical work and indirect experimental evidence have suggested that these Mg nanoclusters are important factors contributing to strain instabilities in Al-Mg alloys. This study provides direct experimental characterization of the interaction of glissile dislocations with these nanoclusters and the stress needed for dislocations to overcome them.

  6. The strength and dislocation microstructure evolution in superalloy microcrystals

    NASA Astrophysics Data System (ADS)

    Hussein, Ahmed M.; Rao, Satish I.; Uchic, Michael D.; Parthasarathay, Triplicane A.; El-Awady, Jaafar A.

    2017-02-01

    In this work, the evolution of the dislocations microstructure in single crystal two-phase superalloy microcrystals under monotonic loading has been studied using the three-dimensional discrete dislocation dynamics (DDD) method. The DDD framework has been extended to properly handle the collective behavior of dislocations and their interactions with large collections of arbitrary shaped precipitates. Few constraints are imposed on the initial distribution of the dislocations or the precipitates, and the extended DDD framework can support experimentally-obtained precipitate geometries. Full tracking of the creation and destruction of anti-phase boundaries (APB) is accounted for. The effects of the precipitate volume fraction, APB energy, precipitate size, and crystal size on the deformation of superalloy microcrystals have been quantified. Correlations between the precipitate microstructure and the dominant deformation features, such as dislocation looping versus precipitate shearing, are also discussed. It is shown that the mechanical strength is independent of the crystal size, increases linearly with increasing the volume fraction, follows a near square-root relationship with the APB energy and an inverse square-root relationship with the precipitate size. Finally, the flow strength in simulations having initial dislocation pair sources show a flow strength that is about one half of that predicted from simulations starting with single dislocation sources. The method developed can be used, with minimal extensions, to simulate dislocation microstructure evolution in general multiphase materials.

  7. Simultaneous bilateral elbow dislocation in an international gymnast

    PubMed Central

    Syed, A. A.; O'Flanagan, J.

    1999-01-01

    Elbow dislocation is a rare injury in elite athletes. We report an unusual case of simultaneous bilateral elbow dislocations with a unilateral radial head fracture in an international female athlete competing on the asymmetrical bars. These injuries require prompt reduction and immediate mobilisation if an abrupt end to a promising career is to be prevented. 




 PMID:10205699

  8. Method to reduce dislocation density in silicon using stress

    DOEpatents

    Buonassisi, Anthony; Bertoni, Mariana; Argon, Ali; Castellanos, Sergio; Fecych, Alexandria; Powell, Douglas; Vogl, Michelle

    2013-03-05

    A crystalline material structure with reduced dislocation density and method of producing same is provided. The crystalline material structure is annealed at temperatures above the brittle-to-ductile transition temperature of the crystalline material structure. One or more stress elements are formed on the crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.

  9. Computation of the lattice Green function for a dislocation

    NASA Astrophysics Data System (ADS)

    Tan, Anne Marie Z.; Trinkle, Dallas R.

    2016-08-01

    Modeling isolated dislocations is challenging due to their long-ranged strain fields. Flexible boundary condition methods capture the correct long-range strain field of a defect by coupling the defect core to an infinite harmonic bulk through the lattice Green function (LGF). To improve the accuracy and efficiency of flexible boundary condition methods, we develop a numerical method to compute the LGF specifically for a dislocation geometry; in contrast to previous methods, where the LGF was computed for the perfect bulk as an approximation for the dislocation. Our approach directly accounts for the topology of a dislocation, and the errors in the LGF computation converge rapidly for edge dislocations in a simple cubic model system as well as in BCC Fe with an empirical potential. When used within the flexible boundary condition approach, the dislocation LGF relaxes dislocation core geometries in fewer iterations than when the perfect bulk LGF is used as an approximation for the dislocation, making a flexible boundary condition approach more efficient.

  10. Dislocation Mechanism of Twinning in Ni-Mn-Ga

    NASA Astrophysics Data System (ADS)

    Zárubová, N.; Ge, Y.; Gemperlová, J.; Gemperle, A.; Hannula, S.-P.

    2012-03-01

    Tensile tests were performed in situ in a transmission electron microscope to investigate the twinning mechanism in non-modulated Ni-Mn-Ga martensite. The reorientation of the twin variants occurs via twinning dislocations. Their generation and movement were followed; the glide plane and Burgers vector were verified. Individual twinning dislocations were visualized.

  11. High purity, low dislocation GaAs single crystals

    NASA Technical Reports Server (NTRS)

    Chen, R. T.; Holmes, D. E.; Kirkpatrick, C. G.

    1983-01-01

    Liquid encapsulated Czochralski crystal growth techniques for producing undoped, high resistivity, low dislocation material suitable for device applications is described. Technique development resulted in reduction of dislocation densities in 3 inch GaAs crystals. Control over the melt stoichiometry was determined to be of critical importance for the reduction of twinning and polycrystallinity during growth.

  12. Collective Dislocation Dynamics and Avalanches during Fatigue of Aluminum

    NASA Astrophysics Data System (ADS)

    Rhouma, W. Ben; Deschanel, S.; Weiss, J.

    2011-09-01

    We present a study of collective dislocation dynamics and plasticity during fatigue of pure Aluminum from the analysis of continuous and discrete acoustic emission (AE). The three stages of macroscopic fatigue behavior (strain-hardening, shakedown, and strain softening) are clearly differentiated in terms of AE. During the first loading cycles, collective dislocation dynamics consists in dislocation avalanches of various sizes and clustered in time. Once a microstructure of dislocation cells and walls is formed, the spreading of such avalanches is restrained, and the discrete AE strongly decreases. Instead, a symmetrical (tension-compression) continuous AE, maximal at plastic yield, is observed, likely associated to a superposition of numerous, small and uncorrelated motions such as dislocation loops initiation from cell walls. However, some discrete AE activity remains during shakedown, a possible signature of sudden rearrangements of the microstructure occurring at scales larger than its wavelength. Finally, the onset of strain softening is associated to a strong increase of discrete AE, in relation with microcracking. Our results suggest that collective dislocation instabilities and the emergence of a dislocation microstructure are interrelated, and challenge future numerical modeling developments of dislocation assemblies.

  13. The Older Worker's Stake in Workers' Compensation

    ERIC Educational Resources Information Center

    Berkowitz, Monroe

    1975-01-01

    State Workers' Compensation programs can add another barrier for older workers to surmount at the hiring gate. State programs do not furnish adequate or equitable protection, and the National Commission on State Workmen's Compensation Laws has made recommendations to improve coverage; new standards must be met by July, 1975. (Author)

  14. The relationship between strain geometry and geometrically necessary dislocations

    NASA Astrophysics Data System (ADS)

    Hansen, Lars; Wallis, David

    2016-04-01

    The kinematics of past deformations are often a primary goal in structural analyses of strained rocks. Details of the strain geometry, in particular, can help distinguish hypotheses about large-scale tectonic phenomena. Microstructural indicators of strain geometry have been heavily utilized to investigate large-scale kinematics. However, many of the existing techniques require structures for which the initial morphology is known, and those structures must undergo the same deformation as imposed macroscopically. Many deformed rocks do not exhibit such convenient features, and therefore the strain geometry is often difficult (if not impossible) to ascertain. Alternatively, crystallographic textures contain information about the strain geometry, but the influence of strain geometry can be difficult to separate from other environmental factors that might affect slip system activity and therefore the textural evolution. Here we explore the ability for geometrically necessary dislocations to record information about the deformation geometry. It is well known that crystallographic slip due to the motion of dislocations yields macroscopic plastic strain, and the mathematics are established to relate dislocation glide on multiple slip systems to the strain tensor of a crystal. This theoretical description generally assumes that dislocations propagate across the entire crystal. However, at any point during the deformation, dislocations are present that have not fully transected the crystal, existing either as free dislocations or as dislocations organized into substructures like subgrain boundaries. These dislocations can remain in the lattice after deformation if the crystal is quenched sufficiently fast, and we hypothesize that this residual dislocation population can be linked to the plastic strain geometry in a quantitative manner. To test this hypothesis, we use high-resolution electron backscatter diffraction to measure lattice curvatures in experimentally deformed

  15. Dislocation core reconstruction induced by carbon segregation in bcc iron

    NASA Astrophysics Data System (ADS)

    Ventelon, Lisa; Lüthi, B.; Clouet, E.; Proville, L.; Legrand, B.; Rodney, D.; Willaime, F.

    2015-06-01

    The relative stability of dislocation core configurations in body-centered-cubic metals is profoundly modified by the presence of solutes. Considering the Fe(C) system, we demonstrate by using density functional theory that carbon atoms destabilize the usual easy core to the benefit of the hard core configuration of the screw dislocation, which is unstable in pure metals. The carbon atom is at the center of a regular prism in a cementitelike local environment. The same dislocation core reconstruction is also found with other solutes (B, N, O) and in W(C). This unexpected low-energy configuration induces a strong solute-dislocation attraction, leading to dislocation core saturation by solute atoms, even for very low bulk solute concentrations. This core reconstruction will constitute an essential factor to account for in solute-segregation related phenomena, such as strain aging.

  16. Linear complexions: Confined chemical and structural states at dislocations.

    PubMed

    Kuzmina, M; Herbig, M; Ponge, D; Sandlöbes, S; Raabe, D

    2015-09-04

    For 5000 years, metals have been mankind's most essential materials owing to their ductility and strength. Linear defects called dislocations carry atomic shear steps, enabling their formability. We report chemical and structural states confined at dislocations. In a body-centered cubic Fe-9 atomic percent Mn alloy, we found Mn segregation at dislocation cores during heating, followed by formation of face-centered cubic regions but no further growth. The regions are in equilibrium with the matrix and remain confined to the dislocation cores with coherent interfaces. The phenomenon resembles interface-stabilized structural states called complexions. A cubic meter of strained alloy contains up to a light year of dislocation length, suggesting that linear complexions could provide opportunities to nanostructure alloys via segregation and confined structural states.

  17. Self-force on dislocation segments in anisotropic crystals.

    PubMed

    Fitzgerald, S P; Aubry, S

    2010-07-28

    A dislocation segment in a crystal experiences a 'self-force', by virtue of the orientation dependence of its elastic energy. If the crystal is elastically isotropic, this force is manifested as a couple acting to rotate the segment toward the lower energy of the pure screw orientation (i.e. acting to align the dislocation line with its Burgers vector). If the crystal is anisotropic, there are additional contributions to the couple, arising from the more complex energy landscape of the lattice itself. These effects can strongly influence the dynamic evolution of dislocation networks, and via their governing role in dislocation multiplication phenomena, control plastic flow in metals. In this paper we develop a model for dislocation self-forces in a general anisotropic crystal, and briefly consider the technologically important example of α-iron, which becomes increasingly anisotropic as the temperature approaches that of the α-γ phase transition at 912 °C.

  18. Room-temperature dislocation climb in copper-niobium interfaces

    SciTech Connect

    Wang, Jian; Hoagland, Richard G; Hirth, John P; Misra, Amit

    2008-01-01

    Using atomistic simulations, we show that dislocations climb efficiently in metallic copper-niobium interfaces through absorption and emission of vacancies in the dislocation core, as well as an associated counter diffusion of Cu atoms in the interfacial plane. The high efficiency of dislocation climb in the interface is ascribed to the high vacancy concentration of 0.05 in the interfacial plane, the low formation energy of 0.12 e V with respect to removal or insertion of Cu atoms, as well as the low kinetic barrier of 0.10 eV for vacancy migration in the interfacial Cu plane. Dislocation climb in the interface facilitates reactions of interfacial dislocations, and enables interfaces to be in the equilibrium state with respect to concentrations ofpoint defects.

  19. Conservative Treatment of Carpometacarpal Dislocation of the Three Last Fingers

    PubMed Central

    2016-01-01

    Posterior carpometacarpal (CMC) dislocation is a rare condition. Treatment is usually surgical though no strict consensus can be found upon literature review. If diagnosed early and no associated fractures are found, CMC dislocation could benefit from conservative treatment comprising closed reduction and splint immobilisation. We report the case of a 26-year-old man diagnosed with a posterior dislocation of the third, fourth, and fifth CMC joints after a fall of 1.5 meters, treated by external reduction under procedural sedation and immobilisation with a cast for 6 weeks. Evolution was excellent with no relapse observed during follow-up. Our aim is to increase physician awareness of CMC dislocation so that they seek this injury in the emergency department. Unrecognised CMC dislocation can lead to neurovascular injuries as well as chronic instability and early articular degeneration. PMID:27703817

  20. Worker-to-Worker Violence in Hospitals

    PubMed Central

    Hamblin, Lydia E.; Essenmacher, Lynnette; Ager, Joel; Upfal, Mark; Luborsky, Mark; Russell, Jim; Arnetz, Judith

    2016-01-01

    Worker-to-worker (Type III) violence is prevalent in health care settings and has potential adverse consequences for employees and organizations. Little research has examined perpetrator characteristics of this type of violence. The current study is a descriptive examination of the common demographic and work-related characteristics of perpetrators of Type III workplace violence among hospital workers. Analysis was based on documented incidents of Type III violence reported within a large hospital system from 2010 to 2012. Nurses were involved as either the perpetrator or target in the five most common perpetrator–target dyads. Incidence rate ratios revealed that patient care associates and nurses were significantly more likely to be perpetrators than other job titles. By examining characteristics of perpetrators and common worker dyads involved in Type III workplace violence, hospital stakeholders and unit supervisors have a starting point to develop strategies for reducing conflict between workers. PMID:26450899

  1. Coal worker's pneumoconiosis

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000130.htm Coal worker's pneumoconiosis To use the sharing features on this page, please enable JavaScript. Coal worker's pneumoconiosis is a lung disease that results ...

  2. Reactions between a <111> screw dislocation and <100> interstitial dislocation loops in alpha-iron modelled at atomic-scale

    SciTech Connect

    Terentyev, Dmitry; Bacon, David J; Osetskiy, Yury N

    2010-03-01

    Interstitial dislocation loops with Burgers vector of <100> type are observed in {alpha}-iron irradiated by neutrons or heavy ions, and their population increases with increasing temperature. Their effect on motion of a 1/2<111> edge dislocation was reported earlier 1. Results are presented of a molecular dynamics study of interactions between a 1/2<111> screw dislocation and <100> loops in iron at temperature in the range 100 to 600 K. A variety of reaction mechanisms and outcomes are observed and classified in terms of the resulting dislocation configuration and the maximum stress required for the dislocation to break away. The highest obstacle resistance arises when the loop is absorbed to form a helical turn on the screw dislocation line, for the dislocation cannot glide away until the turn closes and a loop is released with the same Burgers vector as the line. Other than one situation found, in which no dislocation-loop reaction occurs, the weakest obstacle strength is found when the original <100> loop is restored at the end of the reaction. The important role of the cross-slip and the influence of model boundary conditions are emphasised and demonstrated by examples.

  3. Comparison of dislocation density tensor fields derived from discrete dislocation dynamics and crystal plasticity simulations of torsion

    SciTech Connect

    Jones, Reese E.; Zimmerman, Jonathan A.; Po, Giacomo; Mandadapu, Kranthi

    2016-02-01

    Accurate simulation of the plastic deformation of ductile metals is important to the design of structures and components to performance and failure criteria. Many techniques exist that address the length scales relevant to deformation processes, including dislocation dynamics (DD), which models the interaction and evolution of discrete dislocation line segments, and crystal plasticity (CP), which incorporates the crystalline nature and restricted motion of dislocations into a higher scale continuous field framework. While these two methods are conceptually related, there have been only nominal efforts focused at the global material response that use DD-generated information to enhance the fidelity of CP models. To ascertain to what degree the predictions of CP are consistent with those of DD, we compare their global and microstructural response in a number of deformation modes. After using nominally homogeneous compression and shear deformation dislocation dynamics simulations to calibrate crystal plasticity ow rule parameters, we compare not only the system-level stress-strain response of prismatic wires in torsion but also the resulting geometrically necessary dislocation density fields. To establish a connection between explicit description of dislocations and the continuum assumed with crystal plasticity simulations we ascertain the minimum length-scale at which meaningful dislocation density fields appear. Furthermore, our results show that, for the case of torsion, that the two material models can produce comparable spatial dislocation density distributions.

  4. Comparison of dislocation density tensor fields derived from discrete dislocation dynamics and crystal plasticity simulations of torsion

    DOE PAGES

    Jones, Reese E.; Zimmerman, Jonathan A.; Po, Giacomo; ...

    2016-02-01

    Accurate simulation of the plastic deformation of ductile metals is important to the design of structures and components to performance and failure criteria. Many techniques exist that address the length scales relevant to deformation processes, including dislocation dynamics (DD), which models the interaction and evolution of discrete dislocation line segments, and crystal plasticity (CP), which incorporates the crystalline nature and restricted motion of dislocations into a higher scale continuous field framework. While these two methods are conceptually related, there have been only nominal efforts focused at the global material response that use DD-generated information to enhance the fidelity of CPmore » models. To ascertain to what degree the predictions of CP are consistent with those of DD, we compare their global and microstructural response in a number of deformation modes. After using nominally homogeneous compression and shear deformation dislocation dynamics simulations to calibrate crystal plasticity ow rule parameters, we compare not only the system-level stress-strain response of prismatic wires in torsion but also the resulting geometrically necessary dislocation density fields. To establish a connection between explicit description of dislocations and the continuum assumed with crystal plasticity simulations we ascertain the minimum length-scale at which meaningful dislocation density fields appear. Furthermore, our results show that, for the case of torsion, that the two material models can produce comparable spatial dislocation density distributions.« less

  5. [Posteromedial dislocation of the elbow with lateral condyle and coronoid process fractures: a case report].

    PubMed

    Mirouse, G; Corcos, P; Casabianca, L; Guillon, P

    2014-02-01

    We report the occurrence of a rare injury in a teenager not yet described in the literature: the association of posteromedial elbow dislocation, lateral condyle and coronoid process fractures. The treatment required fixation of lateral condyle and coronoid process thanks to lateral and medial approaches and capsular fixation. This lesion is unstable, such as the terrible triad described in adults. It requires external and anterior stabilization of the elbow. The management of such injuries of the elbow is complex. It must consider both bone and ligament instability, and risk of injury to growth plates.

  6. Re-Training of Older Workers.

    ERIC Educational Resources Information Center

    Iron and Steel Industry Training Board, London (England).

    Designed to assist training staff in the planning and implementation of training for older workers, this guide indicates: the main problem areas; the extent and importance of the various requirements; some industrial experience in dealing with such problems; and some further resources of information on particular aspects of training of adults. The…

  7. Transient vascular compromise of the lunate after fracture-dislocation or dislocation of the carpus.

    PubMed

    White, R E; Omer, G E

    1984-03-01

    Although classic avascular necrosis of the lunate is rare after fracture-dislocation or dislocation of the carpus, these severe carpal injuries can compromise the vascular supply of the lunate. The lunate thus develops a relative increase in radiodensity. Our finding of an incidence of 12.5%--three of 24 cases--suggests a relatively frequent occurrence. The clinical course was transient with resolution of abnormal radiodensity and subjective findings. Moreover, none of the three cases progressed to classic avascular necrosis of the lunate, Kienböck's disease. The clinician should not confuse this transient vascular compromise of the lunate with Kienböck's disease, but should be aware of the entity and its benign, self-limited course and should treat it expectantly.

  8. Competing Processes in Reactions between an Edge Dislocation and Dislocation Loops in a Body-Centred Cubic Metal

    SciTech Connect

    Terentyev, Dmitry; Bacon, David J; Osetskiy, Yury N

    2010-01-01

    Molecular dynamics simulation was used to investigate reactions of a 1/2<111>{l_brace}110{r_brace} edge dislocation with interstitial dislocation loops of 1/2<111> and <100> type in a model of iron. Whether loops are strong or weak obstacles depends not only on loop size and type, but also on temperature and dislocation velocity. These parameters determine whether a loop is absorbed on the dislocation or left behind as it glides away. Absorption requires glide of a reaction segment over the loop surface and cross-slip of dipole dislocation arms attached to the ends of the segment: these mechanisms depend on temperature and strain rate, as discussed here.

  9. Stress-free states of continuum dislocation fields: Rotations, grain boundaries, and the Nye dislocation density tensor

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; Sethna, James P.

    2007-06-01

    We derive general relations between grain boundaries, rotational deformations, and stress-free states for the mesoscale continuum Nye dislocation density tensor. Dislocations generally are associated with long-range stress fields. We provide the general form for dislocation density fields whose stress fields vanish. We explain that a grain boundary (a dislocation wall satisfying Frank’s formula) has vanishing stress in the continuum limit. We show that the general stress-free state can be written explicitly as a (perhaps continuous) superposition of flat Frank walls. We show that the stress-free states are also naturally interpreted as configurations generated by a general spatially dependent rotational deformation. Finally, we propose a least-squares definition for the spatially dependent rotation field of a general (stressful) dislocation density field.

  10. Kink pair production and dislocation motion

    PubMed Central

    Fitzgerald, S. P.

    2016-01-01

    The motion of extended defects called dislocations controls the mechanical properties of crystalline materials such as strength and ductility. Under moderate applied loads, this motion proceeds via the thermal nucleation of kink pairs. The nucleation rate is known to be a highly nonlinear function of the applied load, and its calculation has long been a theoretical challenge. In this article, a stochastic path integral approach is used to derive a simple, general, and exact formula for the rate. The predictions are in excellent agreement with experimental and computational investigations, and unambiguously explain the origin of the observed extreme nonlinearity. The results can also be applied to other systems modelled by an elastic string interacting with a periodic potential, such as Josephson junctions in superconductors. PMID:28004834

  11. Kink pair production and dislocation motion

    NASA Astrophysics Data System (ADS)

    Fitzgerald, S. P.

    2016-12-01

    The motion of extended defects called dislocations controls the mechanical properties of crystalline materials such as strength and ductility. Under moderate applied loads, this motion proceeds via the thermal nucleation of kink pairs. The nucleation rate is known to be a highly nonlinear function of the applied load, and its calculation has long been a theoretical challenge. In this article, a stochastic path integral approach is used to derive a simple, general, and exact formula for the rate. The predictions are in excellent agreement with experimental and computational investigations, and unambiguously explain the origin of the observed extreme nonlinearity. The results can also be applied to other systems modelled by an elastic string interacting with a periodic potential, such as Josephson junctions in superconductors.

  12. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    PubMed Central

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despite routine post-operative skeletal traction in all cases and careful soft tissue interposition. One case showed significant heterotopic ossification which restricted prolonged sitting. This patient needed some occasional medication for pain. PMID:12180614

  13. Disclinations, dislocations, and continuous defects: A reappraisal

    NASA Astrophysics Data System (ADS)

    Kleman, M.; Friedel, J.

    2008-01-01

    Disclinations were first observed in mesomorphic phases. They were later found relevant to a number of ill-ordered condensed-matter media involving continuous symmetries or frustrated order. Disclinations also appear in polycrystals at the edges of grain boundaries; but they are of limited interest in solid single crystals, where they can move only by diffusion climb and, owing to their large elastic stresses, mostly appear in close pairs of opposite signs. The relaxation mechanisms associated with a disclination in its creation, motion, and change of shape involve an interplay with continuous or quantized dislocations and/or continuous disclinations. These are attached to the disclinations or are akin to Nye’s dislocation densities, which are particularly well suited for consideration here. The notion of an extended Volterra process is introduced, which takes these relaxation processes into account and covers different situations where this interplay takes place. These concepts are illustrated by a variety of applications in amorphous solids, mesomorphic phases, and frustrated media in their curved habit space. These often involve disclination networks with specific node conditions. The powerful topological theory of line defects considers only defects stable against any change of boundary conditions or relaxation processes compatible with the structure considered. It can be seen as a simplified case of the approach considered here, particularly suited for media of high plasticity or/and complex structures. It cannot analyze the dynamical properties of defects nor the elastic constants involved in their static properties; topological stability cannot guarantee energetic stability, and sometimes cannot distinguish finer details of the structure of defects.

  14. The Effects of Economic Policies and Employment Assistance Programs on the Well-Being of Displaced Female Apparel Workers

    ERIC Educational Resources Information Center

    Rocha, Cynthia; Strand, Elizabeth B.

    2004-01-01

    This article explores how labor market trends and current employment assistance policies affect reemployment opportunities and emotional well-being in a sample of female dislocated apparel workers. The study follows the displaced women from the time the plant closed for 6 months to assess their financial and emotional well-being as they reentered…

  15. The length change of a dislocation junction in FCC-single crystals under stress

    NASA Astrophysics Data System (ADS)

    Kurinnaya, Raisa; Zgolich, Marina; Starenchenko, Vladimir; Sadritdinova, Gulnora

    2016-01-01

    The product of dislocation reactions among dislocations of non-coplanar slip systems are dislocation junctions. The paper presents the study on the length change of dislocation junctions under stress. It is revealed that dislocation junctions can be destructed by merging of triple dislocation nodes at certain inclination angles of the glide dislocation and the forest dislocation to the junction line and the corresponding lengths of free segments of intersecting dislocations. Dislocation junctions formed at an arbitrary intersection of segments of the reacting dislocation are investigated. The geometry of the intersection of segments of reacting dislocations, at which dislocation junctions are not completely destructed under stress but cease to be an obstacle for further motion of the glide dislocation, is determined. Such junctions remain in the shear zone, presenting an obstacle to other glide dislocations. Conditions under which the length of the dislocation junction increases with an increase in the stress exceeding the original length are found. The formed extended barrier becomes too strong for the acting stress. Higher stresses are required in order to destruct it. The probability of completely destructible junctions under stress, the probability of non-destructible junctions that remain in the shear zone and replenish the density of dislocation debris, as well as the probability of formation of long strong junctions, which are barriers capable of limiting the shear zone, are determined.

  16. Transition of dislocation glide to shear transformation in shocked tantalum

    DOE PAGES

    Hsiung, Luke L.; Campbell, Geoffrey H.

    2017-02-28

    A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa (strain rate: ~1 x 104 sec-1) is presented. While no ω (hexagonal) phase was found in shock-recovered pure Ta and Ta-5W that contain mainly a low-energy cellular dislocation structure, shock-induced ω phase was found to form in Ta-10W that contains evenly distributed dislocations with a stored dislocation density higher than 1 x 1012 cm-2. The TEM results clearly reveal that shock-induced α (bcc) → ω (hexagonal) shear transformation occurs when dynamic recovery reactions which lead the formation low-energy cellular dislocation structure becomemore » largely suppressed in Ta-10W shocked under dynamic (i.e., high strain-rate and high-pressure) conditions. A novel dislocation-based mechanism is proposed to rationalize the transition of dislocation glide to twinning and/or shear transformation in shock-deformed tantalum. Lastly, twinning and/or shear transformation take place as an alternative deformation mechanism to accommodate high-strain-rate straining when the shear stress required for dislocation multiplication exceeds the threshold shear stresses for twinning and/or shear transformation.« less

  17. Period-doubling reconstructions of semiconductor partial dislocations

    DOE PAGES

    Park, Ji -Sang; Huang, Bing; Wei, Su -Huai; ...

    2015-09-18

    Atomic-scale understanding and control of dislocation cores is of great technological importance, because they act as recombination centers for charge carriers in optoelectronic devices. Using hybrid density-functional calculations, we present period-doubling reconstructions of a 90° partial dislocation in GaAs, for which the periodicity of like-atom dimers along the dislocation line varies from one to two, to four dimers. The electronic properties of a dislocation change drastically with each period doubling. The dimers in the single-period dislocation are able to interact, to form a dispersive one-dimensional band with deep-gap states. However, the inter-dimer interaction for the double-period dislocation becomes significantly reduced;more » hence, it is free of mid-gap states. The Ga core undergoes a further period-doubling transition to a quadruple-period reconstruction induced by the formation of small hole polarons. Lastly, the competition between these dislocation phases suggests a new passivation strategy via population manipulation of the detrimental single-period phase.« less

  18. Period-doubling reconstructions of semiconductor partial dislocations

    SciTech Connect

    Park, Ji -Sang; Huang, Bing; Wei, Su -Huai; Kang, Joongoo; McMahon, William E.

    2015-09-18

    Atomic-scale understanding and control of dislocation cores is of great technological importance, because they act as recombination centers for charge carriers in optoelectronic devices. Using hybrid density-functional calculations, we present period-doubling reconstructions of a 90° partial dislocation in GaAs, for which the periodicity of like-atom dimers along the dislocation line varies from one to two, to four dimers. The electronic properties of a dislocation change drastically with each period doubling. The dimers in the single-period dislocation are able to interact, to form a dispersive one-dimensional band with deep-gap states. However, the inter-dimer interaction for the double-period dislocation becomes significantly reduced; hence, it is free of mid-gap states. The Ga core undergoes a further period-doubling transition to a quadruple-period reconstruction induced by the formation of small hole polarons. Lastly, the competition between these dislocation phases suggests a new passivation strategy via population manipulation of the detrimental single-period phase.

  19. 20 CFR 663.160 - Are there particular core services an individual must receive before receiving intensive services...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....160 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult...

  20. 20 CFR 663.160 - Are there particular core services an individual must receive before receiving intensive services...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....160 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Delivery of Adult...

  1. Mortality among rubber workers: VII. Aerospace workers.

    PubMed

    Delzell, E; Monson, R R

    1984-01-01

    This study evaluated cause-specific mortality among 3,161 men who were employed in the aerospace division of a rubber manufacturing company. Compared to other production workers at the plant, aerospace workers in deicer and fuel cell manufacturing jobs experienced a 60% excess of deaths from lung cancer. Deicer and fuel cell workers who were under 65 years of age had lung cancer rates that were approximately twice those of other rubber workers of comparable age. Aerospace division employees also had elevated rates of bladder cancer, leukemia, lymphoma, and multiple myeloma. However, detailed analyses suggested that, with the exception of lung cancer, these cancer excesses were not likely to be attributable to employment in the aerospace division.

  2. Spontaneous Late Intraocular Lens and Capsule Tension Ring Dislocation

    PubMed Central

    Koçak Altıntaş, Ayşe Gül; Omay, Aslıhan Esra; Çelik, Selda

    2017-01-01

    In this report, three cases with pseudoexfoliation (PEX) and advanced age with spontaneous intraocular lens (IOL) and capsule tension ring (CTR) dislocation were presented. All of our cases experienced progressive vision loss without an episode of strenuous physical activity, trauma, or any other ocular disease. Spontaneous dislocation was observed 2.5 to 8 years after uneventful phacosurgery. Each patient underwent complete IOL and CTR removal combined with anterior chamber IOL implantation. No complications were noticed during follow-up. As a result, capsule tension ring does not prevent late IOL dislocation after uncomplicated phacosurgery in the presence of PEX. Therefore, close follow-up is essential for patients with PEX.

  3. Posterior dislocation of the sternoclavicular joint: report of two cases.

    PubMed

    Labronici, Pedro José; Souza, Fabrício Cardoso de; Pires, Robinson Esteves Santos; Santos Filho, Fernando Claudino Dos; Gameiro, Vinicius Schott; Labronici, Gustavo José

    2016-01-01

    The authors report the cases of two young patients who had suffered a sporting accident with posterior traumatic dislocation of sternoclavicular joint. In one of the patients closed reduction was accomplished by keeping the limb in a sling. The second patient, after reduction was done, presented recurrence of the dislocation, thus requiring surgical treatment. It is important to observe the relevance of computed tomography to help diagnosing, as well as monitoring the reduction procedure. The objective of this study was to demonstrate two different types of treatment in a rare injury such as the posterior dislocation of sternoclavicular joint.

  4. Dislocations in extruded Co-49.3 at. pct Al

    NASA Technical Reports Server (NTRS)

    Yaney, D. L.; Nix, W. D.; Pelton, A. R.

    1986-01-01

    Polycrystalline Co-49.3 at. pct Al, which had been extruded at 1505 K, was examined using transmission electron microscopy. Diffraction contrast analysis showed that b = 100 as well as b = 111 line dislocations contribute to elevated temperature deformation in CoAl. Therefore, it was concluded that sufficient slip systems exist in CoAl to allow for general plasticity in the absence of diffusional mechanisms. Line dislocations of the type b = 001 were observed on both 110 and 100 planes while b = 111 line dislocations were observed on 1 -1 0 planes.

  5. [How I Treat. An Anterior Temporomandibular Joint Dislocation].

    PubMed

    Gilon, Y; Johnen, J; Nizet, J L

    2015-09-01

    Anterior dislocation of the temporomandibular joint is not uncommon and requires prompt management. A defect of dislocation reduction can lead to severe functional impairment of a complex, and often active joint. The diagnosis is clinical and relatively obvious. It is made by the frontline medical team, general practitioner or emergency doctor. Recurrent cases are a matter for maxillofacial surgeons. This article describes a conventional technique for anterior dislocation reduction, to achieve urgently. The second part of the article deals with the specialized surgical treatment of relapsing forms.

  6. Complicated Congenital Dislocation of the Knee: A Case Report

    PubMed Central

    Madadi, Firooz; Tahririan, Mohammad A.; Karami, Mohsen; Madadi, Firoozeh

    2016-01-01

    Congenital dislocation of the knee (CDK) is a rare disorder. We report the case of a 7-year-old girl with bilateral knee stiffness, marked anterior bowing of both legs, and inability to walk without aid. Radiologic investigation revealed bilateral knee joint dislocation accompanied by severe anterior bowing of both tibia proximally and posterior bowing of both femur distally, demonstrating a complicated congenital knee dislocation. Two-staged open reduction with proximal tibial osteotomy was performed to align the reduced knee joints. The patient was completely independent in her daily activities after surgical correction. PMID:27847857

  7. Ubiquity of quantum zero-point fluctuations in dislocation glide

    NASA Astrophysics Data System (ADS)

    Landeiro Dos Reis, Marie; Choudhury, Anshuman; Proville, Laurent

    2017-03-01

    Modeling the dislocation glide through atomic scale simulations in Al, Cu, and Ni and in solid solution alloys Al(Mg) and Cu(Ag), we show that in the course of the plastic deformation the variation of the crystal zero-point energy (ZPE) and the dislocation potential energy barriers are of opposite sign. The multiplicity of situations where we have observed the same trend allows us to conclude that quantum fluctuations, giving rise to the crystal ZPE, make easier the dislocation glide in most materials, even those constituted of atoms heavier than H and He.

  8. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies

    DOE PAGES

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; ...

    2015-01-23

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Lastly, our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation andmore » dynamics in these systems.« less

  9. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies

    SciTech Connect

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; Beyerlein, Irene J.

    2015-01-23

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Lastly, our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation and dynamics in these systems.

  10. Lead toxicity in battery workers.

    PubMed

    Qasim, Saeeda Fouzia; Baloch, Malka

    2014-11-01

    Lead poisoning is a medical condition caused by increased levels of lead in the body. Routes of exposure include contaminated air, water, soil, food and consumer products. Occupational exposure is the main cause of lead poisoning in the adults. Two cases of occupational lead poisoning in adult battery workers are hereby presented. Both male patients had initial non-specific symptoms of intermittent abdominal pain, fatigue and headache for 6 - 8 years. Later on, they developed psychosis, slurred speech, tremors of hands and initially underwent treatment for Parkinsonism and Wilson's disease because of clinical misdiagnosis. They were diagnosed with lead poisoning later and were treated successfully with lead chelator (CaNa2 EDTA).

  11. Simulation of the interaction between an edge dislocation and a 1 0 0 interstitial dislocation loop in -iron

    SciTech Connect

    Terentyev, Dmitry; Grammatikopoulos, P.; Bacon, D; Osetsky, Yu N

    2008-01-01

    Atomic-level simulations are used to investigate the interaction of an edge dislocation with h100i interstitial dislocation loops in airon at 300 K. Dislocation reactions are studied systematically for different loop positions and Burgers vector orientations, and results are compared for two different interatomic potentials. Reactions are wide-ranging and complex, but can be described in terms of conventional dislocation reactions in which Burgers vector is conserved. The fraction of interstitials left behind after dislocation breakaway varies from 25 to 100%. The nature of the reactions requiring high applied stress for breakaway is identified. The obstacle strengths of h100i loops, 1/2h111i loops and voids containing the same number (169) of point defects are compared. h100i loops with Burgers vector parallel to the dislocation glide plane are slightly stronger than h100i and 1/2h111i loops with inclined Burgers vector: voids are about 30% weaker than the stronger loops. However, small voids are stronger than small 1/2h111i loops. The complexity of some reactions and the variety of obstacle strengths poses a challenge for the development of continuum models of dislocation behaviour in irradiated iron. 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. The influence of the dislocation distribution heterogeneity degree on the formation of a non-misoriented dislocation cell substructures in f.c.c. metals

    NASA Astrophysics Data System (ADS)

    Cherepanov, D. N.; Selivanikova, O. V.; Matveev, M. V.

    2016-06-01

    Dislocation loops emitted by Frank-Reed source during crossing dislocations of the non-coplanar slip systems are accumulates jogs on the own dislocation line, resulting in the deceleration of the segments of dislocation loops with high jog density. As a result, bending around of the slowed segments the formation of dynamic dipoles in the shear zone occurs. In the present paper we consider formation mechanism of non-misoriented dislocation cell substructure during plastic deformation of f.c.c. metals and conclude that the increase in the degree heterogeneity of dislocation distribution leads to an increase in the jog density and reduce the mean value of arm dynamic dipoles.

  13. Evolution of dislocation density and character in hot rolled titanium determined by X-ray diffraction

    SciTech Connect

    Dragomir, I.C. . E-mail: iuliana.cernatescu@mse.gatech.edu; Li, D.S.; Castello-Branco, G.A.; Garmestani, H.; Snyder, R.L.; Ribarik, G.; Ungar, T.

    2005-07-15

    X-ray Peak Profile Analysis was employed to determine the evolution dislocation density and dislocations type in hot rolled commercially pure titanium specimens. It was found that dislocation type is dominating the deformation mechanism at all rolling reduction levels studied here. A good agreement was found between the texture evolution and changes in dislocation slip system activity during the deformation process.

  14. Bulk Dislocation Core Dissociation Probed by Coherent X Rays in Silicon

    SciTech Connect

    Jacques, V. L. R.; Pinsolle, E.; Ravy, S.; Sauvage-Simkin, M.; Le Bolloc'h, D.; Livet, F.

    2011-02-11

    We report on a new approach to probe bulk dislocations by using coherent x-ray diffraction. Coherent x rays are particularly suited for bulk dislocation studies because lattice phase shifts in condensed matter induce typical diffraction patterns which strongly depend on the fine structure of the dislocation cores. The strength of the method is demonstrated by performing coherent diffraction of a single dislocation loop in silicon. A dissociation of a bulk dislocation is measured and proves to be unusually large compared to surface dislocation dissociations. This work opens a route for the study of dislocation cores in the bulk in a static or dynamical regime, and under various external constraints.

  15. Dislocation Structure and Mobility in hcp ^{4}He.

    PubMed

    Landinez Borda, Edgar Josué; Cai, Wei; de Koning, Maurice

    2016-07-22

    Using path-integral Monte Carlo simulations, we assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp ^{4}He. Our findings provide key insights into recent interpretations of giant plasticity and mass flow junction experiments. First, both dislocations are dissociated into nonsuperfluid Shockley partial dislocations separated by ribbons of stacking fault, suggesting that they are unlikely to act as one-dimensional channels that may display Lüttinger-liquid-like behavior. Second, the centroid positions of the partial cores are found to fluctuate substantially, even in the absence of applied shear stresses. This implies that the lattice resistance to motion of the partial dislocations is negligible, consistent with the recent experimental observations of giant plasticity. Further results indicate that both the structure of the partial cores and the zero-point fluctuations play a role in this extreme mobility.

  16. Plastic anisotropy and dislocation trajectory in BCC metals

    PubMed Central

    Dezerald, Lucile; Rodney, David; Clouet, Emmanuel; Ventelon, Lisa; Willaime, François

    2016-01-01

    Plasticity in body-centred cubic (BCC) metals at low temperatures is atypical, marked in particular by an anisotropic elastic limit in clear violation of the famous Schmid law applicable to most other metals. This effect is known to originate from the behaviour of the screw dislocations; however, the underlying physics has so far remained insufficiently understood to predict plastic anisotropy without adjustable parameters. Here we show that deviations from the Schmid law can be quantified from the deviations of the screw dislocation trajectory away from a straight path between equilibrium configurations, a consequence of the asymmetrical and metal-dependent potential energy landscape of the dislocation. We propose a modified parameter-free Schmid law, based on a projection of the applied stress on the curved trajectory, which compares well with experimental variations and first-principles calculations of the dislocation Peierls stress as a function of crystal orientation. PMID:27221965

  17. Plastic anisotropy and dislocation trajectory in BCC metals.

    PubMed

    Dezerald, Lucile; Rodney, David; Clouet, Emmanuel; Ventelon, Lisa; Willaime, François

    2016-05-25

    Plasticity in body-centred cubic (BCC) metals at low temperatures is atypical, marked in particular by an anisotropic elastic limit in clear violation of the famous Schmid law applicable to most other metals. This effect is known to originate from the behaviour of the screw dislocations; however, the underlying physics has so far remained insufficiently understood to predict plastic anisotropy without adjustable parameters. Here we show that deviations from the Schmid law can be quantified from the deviations of the screw dislocation trajectory away from a straight path between equilibrium configurations, a consequence of the asymmetrical and metal-dependent potential energy landscape of the dislocation. We propose a modified parameter-free Schmid law, based on a projection of the applied stress on the curved trajectory, which compares well with experimental variations and first-principles calculations of the dislocation Peierls stress as a function of crystal orientation.

  18. Localization of Oscillations on Dislocations in Piezoelectric Crystals

    NASA Astrophysics Data System (ADS)

    Gestrin, S. G.; Schukina, E. V.

    2014-05-01

    Longitudinal oscillations localized on dislocations are shown to exist in C4v piezoelectric crystals. Dispersion equations are constructed for axially symmetric and localized screw waves. Frequency regions separating their frequencies from the spectrum of volume oscillations are identified.

  19. Open Anterior Dislocation of the Hip in Togo

    PubMed Central

    Anani, Abalo; Yannick, Dellanh; Gamal, Ayouba; Assang, Dossim

    2016-01-01

    Anterior traumatic dislocations of the hip are much less common than posterior dislocations. To date, 14 cases of open anterior dislocation of the hip associated with such injuries, acetabular and femoral head fractures and femoral vascular and nerve damage have been reported. We present a case of a 23-year-old male who sustained open anterior dislocation of the hip with ipsilateral fracture of the greater trochanter after an accident on the public highway. Additional lesions included an iliac wing fracture and a perineal wound. We report this case because of the rarity and seriousness of this injury due to its progressive complications and difficulties related to its management, which are typical to a developing country like ours. PMID:27247749

  20. Posteromedial dislocation of the ankle without fracture or diastasis.

    PubMed

    Wang, L C; Love, M B

    1993-02-01

    This case report describes a patient with posteromedial dislocation of the ankle without fracture and without disruption of the tibiofibular syndesmosis. The pathogenesis of this uncommon lesion is discussed.

  1. Plastic anisotropy and dislocation trajectory in BCC metals

    NASA Astrophysics Data System (ADS)

    Dezerald, Lucile; Rodney, David; Clouet, Emmanuel; Ventelon, Lisa; Willaime, François

    2016-05-01

    Plasticity in body-centred cubic (BCC) metals at low temperatures is atypical, marked in particular by an anisotropic elastic limit in clear violation of the famous Schmid law applicable to most other metals. This effect is known to originate from the behaviour of the screw dislocations; however, the underlying physics has so far remained insufficiently understood to predict plastic anisotropy without adjustable parameters. Here we show that deviations from the Schmid law can be quantified from the deviations of the screw dislocation trajectory away from a straight path between equilibrium configurations, a consequence of the asymmetrical and metal-dependent potential energy landscape of the dislocation. We propose a modified parameter-free Schmid law, based on a projection of the applied stress on the curved trajectory, which compares well with experimental variations and first-principles calculations of the dislocation Peierls stress as a function of crystal orientation.

  2. Elastic field of approaching dislocation loop in isotropic bimaterial

    NASA Astrophysics Data System (ADS)

    Wu, Wenwang; Xia, Re; Xu, Shucai; Qian, Guian; Zhang, Jinhuan

    2015-10-01

    A semi-analytical solution is developed for calculating interface traction stress (ITS) fields due to elastic modulus mismatch across the interface plane of isotropic perfectly bounded bimaterial system. Based on the semi-analytical approaches developed, ITS is used to correct the bulk elastic field of dislocation loop within infinite homogenous medium, and to produce continuous displacement and stress fields across the perfectly-bounded interface. Firstly, calculation examples of dislocation loops in Al-Cu bimaterial system are performed to demonstrate the efficiency of the developed semi-analytical approach; Then, the elastic fields of dislocation loops in twinning Cu and Cu-Nb bimaterial are analyzed; Finally, the effect of modulus mismatch across interface plane on the elastic field of bimaterial system is investigated, it is found that modulus mismatch has a drastic impact on the elastic fields of dislocation loops within bimaterial system.

  3. Thermal Activation of Dislocations in Large Scale Obstacle Bypass

    SciTech Connect

    Martinez Saez, Enrique; Sobie, Cameron; Wen, Wei; Capolungo, Laurent; Patra, Anirban; McDowell, David L.; Tome, Carlos

    2016-08-18

    Irradiation-created defects diffuse and agglomerate presenting obstacles for the dislocation motion (both glide and climb). This effect leads to hardening and loss of toughness, which might drive the system to failure.

  4. Ligamentous and capsular restraints to experimental posterior elbow joint dislocation.

    PubMed

    Deutch, Søren R; Olsen, Bo S; Jensen, Steen L; Tyrdal, Stein; Sneppen, Otto

    2003-10-01

    Pathological external forearm rotation (PEFR) relates to posterolateral elbow joint instability, and is considered a possible requisite step in a simple posterior elbow joint dislocation. The aim of this study was to evaluate the capsuloligamentous restraint to PEFR. In all, 18 elbow joint specimens were examined in a joint analysis system developed for experimental elbow dislocation. Sequential cutting of capsule and ligaments followed by stability testing provided specific data relating to each capsuloligamentous structure. The primary stabilizers against PEFR in the extended elbow were the anterior capsule and the lateral collateral ligament complex (LCLC), whereas in the flexed elbow the anterior capsule did not have a stabilizing effect. In flexed joint positions, the LCLC seems to be the only immediate stabilizer against PEFR, and thereby against posterolateral instability and possibly against posterior dislocation. The medial collateral ligament did not have any immediate stabilizing effect, but it prevented the final step of the posterior dislocation.

  5. Dislocation Structure and Mobility in hcp He4

    DOE PAGES

    Landinez Borda, Edgar Josue; Cai, Wei; de Koning, Maurice

    2016-07-20

    We assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp 4He using path-integral Monte Carlo simulations. Our findings provide key insights into recent interpretations of giant plasticity and mass flow junction experiments. First, both dislocations are dissociated into nonsuperfluid Shockley partial dislocations separated by ribbons of stacking fault, suggesting that they are unlikely to act as one-dimensional channels that may display Lüttinger-liquid-like behavior. Second, the centroid positions of the partial cores are found to fluctuate substantially, even in the absence of applied shear stresses. This implies that the lattice resistance to motion of themore » partial dislocations is negligible, consistent with the recent experimental observations of giant plasticity. Our results indicate that both the structure of the partial cores and the zero-point fluctuations play a role in this extreme mobility.« less

  6. Dislocation-induced superfluidity in a model supersolid

    NASA Astrophysics Data System (ADS)

    Dasbiswas, Kinjal; Goswami, Debajit; Yoo, Chi-Deuk; Dorsey, Alan

    2010-03-01

    The effect of an edge dislocation in inducing superfluidity is explored by coupling the elastic strain field of the dislocation to the superfluid density, and solving the corresponding Ginzburg-Landau theory. It is shown that superfluid density is induced along a single dislocation below a critical temperature determined by the ground state solution of a 2D Schr"odinger equation with a dipolar potential. This superfluid behavior can be described by a 1D Ginzburg-Landau equation obtained through a weakly nonlinear analysis. We then extend our analysis to a network of dislocation lines considered before by Shevchenko and Toner, which could serve as a model for superflow through solid ^4He. The effect of fluctuations and dynamics are included through a full time dependent Ginzburg-Landau theory.

  7. Thermally-Active Screw Dislocations in Si Nanowires and Nanotubes

    NASA Astrophysics Data System (ADS)

    Dumitrica, Traian; Xiong, Shiyun; Ma, Jihong; Volz, Sebastian

    2014-03-01

    New properties appear when nanomaterials contain dislocations. Understanding whether these features, which arise naturally during growth, are beneficial or problematic becomes essential for developing applications. Here we investigate 110 Si nanowire and nanotube structures containing an axial screw dislocation, as described by objective molecular dynamics coupled with the classical Tersoff potential. By means of direct nonequilibrium molecular dynamics simulations, we uncover significant reductions in thermal conductivity when nanostructures contain axial screw dislocations with closed and open cores. Analysis based on the atomistic Green function method reveals that in nanowires, the effect originates largely in the phonon-phonon scattering due to the enhanced anharmonicity introduced by highly distorted core region of the dislocation. In nanotubes, the inner surface compensates effectively for the missing core region. The uncovered effect can act in combination with other already known thermal conductivity limiting mechanisms, and thus can enable the further optimization of the figure of merit for a new family of complex thermoelectric nanomaterials.

  8. ParaDiS-FEM dislocation dynamics simulation code primer

    SciTech Connect

    Tang, M; Hommes, G; Aubry, S; Arsenlis, A

    2011-09-27

    The ParaDiS code is developed to study bulk systems with periodic boundary conditions. When we try to perform discrete dislocation dynamics simulations for finite systems such as thin films or cylinders, the ParaDiS code must be extended. First, dislocations need to be contained inside the finite simulation box; Second, dislocations inside the finite box experience image stresses due to the free surfaces. We have developed in-house FEM subroutines to couple with the ParaDiS code to deal with free surface related issues in the dislocation dynamics simulations. This primer explains how the coupled code was developed, the main changes from the ParaDiS code, and the functions of the new FEM subroutines.

  9. Dislocation interactions with characteristic interfaces in AgCu eutectic

    NASA Astrophysics Data System (ADS)

    Eftink, Benjamin P.

    In the AgCu eutectic alloy, the observation of deformation twinning in Cu proposed to be induced by direct transmission of deformation twinning partial dislocations in Ag highlights the question of how interfaces in bi-phase materials respond to deformation. AgCu eutectic alloy was produced by both directional solidification and cast water-quenching. Control over processing variables enabled the synthesis of Ag/Cu eutectic with three predominant interface types: ones with a cube-on-cube orientation relationship with {111} Ag||{111}Cu interface habit planes, twin orientation relationship with {111}Ag||{111}Cu interface habit planes, and twin orientation relationship with near {313}Ag||{ 112}Cu interface habit planes. How dislocations interacted with each of the interfaces was determined using in situ and ex situ TEM straining experiments. It was determined that how strain transfers across Ag/Cu interfaces is consistent with criteria of strain transfer across grain boundaries in single phase materials. Specifically, the magnitude of the Burgers vector of the residual dislocation, |bres |, left in the interface should be small. This criterion was determining enough to drive Cu to twin under conditions where otherwise it would not. When transmission of a dislocation would result in a high |bres|, which is common for most slip systems encountering an incoherent twin interface, the interfaces were observed to block the dislocations. It was found that the increased effectiveness of the incoherent twin interfaces to block dislocations compared to the cube-on-cube interfaces resulted in an increased in the yield strength of the material. Interfaces with the cube-on-cube orientation relationship and mutual {111} interface plane between Ag and Cu results in transfer of twinning defects from Ag into Cu. This was found at length scales in the tens of nano-meters to the micron range. Twinning in both phases was observed after both split-Hopkinson pressure bar ex situ straining

  10. Dislocation Damping and Anisotropic Attenuation in the Earth's Upper Mantle

    NASA Astrophysics Data System (ADS)

    Jackson, I.; Farla, R. J.; Fitz Gerald, J. D.; Faul, U.; Zimmerman, M. E.

    2011-12-01

    Seismic anisotropy, attributed to olivine lattice preferred orientation, suggests that tectonic deformation in the Earth's shallow upper mantle involves dislocation creep. Reversible glide of dislocations, generated by the prevailing/fossil tectonic stress, may result in anelastic relaxation that contributes to the reduction of seismic wave speeds and associated attenuation. To test this hypothesis, polycrystalline olivine specimens were synthesised from synthetic (sol-gel) precursors and hot-pressed at high temperature. The hot-pressed material is fully dense, fine-grained and essentially dry and melt-free olivine. Other, coarser-grained material was synthesised from San Carlos olivine powders. These contrasting materials provided the opportunity to distinguish between the influences of grain size and dislocation density. Selected specimens were deformed by dislocation creep either in compression or torsion and characterised for dislocation density via oxidation and backscattered electron imaging. Additionally, the dislocation recovery rate was determined for both olivines at different temperatures and time durations. The results established that a maximum temperature of 1100C should allow a relatively stable dislocation density to be maintained during prolonged mechanical testing (> 50 hours). The shear modulus and associated strain-energy dissipation in both hot-pressed and pre-deformed specimens were subsequently measured at seismic frequencies under conditions of simultaneous high pressure and temperature with torsional forced-oscillation methods. These experiments were carried out with strain amplitudes < 10-5 to permit direct comparison with seismological models. The high-temperature dissipation background, attributed in undeformed fine-grained materials to grain-boundary sliding, and the associated partial relaxation of the shear modulus, are systematically enhanced in the pre-deformed materials - suggesting a role for the dislocations introduced during the

  11. Elastic model of a dislocation center for martensite nucleation

    SciTech Connect

    Vereshchagin, V.P.; Kashchenko, M.P.

    1995-01-01

    The possibility of spontaneous nucleation of a crystal of new phase when the original structure is metastable is usually connected with the catalyzing effect of defects playing the role of nucleation centers. In the case of the {gamma}{r_arrow}{alpha} martensite transformation in iron alloys, even individual dislocations can act as such defects, based on analysis of long-range elastic fields of isolated linear dislocations in a linearly elastic anisotropic continuum, the authors established the existence of a correlation between the geometric characteristics of the elastically deformed state in the vicinity of 60-degree and 30-degree dislocations and the structure and morphological characteristics of {alpha}-martensite observed in massive iron alloy samples. These results suggest that the dislocation affects the pathway of the martensite reaction and allows the authors to say that the specific characteristics of heterogeneous nucleation of new phase for the martensite mechanism of the {gamma}{r_arrow}{alpha} transformation involves singling out a single structural rearrangement variant which is suitable from the standpoint of adapation of the transforming lattice to the characteristic features of the elastically deformed state created by the dislocation. The possibilities for such adaption are limited by the crystallography of the transformation and the reactions of the surrounding austenite occurring when regular connections exist with the morphological characteristics of the martensite crystal, and are not necessarily compatible with the individual features of the elastic field of each dislocation. Considering this, the authors can introduce the concept of a dislocation center for nucleation of a martensite crystal about the region of the dislocation where conditions are realized which are favorable for the formation of a nucleus of martensite crystal of a certain shape and orientation, and they can develop an elastic model corresponding to this concept.

  12. Successful Closed Reduction of a Lateral Elbow Dislocation

    PubMed Central

    Fukuzawa, Takuma; Mitsui, Katsuhiro

    2016-01-01

    In this report, we present a case of lateral elbow dislocation treated with closed reduction. Lateral elbow dislocation is rare, and a closed reduction is reported with even less frequency. The reduction can be hindered by swelling and soft tissue interposition, and we describe the use of a nonoperative reduction technique performed under mild sedation with early physiotherapy to avoid joint stiffness. No additional complication was observed, and the normal range of elbow movement and function was obtained by early physiotherapy. PMID:28097029

  13. Successful Closed Reduction of a Lateral Elbow Dislocation.

    PubMed

    Watanabe, Kenya; Fukuzawa, Takuma; Mitsui, Katsuhiro

    2016-01-01

    In this report, we present a case of lateral elbow dislocation treated with closed reduction. Lateral elbow dislocation is rare, and a closed reduction is reported with even less frequency. The reduction can be hindered by swelling and soft tissue interposition, and we describe the use of a nonoperative reduction technique performed under mild sedation with early physiotherapy to avoid joint stiffness. No additional complication was observed, and the normal range of elbow movement and function was obtained by early physiotherapy.

  14. Pediatric open elbow dislocation without fracture: A case report

    PubMed Central

    Polat, Gökhan; Karademir, Gökhan; Akgül, Turgut; Ceylan, Hasan Hüseyin

    2014-01-01

    INTRODUCTION Elbow dislocations in children are rare injuries. These injuries are often in the form of complex injuries that is accompanied by the median nerve damage and medial epicondyle fracture in the pediatric age group. Open elbow dislocation without fracture in the pediatric age group has been reported very rarely in the literature. PRESENTATION OF CASE The purpose of this study is to present an 8-year-old patient who has open elbow dislocation without fracture accompanying with brachial artery injury. In the clinical examination of the patient, there was an open wound in the transverse antecubital region. After repair of brachial artery injury, open reduction was performed under general anesthesia. In the postoperative clinical examination at 6 months, left elbow flexion was 140°, extension was full and there were no deficit in the supination and pronation of the forearm. DISCUSSION Elbow dislocation without fracture in pediatric patients is a very rare injury. Usually the trauma mechanism of elbow dislocation is falling on outstretched hand with elbow in approximately 30° of flexion. However our patient had fallen on outstretched hand with elbow in full extension. Although this type of trauma mechanism is typical for supracondylar humerus fractures in pediatric age group, in our patient an open posterior elbow dislocation without fracture had occurred. CONCLUSION Pediatric elbow dislocations are rare injuries and the management of these injuries can be technically demanding due to concurrent neurovascular injuries. An open dislocation without fracture is very rare and it should be treated with immediate intervention, an effective teamwork and good rehabilitation. PMID:25460475

  15. Double level arterial injury with neuropraxia following anterior shoulder dislocation

    PubMed Central

    Zaraa, Mourad; Sehli, Heithem; Mahjoub, Sabri; Dridi, Moez; Mbarek, Mondher

    2015-01-01

    Vascular and nervous complications are rare after shoulder dislocation. We report the case of a double level arterial injury with neuropraxia following anterior shoulder dislocation that was diagnosed by MultiDetector-row Computed Tomographic (MDCT) angiography and treated by surgical bypass graft and embolectomy. Our case is original, not only because of the rarity of these complications, but also because of the thromboembolism of brachial artery which could be undiagnosed and could compromise prognosis. PMID:26566344

  16. [Congenital dislocation of the knee: report of 2 cases].

    PubMed

    Ochoa Gómez, L; Sánchez Gimeno, J; García Barrecheguren, E; Marulanda Del Valle, K; Almonte Adón, K; Guerrero Laleona, C

    2015-01-01

    Congenital dislocation of the knee is a rare disease. The diagnosis is made at birth by clinical findings, and confirmed radiologically. It has been associated with various etiologies from intrauterine fetal malpositions to genetic disorders. The prognosis depends on early treatment and whether there are other congenital anomalies. We report two new cases of congenital dislocation of the knee, observed in our hospital during the period of a month, diagnosed immediately after birth, and both with a good clinical outcome.

  17. Comparison of community health worker-led diabetes medication decision-making support for low-income Latino and African American adults with diabetes using e-Health tools versus print materials: A randomized controlled trial

    PubMed Central

    Heisler, Michele; Choi, Hwajung; Palmisano, Gloria; Mase, Rebecca; Richardson, Caroline; Fagerlin, Angela; Montori, Victor M.; Spencer, Michael; An, Laurence C.

    2015-01-01

    Background Health care centers serving low-income communities have scarce resources to support medication decision-making among patients with poorly controlled diabetes. Objective We compared outcomes between community health worker (CHW) use of a tailored, interactive web-based tablet-delivered tool (iDecide) versus use of print educational materials. Design A randomized two-arm trial from 2011-2013. Trial Registration NCT01427660. Setting Community health center in Detroit serving a Latino and African American low-income population. Participants 188 adults with a hemoglobinA1c >7.5% (55%) or who reported questions, concerns, or difficulty taking diabetes medications Primary Funding Sources Agency for Health Care Quality and Research (1R18HS019256-01) and P30DK092926 (MCDTR) Measurements Primary outcomes were changes in knowledge about anti-hyperglycemic medications, patient-reported medication decisional conflict, and satisfaction with anti-hyperglycemic medication information. We also examined changes in diabetes distress, self-efficacy, medication adherence, and A1c. Intervention Participants were randomized to receive a 1-2 hour session with a CHW using either iDecide or printed educational materials and two follow-up calls. Results 94% of participants completed three-month follow-up. Both groups improved across most measures. iDecide participants reported greater improvements in satisfaction with medication information (helpfulness, p=.007; clarity, p=.03) and in diabetes distress compared to the print materials group (p<0.001). There were no differences between groups in other outcomes. Limitations The study was conducted at one health center over a short period, and the CHWs were experienced in behavioral counseling, thus possibly mitigating the need for additional support tools. Conclusions Most outcomes were similarly improved among participants receiving both types of diabetes medication decision-making support. Longer-term evaluations are necessary to

  18. Treatment of Chopart Fracture-Dislocations.

    PubMed

    Klaue, Kaj

    2010-06-01

    The Chopart articular space was used by François Chopart (1743-1795) as a practical space for amputation in cases of distal foot tumor. It corresponds to the center of the foot and allows for essential articulation by means of the talo-calcaneo-navicular joint (coxa pedis). Chopart fracture-dislocations may therefore include fractures of the navicular, the cuboid, the talus, and calcaneus. The treatment priorities should therefore include addressing all of the injured soft tissues by immediate joint reduction or restoring bony alignment, including the avoidance of threatening compartment syndromes. Subsequent anatomical bone and joint reconstruction, if possible, should first address the talar head and the navicular. The anterior process of the calcaneus and the cuboid should be aligned to preserve foot alignment in the sagittal and horizontal planes. In severe joint destructions, isolated fusion of the calcaneo-cuboidal joint may help preserve functional mobility of the foot. Isolated or associated talo-navicular fusion considerably limits functional mobility of the foot.

  19. Reactivity of pyrites and dislocation density

    SciTech Connect

    Pollack, S.S.; Martello, D.V.; Diehl, J.R.; Tamilia, J.V. ); Graham, R.A. )

    1991-01-01

    Highly reactive coal pyrites and unstable museum specimens are easily distinguished from the stable pyrites by the growth of white crystals that cover samples exposed to room atmosphere for short periods of time. Continued exposure to the atmosphere will eventually cause the specimens to fall apart. The term rotten pyrite has been applied to museum specimens that fall apart in this way. SEM studies show that reactive (rotten) pyrites contain between 100 and 10,000 times more dislocations than stable pyrites. Shock-loading of a stable pyrite to 7.5 GPa and 17 GPa increased its reactivity by a factor of two, probably caused by an increase in the number of imperfections. However, shock-loading at 22 GPa decreased the reactivity of pyrite because the imperfections produced at the higher pressure were removed during annealing the sample received at the higher temperature. Although there was a factor of six difference between the most and least reactive shocked MCB (commercial pyrite) samples, shock-loading did not increase the reactivity of the MCB pyrite to that of the Queensland coal pyrite. The results in hand show that while shock-loading produces sufficient imperfections to increase the reactivity of pyrites, there is insufficient data to show that imperfections are the main reason why some coal pyrites are highly reactive. 9 refs., 1 fig., 1 tab.

  20. Dislocation theory of melting for iron, revisited

    SciTech Connect

    Poirier, J.P.; Shankland, T.J.

    1993-11-01

    Melting point T{sub m} of iron at conditions of the Earth`s inner core boundary (ICB) has been calculated from dislocation theory of melting in metals. Monte Carlo calculations were used to estimate uncertainties introduced by uncertainty in the geophysical parameters that are used in the calculations. These calculations take into account the effects of pressure at ICB conditions and of possible freezing point depression resulting from dilution of pure iron in the outer core. With this approach T{sub m} of pure {var_epsilon}-Fe at a pressure of 330 GPa and without freezing point depression is 6160 {plus_minus} 250 K; for a 1000 K freezing point depression it is 6110 K. T{sub m} of pure {gamma}-Fe is 6060 K, a value that is not significantly different. A possible {alpha}{prime} phase would melt at 5600 K. These values agree with calculated shock wave determinations of T{sub m}. Although calculated T{sub m} of the pure phase is little affected by assumptions about the extent of freezing point depression, the estimated temperature of the inner core boundary is lower by the breezing point depression, perhaps 500--1000 K less than T{sub m} of a pure phase.

  1. Dislocation theory of melting for iron, revisited

    SciTech Connect

    Poirier, J. ); Shankland, T.J. )

    1994-07-10

    The melting point T[sub m] of iron at conditions of the Earth's inner core boundary (ICB) has been calculated from the dislocation theory of melting in metals. Monte Carlo calculations were used to estimate uncertainties introduced by uncertainty in the geophysical parameters that are used in the calculations. These calculations take into account the effects of pressure at ICB conditions and of possible freezing point depression resulting from dilution of pure iron in the outer core. With this approach T[sub m] of pure [epsilon]-Fe at a pressure of 330 GPa and without freezing point depression is 6160[plus minus]250 K; for a 1000 K freezing point depression it is 6110 K. T[sub m] of pure [gamma]-Fe is 6060 K, a value that is not significantly different. A possible [alpha][prime] phase would melt at 5600 K. These values agree with calculated shock wave determinations of T[sub m]. Although calculated T[sub m] of the pure phase is little affected by assumptions about the extent of freezing point depression, the estimated temperature of the inner core boundary is lower by the freezing point depression, perhaps 500--1000 K less than T[sub m] of a pure phase. [copyright] 1994 American Institute of Physics

  2. Bilateral posterior shoulder dislocation after electrical shock: A case report

    PubMed Central

    Ketenci, Ismail Emre; Duymus, Tahir Mutlu; Ulusoy, Ayhan; Yanik, Hakan Serhat; Mutlu, Serhat; Durakbasa, Mehmet Oguz

    2015-01-01

    Introduction Posterior dislocation of the shoulder is a rare and commonly missed injury. Unilateral dislocations occur mostly due to trauma. Bilateral posterior shoulder dislocations are even more rare and result mainly from epileptic seizures. Electrical injury is a rare cause of posterior shoulder dislocation. Injury mechanism in electrical injury is similar to epileptic seizures, where the shoulder is forced to internal rotation, flexion and adduction. Presentation of case This report presents a case of bilateral posterior shoulder dislocation after electrical shock. We were able to find a few individual case reports describing this condition. The case was acute and humeral head impression defects were minor. Our treatment in this case consisted of closed reduction under general anesthesia and applying of orthoses which kept the shoulders in abduction and external rotation. A rehabilitation program was begun after 3 weeks of immobilization. After 6 months of injury the patient has returned to work. 20 months postoperatively, at final follow-up, he was painless and capable of performing all of his daily activities. Discussion The amount of bilateral shoulder dislocations after electrical injury is not reported but is known to be very rare. The aim of this case presentation is to report an example for this rare entity, highlight the difficulties in diagnosis and review the treatment options. Conclusion Physical examination and radiographic evaluation are important for quick and accurate diagnosis. PMID:26904192

  3. How to identify dislocations in molecular dynamics simulations?

    NASA Astrophysics Data System (ADS)

    Li, Duo; Wang, FengChao; Yang, ZhenYu; Zhao, YaPu

    2014-12-01

    Dislocations are of great importance in revealing the underlying mechanisms of deformed solid crystals. With the development of computational facilities and technologies, the observations of dislocations at atomic level through numerical simulations are permitted. Molecular dynamics (MD) simulation suggests itself as a powerful tool for understanding and visualizing the creation of dislocations as well as the evolution of crystal defects. However, the numerical results from the large-scale MD simulations are not very illuminating by themselves and there exist various techniques for analyzing dislocations and the deformed crystal structures. Thus, it is a big challenge for the beginners in this community to choose a proper method to start their investigations. In this review, we summarized and discussed up to twelve existing structure characterization methods in MD simulations of deformed crystal solids. A comprehensive comparison was made between the advantages and disadvantages of these typical techniques. We also examined some of the recent advances in the dynamics of dislocations related to the hydraulic fracturing. It was found that the dislocation emission has a significant effect on the propagation and bifurcation of the crack tip in the hydraulic fracturing.

  4. Surface-controlled dislocation multiplication in metal micropillars.

    PubMed

    Weinberger, Christopher R; Cai, Wei

    2008-09-23

    Understanding the plasticity and strength of crystalline materials in terms of the dynamics of microscopic defects has been a goal of materials research in the last 70 years. The size-dependent yield stress observed in recent experiments of submicrometer metallic pillars provides a unique opportunity to test our theoretical models, allowing the predictions from defect dynamics simulations to be directly compared with mechanical strength measurements. Although depletion of dislocations from submicrometer face-centered-cubic (FCC) pillars provides a plausible explanation of the observed size-effect, we predict multiplication of dislocations in body-centered-cubic (BCC) pillars through a series of molecular dynamics and dislocation dynamics simulations. Under the combined effects from the image stress and dislocation core structure, a dislocation nucleated from the surface of a BCC pillar generates one or more dislocations moving in the opposite direction before it exits from the surface. The process is repeatable so that a single nucleation event is able to produce a much larger amount of plastic deformation than that in FCC pillars. This self-multiplication mechanism suggests a need for a different explanation of the size dependence of yield stress in FCC and BCC pillars.

  5. Atomistically-informed Dislocation Dynamics in fcc Crystals

    SciTech Connect

    Martinez, E; Marian, J; Arsenlis, T; Victoria, M; Perlado, J M

    2006-09-06

    We develop a nodal dislocation dynamics (DD) model to simulate plastic processes in fcc crystals. The model explicitly accounts for all slip systems and Burgers vectors observed in fcc systems, including stacking faults and partial dislocations. We derive simple conservation rules that describe all partial dislocation interactions rigorously and allow us to model and quantify cross-slip processes, the structure and strength of dislocation junctions and the formation of fcc-specific structures such as stacking fault tetrahedra. The DD framework is built upon isotropic non-singular linear elasticity, and supports itself on information transmitted from the atomistic scale. In this fashion, connection between the meso and micro scales is attained self-consistently with core parameters fitted to atomistic data. We perform a series of targeted simulations to demonstrate the capabilities of the model, including dislocation reactions and dissociations and dislocation junction strength. Additionally we map the four-dimensional stress space relevant for cross-slip and relate our findings to the plastic behavior of monocrystalline fcc metals.

  6. Temporomandibular chronic dislocation: The long-standing condition

    PubMed Central

    Puche-Torres, Miguel; Iglesias-Gimilio, Maria-Eugenia

    2016-01-01

    Background The temporomandibular joint (TMJ) dislocation can be categorised into three groups: acute, habitual or recurrent and long-standing. The long-standing or protracted lower jaw dislocation refers to a condition that persists for more than one month without reduction. There are a great variety of methods for its treatment, from the manual or non-surgical, to surgical ones like the indirect approach (conservative surgical approach) and direct approach (open joint). Additional procedures in unsuccessful cases may include extra-articular orthognathic techniques to correct a malocclusion until joint replacement. Material and Methods We report four new cases with a minimum of 6 weeks dislocation who were seen since 1995 to 2015 in the Maxillofacial Department of the Clínico Hospital (Valencia, Spain), in which the mean age was 57.5 years. Most of them were bilateral and the gender was predominantly female. Additionally, we have reviewed the related literature. Results All of the cases were successfully treated and half of them required open surgery. Conclusions The report confirms the difficulty of the treatment and reaffirms the necessity to bear in mind the wide variety of methods available for the treatment of this pathology. We stress the difficulties associated with managing the treatment and of suggesting new guidelines. The best option still remains not to delay the diagnostic and to select the appropriate initial treatment. Key words:Temporomandibular luxation, TMJ dislocation, protracted dislocation, long-standing dislocation. PMID:27694782

  7. Dislocation Starvation and Exhaustion Hardening in Mo-alloy Nanofibers

    SciTech Connect

    Chisholm, Claire; Bei, Hongbin; Lowry, M. B.; Oh, Jason; Asif, S.A. Syed; Warren, O.; Shan, Zhiwei; George, Easo P; Minor, Andrew

    2012-01-01

    The evolution of defects in Mo alloy nanofibers with initial dislocation densities ranging from 0 to 1.6 1014 m2 were studied using an in situ push-to-pull device in conjunction with a nanoindenter in a transmission electron microscope. Digital image correlation was used to determine stress and strain in local areas of deformation. When they had no initial dislocations the Mo alloy nanofibers suffered sudden catastrophic elongation following elastic deformation to ultrahigh stresses. At the other extreme fibers with a high dislocation density underwent sustained homogeneous deformation after yielding at much lower stresses. Between these two extremes nanofibers with intermediate dislocation densities demonstrated a clear exhaustion hardening behavior, where the progressive exhaustion of dislocations and dislocation sources increases the stress required to drive plasticity. This is consistent with the idea that mechanical size effects ( smaller is stronger ) are due to the fact that nanostructures usually have fewer defects that can operate at lower stresses. By monitoring the evolution of stress locally we find that exhaustion hardening causes the stress in the nanofibers to surpass the critical stress predicted for self-multiplication, supporting a plasticity mechanism that has been hypothesized to account for the rapid strain softening observed in nanoscale bcc materials at high stresses.

  8. Direct observation of individual dislocation interaction processes with grain boundaries

    PubMed Central

    Kondo, Shun; Mitsuma, Tasuku; Shibata, Naoya; Ikuhara, Yuichi

    2016-01-01

    In deformation processes, the presence of grain boundaries has a crucial influence on dislocation behavior; these boundaries drastically change the mechanical properties of polycrystalline materials. It has been considered that grain boundaries act as effective barriers for dislocation glide, but the origin of this barrier-like behavior has been a matter of conjecture for many years. We directly observe how the motion of individual dislocations is impeded at well-defined high-angle and low-angle grain boundaries in SrTiO3, via in situ nanoindentation experiments inside a transmission electron microscope. Our in situ observations show that both the high-angle and low-angle grain boundaries impede dislocation glide across them and that the impediment of dislocation glide does not simply originate from the geometric effects; it arises as a result of the local structural stabilization effects at grain boundary cores as well, especially for low-angle grain boundaries. The present findings indicate that simultaneous consideration of both the geometric effects and the stabilization effects is necessary to quantitatively understand the dislocation impediment processes at grain boundaries. PMID:27847862

  9. In Situ TEM Observation of Dislocation Evolutionin Polycrystalline UO2

    SciTech Connect

    L. F. HE; 1 M. A. KIRK; Argonne National Laboratory; J. Gan; T. R. ALLEN

    2014-10-01

    In situ transmission electron microscopy observation of polycrystalline UO2 (with average grain size of about 5 lm) irradiated with Kr ions at 600C and 800C was conducted to understand the radiation-induced dislocation evolution under the influence of grain boundaries. The dislocation evolution in the grain interior of polycrystalline UO2 was similar under Kr irradiation at different ion energies and temperatures. As expected, it was characterized by the nucleation and growth of dislocation loops at low irradiation doses, followed by transformation to extended dislocation lines and tangles at high doses. For the first time, a dislocation-denuded zone was observed near a grain boundary in the 1-MeV Kr-irradiated UO2 sample at 800C. The denuded zone in the vicinity of grain boundary was not found when the irradiation temperature was at 600C. The suppression of dislocation loop formation near the boundary is likely due to the enhanced interstitial diffusion toward grain boundary at the high temperature.

  10. Identification of dislocation etch pits in n-type GaAs by NIR transmission microscopy

    NASA Technical Reports Server (NTRS)

    Cao, X. Z.; Witt, A. F.

    1991-01-01

    An optical method is described for identifying dislocation etch pits in n-type GaAS, using near-IR brightfield transmission microscopy. Dislocations are revealed in a nondestructive manner through contrasts that are likely due to impurity decoration of the dislocation lines. By subjecting the same wafers to a photoetching technique, it was established that each etch pit on the surface is associated with a dislocation and that the termination of each (decorated) dislocation is an etch pit.

  11. A single theory for some quasi-static, supersonic, atomic, and tectonic scale applications of dislocations

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohan; Acharya, Amit; Walkington, Noel J.; Bielak, Jacobo

    2015-11-01

    We describe a model based on continuum mechanics that reduces the study of a significant class of problems of discrete dislocation dynamics to questions of the modern theory of continuum plasticity. As applications, we explore the questions of the existence of a Peierls stress in a continuum theory, dislocation annihilation, dislocation dissociation, finite-speed-of-propagation effects of elastic waves vis-a-vis dynamic dislocation fields, supersonic dislocation motion, and short-slip duration in rupture dynamics.

  12. Mortality among rubber workers: V. processing workers.

    PubMed

    Delzell, E; Monson, R R

    1982-07-01

    Cause-specific mortality was evaluated among 2,666 men employed in the processing division of a rubber manufacturing plant. The division was divided into two sections: front processing (compounding, mixing and milling operations) and back processing (extrusion, calendering, cement mixing and rubberized fabrics operations). Mortality rates for all processing workers combined and for men in each section were compared with rates for U.S. White males or for workers employed in other divisions of the same plant. Compared with either referent group, men in the processing division had increased mortality from leukemia, emphysema, and cancers of the stomach, large intestine, and biliary passages and liver. An excess number of deaths from stomach and larger intestine cancer was found predominantly among men in the front processing section (33 observed vs. 17.7 expected deaths, based on rates in nonprocessing workers). Increased mortality from leukemia (14 observed vs. 7.3 expected) and from emphysema (22 observed vs. 11.0 expected) was present among men employed in the back processing section. Examination of mortality from these causes according to age and the year starting work, duration of employment, and years since starting work in the relevant sections of the processing division suggested that observed excesses of stomach cancer, large intestine cancer, leukemia, and emphysema among processing workers are related to occupational exposures. These results are consistent with the findings of studies of other groups of rubber workers.

  13. Statistical description of the motion of dislocation kinks in a random field of impurities adsorbed by a dislocation

    SciTech Connect

    Petukhov, B. V.

    2010-01-15

    A model has been proposed for describing the influence of impurities adsorbed by dislocation cores on the mobility of dislocation kinks in materials with a high crystalline relief (Peierls barriers). The delay time spectrum of kinks at statistical fluctuations of the impurity density has been calculated for a sufficiently high energy of interaction between impurities and dislocations when the migration potential is not reduced to a random Gaussian potential. It has been shown that fluctuations in the impurity distribution substantially change the character of the migration of dislocation kinks due to the slow decrease in the probability of long delay times. The dependences of the position of the boundary of the dynamic phase transition to a sublinear drift of kinks x {proportional_to} t{sup {delta}} ({delta} {sigma} 1) and the characteristics of the anomalous mobility on the physical parameters (stress, impurity concentration, experimental temperature, etc.) have been calculated.

  14. Statistical approach to dislocation dynamics: From dislocation correlations to a multiple-slip continuum theory of plasticity

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; van der Giessen, Erik

    2008-05-01

    Due to recent successes of a statistical-based nonlocal continuum crystal plasticity theory for single-glide in explaining various aspects such as dislocation patterning and size-dependent plasticity, several attempts have been made to extend the theory to describe crystals with multiple-slip systems using ad hoc assumptions. We present here a mesoscale continuum theory of plasticity for multiple-slip systems of parallel edge dislocations. We begin by constructing the Bogolyubov Born Green Yvon Kirkwood integral equations relating different orders of dislocation correlation functions in a grand canonical ensemble. Approximate pair correlation functions are obtained for single-slip systems with two types of dislocations and, subsequently, for general multiple-slip systems of both charges. The effect of the correlations manifests itself in the form of an entropic force in addition to the external stress and the self-consistent internal stress. Comparisons with a previous multiple-slip theory based on phenomenological considerations shall be discussed.

  15. Advanced worker protection system

    SciTech Connect

    Caldwell, B.; Duncan, P.; Myers, J.

    1995-12-01

    The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D&D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D&D costs while providing appropriate protection to DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D&D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project will result in the development of an Advanced Worker Protection System (AWPS). The AWPS will be built around a life support backpack that uses liquid air to provide cooling as well as breathing gas to the worker. The backpack will be combined with advanced protective garments, advanced liquid cooling garment, respirator, communications, and support equipment to provide improved worker protection, simplified system maintenance, and dramatically improve worker productivity through longer duration work cycles. Phase I of the project has resulted in a full scale prototype Advanced Worker Protection Ensemble (AWPE, everything the worker will wear), with sub-scale support equipment, suitable for integrated testing and preliminary evaluation. Phase II will culminate in a full scale, certified, pre-production AWPS and a site demonstration.

  16. Characterization of dislocation structures in silicon carbide single crystals

    NASA Astrophysics Data System (ADS)

    Vetter, William M.

    1999-07-01

    Two types of defects in PVT-grown 6H and 4H-SiC crystals were studied: screw dislocations that follow the axial direction of the crystal and dislocations that follow directions in the crystal's basal plane. The screw dislocations possessed a range of Burgers vector magnitudes, multiples of the axial parameter c, that could be determined by x-ray topographic image analysis. Hollow cores termed "micropipes" were observed when Burgers, vectors were larger than 3c. The micropipes were studied by a variety of methods: optical microscopy, laser scanning confocal microscopy, scanning electron microscopy, transmission electron microscopy and atomic force microscopy. The micropipes were tubes 0.1 to 10mum in diameter. They were faceted, primarily along the {101¯0} planes, but also had {112¯0} facets. When encountering the growth surface of a crystal, they flared out into a trumpet-shape. Growth spirals sometimes occurred, originating from the trumpets' rims. The screw dislocations are visible in back-reflection synchrotron white beam x-ray topographs of basal-cut SiC wafers in striking contrast as black rings surrounding white circles, though such topographs are contaminated by a series of harmonic reflections, g = (0006n), where n = 3 to 16. By calculating and considering their intensities, and comparison with a g = 00018 Lang topograph taken with CuKalpha1 radiation, the g = 00024 harmonic was shown to be the most important contributor. Basal plane dislocations were seen in x-ray topographs of SiC looping from the points where screw dislocations occurred. Their extinction behavior showed they belonged to the set b = 13 <112¯0>. In some transmission electron micrographs, perfect dislocations with similar extinction behavior, along with partial dislocations with b = 13 <101¯0>, were seen originating from the micropipes' walls, curving out into the crystal a distance of 1 to 3mum, then back to terminate at the micropipe. Others led out of the field of view. Contrast is

  17. The Adolescent Worker.

    ERIC Educational Resources Information Center

    Borman, Kathryn M., Ed.; And Others

    The Adolescent Worker Study was designed to provide an in-depth analysis of the job experiences and related life histories of out-of-school working youth. To do this, a team of investigators first identified work sites across a range of industrial sectors that were currently engaged in hiring young workers between the ages of 17 and 21. Then, the…

  18. Special Issue: Rural Workers.

    ERIC Educational Resources Information Center

    Goodson, Elizabeth; And Others

    1995-01-01

    The issue discusses the role of the International Labour Office in the field of workers' education for rural workers and their organizations. Articles discuss labor conditions, child labor in agriculture, gender and equality training, trade unions, fair trade, and changing patterns of food production. Appendixes include information about…

  19. Migrant Farm Workers.

    ERIC Educational Resources Information Center

    Slesinger, Doris P.; Pfeffer, Max J.

    This paper documents migrant farm workers as being among the most persistently underprivileged groups in American society. Migrant farm workers typically receive low wages from irregular employment and live in poverty with access to only substandard housing and inadequate health care. The lack of economic improvement stems from a number of…

  20. Workers Kaleidoscope: 2001.

    ERIC Educational Resources Information Center

    American Federation of Labor and Congress of Industrial Organizations, Washington, DC.

    This manual was prepared to provide union leaders, organizers, and local officers with information about the experiences of Asian-American, Black, Hispanic-American, female, and part-time workers. The Asian-American workers section includes information on Chinese, Japanese, Filipinos, Koreans, Asian-Indians, Southeast Asians, and Pacific Islanders…