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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, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 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...

  3. 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...

  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 663.105 - 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...

  6. 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...

  7. 20 CFR 663.200 - What are intensive 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 intensive services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.200 What are intensive services for adults and dislocated workers?...

  8. 20 CFR 663.200 - What are intensive 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 intensive services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.200 What are intensive services for adults and dislocated workers?...

  9. 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...

  10. 20 CFR 663.200 - What are intensive 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 intensive services for adults and..., DEPARTMENT OF LABOR (CONTINUED) ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.200 What are intensive services for adults and dislocated workers?...

  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 663.200 - What are intensive 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 intensive services for adults and..., DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.200 What are intensive services for adults and dislocated workers? (a)...

  13. 20 CFR 663.200 - What are intensive 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 intensive services for adults and..., DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Intensive Services § 663.200 What are intensive services for adults and dislocated workers? (a)...

  14. 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..., 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...

  15. 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…

  16. 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...

  17. 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...

  18. 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..., 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, 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...

  20. 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...

  1. 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..., 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 663.115 - 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...

  3. 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...

  4. 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...

  5. 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...

  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 663.610 - 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...

  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, 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...

  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, 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...

  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, 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 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...

  19. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., all of the core services described in WIA section 134(d)(2) and 20 CFR 662.240 must be provided in... 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...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., all of the core services described in WIA section 134(d)(2) and 20 CFR 662.240 must be provided in... 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...

  1. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... core services described in WIA section 134(d)(2) and 20 CFR 662.240 must be provided in each local area... 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...

  2. 20 CFR 663.150 - What core services must be provided to adults and dislocated workers?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., all of the core services described in WIA section 134(d)(2) and 20 CFR 662.240 must be provided in... 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...

  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

    ....150 What core services must be provided to adults and dislocated workers? (a) At a minimum, all of the core services described in WIA section 134(d)(2) and 20 CFR 662.240 must be provided in each local area... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What core services must be provided to...

  4. 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

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are the eligibility criteria for core... Through the One-Stop Delivery System § 663.115 What are the eligibility criteria for core services for dislocated workers in the adult and dislocated worker programs? (a) To be eligible to receive core...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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

    ... 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and dislocated... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What is the role of the adult and dislocated... AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR ADULT AND DISLOCATED WORKER ACTIVITIES UNDER TITLE...

  10. 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…

  11. 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 CFR part 662. Consistent with those provisions: (1) Core services for adults and dislocated... 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...

  12. 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/dislocated worker programs concurrently? 664.500 Section 664.500 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR YOUTH ACTIVITIES UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT...

  13. 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...

  14. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  15. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  16. 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

    ... partners described in 20 CFR part 662. Consistent with those provisions: (1) Core services for adults and... worker programs in the One-Stop delivery system? 663.100 Section 663.100 Employees' Benefits EMPLOYMENT... the One-Stop Delivery System § 663.100 What is the role of the adult and dislocated worker programs...

  17. Dislocated Workers: Neighbors, Friends, Relatives.

    ERIC Educational Resources Information Center

    Blessington, Robert

    1989-01-01

    Worker dislocation is a major problem in Wisconsin. Services needed include provision of coping mechanisms, job search methods, and retraining. A partnership between the state and the Wisconsin American Federation of Labor-Congress of Industrial Organizations was created to provide these services and referrals, as well as preventive training…

  18. Worker Dislocation. Case Studies of Causes and Cures.

    ERIC Educational Resources Information Center

    Cook, Robert F., Ed.

    Case studies were made of the following dislocated worker programs: Cummins Engine Company Dislocated Worker Project; GM-UAW Metropolitan Pontiac Retraining and Employment Program; Minnesota Iron Range Dislocated Worker Project; Missouri Dislocated Worker Program Job Search Assistance, Inc.; Hillsborough, North Carolina, Dislocated Worker Project;…

  19. Community College Adjustment among Dislocated Workers

    ERIC Educational Resources Information Center

    Schwitzer, Alan M.; Duggan, Molly H.; Laughlin, Janet T.; Walker, Martha A.

    2011-01-01

    Community colleges often are catalysts for economic and workforce development in localities with high unemployment or large numbers of dislocated workers. Increasingly, dislocated workers--individuals who have experienced job loss due to occupational closings, reduced workforces, or severe local economic downturns--are enrolling in educational and…

  20. 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

    ... Adult and Dislocated Worker Programs; Request for Comment AGENCY: Employment and Training Administration... intensive services and training provided under the Workforce Investment Act (WIA) Adult and Dislocated... WIA Adult and Dislocated Worker programs will be required to participate in the study during a...

  1. 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…

  2. 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)

  3. 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…

  4. Workers Dislocated by Economic Change: Toward New Institutions for Midcareer Worker Transformation. Research Paper.

    ERIC Educational Resources Information Center

    Bendick, Marc, Jr.

    The federal government needs to provide employment and training assistance to help dislocated workers to become reemployed. Worker mobility assistance should not be focused upon as a major thrust of reemployment programs, since American workers are remarkably resistant to pressures to move to more promising labor markets. Efficient and effective…

  5. 77 FR 37923 - Comment Request for Information Collection for the Workforce Investment Act (WIA) Adult and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... Investment Act (WIA) Adult and Dislocated Worker Programs Gold Standard Evaluation (WIA Evaluation); New...: New collection. Title of Collection: WIA Adult and Dislocated Worker Programs Gold Standard...

  6. Helping the Dislocated Worker: Sample Programs. Research and Development Series No. 243B.

    ERIC Educational Resources Information Center

    Ashley, William L.; Zahniser, Gale L.

    This report, one in a series of three publications for vocational program developers and others to use in planning and developing a community-based response to worker dislocation, deals with programs for dislocated workers that have been developed and supported by private sector and local community efforts and resources. Reviewed in the first…

  7. Helping the Dislocated Worker: Planning Community Services. Research and Development Series No. 243A.

    ERIC Educational Resources Information Center

    Zahniser, Gale L.; Ashley, William L.

    This guide, one in a series of three publications for vocational program developers and others to use in planning and developing a community-based response to worker dislocation, provides a generic approach to program development. Discussed first are the causes, future, and impact of worker dislocation. The next chapter is devoted to various…

  8. 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 also…

  9. 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 ...

  10. 20 CFR 663.120 - Are displaced homemakers eligible for dislocated worker activities under WIA?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Partnership Act. (b) Under the dislocated worker program in JTPA, displaced homemakers are defined as... with Dependent Children (AFDC) as well as those who had been dependent on the income of another...

  11. 20 CFR 663.120 - Are displaced homemakers eligible for dislocated worker activities under WIA?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Partnership Act. (b) Under the dislocated worker program in JTPA, displaced homemakers are defined as... with Dependent Children (AFDC) as well as those who had been dependent on the income of another...

  12. [Couch-netting operation for dislocation of adult lens].

    PubMed

    Jiang, B L; Tang, Y Z

    1992-06-01

    Clinical data of 12 adult cases of dislocation of lens treated with couching-netting operating were analysed, including cases of traumatic cataracts with complications of glaucoma and cataract couching surgical complication of phacolysis. The result was rather satisfactory. Eye sight was corrected, most of the corrective vision was over 0.5 level, intraocular pressure was controlled and no serious complication was found. According to the authors experience, couching-netting was recommended as a simple and effective method for treating dislocation of adult lens.

  13. 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:…

  14. Dislocations

    MedlinePlus

    Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a ... one, seek medical attention. Treatment depends on which joint you dislocate and the severity of the injury. It might include manipulations to reposition your bones, ...

  15. 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,…

  16. 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…

  17. Study of the Implementation of the Economic Dislocation and Worker Adjustment Assistance Act. Research and Evaluation Report Series 91-G.

    ERIC Educational Resources Information Center

    SRI International, Menlo Park, CA.

    The design and operations of the Economic Dislocation and Worker Adjustment Assistance (EDWAA) Act program in its implementation year were examined through case studies conducted in 15 states and 30 substate areas. During 6- to 8-day visits to each state, field researchers conducted discussions with state and substate respondents. States almost…

  18. 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

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

    PubMed

    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

  20. Dimensions of Problem Drinking among Young Adult Restaurant Workers

    PubMed Central

    Moore, Roland S.; Cunradi, Carol B.; Duke, Michael R.; Ames, Genevieve M.

    2009-01-01

    Background Nationwide surveys identify food service workers as heavy alcohol users. Objectives This article analyzes dimensions and correlates of problem drinking among young adult food service workers. Methods A telephone survey of national restaurant chain employees yielded 1294 completed surveys. Results Hazardous alcohol consumption patterns were seen in 80% of men and 64% of women. Multivariate analysis showed that different dimensions of problem drinking measured by the AUDIT were associated with workers' demographic characteristics, smoking behavior and job category. Conclusions & Scientific Significance These findings offer evidence of extremely high rates of alcohol misuse among young adult restaurant workers. PMID:20180660

  1. Dislocated Workers. A Look Back at the Redwood Employment Training Programs. Briefing Report to Congressional Requesters.

    ERIC Educational Resources Information Center

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

    A study examined implementation of the Redwood worker assistance programs implemented to help mitigate the loss of jobs by timber workers in Northern California upon expansion of the Redwood National Park in 1978. The benefits provided to workers under the Redwood Employee Protection Program (REPP) were generous. As of December 1988, REPP had…

  2. 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…

  3. Educational and Employment Experiences of the Younger Adult Worker.

    ERIC Educational Resources Information Center

    Mertens, Donna M.; Gardner, John A.

    The Younger Adult Worker (YAW) study examined the systematic long-term relationship between exposure to vocational education and various indices of educational and employment outcomes. A telephone survey of 1539 young adults between the ages of 20 and 34 supplemented information from the l966-78 National Longitudinal Surveys of Labor Market…

  4. 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…

  5. Dealing with Involuntary Job Loss. Northwest Dislocated Worker Projects Address More Than Retraining and Re-employment. Ideas for Action in Education and Work.

    ERIC Educational Resources Information Center

    Northwest Regional Educational Lab., Portland, OR. Education and Work Program.

    This issue discusses the problems that frequently accompany involuntary job loss. The types of problems experienced by dislocated workers are discussed under these categories: emotional, family, financial, physical health, job skill obsolescence, and lack of basic academic skills. The report also presents approaches that were taken by four…

  6. 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,…

  7. Compassion fatigue and the adult protective services social worker.

    PubMed

    Bourassa, Dara Bergel

    2009-04-01

    Compassion fatigue is a relatively new term that describes the symptoms that are experienced by social workers and other helping professionals who work with clients experiencing trauma. This article defines the concept of compassion fatigue and relates compassion fatigue to Adult Protective Services (APS) social workers. It is proposed that APS social workers may be susceptible to the deleterious effects of compassion fatigue due to the nature of their work and environment. Suggestions for avoidance of compassion fatigue are also discussed, including self-care strategies and the need for continuing education regarding this phenomenon.

  8. 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

  9. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult - A Rare Association.

    PubMed

    Kembhavi, Raghavendra S; James, Boblee

    2016-08-01

    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

  10. 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…

  11. 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

  12. Atlanto axial rotatory dislocation in adults: a rare complication of an epileptic seizure--case report.

    PubMed

    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.

  13. [Treatment of chronic hip dislocation in adults by recentered total prosthesis. Apropos of 43 cases].

    PubMed

    Gau, M; Simonnet, J H; Rocca, A; Aubaniac, J M

    1988-01-01

    Forty-three total hip prostheses were inserted in 33 adults suffering from a chronic high dislocation of the hip. Ten patients had a bilateral arthroplasty. The authors decided to keep in this series only hips presenting with a very considerable upward displacement of the femoral head of type IV in Crowe, Maini and Ranawat's classification. All the hips were treated in the same way with pre-operative planning using template tracings to anticipate problems of length and choice of implant. The acetabular cup was placed in the old acetabulum with downward displacement of the femur. The results were studied in 39 prostheses with a mean follow-up of five-and-a-half years (two years to nine-and-a-half years). The mean age of the patients was 48 and-a-half years (28 to 76 years). A satisfactory result was obtained in 79.5 per cent of cases. The mean downward displacement of the femur was 4.8 cm. Complications included one death from pulmonary embolus, two phlebitides, two fractures of the femoral shaft and four dislocations. There were nos cases of sepsis or neurological complications. The authors advise the use of custom-made implants, consider the tactical problems relative to the opposite hip. It is concluded that the value of the method often lies in the transformation of the life of these young patients by a "functional miracle", but the operative indications need to be considered carefully, since the procedures are sometimes extensive, often difficult and always require technical skill.

  14. Lateral subtalar dislocation.

    PubMed

    Sharda, Praveen; DuFosse, Julian

    2008-07-01

    Subtalar dislocations are rare in routine orthopedic practice. While many of these dislocations are a result of high-energy injuries such as fall from a height or traffic accidents, it is not uncommon for patients to present after slipping down a few stairs. Two types of dislocation have been described, medial and lateral. The type of dislocation is described according to the position of the foot. In lateral subtalar dislocation the head of talus is found medially and the calcaneus is dislocated laterally. The navicular may lie dorsolateral to the talus. The reverse is true of lateral dislocation. Medial dislocation has been referred to as "basketball foot" due to its preponderance in basketball players.4 The deciding factor is the inverted or everted position of the foot when the force is dissipated through the weak talonavicular and talocalcaneal ligaments. This article presents a case of an adult with lateral subtalar dislocation following a fall.

  15. Atlantoaxial dislocation adjacent to kyphotic deformity in a case of adult Larsen syndrome.

    PubMed

    Sahoo, Sushanta K; Deepak, Arsikere N; Salunke, Pravin

    2016-01-01

    Kyphotic deformity is often seen in Larsen syndrome. However, its progress in adults is not clear. The adjacent level compression in these patients adds to the difficulty regarding the level that needs to be operated. A 56-year-old male presented with neck pain and spastic quadriplegia. Radiology showed kyphotic deformity (sequelae of Larsen syndrome) with atlantoaxial dislocation. Cord compression was apparent at both levels but careful evaluation showed C1-2 level compression and some compression below the kyphotic deformity. The kyphotic spine was already fused and the canal diameter was adequate. The adjacent level C1-2 was fused and he improved dramatically. Correction of long-standing kyphotic deformity may not be necessary, as it unlikely to progress because of its tendency to fuse naturally. Rather, the adjacent levels are likely to compress the cord due to excessive stress. A proper clinical history and a thorough radiological examination help the surgeon to make an appropriate decision. PMID:27217658

  16. 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.

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

    PubMed

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

    2016-01-01

    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. PMID:27309488

  18. 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,…

  19. 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…

  20. Economic Dislocation and Worker Adjustment Assistance Act. Joint Hearings on S. 538 to Implement the Recommendations of the Secretary of Labor's Task Force on Economic Adjustment and Worker Dislocation, and for Other Purposes, before the Subcommittee on Labor and the Subcommittee on Employment and Productivity of the Committee on Labor and Human Resources. United States Senate, One-Hundredth Congress, First Session (March 10 and 26, 1987).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Human Resources.

    This congressional report on Senate Bill 538 contains the testimony that was given at joint hearings to debate the passage of the Economic Dislocation and Worker Adjustment Assistance Act. This act, which is based primarily on the recommendations of U.S. Secretary of Labor Brock's blue ribbon task force: (1) creates displaced worker units at the…

  1. 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…

  2. 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.

  3. Risk indicators for tooth loss in adult workers.

    PubMed

    Batista, Marília Jesus; Rihs, Lílian Berta; Sousa, Maria da Luz Rosário de

    2012-01-01

    Tooth loss continues to be a prevalent condition in Brazilian adults and elderly individuals. The aim of this cross-sectional study, conducted among workers in a wholesale grocery chain in the State of São Paulo, was to identify risk indicators for tooth loss in adults. The presence of caries and periodontal status were examined in 387 adults aged 20-64 years, according to World Health Organization criteria. Two outcomes were analyzed: loss of one or more teeth, and loss of four or more teeth. Independent variables analyzed were demographic and socioeconomic factors, clinical conditions, use of dental services, and self-perceived oral health. Poisson regression models were used for multivariate statistical analysis. Participants were missing a mean of 5.38 teeth, and 76.9% (n = 297) had lost at least one tooth; the most frequently lost teeth were permanent molars. Older age and the presence of visible dental biofilm were associated significantly with the two tooth loss outcomes (p < 0.05). Individuals who had visited the dentist 3 or more years previously showed a lower prevalence of tooth loss (prevalence ratio = 0.79; 95% confidence interval, 0.68-0.91). Those with lower household incomes were significantly more likely to have lost four or more teeth (prevalence ratio = 1.35; 95% confidence interval, 1.07-1.70). Study results indicated that age and dental biofilm were risk indicators for tooth loss, independently of socioeconomic factors. These risk indicators should be considered when planning oral health programs for adults.

  4. Risk indicators for tooth loss in adult workers.

    PubMed

    Batista, Marília Jesus; Rihs, Lílian Berta; Sousa, Maria da Luz Rosário de

    2012-01-01

    Tooth loss continues to be a prevalent condition in Brazilian adults and elderly individuals. The aim of this cross-sectional study, conducted among workers in a wholesale grocery chain in the State of São Paulo, was to identify risk indicators for tooth loss in adults. The presence of caries and periodontal status were examined in 387 adults aged 20-64 years, according to World Health Organization criteria. Two outcomes were analyzed: loss of one or more teeth, and loss of four or more teeth. Independent variables analyzed were demographic and socioeconomic factors, clinical conditions, use of dental services, and self-perceived oral health. Poisson regression models were used for multivariate statistical analysis. Participants were missing a mean of 5.38 teeth, and 76.9% (n = 297) had lost at least one tooth; the most frequently lost teeth were permanent molars. Older age and the presence of visible dental biofilm were associated significantly with the two tooth loss outcomes (p < 0.05). Individuals who had visited the dentist 3 or more years previously showed a lower prevalence of tooth loss (prevalence ratio = 0.79; 95% confidence interval, 0.68-0.91). Those with lower household incomes were significantly more likely to have lost four or more teeth (prevalence ratio = 1.35; 95% confidence interval, 1.07-1.70). Study results indicated that age and dental biofilm were risk indicators for tooth loss, independently of socioeconomic factors. These risk indicators should be considered when planning oral health programs for adults. PMID:23018226

  5. Worker honey bee ovary development: seasonal variation and the influence of larval and adult nutrition.

    PubMed

    Hoover, Shelley E R; Higo, Heather A; Winston, Mark L

    2006-01-01

    We examined the effect of larval and adult nutrition on worker honey bee (Apis mellifera L.) ovary development. Workers were fed high or low-pollen diets as larvae, and high or low-protein diets as adults. Workers fed low-protein diets at both life stages had the lowest levels of ovary development, followed by those fed high-protein diets as larvae and low- quality diets as adults, and then those fed diets poor in protein as larvae but high as adults. Workers fed high-protein diets at both life stages had the highest levels of ovary development. The increases in ovary development due to improved dietary protein in the larval and adult life stages were additive. Adult diet also had an effect on body mass. The results demonstrate that both carry-over of larval reserves and nutrients acquired in the adult life stage are important to ovary development in worker honey bees. Carry-over from larval development, however, appears to be less important to adult fecundity than is adult nutrition. Seasonal trends in worker ovary development and mass were examined throughout the brood rearing season. Worker ovary development was lowest in spring, highest in mid-summer, and intermediate in fall.

  6. Economic Dislocation and Worker Adjustment Assistance Act, H.R. 1122. Hearing before the Subcommittees on Labor-Management Relations and Employment Opportunities of the Committee on Education and Labor. House of Representatives, One Hundredth Congress, First Session (March 17, 1987).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    This congressional hearing focuses on the Economic Dislocation and Worker Adjustment Assistance Act, which includes features of the prior year's Labor-Management Notification and Consultation Act of 1985 as well as new provisions enacting economic dislocation and worker adjustment task force recommendations. Testimony includes statements and…

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... include services such as transportation, child care, dependent care, housing, and needs-related payments... develop a policy on supportive services that ensures resource and service coordination in the local...

  8. 20 CFR 671.140 - What are the allowable activities and what dislocated workers may be served under national...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... of the 6th week following the date of the emergency grant award; (2) Trade-impacted workers who are... that provide food, clothing, shelter and other humanitarian assistance for disaster victims; and...

  9. 20 CFR 631.30 - Designation or creation and functions of a State dislocated worker unit or office, and rapid...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... industry and labor market trends; programs and services available to veterans; and other fields necessary... equal participation by workers and management, with members often selected in an informal fashion;...

  10. 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…

  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

    ... unit or office may be an existing organization or new organization formed for this purpose (section 311... company or group, including the workers, purchase the plant and continue it in operation. (5) Rapid...-management committee, including providing immediate financial assistance to cover the start-up costs of...

  12. 20 CFR 671.140 - What are the allowable activities and what dislocated workers may be served under national...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (e) Temporary employment assistance is authorized on disaster projects that provide food, clothing, shelter and other humanitarian assistance for disaster victims; and on projects that perform demolition... located within the disaster area. For such temporary jobs, each eligible worker is limited to no more...

  13. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation

    PubMed Central

    Saltzman, Bryan M.; Harris, Joshua D.; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  14. 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.

  15. 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. PMID:26846232

  16. Adult Workforce Education Is Reaching Out to Displaced Workers

    ERIC Educational Resources Information Center

    Claypool, Christine Ryan

    2005-01-01

    It was the year 2002. Ohio was reeling from a decline in the manufacturing sector, which left thousands of northwestern Ohio workers unemployed. When the U.S. economy suffers from a recession, states like Ohio that rely heavily upon employment in manufacturing experience the impact first, according to Neal Eiber of Apollo Career Center Adult…

  17. 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.

  18. Polyvalent Adult Education Centre (An Integrated Approach to Adult Education for Workers).

    ERIC Educational Resources Information Center

    Koshy, T. A.; And Others

    A project to upgrade the vocational skills of Indian workers is presented. This project is designed to plan and develop integrated educational and training courses of various duration for workers and prospective workers, through the establishment of Polyvalent Centers. These centers are institutions providing opportunity for many-sided education…

  19. Measles Outbreak among Previously Immunized Adult Healthcare Workers, China, 2015.

    PubMed

    Zhang, Zhengyi; Zhao, Yuan; Yang, Lili; Lu, Changhong; Meng, Ying; Guan, Xiaoli; An, Hongjin; Zhang, Meizhong; Guo, Wenqin; Shang, Bo; Yu, Jing

    2016-01-01

    Measles is caused by measles virus belonging to genus Morbillivirus of the family Paramyxoviridae. Vaccination has played a critical role in controlling measles infection worldwide. However, in the recent years, outbreaks of measles infection still occur in many developing countries. Here, we report an outbreak of measles among healthcare workers and among the 60 measles infected patients 50 were healthcare workers including doctors, nurses, staff, and medics. Fifty-one patients (85%) tested positive for IgM antibodies against the measles virus and 50 patients (83.3%) tested positive for measles virus RNA. Surprisingly, 73.3% of the infected individuals had been previously immunized against measles. Since there is no infection division in our hospital, the fever clinics are located in the Emergency Division. In addition, the fever and rash were not recognized as measles symptoms at the beginning of the outbreak. These factors result in delay in isolation and early confirmation of the suspected patients and eventually a measles outbreak in the hospital. Our report highlights the importance of following a two-dose measles vaccine program in people including the healthcare workers. In addition, vigilant attention should be paid to medical staff with clinical fever and rash symptoms to avoid a possible nosocomial transmission of measles infection. PMID:27366157

  20. Measles Outbreak among Previously Immunized Adult Healthcare Workers, China, 2015

    PubMed Central

    Zhang, Zhengyi; Zhao, Yuan; Yang, Lili; Lu, Changhong; Meng, Ying; Guan, Xiaoli; An, Hongjin; Zhang, Meizhong; Guo, Wenqin; Shang, Bo; Yu, Jing

    2016-01-01

    Measles is caused by measles virus belonging to genus Morbillivirus of the family Paramyxoviridae. Vaccination has played a critical role in controlling measles infection worldwide. However, in the recent years, outbreaks of measles infection still occur in many developing countries. Here, we report an outbreak of measles among healthcare workers and among the 60 measles infected patients 50 were healthcare workers including doctors, nurses, staff, and medics. Fifty-one patients (85%) tested positive for IgM antibodies against the measles virus and 50 patients (83.3%) tested positive for measles virus RNA. Surprisingly, 73.3% of the infected individuals had been previously immunized against measles. Since there is no infection division in our hospital, the fever clinics are located in the Emergency Division. In addition, the fever and rash were not recognized as measles symptoms at the beginning of the outbreak. These factors result in delay in isolation and early confirmation of the suspected patients and eventually a measles outbreak in the hospital. Our report highlights the importance of following a two-dose measles vaccine program in people including the healthcare workers. In addition, vigilant attention should be paid to medical staff with clinical fever and rash symptoms to avoid a possible nosocomial transmission of measles infection. PMID:27366157

  1. 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…

  2. Interacting with Adults with Congenital Deafblindness: The Experiences of Disability Support Workers

    ERIC Educational Resources Information Center

    Prain, Meredith; McVilly, Keith R.; Ramcharan, Paul

    2012-01-01

    Background: This study aimed to gain greater insight into the perspectives of staff on their interactions with adults with congenital deafblindness in light of the research literature reporting these interactions to be lacking in quality and quantity. Method: Data from interviews with 8 disability support workers were analysed using the approach…

  3. 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…

  4. 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, 1967).…

  5. 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...

  6. 20 CFR 663.600 - What priority must be given to low-income adults and public assistance recipients served with...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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,…

  11. 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

  12. Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age.

    PubMed

    Paoli, Pier P; Donley, Dion; Stabler, Daniel; Saseendranath, Anumodh; Nicolson, Susan W; Simpson, Stephen J; Wright, Geraldine A

    2014-06-01

    Dietary sources of essential amino acids (EAAs) are used for growth, somatic maintenance and reproduction. Eusocial insect workers such as honeybees are sterile, and unlike other animals, their nutritional needs should be largely dictated by somatic demands that arise from their role within the colony. Here, we investigated the extent to which the dietary requirements of adult worker honeybees for EAAs and carbohydrates are affected by behavioural caste using the Geometric Framework for nutrition. The nutritional optimum, or intake target (IT), was determined by confining cohorts of 20 young bees or foragers to liquid diets composed of specific proportions of EAAs and sucrose. The IT of young, queenless bees shifted from a proportion of EAAs-to-carbohydrates (EAA:C) of 1:50 towards 1:75 over a 2-week period, accompanied by a reduced lifespan on diets high in EAAs. Foragers required a diet high in carbohydrates (1:250) and also had low survival on diets high in EAA. Workers exposed to queen mandibular pheromone lived longer on diets high in EAA, even when those diets contained 5× their dietary requirements. Our data show that worker honeybees prioritize their intake of carbohydrates over dietary EAAs, even when overeating EAAs to obtain sufficient carbohydrates results in a shorter lifespan. Thus, our data demonstrate that even when young bees are not nursing brood and foragers are not flying, their nutritional needs shift towards a diet largely composed of carbohydrates when they make the transition from within-hive duties to foraging.

  13. 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...

  14. 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...

  15. Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age.

    PubMed

    Paoli, Pier P; Donley, Dion; Stabler, Daniel; Saseendranath, Anumodh; Nicolson, Susan W; Simpson, Stephen J; Wright, Geraldine A

    2014-06-01

    Dietary sources of essential amino acids (EAAs) are used for growth, somatic maintenance and reproduction. Eusocial insect workers such as honeybees are sterile, and unlike other animals, their nutritional needs should be largely dictated by somatic demands that arise from their role within the colony. Here, we investigated the extent to which the dietary requirements of adult worker honeybees for EAAs and carbohydrates are affected by behavioural caste using the Geometric Framework for nutrition. The nutritional optimum, or intake target (IT), was determined by confining cohorts of 20 young bees or foragers to liquid diets composed of specific proportions of EAAs and sucrose. The IT of young, queenless bees shifted from a proportion of EAAs-to-carbohydrates (EAA:C) of 1:50 towards 1:75 over a 2-week period, accompanied by a reduced lifespan on diets high in EAAs. Foragers required a diet high in carbohydrates (1:250) and also had low survival on diets high in EAA. Workers exposed to queen mandibular pheromone lived longer on diets high in EAA, even when those diets contained 5× their dietary requirements. Our data show that worker honeybees prioritize their intake of carbohydrates over dietary EAAs, even when overeating EAAs to obtain sufficient carbohydrates results in a shorter lifespan. Thus, our data demonstrate that even when young bees are not nursing brood and foragers are not flying, their nutritional needs shift towards a diet largely composed of carbohydrates when they make the transition from within-hive duties to foraging. PMID:24623119

  16. 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

  17. Honey bee workers that are pollen stressed as larvae become poor foragers and waggle dancers as adults.

    PubMed

    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

  18. Honey bee workers that are pollen stressed as larvae become poor foragers and waggle dancers as adults.

    PubMed

    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

  19. 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. PMID:27030775

  20. 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.

  1. 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.

  2. 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.

  3. Legislative Side-By-side for The AEEG Act of Congressmen Kennedy and Hinojosa. WIA I and II & Related. To Advance the Recommendations of the National Commission On Adult Literacy and "Reach Higher, America"

    ERIC Educational Resources Information Center

    Council for Advancement of Adult Literacy (NJ1), 2009

    2009-01-01

    The purpose of this report is to help advance the recommendations of the National Commission on Adult Literacy, for the Adult Education and Economic Growth Act under development by Congressmen Patrick Kennedy and Reuben Hinojosa. Current law is compared to National Commission amendments in such areas as: Adult and Dislocated Worker Employment and…

  4. 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. PMID:21692242

  5. Adult Higher Education. A Case Study on the Workers' Colleges in the People's Republic of China.

    ERIC Educational Resources Information Center

    Bo, Yu; Yan, Xu Hong

    A case study of the workers' colleges in China was undertaken by the Central Institute for Educational Research in Beijing and the Unesco International Institute for Educational Planning in Paris. Workers' colleges provide formal higher education for inservice workers with either full-time or diverse patterns of part-time studies, and the study…

  6. 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

  7. 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

    2010-07-01

    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 Carlo

  8. 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.

  9. The role of the social worker in the adult critical care unit: a systematic review of the literature.

    PubMed

    Hartman-Shea, Katherine; Hahn, Anne P; Fritz Kraus, Joanne; Cordts, Grace; Sevransky, Jonathan

    2011-01-01

    Social workers provide care to patients and families in the adult critical care unit. We conducted a systematic review of the literature to more clearly identify the role of the social worker practicing in the intensive care unit. We conducted a comprehensive search of the literature using the Pubmed, Embase, ISI, Scopus, and Social Work Abstracts databases using the terms "intensive care," "critical care," and "social work." Articles were selected for review if they met the following criteria: formal studies or opinion papers whose primary focus was the role or scope of practice of the social worker in the adult critical care unit. Articles were selected and reviewed independently by two social work investigators. Our search retrieved 550 potentially relevant articles. Twelve full-text articles were deemed eligible for abstracting. Three of the articles were studies that examined different aspects of social work practice including implementation of a family assistance program, social work response to anxiety levels of families in critical care and common activities of critical care social workers. Nine articles were primarily opinion pieces. All of the opinion articles described psychosocial support and counseling as a primary role of critical care social work. Other frequently identified roles were crisis intervention, psychosocial assessment, facilitating communication, end-of-life care, and practical assistance. There is little empiric data describing the role of the critical care social worker. Consistent themes from the articles identified include the role of social workers as counseling professionals, facilitators of communication, and resource agents. Further research to identify formal assessment tools and outcome studies of specific counseling techniques will provide important information for best practice guidelines in this area.

  10. Promoting safer sexual practices among young adults: a survey of health workers in Moshi Rural District, Tanzania.

    PubMed

    Ngomuo, E T; Klepp, K I; Rise, J; Mnyika, K S

    1995-01-01

    As part of the national effort to prevent further spread of HIV/AIDS, rural health workers in Tanzania are asked to promote safer sex practices among the sexually active population. We conducted a survey among health workers in Moshi Rural District, Kilimanjaro, designed to assess their attitudes, perceived norms and self-efficacy with respect to the promotion of safer sexual practices among young adults 15-35 years old. Health workers at all private and governmental health facilities were included (n = 342; participation rate of 68.4%). We observed relatively strong associations between the frequency and quality of reported counselling behaviour and perceived norms, attitudes and self-efficacy (standardized regression coefficients (beta) of 0.329, 0.252 and 0.159 respectively). In addition, exposure to behaviour change strategies during formal training and marital status of the health workers were associated with counselling behaviour (beta of 0.133 and 0.118 respectively). Overall, these factors accounted for 40.8% of the observed variance in reported counselling behaviour. It is recommended that continued education for health workers focus on providing normative support for promoting safer sex, provide information which may help foster positive attitudes and teach practical counselling skills to further increase the self-efficacy regarding counselling young people.

  11. Temporomandibular joint dislocation

    PubMed Central

    Sharma, Naresh Kumar; Singh, Akhilesh Kumar; Pandey, Arun; Verma, Vishal; Singh, Shreya

    2015-01-01

    Temporomandibular joint (TMJ) dislocation is an uncommon but debilitating condition of the facial skeleton. The condition may be acute or chronic. Acute TMJ dislocation is common in clinical practice and can be managed easily with manual reduction. Chronic recurrent TMJ dislocation is a challenging situation to manage. In this article, we discuss the comprehensive review of the different treatment modalities in managing TMJ dislocation. PMID:26668447

  12. 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 1920s"…

  13. Prevalence and determinants of asthma in adult male leather tannery workers in Karachi, Pakistan: A cross sectional study

    PubMed Central

    Shahzad, Khurram; Akhtar, Saeed; Mahmud, Sadia

    2006-01-01

    Background This study aimed to estimate the prevalence and to identify some risk factors of adult asthma in male leather tannery workers in Karachi, Pakistan. Methods A cross sectional study was conducted from August 2003 to March 2004 on leather tannery workers of Karachi, Pakistan. Data were collected from 641 workers engaged in 95 different tanneries in Korangi industrial area selected as sample of convenience. Face to face interviews were performed using a structured pre-tested questionnaire by trained data collectors. Results Prevalence of adult asthma was 10.8% (69/641) in this study population. The prevalence of perceived work-related asthma was 5.3% (34/641). Multivariable logistic regression model showed that after taking into account the age effect, the leather tannery worker were more likely to be asthmatic, if they were illiterate (adjusted OR = 2.13, 95% CI: 1.17–3.88), of Pathan ethnicity (adjusted OR = 2.69; 95% CI: 1.35–5.36), ever-smoked (adjusted OR = 2.22, 95% CI: 1.16–4.26), reportedly never used gloves during different tanning tasks (OR = 3.28; 95% CI : 1.72–6.26). Also, the final model showed a significant interaction between perceived allergy and duration of work. Those who perceived to have allergy were more likely to have asthma if their duration of work was 8 years (adjusted OR = 2.26; 95% CI: 1.19 – 4.29) and this relationship was even stronger if duration was 13 years (adjusted OR = 3.67; 95% CI: 1.98–6.79). Conclusion Prevalence of asthma in leather tannery workers appears to be high and is associated with educational status, ethnicity, smoking, glove use, perceived to have allergy and duration of work. PMID:17144930

  14. 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'…

  15. 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

    2012-01-01

    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.

  16. 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

    2012-01-01

    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. PMID:21982827

  17. 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...

  18. Bilateral Anterior Shoulder Dislocation

    PubMed Central

    Siu, Yuk Chuen; Lui, Tun Hing

    2014-01-01

    Introduction: Unilateral anterior shoulder dislocation is one of the most common problems encountered in orthopedic practice. However, simultaneous bilateral anterior dislocation of the shoulders is quite rare. Case Presentation: We report a case of a 75-year-old woman presented with simultaneous bilateral anterior shoulder dislocation following a trauma, complicated with a traction injury to the posterior cord of the brachial plexus. Conclusions: Bilateral anterior shoulder dislocation is very rare. The excessive traction force during closed reduction may lead to nerve palsy. Clear documentation of neurovascular status and adequate imaging before and after a reduction should be performed. PMID:25685749

  19. Conservative treatment of the isolated dislocation of the pisiform bone.

    PubMed

    Saleh, Waleed Riad; Yajima, Hiroshi; Nakanishi, Akito

    2014-08-01

    We report isolated dislocation of the right pisiform bone dislocated distal and medial to the triquetrum bone in a young adult after a fall. Manipulation and closed reduction under intravenous regional anaesthesia resulted in full functional recovery and a good radiological outcome.

  20. 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…

  1. 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.

  2. Parallel Dislocation Simulator

    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.

  3. 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…

  4. 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…

  5. 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.

  6. Assessing an Untapped Supply of Information Technology Workers: Adult Women and Underrepresented Minorities.

    ERIC Educational Resources Information Center

    Spahn, Karen

    This paper presents the results of a research study (Spring 2001 completion) on adult women and minority students returning to a non-traditional four-year university designed for working adults over a five-year period (1995-2000). The study analyzed several unique student populations--graduates (recent and alumni), still enrolled, and not enrolled…

  7. The burden of traumatic brain injury among adolescent and young adult workers in Washington State

    PubMed Central

    Graves, Janessa M.; Sears, Jeanne M.; Vavilala, Monica S.; Rivara, Frederick P.

    2012-01-01

    Objective This study describes injury characteristics and costs of work-related traumatic brain injury (WRTBI) among 16–24 year olds in Washington State between 1998 and 2008. Methods WRTBIs were identified in the Washington Trauma Registry (WTR) and linked to workers’ compensation (WC) claims data. Medical and time-loss compensation costs were compared between workers with isolated TBI and TBI with other trauma. Results Of 273 WRTBI cases identified, most (61.5%) were TBI with other trauma. One-third of WRTBI did not link to a WC claim. Medical costs averaged $88,307 (median $16,426) for isolated TBI cases, compared to $73,669 (median $41,167) for TBI with other trauma. Conclusions Results highlight the financial impact of WRTBI among young workers. Multiple data sources provided a more comprehensive picture than a single data source alone. This linked-data approach holds great potential for future traumatic occupational injury research. PMID:23710080

  8. Family and Career Transitions Resource Guide (FACT). A Resource Guide for Use in Adult Job Readiness and Single Parent Homemaker Instructional Programs.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Div. of Vocational and Career Education.

    This resource guide introduces a curriculum designed to help instructors meet the needs of special adult audiences--displaced homemakers, single parents, dislocated workers, and economically depressed families. It is organized according to four practical problems: (1) personal development; (2) career exploration; (3) employability; and (4)…

  9. 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

  10. Surgical hip dislocation: techniques for success.

    PubMed

    Ricciardi, Benjamin F; Sink, Ernest L

    2014-01-01

    Surgical hip dislocation (SHD) is a versatile approach used to address both intra-articular and extra-articular pathology around the hip joint in both pediatric and adult patients. It allows anterior dislocation of the femoral head for direct visualization of the hip joint while preserving femoral head vascularity and minimizing trauma to the abductor musculature. Previously described indications for SHD include femoroacetabular impingement, deformity resulting from Legg-Calve-Perthes disease, slipped capital femoral epiphysis, periarticular trauma, benign lesions of the hip joint, and osteochondral lesions. In this review, we will describe current surgical techniques, indications, and clinical outcomes for SHD. PMID:25207733

  11. Prevalence of cytomegalovirus infection among health care workers in pediatric and immunosuppressed adult units.

    PubMed

    Sobaszek, A; Fantoni-Quinton, S; Frimat, P; Leroyer, A; Laynat, A; Edme, J L

    2000-11-01

    The prevalence of cytomegalovirus (CMV) infection varies not only from one country to another, but also with social, economic, and environmental conditions and with professional activity. Health care workers in contact with the main vectors of the CMV (i.e., children and immunosuppressed patients) are particularly exposed to the infection. We assessed the prevalence of the virus among health care personnel in light of CMV epidemiology and the recent shift in living conditions and family size. Our study was included in a broader program evaluating the risk of infection among female hospital workers of childbearing age. The goal of the program was to implement appropriate preventive measures for personnel who were not immune to the infection. Consequently, we included only female caregivers who worked with children or immunosuppressed patients. The study was based on a clinical examination, a medical and occupational questionnaire, the assessment of tasks performed; and CMV serologic testing. The overall seroprevalence was 44.25% in our population (n = 400) and was comparable regardless of the place of work. Prevalence differed significantly with age and parity, and we also found that it was higher among personnel who worked in closer contact with the patients (nurse's aides, pediatric nurse's aides) than among those whose tasks required more technical skills (nurses, pediatric nurses) (57.3% vs 34.5%, P < 0.01). The logistic regression analysis between prevalence of CMV antibodies, age, parity, and type of job showed that "contact job" was as significant a factor as parity to explain immunization in our population (odds ratio, 2.2). We also determined a correlation between the prevalence of CMV antibodies and tasks performed. In addition, we found a non-negligible group of non-immune personnel (55.75%) and young workers (mean age: 33.4) who were potentially exposed to infection. This points to the need to establish a prevention program. PMID:11094790

  12. New Dimensions of Workers' Education

    ERIC Educational Resources Information Center

    Whitehouse, John R. W.

    1978-01-01

    The author suggests that labor education, by its organization through trade unions, is clearly distinguished from general adult education activities, although workers obviously participate in adult education. He discusses various ILO workers' education programs around the world. (MF)

  13. Medial subtalar dislocation.

    PubMed

    Kinik, H; Oktay, O; Arikan, M; Mergen, E

    1999-01-01

    We report a medial subtalar dislocation without fracture in an eighteen year old male injured during basketball game. He was successfully treated with closed reduction and cast immobilization. At one year follow-up he was symptomless.

  14. Acute traumatic patellar dislocation.

    PubMed

    Duthon, V B

    2015-02-01

    Inaugural traumatic patellar dislocation is most often due to trauma sustained during physical or sports activity. Two-thirds of acute patellar dislocations occur in young active patients (less than 20 years old). Non-contact knee sprain in flexion and valgus is the leading mechanism in patellar dislocation, accounting for as many as 93% of all cases. The strong displacement of the patella tears the medial stabilizing structures, and notably the medial patellofemoral ligament (MPFL), which is almost always injured in acute patellar dislocation, most frequently at its femoral attachment. Lateral patellar glide can be assessed with the knee in extension or 20° flexion. Displacement by more than 50% of the patellar width is considered abnormal and may induce apprehension. Plain X-ray and CT are mandatory to diagnose bony risk factors for patellar dislocation, such as trochlear dysplasia or increased tibial tubercle-trochlear groove distance (TT-TG), and plan correction. MRI gives information on cartilage and capsulo-ligamentous status for treatment planning: free bodies or osteochondral fracture have to be treated surgically. If patellar dislocation occurs in an anatomically normal knee and osteochondral fracture is ruled out on MRI, non-operative treatment is usually recommended.

  15. Living 'a life like ours': support workers' accounts of substitute decision-making in residential care homes for adults with intellectual disabilities.

    PubMed

    Dunn, M C; Clare, I C H; Holland, A J

    2010-02-01

    In England and Wales, the Mental Capacity Act 2005 (MCA) provides a new legal framework to regulate substitute decision-making relating to the welfare of adults who lack the capacity to make one or more autonomous decisions about their care and support. Any substitute decision made on behalf of an adult lacking capacity must be in his/her 'best interests'. However, the value of adopting established principles and procedures for substitute decision-making in practice is uncertain, and little is known about the legal or ethical dynamics of social care support, including the day-to-day residential support provided to adults with intellectual disabilities (ID). Methods This paper reports a qualitative, grounded theory analysis of 21 interviews with support workers working in residential care homes for adults with ID, and observations of care practices. Results In contrast to the narrow legal responsibilities placed upon them, it is argued that support workers interpret substitute decision-making within a broad moral account of their care role, orientating their support towards helping residents to live 'a life like ours'. In so doing, support workers describe how they draw on their own values and life experiences to shape the substitute decisions that they make on behalf of residents. Conclusions Support workers' accounts reveal clear discrepancies between the legal regulation of substitute decision-making and the ways that these support workers make sense of their work. Such discrepancies have implications both for the implementation of the MCA, and for the role of support workers' values in the conceptualisation and delivery of 'good' care.

  16. A Community College Program Serving Female Displaced Workers.

    ERIC Educational Resources Information Center

    Sherman, Ruth

    1989-01-01

    Discusses the Bunker Hill Community College program designed to draw on the experience of female dislocated workers. Discusses the types of women this program serves. Provides an example of each type of woman. Discusses the enormous employment problems of dislocated female workers and how education might help them overcome these difficulties. (JS)

  17. Cost-Effectiveness Analysis of a Community Health Worker Intervention for Low-Income Hispanic Adults with Diabetes

    PubMed Central

    Brown, H. Shelton; Pagán, José A.; Arcari, Christine M.; Martinez, Martha; Smith, Kirk; Reininger, Belinda

    2012-01-01

    Introduction The objective of our study was to estimate the long-term cost-effectiveness of a lifestyle modification program led by community health workers (CHWs) for low-income Hispanic adults with type 2 diabetes. Methods We forecasted disease outcomes, quality-adjusted life years (QALYs) gained, and lifetime costs associated with attaining different hemoglobin A1c (A1c) levels. Outcomes were projected 20 years into the future and discounted at a 3.0% rate. Sensitivity analyses were conducted to assess the extent to which our results were dependent on assumptions related to program effectiveness, projected years, discount rates, and costs. Results The incremental cost-effectiveness ratio of the intervention ranged from $10,995 to $33,319 per QALY gained when compared with usual care. The intervention was particularly cost-effective for adults with high glycemic levels (A1c > 9%). The results are robust to changes in multiple parameters. Conclusion The CHW program was cost-effective. This study adds to the evidence that culturally sensitive lifestyle modification programs to control diabetes can be a cost-effective way to improve health among Hispanics with diabetes, particularly among those with high A1c levels. PMID:22916995

  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. PMID:26237722

  19. 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.

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

    PubMed

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

    2015-03-01

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

    PubMed

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

    2015-03-01

    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.

  2. 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

  3. A Qualitative Study of the Dislocated Working Class

    ERIC Educational Resources Information Center

    Fouad, Nadya A.; Cotter, Elizabeth W.; Carter, Laura; Bernfeld, Steven; Gray, India; Liu, Jane P.

    2012-01-01

    This qualitative study examines factors that influence the career decisions of dislocated workers. The research focuses on individuals identified as working class, as this group has been relatively ignored in past research compared to individuals from higher socioeconomic statuses. Participants include 13 individuals (10 females and 3 males)…

  4. Supersonic Dislocation Bursts in Silicon

    PubMed Central

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

    2016-01-01

    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 × 1012 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. PMID:27264746

  5. Supersonic Dislocation Bursts in Silicon

    DOE PAGES

    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 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

  6. 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.

  7. Congenital hip dislocation (image)

    MedlinePlus

    ... by a blow, fall, or other trauma, a dislocation can also occur from birth. The cause is unknown but genetic factors may play a role. Problems resulting from very mild developmental dysplasia of the hip may not become apparent until the person is ...

  8. Dorsal radiocarpal fracture dislocation.

    PubMed

    Tanzer, T L; Horne, J G

    1980-11-01

    A case of a rare radiocarpal fracture dislocation in a 17-year-old girl, with persisting loss of radiocarpal joint space following reduction under hematoma block, is described. The wrist joint was exposed, and two osteochondral fragments were rotated 90 degrees and secured with 2.7-mm AO screws. Satisfactory healing followed 3 months postinjury.

  9. 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. PMID:24608542

  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. 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. PMID:26471950

  12. 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. PMID:20478660

  13. Career Services for Adults: Worker Access to Educational Opportunities. Final Report, October 1, 1978-September 30, 1979.

    ERIC Educational Resources Information Center

    College Entrance Examination Board, New York, NY. Future Directions for a Learning Society.

    A Project designed, demonstrated, and disseminated a Study Organizer Center (SOC) for United Auto Workers (UAW) employees. This SOC was to provide information and services to help the workers better understand their tuition refund program, formulate personal occupational objectives, and pursue their interest through existing educational…

  14. The prevalence and effects of Adult Attention-Deficit/hyperactivity Disorder (ADHD) on the performance of workers: Results from the WHO World Mental Health Survey Initiative

    PubMed Central

    de Graaf, Ron; Kessler, Ronald C.; Fayyad, John; ten Have, Margreet; Alonso, Jordi; Angermeyer, Matthias; Borges, Guilherme; Demyttenaere, Koen; Gasquet, Isabelle; de Girolamo, Giovanni; Haro, Josep Maria; Jin, Robert; Karam, Elie G; Ormel, Johan; Posada-Villa, José

    2009-01-01

    Objectives To estimate the prevalence and workplace consequences of adult attention-deficit/hyperactivity disorder (ADHD). Methods Ann ADHD screen was administered to 18–44 year-old respondents in ten national surveys in the WHO World Mental Health (WMH) Survey Initiative (n = 7075 in paid or self employment; response rate 45.9–87.7% across countries). Blinded clinical reappraisal interviews were administered in the US to calibrate the screen. Days out of role were measured in the WHO Disability Assessment Schedule (WHO-DAS). Questions were also asked about ADHD treatment. Results An average of 3.5% of workers in the ten countries was estimated to meet DSM-IV criteria for adult ADHD (inter-quartile range: 1.3–4.9%). ADHD was more common among males than females and less common among professionals than other workers. ADHD was associated with a statistically significant 22.1 annual days of excess lost role performance compared to otherwise similar respondents without ADHD. No difference in the magnitude of this effect was found by occupation, education, age, gender, or partner status. This effect was most pronounced in Colombia, Italy, Lebanon, and the US. Although only a small minority of workers with ADHD ever received treatment for this condition, higher proportions were treated for comorbid mental-substance disorders. Conclusions ADHD is a relatively common condition among working people in the countries studied and is associated with high work impairment in these countries. This impairment, in conjunction with the low treatment rate and the availability of cost-effective therapies, suggests that ADHD would be a good candidate for targeted workplace screening and treatment programs. Main messages A high proportion of childhood ADHD persists into adulthood. An average of 3.5% of workers in nationally representative surveys carried out in 10 countries met criteria for current DSM-IV adult ADHD. Workers with ADHD have an average 8.4 excess sickness absence

  15. Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers

    PubMed Central

    Borges, Andreia A.; Humann, Fernanda C.; Oliveira Campos, Lucio A.; Tavares, Mara G.; Hartfelder, Klaus

    2011-01-01

    In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males. PMID:22215977

  16. Serving Dislocated Farmers: An Evaluation of the EDWAA Farmers and Ranchers Demonstration. Research and Evaluation Report Series 94-C.

    ERIC Educational Resources Information Center

    Visher, Mary G.; Walsh, Stephen

    The Farmers and Ranchers Demonstration Project, funded by the Economic Dislocation and Workers Adjustment Act, provided funding for employment and training services to dislocated and at-risk farmers and ranchers and their dependents and employees in four states (Iowa, Minnesota, North Dakota, and South Dakota) from July 1, 1990 to September 30,…

  17. Congenital Dislocation of the Hip

    PubMed Central

    Premi, J. M.

    1976-01-01

    The implications of a diagnosis of congenital dislocation of the hip and the importance of the role of the family physician in early detection and treatment are identified. A review of the salient clinical features of congenital dislocation of the hip is undertaken. The results of a survey carried out in the author's practice on an unusual incidence of congenital dislocated hip are reviewed. PMID:21308053

  18. Dislocation and fracture-dislocation of the carpometacarpal joints.

    PubMed

    Jebson, P J; Engber, W D; Lange, R H

    1994-02-01

    Dislocations and fracture-dislocations of the carpometacarpal joints are rare. Diagnosis requires a high index of suspicion, careful examination, and appropriate radiography. Treatment is controversial and is based upon the injury pattern and the surgeon's experience and preference. This article reviews the pertinent anatomy, mechanism of injury, evaluation, and treatment of patients with carpometacarpal joint injuries.

  19. 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.

  20. 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…

  1. 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

  2. 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...

  3. 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...

  4. 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.

  5. 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. PMID:26996903

  6. Moving Dislocations in Disordered Alloys.

    SciTech Connect

    Marian, J; Caro, A

    2006-11-18

    Using atomistic simulations of dislocation motion in Ni and Ni-Au alloys we report a detailed study of the mobility function as a function of stress, temperature and alloy composition. We analyze the results in terms of analytic models of phonon radiation and their selection rules for phonon excitation. We find a remarkable agreement between the location of the cusps in the {sigma}-v relation and the velocity of waves propagating in the direction of dislocation motion. We identify and characterize three regimes of dissipation whose boundaries are essentially determined by the direction of motion of the dislocation, rather than by its screw or edge character.

  7. Dislocation after total knee arthroplasty.

    PubMed

    Wazir, N N; Shan, Y; Mukundala, V V; Gunalan, R

    2007-05-01

    Two cases of dislocation of total knee arthroplasty presented to us within the same week. The first patient is a 71-year-old woman who underwent bilateral primary total knee arthroplasty. The left knee dislocated three weeks after the surgery. Due to failure of conservative measures, she underwent revision total knee arthroplasty. The other patient is a 72-year-old woman presenting ten years after primary total knee arthroplasty, with a traumatic dislocation of the knee joint. She was treated as an outpatient with closed manipulative reduction.

  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. Dislocation Detection Through Harmonic Generation

    NASA Astrophysics Data System (ADS)

    Reinhardt, B. T.; Kropf, M.; Boudraeu, K.; Guers, M. J.; Tittmann, B. R.

    2010-02-01

    A fundamental goal of ultrasonic nondestructive evaluation is to characterize material defects before failure. During material fatigue, dislocations tend to nucleate, becoming sources of stress concentration. Eventually, cracks start to form and lead to material failure. Recent research has indicated that nonlinear harmonic generation can be used to distinguish between materials of high and low dislocation densities. This research reports nonlinear harmonic generation measurements to distinguish between those areas of high and low dislocation densities in copper bars. The copper bars were subjected to flexural fatigue. Periodic scans were taken in order to track dislocation development during the fatigue life of the material. We show that this technique provides improved early detection for critical components of failure.

  10. 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.

  11. Perilunar carpal dislocations treatment outcome.

    PubMed

    Gagała, Jacek; Tarczyńska, Marta; Kosior, Piotr

    2006-06-30

    Background. The aim of the study was to analyze late outcomes of perilunar carpal dislocations, depending on the type of the injury, time of the diagnosis and the treatment methods. Material and methods. The material is constituted by 37 patients treated in our department between 1981-2004 because of perilunar dislocation. In group were 2 women and 35 men, aged 19-56 (mean 31 years). All patients were asked for control visit. DASH and Mayo score were used to evaluate the outcome. Range of wrist motion, its stability, grip strength and X-ray pictures were analyzed. Results. Better follow-up results were observed in persons with early diagnosed dislocations of the wrist. The best outcomes were observed in group with perilunar early diagnosed dislocations, which were treated by open reduction. Posttraumatic wrist instability often was diagnosed in patients with dislocation of lunar bone and late-diagnosed transscaphoid perilunar carpal dislocations. Conclusions. The data we obtained show, that the consequences of late-diagnosed and late-treated injuries of the wrist are instability, pain, decrease in range of motion and hand skills. PMID:17592406

  12. 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.

  13. Recurrent posttraumatic trapeziometacarpal joint dislocation in a child: A case report.

    PubMed

    Gaillard, Julien; Fitoussi, Franck

    2016-04-01

    Traumatic trapeziometacarpal joint dislocation of the thumb accounts for less than 1% of all hand injuries. This injury is even less common in children. Optimal treatment strategies for this injury are still the subject of debate for both children and adults. We report a case of recurrent posttraumatic trapeziometacarpal joint dislocation in an eight-year-old girl. We believe our case is the first report of recurrent acute dislocation leading to chronic dislocation in the English medical literature. Restoring the anatomy and biomechanics of the trapeziometacarpal joint is essential when treating these injuries; for this reason, surgical treatment is usually indicated. Overall, the prognosis of trapeziometacarpal dislocation treated acutely is favorable and stable over time. However, the role of open surgery and ligament reconstruction remains controversial, especially in children. PMID:27117129

  14. Congenital dislocation of the knee.

    PubMed

    Ko, J Y; Shih, C H; Wenger, D R

    1999-01-01

    Between February 1988 and June 1995, 24 congenital dislocations of the knee joints (17 patients) were reduced with closed methods including immediate reduction, serial casting, or traction in patients from 10 min to 26 days old. At an average follow-up of 4 years and 10 months, an excellent or good result was achieved if there were no associated anomalies. Fair or poor results were the result of delayed treatment or associated musculoskeletal anomalies including arthrogryposis multiplex congenita or Larsen's syndrome. Routine check of the hip dislocation is suggested. Diagnosis with manual testing was difficult, and other methods such as radiography or sonography were suggested in combination to detect hip dysplasia. The dislocated knee should be reduced before treating the hip dislocation. Concomitant treatment of the congenital dislocation of the knee and the hip with Pavlik harness provided satisfactory results. When late, progressive, genu valgus deformity occurred because of global instability of the knee and asymmetric physeal growth, reconstruction of the medial structures of the knee and prolonged bracing provided good results. PMID:10088699

  15. Modeling hydrogen transport by dislocations

    NASA Astrophysics Data System (ADS)

    Dadfarnia, Mohsen; Martin, May L.; Nagao, Akihide; Sofronis, Petros; Robertson, Ian M.

    2015-05-01

    Recent experimental studies of the microstructure beneath fracture surfaces of specimens fractured in the presence of high concentrations of hydrogen suggest that the dislocation structure and hydrogen transported by mobile dislocations play important roles in establishing the local conditions that promote failure. The experiments demonstrate that hydrogen is responsible for the copious plasticity in large volumes of material before the onset of fracture and further afield from a crack tip. A revised model for hydrogen transport that accounts for hydrogen carried by dislocations along with stress driven diffusion and trapping at other microstructural defects is proposed. With the use of this new model, numerical simulation results for transient hydrogen profiles in the neighborhood of a crack tip are presented. Based on hydrogen-enhanced dislocation mobility and density, the results indicate that dislocation transport can contribute to the elevation of the local hydrogen concentrations ahead of the crack to levels above those predicted by the classical diffusion model and to distributions that extend farther afield.

  16. 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.

  17. Dislocation-density function dynamics - An all-dislocation, full-dynamics approach for modeling intensive dislocation structures

    NASA Astrophysics Data System (ADS)

    Leung, H. S.; Ngan, A. H. W.

    2016-06-01

    It has long been recognized that a successful strategy for computational plasticity will have to bridge across the meso scale in which the interactions of high quantities of dislocations dominate. In this work, a new meso-scale scheme based on the full dynamics of dislocation-density functions is proposed. In this scheme, the evolution of the dislocation-density functions is derived from a coarse-graining procedure which clearly defines the relationship between the discrete-line and density representations of the dislocation microstructure. Full dynamics of the dislocation-density functions are considered based on an "all-dislocation" concept in which statistically stored dislocations are preserved and treated in the same way as geometrically necessary dislocations. Elastic interactions between dislocations in a 3D space are treated in accordance with Mura's formula for eigen stress. Dislocation generation is considered as a consequence of dislocations to maintain their connectivity, and a special scheme is devised for this purpose. The model is applied to simulate a number of intensive microstructures involving discrete dislocation events, including loop expansion and shrinkage under applied and self stress, dipole annihilation, and Orowan looping. The scheme can also handle high densities of dislocations present in extensive microstructures.

  18. 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.

  19. Irreducible dislocation of the knee.

    PubMed

    Schaefer, R A; Bellafiore, V A; Corzatt, R D

    1999-11-01

    Irreducible knee dislocation is a rare injury. This case report describes a knee dislocation in a 39-year-old male U.S. Army noncommissioned officer who was injured while playing in a softball game. Arthroscopy showed the medial collateral ligament and capsule to be locked in the intercondylar notch, covering the medial femoral condyle. Arthrotomy and open reduction were required. Staged posterior cruciate ligament reconstruction using patellar tendon autograft was later performed. Review of the magnetic resonance imaging scan showed the irreducible lesion. The diagnostic clinical and radiographic features of this unusual injury are described.

  20. Bipolar dislocation of the clavicle.

    PubMed

    Jiang, Wei; Gao, Shu-Guang; Li, Yu-Sheng; Lei, Guang-Hua

    2012-11-01

    Bipolar dislocation of the clavicle at acromioclavicular and sternoclavicular joint is an uncommon traumatic injury. The conservative treatments adopted in the past is associated with redislocation dysfunction and deformity. A 41 years old lady with bipolar dislocation of right shoulder is treated surgically by open reduction and internal fixation by oblique T-plate at sternoclavicular joint and Kirschner wire stabilization at acromioclavicular joint. The patient showed satisfactory recovery with full range of motion of the right shoulder and normal muscular strength. The case reported in view of rarity and at 2 years followup. PMID:23325981

  1. Dislocation nonlinearity and nonlinear wave processes in polycrystals with dislocations

    NASA Astrophysics Data System (ADS)

    Nazarov, V. E.

    2016-09-01

    Based on the modification of the linear part of the Granato-Lücke dislocation theory of absorption, the equation of state of polycrystalline solids with dissipative and reactive nonlinearity has been derived. The nonlinear effects of the interaction and self-action of longitudinal elastic waves in such media have been theoretically studied.

  2. Drift of dislocation tripoles under ultrasound influence.

    PubMed

    Murzaev, R T; Bachurin, D V; Nazarov, A A

    2016-01-01

    Numerical simulations of dynamics of different stable dislocation tripoles under influence of monochromatic standing sound wave were performed. The basic conditions necessary for the drift and mutual rearrangements between dislocation structures were investigated. The dependence of the drift velocity of the dislocation tripoles as a function of the frequency and amplitude of the external influence was obtained. The results of the work can be useful in analysis of motion and self-organization of dislocation structure under ultrasound influence. PMID:26278625

  3. Simultaneous double interphalangeal dislocation in one finger.

    PubMed

    Takami, H; Takahashi, S; Ando, M

    2000-01-01

    Isolated dislocation of the proximal or distal interphalangeal joint of a finger is common, but simultaneous dislocation of both joints is rare. Three cases of simultaneous dislocations of both interphalangeal joints in the same finger are reported. Closed reduction was easily achieved in all cases.

  4. Financial Dislocations among Divorcing Families.

    ERIC Educational Resources Information Center

    Little, Marilyn J.

    Extensive economic changes may be brought about by divorce. In an attempt to demonstrate that the degree of financial dislocation following divorce depends on three factors--custody arrangements, wife's employment, and social class--data on men's and women's employment, income, and support payments were gathered for 222 divorcing families. Total…

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Prevalences of sexually transmitted infections in young adults and female sex workers in Peru: a national population-based survey

    PubMed Central

    Cárcamo, César P; Campos, Pablo E; García, Patricia J; Hughes, James P; Garnett, Geoff P; Holmes, King K

    2012-01-01

    Summary Background We assessed prevalences of seven sexually transmitted infections (STIs) in Peru, stratified by risk behaviours, to help to define care and prevention priorities. Methods In a 2002 household-based survey of the general population, we enrolled randomly selected 18–29-year-old residents of 24 cities with populations greater than 50 000 people. We then surveyed female sex workers (FSWs) in these cities. We gathered data for sexual behaviour; vaginal specimens or urine for nucleic acid amplification tests for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; and blood for serological tests for syphilis, HIV, and (in subsamples) herpes simplex virus 2 (HSV2) and human T-lymphotropic virus. This study is a registered component of the PREVEN trial, number ISRCTN43722548. Findings 15 261 individuals from the general population and 4485 FSWs agreed to participate in our survey. Overall prevalence of infection with HSV2, weighted for city size, was 13·5% in men, 13·6% in women, and 60·6% in FSWs (all values in FSWs standardised to age composition of women in the general population). The prevalence of C trachomatis infection was 4·2% in men, 6·5% in women, and 16·4% in FSWs; of T vaginalis infection was 0·3% in men, 4·9% in women, and 7·9% in FSWs; and of syphilis was 0·5% in men, 0·4% in women, and 0·8% in FSWs. N gonorrhoeae infection had a prevalence of 0·1% in men and women, and of 1·6% in FSWs. Prevalence of HIV infection was 0·5% in men and FSWs, and 0·1% in women. Four (0·3%) of 1535 specimens were positive for human T-lymphotropic virus 1. In men, 65·0% of infections with HIV, 71·5% of N gonorrhoeae, and 41·4% of HSV2 and 60·9% of cases of syphilis were in the 13·3% who had sex with men or unprotected sex with FSWs in the past year. In women from the general population, 66·7% of infections with HIV and 16·7% of cases of syphilis were accounted for by the 4·4% who had been paid for sex by any of

  10. Geriatric Service Worker.

    ERIC Educational Resources Information Center

    Seton Hill Coll., Greensburg, PA.

    This curriculum for training geriatric service workers is designed to incorporate additional communication and group skills along with the basic knowledge and skills necessary to work with older adults. The curriculum is organized in four modules. Each module is assigned a time frame and a credit unit base. The modules are divided into four major…

  11. Dislocation of the knee: imaging findings.

    PubMed

    Shearer, Damon; Lomasney, Laurie; Pierce, Kenneth

    2010-01-01

    Dislocations of the knee are relatively uncommon injuries. However, the incidence of this injury appears to be increasing. Knee dislocations are most often high velocity blunt injuries, with motor vehicle accidents being a frequent etiology. Other causes include falls from height, athletic injuries, farming and industrial accidents, and even low velocity mechanisms such as a misstep into a hole. Likewise, minor trauma in the morbidly obese is increasingly recognized as a mechanism of knee dislocation. Multiple forms of dislocation exist, with the common factor being disruption of the tibiofemoral articulation. Dislocation can occur in a variety of directions depending on the mechanism of injury. The most common dislocation is anterior, which may be seen in hyperextension injuries such as martial arts kicking. The "dashboard injury" of motor vehicle accidents can result in a posterior dislocation of the knee. Lateral and rotary dislocations are less common. Knee dislocation is more commonly diagnosed in men, with a mean age of 23 to 31 years old. This is the very patient population encountered by Special Operations Forces (SOF) healthcare providers. Given the mechanisms of injury noted above, it is reasonable to conclude that knee dislocations may be seen in a young, active SOF patient population, particularly those engaged in parachuting, fast-roping/rappelling, driving at high speeds during military operations, and mixed martial arts. PMID:20306414

  12. 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.

  13. Mobility Laws in Dislocation Dynamics Simulations

    SciTech Connect

    Cai, W; Bulatov, V V

    2003-10-21

    Prediction of the plastic deformation behavior 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 existing dislocation dynamics (DD) codes to handle a sufficiently large number of dislocation lines, to establish a statistically representative model of crystal plasticity. A new massively-parallel DD code is developed that is capable of modeling million-dislocation systems by employing thousands of processors. We discuss an important ingredient of this code--the mobility laws dictating the behavior of individual dislocations. They are materials input for DD simulations and are constructed based on the understanding of dislocation motion at the atomistic level.

  14. 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

  15. Robust atomistic calculation of dislocation line tension

    NASA Astrophysics Data System (ADS)

    Szajewski, B. A.; Pavia, F.; Curtin, W. A.

    2015-12-01

    The line tension Γ of a dislocation is an important and fundamental property ubiquitous to continuum scale models of metal plasticity. However, the precise value of Γ in a given material has proven difficult to assess, with literature values encompassing a wide range. Here results from a multiscale simulation and robust analysis of the dislocation line tension, for dislocation bow-out between pinning points, are presented for two widely-used interatomic potentials for Al. A central part of the analysis involves an effective Peierls stress applicable to curved dislocation structures that markedly differs from that of perfectly straight dislocations but is required to describe the bow-out both in loading and unloading. The line tensions for the two interatomic potentials are similar and provide robust numerical values for Al. Most importantly, the atomic results show notable differences with singular anisotropic elastic dislocation theory in that (i) the coefficient of the \\text{ln}(L) scaling with dislocation length L differs and (ii) the ratio of screw to edge line tension is smaller than predicted by anisotropic elasticity. These differences are attributed to local dislocation core interactions that remain beyond the scope of elasticity theory. The many differing literature values for Γ are attributed to various approximations and inaccuracies in previous approaches. The results here indicate that continuum line dislocation models, based on elasticity theory and various core-cut-off assumptions, may be fundamentally unable to reproduce full atomistic results, thus hampering the detailed predictive ability of such continuum models.

  16. 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.

  17. 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.

  18. 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.

  19. 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…

  20. 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. PMID:26871192

  1. 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.…

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Statistics of dislocation pinning at localized obstacles

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  7. A rare variant of knee dislocation

    PubMed Central

    HUSSIN, P.; MAWARDI, M.; AB HALIM, A.H.

    2016-01-01

    Knee dislocation is a rare injury. It represents less than 0.2% of orthopaedic injuries. This case reports a rare form of knee dislocation caused by the impact of a high-energy trauma. In these cases the appropriate assessment and management is needed to ensure that patient receives the proper treatment. PMID:27381692

  8. Obesity. A risk factor for knee dislocation.

    PubMed

    Marin, E L; Bifulco, S S; Fast, A

    1990-06-01

    Complete dislocation of the knee joint is a severe injury that is commonly the result of high-velocity injuries and often associated with disruption of the popliteal artery. We report two cases in which obesity appeared to be the principal cause of knee dislocation with vascular compromise. Preventive measures in extremely obese patients are recommended.

  9. Dislocation of the cuboid bone without fracture.

    PubMed

    Gough, D T; Broderick, D F; Januzik, S J; Cusack, T J

    1988-10-01

    A 37-year-old man presented following an inversion plantar flexion injury to the left foot and ankle. Dislocation of the cuboid without associated fracture was identified and successfully treated by closed reduction. The patient was immobilized in a walking cast for seven weeks after surgery and no further dislocation occurred.

  10. 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.

  11. Geometric approach to dislocation and disclination theory

    SciTech Connect

    Nesterov, A.I.; Ovchinnikov, S.G.

    1988-05-01

    Cartan structure equations are used to create a four-dimensional geometric description of dislocations in continuum theory. It is shown that the dislocation distribution is determined by the torsion tensor, while the disclination distribution is determined by the curvature tensor. An analogy to electrodynamics is offered.

  12. [Bipolar forearm dislocation or floating forearm (a case report)].

    PubMed

    Daoudi, A; Elibrahimi, A; Loudiyi, W D; Elmrini, A; Chakour, K; Boutayeb, F

    2009-02-01

    Bipolar dislocation of the forearm or floating forearm is a rare injury. It combines concomitant elbow and wrist dislocation. Only six cases have been reported in the literature. The diagnosis of wrist dislocation may initially be missed and therefore the prognosis will be worse. The authors report a case of a bipolar dislocation with a posterior dislocation of the elbow and a perilunate dislocation of the wrist.

  13. Initial dislocation structure and dynamic dislocation multiplication in Mo single crystals

    SciTech Connect

    Hsiung, L M; Lassila, D H

    2000-03-22

    Initial dislocation structure in annealed high-purity Mo single crystals and deformation substructure in a crystal subjected to 1% compression have been examined and studied in order to investigate dislocation multiplication mechanisms in the early stages of plastic deformation. The initial dislocation density is in a range of 10{sup 6} {approx} 10{sup 7} cm{sup -2}, and the dislocation structure is found to contain many grown-in superjogs along dislocation lines. The dislocation density increases to a range of 10{sup 8} {approx} 10{sup 9} cm{sup -2}, and the average jog height is also found to increase after compressing for a total strain of 1%. It is proposed that the preexisting jogged screw dislocations can act as (multiple) dislocation multiplication sources when deformed under quasi-static conditions. Both the jog height and length of link segment (between jogs) can increase by stress-induced jog coalescence, which takes place via the lateral migration (drift) of superjogs driven by unbalanced line-tension partials acting on link segments of unequal lengths. Applied shear stress begins to push each link segment to precede dislocation multiplication when link length and jog height are greater than critical lengths. This dynamic dislocation multiplication source is subsequently verified by direct simulations of dislocation dynamics under stress to be crucial in the early stages of plastic deformation in Mo single crystals.

  14. Double Dislocation of Interphalangeal Joints Accompanied with Contralateral Shoulder Dislocation: A Case Report.

    PubMed

    Raval, Pradyumna Ramchandra; Jariwala, Arpit

    2016-02-01

    Dislocation of any joint is an orthopaedic emergency and needs immediate attention by the attending physician. A delay in reducing a dislocated joint can lead to disastrous complications both immediately as well as in the long run. Although anterior dislocation of a shoulder joint is by far the commonest dislocation encountered by any emergency care physician, other joints may also get dislocated. In certain cases two joints may get dislocated simultaneously. Such dislocation is known as a double dislocation. Double dislocation of the proximal interphalangeal joint and the distal interphalangeal joint in the same finger is a rare injury. High impact loading at the fingertip is the primary cause in most cases and it is often associated with younger individuals playing contact sports. The right little finger is the digit commonly involved and this injury is evident in football players more often than not. Although closed reduction is a preferred treatment, it may not be always successful. Time of presentation, tendon interposition, associated swelling and co-existent phalangeal fractures are certain key impediments to a successful closed reduction manoeuvre. In patients with an open injury, a thorough wash out and appropriate antibiotic cover is mandatory. We report a rare case of double dislocation of the interphalangeal joints accompanied with contralateral shoulder dislocation in an elderly man sustained after a fall which was treated successfully with closed reduction and early mobilization. PMID:27028386

  15. Dislocation patterning in a two-dimensional continuum theory of dislocations

    NASA Astrophysics Data System (ADS)

    Groma, István; Zaiser, Michael; Ispánovity, Péter Dusán

    2016-06-01

    Understanding the spontaneous emergence of dislocation patterns during plastic deformation is a long standing challenge in dislocation theory. During the past decades several phenomenological continuum models of dislocation patterning were proposed, but few of them (if any) are derived from microscopic considerations through systematic and controlled averaging procedures. In this paper we present a two-dimensional continuum theory that is obtained by systematic averaging of the equations of motion of discrete dislocations. It is shown that in the evolution equations of the dislocation densities diffusionlike terms neglected in earlier considerations play a crucial role in the length scale selection of the dislocation density fluctuations. It is also shown that the formulated continuum theory can be derived from an averaged energy functional using the framework of phase field theories. However, in order to account for the flow stress one has in that case to introduce a nontrivial dislocation mobility function, which proves to be crucial for the instability leading to patterning.

  16. 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.

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

    DOE PAGES

    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.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

  18. 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.

  19. Worker Education.

    ERIC Educational Resources Information Center

    Yiziang, Zeng; And Others

    1988-01-01

    Describes worker education in China as an important part of the national educational plan and an indispensible foundation for the work of developing enterprisers. Basic tasks are the development of the mind, preparation of specialists, improving workers, and modernization of socialist enterprises. (JOW)

  20. Atlantoaxial dislocation and Down's syndrome.

    PubMed Central

    Whaley, W J; Gray, W D

    1980-01-01

    The phenotypic features of Down's syndrome are easily recognized and include characteristic facial features, hypotonia, ligament laxity, transverse palmar creases and mental subnormality. Associated manifestations and complications are also familiar and involve almost every organ system. Congenital heart defects, bowel malformations and a tendency to leukemia are common attendant problems. Less common, however, are defects of the skeletal system; in fact, the most recent edition of a standard pediatric textbook makes no mention of anomalies of the vertebral column. The purpose of this paper is to call attention to the association between Down's syndrome and atlantoaxial dislocation, which in our patient resulted in quadriplegia and eventually death. Images FIG. 1 FIG. 2 PMID:6448087

  1. Recurrent Dislocation of the Patella

    PubMed Central

    Benítez, Gustavo

    2015-01-01

    Purpose: To evaluate results of medial patellofemoral ligament (MPFL) reconstruction associated with lateral release and advancement of vastus medialis in recurrent dislocation of the patella. Methods: We retrospectively evaluated 11 patients with a mean follow-up of 19 months. Mean age was 23, mainly women. We did MPFL reconstruction with semitendinosus or gracilis tendon depending on BMI, associated with advancement of vastus medialis and lateral release. Results: Mean Kujala score improved from 46,54 pts. preoperative to 88,36 postoperative. Our main complication was 1 patient with rigid knee, who required movilization under anesthesia and arthroscopic arthrolisis to improve her outcome. Conclusion: The combination of this techniques are a good alternative to treat patients with recurrent patella disclocation, with good short and mid-term results. Biomechanic intra and postop complications of MPFL reconstruction are related to patellar fixation, anatomic positioning of femoral tunnel and knee position of the graft fixation.

  2. Dislocation-obstacle interactions in aluminum alloys

    NASA Astrophysics Data System (ADS)

    Clark, Blythe Gore

    Dislocation-obstacle interactions play a significant role in determining the mechanical response of a material. Because higher stresses are needed for dislocations to bypass obstacles, these interactions reduce dislocation mobility and increase the yield strength of a material, as well as improve the work-hardening rate and the resistance to coarsening. The phenomenon of dislocation-obstacle interactions can be advantageous, as in the case of particle-strengthening to increase the creep strength of a material, or disadvantageous, as in embrittlement of a metal due to radiation-induced defects. In order to accelerate the time from development to implementation of a new material, optimize production parameters, and accurately predict the behavior of a material while in service, it is necessary to develop robust material models based on fundamental physical inputs. Through careful experimentation, the nature of dislocation-obstacle interactions can be assessed, allowing key physical parameters to be identified and clarified. These can serve as the basis for developing new and accurate material models. This thesis examines two types of dislocation-obstacle interactions: dislocation-particle interactions during creep deformation, and dislocation-loop interactions during deformation at room temperature. Dislocation-particle interaction studies in Al-Zn-Mg-Cu-Zr, Al-4Mg-0.3Sc, and Al-0.3Sc showed that temperature, coherency, and particle size play a role in determining the dominant bypass mechanism, and that interactions are more complex than what is considered in current models. A new mechanism for elevated temperature bypass of particles during creep deformation was revealed, in which dislocations interact directly with the particle-matrix interface, altering the interfacial structure, and affecting subsequent dislocation interactions. These results are discussed in relation to macroscopic behavior in steady-state creep experiments. In addition, dislocation

  3. Dislocation Creep in Magnesium Calcite

    NASA Astrophysics Data System (ADS)

    Xu, L.; Xiao, X.; Evans, B. J.

    2003-12-01

    To investigate the effect of dissolved Mg on plastic deformation of calcite, we performed triaxial deformation experiments on synthetic calcite with varying amount of Mg content. Mixtures of powders of calcite and dolomite were isostatically hot pressed (HIP) at 850° C and 300 MPa confining pressure for different intervals (2 to 20hrs) resulting in homogeneous aggregates of high-magnesium calcite; Mg content varied from 0.07 to 0.17 mol%. Creep tests were performed at differential stresses from 20 to 160 MPa at 700 to 800° C. Grain sizes before and after deformation were determined from the images obtained from scanning electron microscope (SEM) and optical microscope. Grain sizes are in the range of 5 to 20 microns depending on the HIP time, and decrease with increasing magnesium content. Both BSE images and chemical analysis suggest that all dolomite are dissolved and the Mg distribution is homogeneous through the sample, after 2 hrs HIP. At stresses below 40 MPa, the samples deformed in diffusion region (Coble creep), as described previously by Herwegh. The strength decreases with increasing magnesium content, owing to the difference of grain size. At stresses above 80 MPa, the stress exponent is greater than 3, indicating an increased contribution of dislocation creep. The transition between diffusion to dislocation creep occurs at higher stresses for the samples with higher magnesium content and smaller grain size. Preliminary data suggests a slight increase in strength with increasing magnesium content, but more tests are needed to verify this effect. In a few samples, some strain weakening may have been evident. The activation energy in the transition region (at 80 MPa) is ˜200 KJ/mol with no dependence on magnesium content, agreeing with previous measurements of diffusion creep in natural and synthetic marbles.

  4. 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.

  5. 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

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    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.

  8. 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

  9. Community Adult Education; Evidence Submitted to the Russell Committee on Adult Education in England and Wales by the Workers' Educational Association (West Lancashire & Cheshire District) and the Liverpool Educational Priority Area Action/Research Project.

    ERIC Educational Resources Information Center

    Lovett, T. O.

    This paper discusses six roles which an adult education agency can fill in an Educational Priority Area and illustrates each one with examples from the Liverpool E.P.A. Project. These roles are: (1) adult education cum community development; (2) adult education as a resource in community development work; (3) adult education as an aid to parents…

  10. “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

  11. 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.

  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. 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 ...

  15. Analysis of dislocation pile-ups using a dislocation-based continuum theory

    NASA Astrophysics Data System (ADS)

    Schulz, K.; Dickel, D.; Schmitt, S.; Sandfeld, S.; Weygand, D.; Gumbsch, P.

    2014-03-01

    The increasing demand for materials with well-defined microstructure, accompanied by the advancing miniaturization of devices, is the reason for the growing interest in physically motivated, dislocation-based continuum theories of plasticity. In recent years, various advanced continuum theories have been introduced, which are able to described the motion of straight and curved dislocation lines. The focus of this paper is the question of how to include fundamental properties of discrete dislocations during their motion and interaction in a continuum dislocation dynamics (CDD) theory. In our CDD model, we obtain elastic interaction stresses for the bundles of dislocations by a mean-field stress, which represents long-range stress components, and a short range corrective stress component, which represents the gradients of the local dislocation density. The attracting and repelling behavior of bundles of straight dislocations of the same and opposite sign are analyzed. Furthermore, considering different dislocation pile-up systems, we show that the CDD formulation can solve various fundamental problems of micro-plasticity. To obtain a mesh size independent formulation (which is a prerequisite for further application of the theory to more complex situations), we propose a discretization dependent scaling of the short range interaction stress. CDD results are compared to analytical solutions and benchmark data obtained from discrete dislocation simulations.

  16. Dislocation dynamics simulations of interactions between gliding dislocations and radiation induced prismatic loops in zirconium

    NASA Astrophysics Data System (ADS)

    Drouet, Julie; Dupuy, Laurent; Onimus, Fabien; Mompiou, Frédéric; Perusin, Simon; Ambard, Antoine

    2014-06-01

    The mechanical behavior of Pressurized Water Reactor fuel cladding tubes made of zirconium alloys is strongly affected by neutron irradiation due to the high density of radiation induced dislocation loops. In order to investigate the interaction mechanisms between gliding dislocations and loops in zirconium, a new nodal dislocation dynamics code, adapted to Hexagonal Close Packed metals, has been used. Various configurations have been systematically computed considering different glide planes, basal or prismatic, and different characters, edge or screw, for gliding dislocations with -type Burgers vectors. Simulations show various interaction mechanisms such as (i) absorption of a loop on an edge dislocation leading to the formation of a double super-jog, (ii) creation of a helical turn, on a screw dislocation, that acts as a strong pinning point or (iii) sweeping of a loop by a gliding dislocation. It is shown that the clearing of loops is more favorable when the dislocation glides in the basal plane than in the prismatic plane explaining the easy dislocation channeling in the basal plane observed after neutron irradiation by transmission electron microscopy.

  17. Unloading behavior of dislocations emitted from a crack

    NASA Astrophysics Data System (ADS)

    Zhao, Rui-Huan; Li, J. C. M.

    1985-12-01

    Upon unloading, dislocations emitted from a crack can be retracted partially (stationary crack with lattice friction for dislocation motion) or completely (moving crack or zero friction for dislocation motion). The behavior of the plastic zone, the dislocation distribution, and the dislocation-free zone during the retraction process are studied by computer simulation. A propagating crack always moves forward upon unloading until all the dislocations are retracted. Its speed could be much faster during retraction than during the emission of dislocations. The rate of dislocation retraction or crack motion is slow in the beginning but then suddenly the crack jumps forward to retract all the rest of dislocations. This incubation period before the sudden crack surge seems to depend on the size of the dislocation-free zone.

  18. Atomistic modeling of dislocation-interface interactions

    SciTech Connect

    Wang, Jian; Valone, Steven M; Beyerlein, Irene J; Misra, Amit; Germann, T. C.

    2011-01-31

    Using atomic scale models and interface defect theory, we first classify interface structures into a few types with respect to geometrical factors, then study the interfacial shear response and further simulate the dislocation-interface interactions using molecular dynamics. The results show that the atomic scale structural characteristics of both heterophases and homophases interfaces play a crucial role in (i) their mechanical responses and (ii) the ability of incoming lattice dislocations to transmit across them.

  19. Dislocation shielding of a cohesive crack

    NASA Astrophysics Data System (ADS)

    Bhandakkar, Tanmay K.; Chng, Audrey C.; Curtin, W. A.; Gao, Huajian

    2010-04-01

    Dislocation interaction with a cohesive crack is of increasing importance to computational modelling of crack nucleation/growth and related toughening mechanisms in confined structures and under cyclic fatigue conditions. Here, dislocation shielding of a Dugdale cohesive crack described by a rectangular traction-separation law is studied. The shielding is completely characterized by three non-dimensional parameters representing the effective fracture toughness, the cohesive strength, and the distance between the dislocations and the crack tip. A closed form analytical solution shows that, while the classical singular crack model predicts that a dislocation can shield or anti-shield a crack depending on the sign of its Burgers vector, at low cohesive strengths a dislocation always shields the cohesive crack irrespective of the Burgers vector. A numerical study shows the transition in shielding from the classical solution of Lin and Thomson (1986) in the high strength limit to the solution in the low strength limit. An asymptotic analysis yields an approximate analytical model for the shielding over the full range of cohesive strengths. A discrete dislocation (DD) simulation of a large (>10 3) number of edge dislocations interacting with a cohesive crack described by a trapezoidal traction-separation law confirms the transition in shielding, showing that the cohesive crack does behave like a singular crack at very high cohesive strengths (˜7 GPa), but that significant deviations in shielding between singular and cohesive crack predictions arise at cohesive strengths around 1GPa, consistent with the analytic models. Both analytical and numerical studies indicate that an appropriate crack tip model is essential for accurately quantifying dislocation shielding for cohesive strengths in the GPa range.

  20. Medial dislocation of the medial meniscus.

    PubMed

    Chan, S K L; Robb, C A; Singh, T; Chugh, S

    2010-01-01

    We present the first reported case of symptomatic medial dislocation of the medial meniscus in a patient who had no previous history of trauma and who had an otherwise normal knee. The treatment of instability of the medial meniscus is controversial and studies have indicated that certain individuals without a firm meniscal bony insertion may be predisposed to meniscal dislocation. In our patient, the meniscal instability interfered with daily activities. Operative stabilisation by reconstruction of the meniscotibial ligaments cured the symptoms.

  1. Congenital Dislocation of the Hip

    PubMed Central

    Specht, Elmer E.

    1976-01-01

    Congenital dislocation or subluxation of the hip (congenital acetabular dysplasia) is a complete or partial displacement of the femoral head out of the acetabulum. The physical signs essential for diagnosis are age related. In newborns the tests for instability are the most sensitive. After the neonatal period, and until the age of walking, tightness of the adductor muscles is the most reliable sign. Early diagnosis is vital for successful treatment of this partially genetically determined condition. Various therapeutic measures, ranging from abduction splinting to open reduction and osteotomy, may be required. Following diagnosis in the first month of life, the average treatment time in one recent series was only 2.3 months from initiation of therapy to attainment of a normal hip. When the diagnosis was not made until 3 to 6 months of age, ten months of treatment was required to achieve the same outcome. When the diagnosis is not made, or the treatment is not begun until after the age of 6, a normal hip will probably not develop in any patient. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9. PMID:1251603

  2. Dislocation electrical conductivity of synthetic diamond films

    SciTech Connect

    Samsonenko, S. N. Samsonenko, N. D.

    2009-05-15

    A relationship between the electric resistance of single-crystal homoepitaxial and polycrystalline diamond films and their internal structure has been investigated. It is established that the electrical conductivity of undoped homoepitaxial and polycrystalline diamond films is directly related to the dislocation density in them. A relation linking the resistivity {rho} ({approx}10{sup 13}-10{sup 15} {omega} cm) with the dislocation density {gamma} ({approx}10{sup 14}-4 x 10{sup 16} m{sup -2}) is obtained. The character of this correlation is similar for both groups of homoepitaxial and polycrystalline diamond films. Thin ({approx}1-8 {mu}m) homoepitaxial and polycrystalline diamond films with small-angle dislocation boundaries between mosaic blocks exhibit dislocation conductivity. The activation energy of dislocation acceptor centers was calculated from the temperature dependence of the conductivity and was found to be {approx}0.3 eV. The conduction of thick diamond films (h > 10 {mu}m) with the resistivity {rho} {approx} 10{sup 8} {omega} cm is determined by the conduction of intercrystallite boundaries, which have a nondiamond hydrogenated structure. The electronic properties of the diamond films are compared with those of natural semiconductor diamonds of types IIb and Ic, in which dislocation acceptor centers have activation energies in the range 0.2-0.35 eV and are responsible for hole conduction.

  3. Chronic Knee Dislocation After Total Knee Arthroplasty.

    PubMed

    Ross, John P; Brown, Nicholas M; Levine, Brett R

    2015-12-01

    Knee dislocation after total knee arthroplasty (TKA), although rare, is a dangerous injury that can lead to neurovascular compromise and permanent disability. Chronic dislocation after TKA is even less common and is defined as dislocation that is present for 4 weeks or more. There are few reports of its management. Chronic dislocation may be complicated further by concomitant extensor mechanism disruption, ligamentous instability, and/or capsular contracture. This article describes 3 cases of chronically dislocated TKAs and the challenges encountered in treating this difficult problem. A higher level of constraint was required to maintain knee stability, and an extensor mechanism allograft was needed in 2 of the 3 reported patients. The preferred technique at the authors' institution is a complete allograft composite, tensioned in full extension. In the setting of a chronically dislocated TKA, the authors now recommend revision surgery with an enhanced measure of constraint (constrained condylar device or hinged knee prosthesis), reconstruction of the extensor mechanism when necessary, and restoration of the joint while compensating for concomitant bony defects. Even when surgeons follow these principles, it is important to inform the patient that long-term outcomes will likely be inferior to those of revision surgery for other causes.

  4. 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.

  5. The Role of Soviet Trade Unions in the Lifelong Education of Workers. Adult Education in Europe. Studies and Documents No. 17.

    ERIC Educational Resources Information Center

    Yazykova, V. S.

    In the U.S.S.R., the trade unions see the continuous growth of the general educational, cultural and technical level of all workers as one of the conditions of social and scientific progress in the interests of the working class. The role of the unions in the lifelong education of the population is determined by their status in the political…

  6. Skills Training of Health Workers in the Use of a Non Surgical Device (PrePex) for Adult Safe Male Circumcision

    PubMed Central

    Galukande, Moses; Duffy, Kevin; Bitega, Jean Paul; Wooding, Nick

    2014-01-01

    Background Safe Male Circumcision (SMC) is a proven approach for partial protection of men from acquisition of HIV infection. Several sub-Saharan African countries have a target to circumcise 80% of males aged 15 to 49. The use of devices such as PrePex would aid scaling up of SMC. Since most health workers would have no prior experience with use of devices, skills training is needed. This paper explores a skills transfer model at an urban site in Uganda. Objective To assess the practicability and feasibility of rapid short duration training for safe PrePex device use. Methods A prospective study, conducted over 8 weeks (August–October 2012) at International Hospital Kampala, an urban Kampala hospital, examining the performance of various health worker cadres after training in the use of a non-surgical device (PrePex). The prospective study obtained approval from the Makerere School of Medicine Research and Ethics Committee and the Uganda National Council of Science and Technology. If eligible, and after the subject signed the informed consent form, they were enrolled into the study. Results Ten health workers were successfully trained in use of PrePex during a 3 day non-residential on-the-job training course. After the first three days of training, the trained health workers performed 561 placements and 529 device removals successfully. Over all adverse events (AE) rates were below ≤2%; however, there were some differences in AE rates across the cadres trained but not significant (p>0.25 for moderate AEs). Conclusion Rapid training for safe use of the PrePex device is feasible for the range of health workers available for SMC in resource limited settings, but among those with past SMC experience. PMID:25118716

  7. Living "a Life like Ours": Support Workers' Accounts of Substitute Decision-Making in Residential Care Homes for Adults with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Dunn, M. C.; Clare, I. C. H.; Holland, A. J.

    2010-01-01

    Background: In England and Wales, the "Mental Capacity Act 2005" (MCA) provides a new legal framework to regulate substitute decision-making relating to the welfare of adults who lack the capacity to make one or more autonomous decisions about their care and support. Any substitute decision made on behalf of an adult lacking capacity must be in…

  8. 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.

  9. 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…

  10. Visualizing dislocation nucleation by indenting colloidal crystals.

    PubMed

    Schall, Peter; Cohen, Itai; Weitz, David A; Spaepen, Frans

    2006-03-16

    The formation of dislocations is central to our understanding of yield, work hardening, fracture, and fatigue of crystalline materials. While dislocations have been studied extensively in conventional materials, recent results have shown that colloidal crystals offer a potential model system for visualizing their structure and dynamics directly in real space. Although thermal fluctuations are thought to play a critical role in the nucleation of these defects, it is difficult to observe them directly. Nano-indentation, during which a small tip deforms a crystalline film, is a common tool for introducing dislocations into a small volume that is initially defect-free. Here, we show that an analogue of nano-indentation performed on a colloidal crystal provides direct images of defect formation in real time and on the single particle level, allowing us to probe the effects of thermal fluctuations. We implement a new method to determine the strain tensor of a distorted crystal lattice and we measure the critical dislocation loop size and the rate of dislocation nucleation directly. Using continuum models, we elucidate the relation between thermal fluctuations and the applied strain that governs defect nucleation. Moreover, we estimate that although bond energies between particles are about fifty times larger in atomic systems, the difference in attempt frequencies makes the effects of thermal fluctuations remarkably similar, so that our results are also relevant for atomic crystals.

  11. Vascular and orthopedic complications of knee dislocation.

    PubMed

    Jones, R E; Smith, E C; Bone, G E

    1979-10-01

    Experience with complete dislocation of the knee in 22 consecutive patients during a six year period was analyzed. Major vascular complications occurred in nine of 13 extremities with anterior dislocation, one of seven extremities with posterior dislocation and none of two extremities with lateral dislocation. Liberal use of trans-femoral ateriography for diagnosis disclosed significant arterial injuries in four of 15 limbs, despite postreduction pedal pulses which were apparently normal. Limb salvage was accomplished in 20 of 21 survivors and in eight of nine with associated vascular complications. All patients demonstrated severe instability of the ligamentous structures of the knee consistent with the type of dislocation. Posterior instability was severe in all patients, an indication of disruption of the posterior cruciate ligament in every instance. Adequate follow-up information was available on 12 knees that had primary ligamentous repair, ten of which were stable to stress testing. Postoperative immobilization was accomplished by external skeletal fixation, skeletal traction or long leg posterior plaster splint. PMID:483133

  12. 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.

  13. Isolated dorsal dislocation of the tarsal naviculum

    PubMed Central

    Hamdi, Kaziz; Hazem, Ben Ghozlen; Yadh, Zitoun; Faouzi, Abid

    2015-01-01

    Isolated dislocation of the tarsal naviculum is an unusual injury, scarcely reported in the literature. The naviculum is surrounded by the rigid bony and ligamentous support hence fracture dislocation is more common than isolated dislocation. The mechanism and treatment options remain unclear. In this case report, we describe a 31 year old man who sustained an isolated dorsal dislocation of the left tarsal naviculum, without fracture, when he was involved in a motor vehicle collision. The reported mechanism of the dislocation is a hyper plantar flexion force applied to the midfoot, resulting in a transient disruption of the ligamentous support of the naviculum bone, with dorsal displacement of the bone. The patient was treated with open reduction and Krischner-wire fixation of the navicular after the failure of closed reduction. The wires were removed after 6 weeks postoperatively. Physiotherapy for stiffness and midfoot pain was recommended for 2 months. At 6 months postoperatively, limping, midfoot pain and weakness were reported, no X-ray abnormalities were found. The patient returned to his obvious activities with a normal range of motion. PMID:26806978

  14. Proximal interphalangeal joint dislocations without fractures.

    PubMed

    Vicar, A J

    1988-02-01

    Injuries to the proximal interphalangeal joint are extremely common. An understanding of the complex anatomy of this joint is essential for diagnosis and treatment of proximal interphalangeal joint sprains and dislocations. Lateral injuries are among the commonest injuries in the hand. These are often stable after reduction, requiring only closed treatment. Occasionally, however, the collateral ligament can be trapped in the joint and require open reduction. Dorsal dislocations represent the most common dislocation in the hand. These, too, are usually stable after reduction and can be treated by closed methods. On occasion, however, these dislocations will be open or irreducible by closed means, requiring surgical intervention and repair of damaged structures. Complex rotary dislocations are exactly that: complex. An exact understanding of the damaged structures and causes of irreducibility frequently makes this an injury often requiring open reduction and selective repair of damaged soft tissue structures. Fortunately, prompt diagnosis, reduction, and institution of appropriate treatment can usually afford the patient good function after these injuries. It must be noted that stiffness is more common than instability, and active range-of-motion exercises instituted at the proper time are essential. These joints will often remain permanently thicker after injury in spite of optimal care, and tenderness and soreness with use may persist for 6 to 12 months.

  15. 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…

  16. Screw dislocation-driven epitaxial solution growth of ZnO nanowires seeded by dislocations in GaN substrates.

    PubMed

    Morin, Stephen A; Jin, Song

    2010-09-01

    In the current examples of dislocation-driven nanowire growth, the screw dislocations that propagate one-dimensional growth originate from spontaneously formed highly defective "seed" crystals. Here we intentionally utilize screw dislocations from defect-rich gallium nitride (GaN) thin films to propagate dislocation-driven growth, demonstrating epitaxial growth of zinc oxide (ZnO) nanowires directly from aqueous solution. Atomic force microscopy confirms screw dislocations are present on the native GaN surface and ZnO nanowires grow directly from dislocation etch pits of heavily etched GaN surfaces. Furthermore, transmission electron microscopy confirms the existence of axial dislocations. Eshelby twist in the resulting ZnO nanowires was confirmed using bright-/dark-field imaging and twist contour analysis. These results further confirm the connection between dislocation source and nanowire growth. This may eventually lead to defect engineering strategies for rationally designed catalyst-free dislocation-driven nanowire growth for specific applications.

  17. 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.

  18. Electron paramagnetic resonance at dislocations in germanium

    SciTech Connect

    Pakulis, E.J.

    1982-06-01

    The first observation of the paramagnetic resonance of electrons at dislocations in germanium single crystals is reported. Under subband gap optical excitation, two sets of lines are detected: four lines about the <111> axes with g/sub perpendicular to/ = 0.34 and g/sub parallel/ = 1.94, and 24 lines with g/sub perpendicular to/ = 0.73 and g/sub parallel/ = 1.89 about <111> axes with the six-fold 1.2/sup 0/ distortion. This represents the first measurement of the disortion angle of a dislocation dangling bond. The possibility that the distortion results from a Peierls transition along the dislocation line is discussed.

  19. Dislocation filtering in GaN nanostructures.

    PubMed

    Colby, Robert; Liang, Zhiwen; Wildeson, Isaac H; Ewoldt, David A; Sands, Timothy D; García, R Edwin; Stach, Eric A

    2010-05-12

    Dislocation filtering in GaN by selective area growth through a nanoporous template is examined both by transmission electron microscopy and numerical modeling. These nanorods grow epitaxially from the (0001)-oriented GaN underlayer through the approximately 100 nm thick template and naturally terminate with hexagonal pyramid-shaped caps. It is demonstrated that for a certain window of geometric parameters a threading dislocation growing within a GaN nanorod is likely to be excluded by the strong image forces of the nearby free surfaces. Approximately 3000 nanorods were examined in cross-section, including growth through 50 and 80 nm diameter pores. The very few threading dislocations not filtered by the template turn toward a free surface within the nanorod, exiting less than 50 nm past the base of the template. The potential active region for light-emitting diode devices based on these nanorods would have been entirely free of threading dislocations for all samples examined. A greater than 2 orders of magnitude reduction in threading dislocation density can be surmised from a data set of this size. A finite element-based implementation of the eigenstrain model was employed to corroborate the experimentally observed data and examine a larger range of potential nanorod geometries, providing a simple map of the different regimes of dislocation filtering for this class of GaN nanorods. These results indicate that nanostructured semiconductor materials are effective at eliminating deleterious extended defects, as necessary to enhance the optoelectronic performance and device lifetimes compared to conventional planar heterostructures. PMID:20397703

  20. 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.

  1. Screw dislocation in functionally graded magnetoelectroelastic solids

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Ze; Kuna, Meinhard

    2014-02-01

    A screw dislocation in a functionally graded magnetoelectroelastic material is investigated. The material properties exponentially changing along both x and y directions are considered and the mechanical-electric-magnetic coupling is discussed. Closed-form expressions for the mechanical, electric and magnetic components are derived using the general stress function method. The solutions can be applied as a fundamental result and reduced into the classic and piezoelectric cases. The study puts forth a direct way for screw dislocation analysis in inhomogeneous structures with multifield coupling.

  2. 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.

  3. 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. PMID:27477475

  4. Subtalar Dislocation in a Basketball Player.

    PubMed

    Crosby, L A

    1989-10-01

    In brief: Easily mistaken for an ankle fracture during the initial examination, medial subtalar dislocation-also known as 'basketball foot'-requires plaster immobilization for no more than 3 weeks. To extend immobilization beyond this time can lead to reduced range of motion in the subtalar joint, making it difficult for the athlete to resume sports activities. Encouraging toe motion while the patient is still in the cast prevents tendon adhesions. In this case report, the author discusses the importance of short-term immobilization and early rehabilitation for a 21-year-old basketball player recovering from medial subtalar dislocation.

  5. Dislocation Content of Micropipes in SiC

    NASA Astrophysics Data System (ADS)

    Heindl, J.; Dorsch, W.; Strunk, H. P.; Müller, St. G.; Eckstein, R.; Hofmann, D.; Winnacker, A.

    1998-01-01

    Silicon carbide, a potentially powerful device material, suffers from microscopic hollow defects called micropipes. Their nature is not satisfactorily clarified yet. Our analysis shows that they are hollow core dislocations according to Frank's model, but contain dislocations of mixed type.

  6. 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...

  7. 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...

  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. On the auxiliary lattices and dislocation reactions at triple junctions.

    PubMed

    Gertsman, V Y

    2002-03-01

    Coincidence site and displacement shift complete lattices of triple junctions are analysed. Dislocation reactions at triple junctions are considered. It is shown that in alpha=1 junctions no trapped residual triple-junction dislocation is geometrically necessary for dislocation transmission between adjoining grain boundaries. However, the situation is different for alpha (unequal) 1 triple junctions, where in some cases the residual dislocation cannot leave the triple junction for a grain boundary without generating a stacking-fault-like defect.

  10. 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.

  11. Dislocation dynamics in solid solutions of covalent crystals

    NASA Astrophysics Data System (ADS)

    Petukhov, B. V.

    2016-09-01

    The dislocation mechanism of solid solution strengthening of covalent semiconductor crystals has been studied. The change in the regularities of dislocation dynamics in solid solutions from those in the components of the solution is connected with the manifestation of the nonlinear drift of dislocation kinks. The theory developed suggests an explanation of specificities of the dislocation mobility in a Ge1- c Si c solid solution.

  12. "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 trapped in…

  13. The Use of Ultrasound to Measure Dislocation Density

    NASA Astrophysics Data System (ADS)

    Barra, Felipe; Espinoza-González, Rodrigo; Fernández, Henry; Lund, Fernando; Maurel, Agnès; Pagneux, Vincent

    2015-08-01

    Dislocations are at the heart of the plastic behavior of materials yet they are very difficult to probe experimentally. Lack of a practical nonintrusive measuring tool for, say, dislocation density, seriously hampers modeling efforts, as there is little guidance from data in the form of quantitative measurements, as opposed to visualizations. Dislocation density can be measured using transmission electron microscopy (TEM) and x-ray diffraction (XRD). TEM can directly show the strain field around dislocations, which allows for the counting of the number of dislocations in a micrograph. This procedure is very laborious and local, since samples have to be very small and thin, and is difficult to apply when dislocation densities are high. XRD relies on the broadening of diffraction peaks induced by the loss of crystalline order induced by the dislocations. This broadening can be very small, and finding the dislocation density involves unknown parameters that have to be fitted with the data. Both methods, but especially TEM, are intrusive, in the sense that samples must be especially treated, mechanically and chemically. A nonintrusive method to measure dislocation density would be desirable. This paper reviews recent developments in the theoretical treatment of the interaction of an elastic wave with dislocations that have led to formulae that relate dislocation density to quantities that can be measured with samples of cm size. Experimental results that use resonant ultrasound spectroscopy supporting this assertion are reported, and the outlook for the development of a practical, nonintrusive, method to measure dislocation density is discussed.

  14. 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.

  15. Metatarsal Shaft Fracture with Associated Metatarsophalangeal Joint Dislocation.

    PubMed

    Tung, Taranjit Singh

    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

  16. 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

  17. [Open total dislocation of the talus].

    PubMed

    Grabski, R S; Sosiński, R

    1992-01-01

    A case of 35 years old patient with open, total, fixed dislocation of the talus reduced with heel traction is presented. The Sudeck syndrome subsided after one year. Weight bearing was not allowed for 7 months. An examination after 2.5 years revealed minor osteoarthritis, full range of movement in the foot but limited walking capability. PMID:7555299

  18. An unusual variant of perilunate fracture dislocations

    PubMed Central

    Morin, Matthew L.; Becker, Giles W.

    2016-01-01

    Abstract Trans-scaphoid, trans-radial styloid, trans-triquetral perilunate fracture dislocations are rare. We describe a 19-year-old male who suffered this injury after crashing his bicycle. He underwent open reduction internal fixation and percutaneous pinning. Scaphoid union was achieved at 8 weeks. Near complete range of painless motion was achieved by 4 months. PMID:27583261

  19. An unusual variant of perilunate fracture dislocations.

    PubMed

    Morin, Matthew L; Becker, Giles W

    2016-01-01

    Trans-scaphoid, trans-radial styloid, trans-triquetral perilunate fracture dislocations are rare. We describe a 19-year-old male who suffered this injury after crashing his bicycle. He underwent open reduction internal fixation and percutaneous pinning. Scaphoid union was achieved at 8 weeks. Near complete range of painless motion was achieved by 4 months. PMID:27583261

  20. The origin of dislocations in multilayers

    NASA Astrophysics Data System (ADS)

    Humphreys, C. J.; Maher, D. M.; Eaglesham, D. J.; Kvam, E. P.; Salisbury, I. G.

    1991-06-01

    This paper will consider some fundamental questions concerning the source, nucleation and propagation of dislocations in multilayers, particularly semiconductor epilayers. The concept of a “critical thickness” for the introduction of misfit dislocations in a strained layer will be considered, and X-ray topography and electron microscopy results will be presented which demonstrate that the concept of a critical thickness is not as well defined as previously supposed. Theoretical considerations for the source of misfit dislocations in epilayers grown on dislocation free substrates indicate that surface sources are improbable in low mismatched systems at typical growth temperatures, however the experimental evidence is that the nucleation of misfit dislocations is relatively easy. A new regenerative source with unique properties has been identified in the GeSi/Si system and we have called this source the diamond defect because of its diamond shape (it is a four-sided planar fault on a {111} plane with <110> sides so that two opposing internal angles are 60° and the other two are 120°). This defect operates like a FrankRead source, but it has the unique property that it can repetitively produce dislocations with two different Burgers vectors on the same glide plane, and it can generate orthogonal bundles of misfit dislocations. Whether this source exists more widely in other materials systems requires further assessment. The important role of misfit dislocations in trace impurity gettering is demonstrated. Cet article aborde des questions fondamentales qui concernent la germination et la propagation des dislocations dans les multicouches, et en particulier dans les semiconducteurs épitaxiés. Nous considérons le concept d'épaisseur critique pour l'apparition des dislocations de désadaptation de réseau dans les couches contraintes. Les résultats de topographie X et de microscopie électronique qui sont présentés montrent que le concept d

  1. Temporomandibular joint dislocation: experiences from Zaria, Nigeria

    PubMed Central

    Fomete, Benjamin; Obiadazie, Athanasius Chukwudi; Idehen, Kelvin; Okeke, Uche

    2014-01-01

    Objectives Dislocation of the temporomandibular joint may occur for various reasons. Although different invasive methods have been advocated for its treatment, this study highlights the value of non-invasive treatment options even in chronic cases in a resource-poor environment. Materials and Methods A seven-year retrospective analysis of all patients managed for temporomandibular joint dislocation in our department was undertaken. Patient demographics, risk factors associated with temporomandibular joint dislocation and treatment modalities were retrieved from patient records. Results In all, 26 patients were managed over a seven-year period. Males accounted for 62% of the patients, and yawning was the most frequent etiological factor. Conservative treatment methods were used successfully in 86.4% of the patients managed. Two (66.7%) of the three patients who needed surgical treatment developed complications, while only one (5.3%) patient who was managed conservatively developed complications. Conclusion Temporomandibular joint dislocation appears to be associated with male sex, middle age, yawning, and low socio-economic status, although these observed relationships were not statistically significant. Non-invasive methods remain an effective treatment option in this environment in view of the low socio-economic status of the patients affected. PMID:25045637

  2. Simultaneous dislocation of all five carpometacarpal joints.

    PubMed

    Fayman, M; Hugo, B; de Wet, H

    1988-07-01

    A case of unique combination of simultaneous dislocation of all five carpometacarpal joints is presented. The mechanism of injury in this case seems to be some manner of punching with a closed fist rather than direct violence. Satisfactory results were achieved using simple principles of manipulation under anesthesia, open reduction, and skeletal fixation, followed by intensive physiotherapy.

  3. 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.

  4. Screw dislocation driven growth of nanomaterials.

    PubMed

    Meng, Fei; Morin, Stephen A; Forticaux, Audrey; Jin, Song

    2013-07-16

    Nanoscience and nanotechnology impact our lives in many ways, from electronic and photonic devices to biosensors. They also hold the promise of tackling the renewable energy challenges facing us. However, one limiting scientific challenge is the effective and efficient bottom-up synthesis of nanomaterials. We can approach this core challenge in nanoscience and nanotechnology from two perspectives: (a) how to controllably grow high-quality nanomaterials with desired dimensions, morphologies, and material compositions and (b) how to produce them in a large quantity at reasonable cost. Because many chemical and physical properties of nanomaterials are size- and shape-dependent, rational syntheses of nanomaterials to achieve desirable dimensionalities and morphologies are essential to exploit their utilities. In this Account, we show that the dislocation-driven growth mechanism, where screw dislocation defects provide self-perpetuating growth steps to enable the anisotropic growth of various nanomaterials at low supersaturation, can be a powerful and versatile synthetic method for a wide variety of nanomaterials. Despite significant progress in the last two decades, nanomaterial synthesis has often remained an "art", and except for a few well-studied model systems, the growth mechanisms of many anisotropic nanostructures remain poorly understood. We strive to go beyond the empirical science ("cook-and-look") and adopt a fundamental and mechanistic perspective to the anisotropic growth of nanomaterials by first understanding the kinetics of the crystal growth process. Since most functional nanomaterials are in single-crystal form, insights from the classical crystal growth theories are crucial. We pay attention to how screw dislocations impact the growth kinetics along different crystallographic directions and how the strain energy of defected crystals influences their equilibrium shapes. Furthermore, such inquiries are supported by detailed structural investigation to

  5. 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…

  6. Treatment of an open medial tibiotalar dislocation with no associated fracture.

    PubMed

    Bhullar, Preetinder S; Grant, Daniel R; Foreman, Mark; Krueger, Chad A

    2014-01-01

    Tibiotalar dislocations without associated fractures are very uncommon in adults, and only a few studies have been published regarding this injury. More than 50% of these dislocations will be posteromedial, with a high incidence of open injuries, and 25% are pure posterior dislocations. In the present report, we discuss our experience and management of a medial tibiotalar dislocation with no associated fracture. In the present case, the patient was brought to the operating room on presentation to our facility and underwent irrigation and debridement with primary closure of his wound. He was immobilized postoperatively. The patient tolerated the operation well and did not sustain any postoperative complications. He was able to regain function of the injured extremity until he was lost to follow-up. Regarding treatment, the surgery should be speedy, gentle to the soft tissue, and with as little implanted material as possible. Although we do not advocate that our management and treatment of this injury become the standard, the present case provides a good example of some of the challenges often encountered when treating these injuries. PMID:25135103

  7. Partial Dislocations in Graphene and Their Atomic Level Migration Dynamics.

    PubMed

    Robertson, Alex W; Lee, Gun-Do; He, Kuang; Fan, Ye; Allen, Christopher S; Lee, Sungwoo; Kim, Heeyeon; Yoon, Euijoon; Zheng, Haimei; Kirkland, Angus I; Warner, Jamie H

    2015-09-01

    We demonstrate the formation of partial dislocations in graphene at elevated temperatures of ≥500 °C with single atom resolution aberration corrected transmission electron microscopy. The partial dislocations spatially redistribute strain in the lattice, providing an energetically more favorable configuration to the perfect dislocation. Low-energy migration paths mediated by partial dislocation formation have been observed, providing insights into the atomistic dynamics of graphene during annealing. These results are important for understanding the high temperature plasticity of graphene and partial dislocation behavior in related crystal systems, such as diamond cubic materials.

  8. 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.

  9. 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.

  10. Observation of Dislocation Dynamics in the Electron Microscope

    SciTech Connect

    Lagow, B W; Robertson, I M; Jouiad, M; Lassila, D H; Lee, T C; Birnbaum, H K

    2001-08-21

    Deformation experiments performed in-situ in the transmission electron microscope have led to an increased understanding of dislocation dynamics. To illustrate the capability of this technique two examples will be presented. In the first example, the processes of work hardening in Mo at room temperature will be presented. These studies have improved our understanding of dislocation mobility, dislocation generation, and dislocation-obstacle interactions. In the second example, the interaction of matrix dislocations with grain boundaries will be described. From such studies predictive criteria for slip transfer through grain boundaries have been developed.

  11. Observation of dislocation dynamics in the electron microscope

    SciTech Connect

    Lagow, B W; Robertson, I M; Jouiad, M; Lassila, D H; Lee, T C; Birnbaum, H K

    2001-01-17

    Deformation experiments performed in-situ in the transmission electron microscope have led to an increased understanding of dislocation dynamics. To illustrate the capability of this technique two examples will be presented. In the first example, the processes of work hardening in Mo at room temperature will be presented. These studies have improved our understanding of dislocation mobility, dislocation generation, and dislocation-obstacle interactions. In the second example, the interaction of matrix dislocations with grain boundaries will be described. From such studies predictive criteria for slip transfer through grain boundaries have been developed.

  12. 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.

  13. Dislocation dynamics in hexagonal close-packed crystals

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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 < c + a > and other dislocations with large Burgers vectors defined as composite dislocations are examined and a new topological operation is proposed to enable their dissociation. 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.

  14. Observation of dislocations and twins in explosively compacted alumina

    SciTech Connect

    Yust, C.S.; Harris, L.A.

    1980-01-01

    The microstructure at the half-radius position of a polycrystalline alumina rod formed by explosive compaction has been studied by transmission electron microscopy. The as-compacted lattice is composed of differently misoriented bands aligned predominantly in one direction. Such bands may correspond to frequently observed shock lamellae. The band edges are defined by dislocation arrays lying on the basal planes of the hexagonal alumina lattice. The dislocations have Burgers vectors of the type (1120) and (1010), which are the Burgers vectors of slip dislocations in the basal plane. Basal plane twinning is also observed, and the twin boundaries are found to contain interfacial dislocations. While dislocation generation occurs primarily on basal planes, some dislocation activity is also noted on prism, (1100), and on rhombohedral, (1101), planes. Nonbasal twinning, however, has not been detected. The lattice damage is discussed in terms of possible dislocation and twinning mechanisms.

  15. Sports-related shoulder dislocations: a state-hospital experience.

    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 incidence of sports-related shoulder dislocations and their characteristics and the sports events involved. All patients with shoulder dislocation related to sporting activities admitted to the hospital from January 1999 to December 2002 were included in the study. There were 18 sports-related shoulder dislocations out of 106 all shoulder dislocations admitted during this 4-year period. The average age of the patients was 25.4 years. All but two were male. All were anterior dislocations. Recurrent dislocation constitutes 78% of the cases with an average of 3 times re-dislocation. Rugby and badminton were the major contributors to the injuries followed by volleyball, soccer and swimming. Conservative treatment was successfully instituted for 88% of the patients and 12% opted for surgical intervention.

  16. Dislocation dynamics in hexagonal close-packed crystals

    DOE PAGES

    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 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

  17. Sports-related shoulder dislocations: a state-hospital experience.

    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 incidence of sports-related shoulder dislocations and their characteristics and the sports events involved. All patients with shoulder dislocation related to sporting activities admitted to the hospital from January 1999 to December 2002 were included in the study. There were 18 sports-related shoulder dislocations out of 106 all shoulder dislocations admitted during this 4-year period. The average age of the patients was 25.4 years. All but two were male. All were anterior dislocations. Recurrent dislocation constitutes 78% of the cases with an average of 3 times re-dislocation. Rugby and badminton were the major contributors to the injuries followed by volleyball, soccer and swimming. Conservative treatment was successfully instituted for 88% of the patients and 12% opted for surgical intervention. PMID:16381278

  18. 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,...

  19. 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,...

  20. Superclimb of Dislocations in Solid 4He

    NASA Astrophysics Data System (ADS)

    Kuklov, Anatoly

    2011-03-01

    Edge dislocation with superfluid core can perform superclimb -- non-conservative motion (climb) assisted by superflow along its core. Such dislocation, with Burgers vector along the C-axis, has been found in ab initio simulations of hcp solid 4. Uniform network of superclimbing dislocations can induce isochoric compressibility which is finite (in contrast to ideal solid where it vanishes) and, practically, independent of the network density. Here N is total number of atoms and is chemical potential. Such giant response has been observed by Ray and Hallock during superfluid flow events through solid He4. Study of superclimbing dislocation within the model of Granato-Lücke string, subjected to Peierls potential and to vanishing bias by , has found that exhibits wide peak in the intermediate range of temperatures (T) - above some determined by Peierls energy and below above which superfluidity of the core essentially vanishes. Non-Luttinger type behavior characterized by K scaling as some power χ of dislocation length is observed in the wide peak region. Biasing superclimbing dislocation by finite μ (due to a contact with liquid through vycor electrodes,) can induce core roughening caused by thermally assisted tunneling of jog-antijog pairs through the barrier produced by combination of Peierls potential and the bias. The threshold for this effect scales as with some power a~ 1.7. The roughening is found to be hysteretic below some temperature Thyst , with TR determining temperature of thermal roughening, He exhibits strong and narrow resonant peak leading to a dip in the core superfluid sound velocity. This mechanism is proposed as an explanation for a strong and narrow dip observed in critical superflow rate. It is found that the dip characteristics are sensitive to the bias by μ and, therefore, this can be used as a test for the proposed mechanism. It is also predicted that the dip depth at given μc ~ 1 /La should be periodic in χ with the period T . This

  1. First principles determination of dislocation properties.

    SciTech Connect

    Hamilton, John C.

    2003-12-01

    This report details the work accomplished on first principles determination of dislocation properties. It contains an introduction and three chapters detailing three major accomplishments. First, we have used first principle calculations to determine the shear strength of an aluminum twin boundary. We find it to be remarkably small ({approx}17 mJ/m{sup 2}). This unexpected result is explained and will likely pertain for many other grain boundaries. Second, we have proven that the conventional explanation for finite grain boundary facets is wrong for a particular aluminum grain boundary. Instead of finite facets being stabilized by grain boundary stress, we find them to originate from kinetic effects. Finally we report on a new application of the Frenkel-Kontorova model to understand reconstructions of (100) type surfaces. In addition to the commonly accepted formation of rectangular dislocation arrays, we find numerous other possible solutions to the model including hexagonal reconstructions and a clock-rotated structure.

  2. 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.

  3. Phonon Drag Dislocations at High Pressures

    SciTech Connect

    Wolfer, W.G.

    1999-10-19

    Phonon drag on dislocations is the dominant process which determines the flow stress of metals at elevated temperatures and at very high plastic deformation rates. The dependence of the phonon drag on pressure or density is derived using a Mie-Grueneisen equation of state. The phonon drag is shown to increase nearly linearly with temperature but to decrease with density or pressure. Numerical results are presented for its variation for shock-loaded copper and aluminum. In these cases, density and temperature increase simultaneously, resulting in a more modest net increase in the dislocation drag coefficient. Nevertheless, phonon drag increases by more than an order of magnitude during shock deformations which approach melting. Since the dependencies of elastic moduli and of the phonon drag coefficient on pressure and temperature are fundamentally different, the effect of pressure on the constitutive law for plastic deformation can not simply be accounted for by its effect on the elastic shear modulus.

  4. 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.

  5. Energetics and Noise in dislocation patterning.

    SciTech Connect

    Thomson, R. M.; Koslowski, M.; LeSar, R. ,

    2004-01-01

    The competition between energy and noise in the patterning transition in deformation is explored by employing a 2D model of parallel straight edge dislocations. We define a generalized force for ordering and show that at mechanical equilibrium, the ordering force is equal to the average back stress noise on the slip plane. We consider a system subjected to a total external strain that is a uniform linear function of time. When the external stress reaches a critical value that depends on the instantaneous state of strain and dislocation content, a discrete strain event occurs (what we have called elsewhere a percolation event) with the formation of one or perhaps a few micro slip steps on the surface. Within these micro slip bands, the dislocation content increases in a time short compared to the time between strain events. After the stress drop associated with the stain event, the strain stops. During the time between events, the configuration relaxes to a new equilibrium configuration, which may include thermally generated recovery. As the stress again builds owing to the continuously increasing total strain, it reaches a new critical stress determined by the newly achieved dislocation configuration. Our modeling addresses the changes during the relaxation of the system in the time between events. In our model, the initial state is a random configuration i.e., it does not contain any memory of the previous state of the deforming system. This is an extreme assumption, because in a real system, the order will evolve from one event to the next. Nevertheless, if the real system does order, we expect this to be captured in the model - we will simply be careful not to predict the quantitative order in the evolving system from our modeling.

  6. Dislocation Microstructures in Experimentally Deformed wet Olivine

    NASA Astrophysics Data System (ADS)

    Sharp, T. G.; Jung, H.; Karato, S.

    2002-12-01

    Seismic anisotropy in the upper mantle is generally considered to be the result of lattice preferred orientations (LPOs) of olivine as a result of mantle flow. Therefore seismic anisotropy in the upper mantle can be used to probe fabrics and therefore flow directions. Jung and Karato (2001) have demonstrated that fabrics developed in experimentally deformed olivine are dependent on H2O fugacity and stress. Fabric type C, which develops at moderate experimental stresses and high H2O fugacities, has [001] subparallel to the slip direction and (100) subparallel to the shear plane. Fabric type B, which develops at high stresses and high H2O fugacities has [001] subparallel to the slip direction and (010) subparallel to the shear plane. To investigate the role of H2O in olivine fabric transitions, we are using high-resolution and conventional transmission electron microscopy (HRTEM and TEM) to characterize the dislocation microstructures and core structures in experimentally deformed samples of Fabric types B and C. Initial results for Fabric type C (sample JK11 of Jung and Karato, 2001) show a dominance of mixed-character and screw dislocations with Burgers vectors b = [001]. This Burgers vector, combined with the (100) being subparallel to the shear plane, is consistent with the (100)[001] slip system being dominant in the C-type fabric. This slip system, which is of minor importance in dry olivine, may be favored in wet samples by changes in the dislocation core structure. We are currently using HRTEM imaging to characterize the dislocation core structures in deformed samples with type C and type B fabrics.

  7. Reducing workers' compensation costs.

    PubMed

    Killian, M J

    1994-01-01

    Employers can reduce their workers' compensation costs by encouraging internal communication and education before and after injuries occur. Comprehensive workers' compensation programs can be developed by integrating the management of employee benefits and workers' compensation claims. PMID:10133659

  8. 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°.

  9. 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°. PMID:27499325

  10. 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.

  11. Atomistic simulation of oxide dislocations and interfaces

    NASA Astrophysics Data System (ADS)

    Parker, S. C.; de Leeuw, N. H.; Harris, D. J.; Higgins, F. M.; Oliver, Pe M.; Redfern, S. E.; Watson, G. W.

    Atomistic simulation techniques have been used to study screw dislocations, grain boundaries, thin films and surfaces. The results show that the a/2<110> screw dislocations in bulk MgO and NiO are more stable than the a<100> although the latter are stabilised by vacancies. Adsorption of MgO units at the a<100> spiral dislocation shows a complicated two-layer growth mechanism. Self-diffusion through MgO grain boundaries is shown to be faster than in the bulk crystal, with pipe diffusion the energetically most favourable route. Study of thin iron oxide films on MgO found that the most stable MgO/Fe3O4 /(001) interface is an open structure with closely matching spacing between substrate Mg ions and oxygens of the film. The interaction of water with oxides MgO and SiO2 has been investigated. The dominance of the MgO surface is shown through facetting of the less stable and surfaces. The low-coordinated surface sites hence formed are the most reactive towards adsorption of water and dissolution. Similarly, α-quartz surfaces with dangling bonds are more reactive towards water and NaOH than the fully-coordinated surface sites.

  12. 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.

  13. Types of Traumatic Lens Dislocations at Larkana.

    PubMed

    Shah, Syed Imtiaz Ali; Shah, Shujaat Ali; Rai, Partab; Siddiqui, Shahid Jamal; Abbasi, Safdar Ali; Katpar, Naeem Akhtar

    2016-08-01

    The objective of this study was to determine the pattern of traumatic lens dislocations presenting at our institute. This may help develop the preventive strategies. The number of cases of traumatic lens dislocations, presented at the Department of Ophthalmology, Chandka Medical College, Larkana, Pakistan, from January 2002 to June 2015, were 59 including 61.02% (n=36) males and 38.98% (n=23) females. Cause of trauma was wood or plant impalement in 35.6% (n=21) cases, cracker blast in 13.55% (n=8) cases, fall on ground in 11.86% (n=7) cases, penetrating injuries with needle, scissors or knife in 10.16% (n=6) cases, road traffic accidents in 10.16% (n=6) cases, sports injuries (cricket ball and gulle danda) in 8.47% (n=5) cases, firearm injuries in 5.1% (n=3) cases, and fist hitting in 5.1% (n=3) cases. Lens was dislocated posteriorly in 33.90% (n=20) cases, anteriorly in 25.42% (n=15) cases, inferiorly in 11.86% (n=7) cases, medially in 10.17% (n=6) cases, laterally in 10.17% (n=6) cases, superiorly in 6.78% (n=4) cases, and a single (1.69%) case of lenticele was seen. PMID:27539772

  14. 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

  15. Probing the character of ultra-fast dislocations.

    PubMed

    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.

  16. Probing the character of ultra-fast dislocations

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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.

  17. 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

  18. Probing the character of ultra-fast dislocations

    DOE PAGES

    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 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

  19. 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.

  20. 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

  1. 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

  2. Thermally Induced Dynamics of Dislocations in Graphene at Atomic Resolution.

    PubMed

    Gong, Chuncheng; Robertson, Alex W; He, Kuang; Lee, Gun-Do; Yoon, Euijoon; Allen, Christopher S; Kirkland, Angus I; Warner, Jamie H

    2015-10-27

    Thermally induced dislocation movements are important in understanding the effects of high temperature annealing on modifying the crystal structure. We use an in situ heating holder in an aberration corrected transmission electron microscopy to study the movement of dislocations in suspended monolayer graphene up to 800 °C. Control of temperature enables the differentiation of electron beam induced effects and thermally driven processes. At room temperature, the dynamics of dislocation behavior is driven by the electron beam irradiation at 80 kV; however at higher temperatures, increased movement of the dislocation is observed and provides evidence for the influence of thermal energy to the system. An analysis of the dislocation movement shows both climb and glide processes, including new complex pathways for migration and large nanoscale rapid jumps between fixed positions in the lattice. The improved understanding of the high temperature dislocation movement provides insights into annealing processes in graphene and the behavior of defects with increased heat.

  3. Lens dislocation has a possible relationship with laser iridotomy.

    PubMed

    Mutoh, Tetsuya; Barrette, Kevin F; Matsumoto, Yukihiro; Chikuda, Makoto

    2012-01-01

    We report our recent experience of four eyes with spontaneous lens dislocation in four patients with no history of trauma or any systemic disease associated with zonular dialysis. Lens dislocation developed with 0.5 to 6 months following laser iridotomy. All patients were male and two eyes were complicated with acute primary angle closure glaucoma preoperatively. Case 1 showed bilateral lens dislocation, while cases 2 and 3 involved unilateral lens dislocation. Cases 2 and 3 showed lenses completely dislocated into the vitreous cavity. All cases needed lens removal and scleral fixation of intraocular lenses. Final visual acuity was 1.2 in all cases. We suspect that laser iridotomy may induce localized zonular dialysis that results in progressive zonular weakness, leading to lens dislocation. PMID:23271880

  4. 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.

  5. Pattern formation in a minimal model of continuum dislocation plasticity

    NASA Astrophysics Data System (ADS)

    Sandfeld, Stefan; Zaiser, Michael

    2015-09-01

    The spontaneous emergence of heterogeneous dislocation patterns is a conspicuous feature of plastic deformation and strain hardening of crystalline solids. Despite long-standing efforts in the materials science and physics of defect communities, there is no general consensus regarding the physical mechanism which leads to the formation of dislocation patterns. In order to establish the fundamental mechanism, we formulate an extremely simplified, minimal model to investigate the formation of patterns based on the continuum theory of fluxes of curved dislocations. We demonstrate that strain hardening as embodied in a Taylor-type dislocation density dependence of the flow stress, in conjunction with the structure of the kinematic equations that govern dislocation motion under the action of external stresses, is already sufficient for the formation of dislocation patterns that are consistent with the principle of similitude.

  6. A closed-form criterion for dislocation emission in nano-porous materials under arbitrary thermomechanical loading

    NASA Astrophysics Data System (ADS)

    Wilkerson, J. W.; Ramesh, K. T.

    2016-01-01

    Our traditional view of void nucleation is associated with interface debonding at second-phase particles. However, under extreme dynamic loading conditions second-phase particles may not necessarily be the dominant source of void nucleation sites. A few key experimental observations of laser spall surfaces support this assertion. Here, we describe 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. It is therefore 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 derive the desired criterion by making use of stability arguments applied to the analytic solutions for the elastic interactions of dislocations and voids. Our analysis significantly extends that of Lubarda and co-workers by accounting for a more general stress state, finite porosity, surface tension, as well as temperature and pressure dependence. The resulting simple stress-based criterion is validated against a number of molecular dynamics simulations with favorable agreement.

  7. Head size and dislocation rate in primary total hip arthroplasty

    PubMed Central

    Singh, Somesh P; Bhalodiya, Haresh P

    2013-01-01

    Background: Dislocation after total hip arthroplasty (THA) has a multifactorial etiology with variables such as surgical approach, component orientation and position, type of cup, stem and head size. Review of the literature regarding the relationship of head size and dislocation rate in THA is suggestive that large femoral head size is associated with lower dislocation rate after THA. However, limited data is available as a proof of this hypothesis. The purpose of this study was to determine that the use of large head size would lead to a decreased incidence of dislocations following THA. Materials and Methods: 317 primary THAs were performed using the posterolateral approach with posterior soft-tissue repair between January 2006 and December 2009. Cases were divided into two groups (A and B). Femoral head diameter size 36 mm was used in 163 THA in group A and 28 mm in 154 THA in group B. Average period of followup being 2 years (6 month to 4 years). Patients were routinely followed at definite intervals and were specifically assessed for dislocation. Results: One or more dislocations occurred in 11 out of 317 hips with the overall rate of dislocation being 3.47%. Dislocation rate was 0.6% in 36 mm head size and 6.49% with 28 mm head size (P value is 0.0107). Keeping the stem design variable as a constant, the difference in the rate of dislocation between the two groups was again found to be statistically significant for both un-cemented and cemented stem. Conclusion: Dislocation rate decreased significantly as the size of the head increased in primary THA. However, longer followup is necessary as rate of dislocation or in vivo highly cross linked poly failure or fracture may increase in future affecting the rate of dislocations in primary THA. PMID:24133302

  8. 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

  9. Dislocation of the Temporomandibular Joint and Relocation Procedures.

    PubMed

    White, Thomas; Hedderick, Viki; Ramponi, Denise R

    2016-01-01

    Temporomandibular joint (TMJ) dislocation requires prompt medical attention due to the crucial impact of airway, nutrition acquisition, and communication. Recognition of this injury by the practitioner, based on clinical presentation and history, is paramount for identification of accurate diagnosis and prompt treatment of TMJ dislocation. Relocation or reduction methods vary on the basis of the severity of the injury and whether it is an acute or chronic dislocation. PMID:27482989

  10. New mechanism for dislocation blocking in strained layer epitaxial growth

    SciTech Connect

    Stach, E.A.; Schwarz, K.W.; Hull, R.; Ross, F.M.; Tromp, R.M.

    1999-09-14

    Dislocation interactions play a critical role in plasticity and heteroepitaxial strain relaxation. We use real time transmission electron microscopy observations of the interaction between threading and misfit dislocations in SiGe heterostructures to investigate interactions quantitatively. In addition to the expected long range blocking of threading segments, we observe a new short range mechanism which is significantly more effective. Simulations show that this reactive blocking occurs when two dislocations with the same Burgers vector reconnect.

  11. 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.

  12. 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

  13. 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. PMID:24010425

  14. Dislocation luminescence in GaN single crystals under nanoindentation.

    PubMed

    Huang, Jun; Xu, Ke; Fan, Ying Min; Wang, Jian Feng; Zhang, Ji Cai; Ren, Guo Qiang

    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.

  15. 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

  16. Exploring the limit of dislocation based plasticity in nanostructured metals.

    PubMed

    Hughes, D A; Hansen, N

    2014-04-01

    A twofold decrease to an unexplored scale of 5 nm was produced in Cu by applying a large sliding load in liquid nitrogen. Statistical and universal scaling analyses of deformation induced high angle boundaries, dislocation boundaries, and individual dislocations observed by high resolution electron microscopy reveal that dislocation processes still dominate. Dislocation based plasticity continues far below the transition suggested by experiment and molecular dynamics simulations, with a limit below 5 nm. Very high strength metals may emerge based on this enhanced structural refinement. PMID:24745438

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

    PubMed

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

    2016-09-18

    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

  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. 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.

  20. 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.

  1. 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.

  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. High-resolution three-dimensional imaging of dislocations.

    PubMed

    Barnard, J S; Sharp, J; Tong, J R; Midgley, P A

    2006-07-21

    Dislocations and their interactions govern the properties of many materials, ranging from work hardening in metals to device pathology in semiconductor laser diodes. However, conventional electron micrographs are simply two-dimensional projections of three-dimensional (3D) structures, and even stereo microscopy cannot reveal the true 3D complexity of defect structures. Here, we describe an electron tomographic method that yields 3D reconstructions of dislocation networks with a spatial resolution three orders of magnitude better than previous work. We illustrate the method's success with a study of dislocations in a GaN epilayer, where dislocation densities of 1010 per square centimeter are common.

  4. Dislocation Mechanics of High-Rate Deformations

    NASA Astrophysics Data System (ADS)

    Armstrong, Ronald W.; Li, Qizhen

    2015-10-01

    Four topics associated with constitutive equation descriptions of rate-dependent metal plastic deformation behavior are reviewed in honor of previous research accomplished on the same issues by Professor Marc Meyers along with colleagues and students, as follow: (1) increasing strength levels attributed to thermally activated dislocation migration at higher loading rates; (2) inhomogeneous adiabatic shear banding; (3) controlling mechanisms of deformation in shock as compared with shock-less isentropic compression experiments and (4) Hall-Petch-based grain size-dependent strain rate sensitivities exhibited by nanopolycrystalline materials. Experimental results are reviewed on the topics for a wide range of metals.

  5. Anterior Shoulder Dislocations in Busy Emergency Departments

    PubMed Central

    Janitzky, Angelika A.; Akyol, Can; Kesapli, Mustafa; Gungor, Faruk; Imak, Arefe; Hakbilir, Oktay

    2015-01-01

    Abstract Shoulder joint is the most common joint requiring reduction by emergency physicians. Successful reduction is based on the overcoming of resistance of the shoulder muscles. Pain is the most important factor in resistance increase and sedation; analgesia and, in certain cases, intra-articular anesthesia are preferred for reduction. The external rotation (ER) method can provide successful reduction without causing an increase in muscle resistance if applied slowly and gently. The aim of this study was, therefore, to determine the usefulness of the ERWOSA method in the reduction of acute anterior shoulder dislocations (AASDs). This was a retrospective descriptive study. The records of patients admitted to the emergency department with anterior shoulder dislocation between 2009 and 2011 were reviewed for demographic data, sedation, analgesia, and discharge times. Patients were then divided into ERWOSA (n = 80) and external rotation and sedation-analgesia (ERASA, n = 59) groups, with regard to the application of SA (sedation-analgesia). The study data were analyzed using SPSS version 22.0 software for Windows. Numerical data were presented as mean ± standard deviation and categorical data as rates. A total of 139 patients were included in the study. The patients’ average age was 35 ± 14 years, 108 (77.7%) were male. Successful reduction rates for 59 male and 21 female patients in the ERWOSA group were 83% and 66.7% (78.7% total success), respectively. Successful reduction rates for 49 male and 10 female patients in the ERASA group were 87.7% and 90% (88.1% total success), respectively. The length of stay of the ERWOSA and ERASA groups in emergency services were found to be significantly different, with 55 ± 17 and 118 ± 23 minutes for each group, respectively. There were no complications. The ER method can be used in reduction of anterior shoulder dislocations without sedation and analgesia, if applied slowly enough to overcome

  6. [Acute perilunar dislocations: algorithm for treatment].

    PubMed

    Towfigh, H

    2001-01-01

    In most cases, perilunar dislocations of the wrist are caused by high speed accidents. Usually these injuries occur by a fall on the dorsiflexed superextension of the hand. The instability caused by injuries of various erticular structures (ligament, bone) show various developmental stages. Clinical symptoms are reduced and painful movement, instability of the carpus, snapping and swelling. The diagnosis is established by X-ray, cinematography, arthrography MRT or CT. Perilunar instability with or without associated fractures and particularly de Quervain must be reduced and treated operatively including suture of the ligament and stabilization of the fracture. PMID:11824286

  7. The Education of Adult Migrant Farmworkers. Volume One: A Resource Base for Administrators And Teachers of Adult Education. Volume Two: Applications for Teachers and Administrators of Adult Education.

    ERIC Educational Resources Information Center

    Slaughter & Associates, Woodland Hills, CA.

    As the result of an extensive survey of the literature, analysis of current state plans for educating migrant farm workers, and site visits to nine programs serving adult farm workers in California, Florida, New York, Pennsylvania, Texas, and Washington, a two-volume final technical report on adult migrant farm worker education is presented. The…

  8. A computational method for dislocation-precipitate interaction

    NASA Astrophysics Data System (ADS)

    Takahashi, Akiyuki; Ghoniem, Nasr M.

    A new computational method for the elastic interaction between dislocations and precipitates is developed and applied to the solution of problems involving dislocation cutting and looping around precipitates. Based on the superposition principle, the solution to the dislocation-precipitate interaction problem is obtained as the sum of two solutions: (1) a dislocation problem with image stresses from interfaces between the dislocation and the precipitate, and (2) a correction solution for the elastic problem of a precipitate with an initial strain distribution. The current development is based on a combination of the parametric dislocation dynamics (PDD) and the boundary element method (BEM) with volume integrals.The method allows us to calculate the stress field both inside and outside precipitates of elastic moduli different from the matrix, and that may have initial coherency strain fields. The numerical results of the present method show good convergence and high accuracy when compared to a known analytical solution, and they are also in good agreement with molecular dynamics (MD) simulations. Sheared copper precipitates (2.5 nm in diameter) are shown to lose some of their resistance to dislocation motion after they are cut by leading dislocations in a pileup. Successive cutting of precipitates by the passage of a dislocation pileup reduces the resistance to about half its original value, when the number of dislocations in the pileup exceeds about 10. The transition from the shearable precipitate regime to the Orowan looping regime occurs for precipitate-to-matrix elastic modulus ratios above approximately 3-4, with some dependence on the precipitate size. The effects of precipitate size, spacing, and elastic modulus mismatch with the host matrix on the critical shear stress (CSS) to dislocation motion are presented.

  9. Implicit integration methods for dislocation dynamics

    DOE PAGES

    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 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

  10. 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.

  11. Congenital dislocation of the hip. A review.

    PubMed

    Sherk, H H; Pasquariello, P S; Watters, W C

    1981-08-01

    Congenital dislocation of the hip usually results from capsular stretching caused by fetal malposition and crouching late in the third trimester. Early recognition of hip dislocation or instability soon after birth permits prompt treatment. Ortolani's and Barlow's maneuvers, respectively, reduce into and displace from the acetabulum a femoral head that is insecurely contained therein. The diagnosis of CDH in the first month of life usually depends on these clinical components of the physical examination of the newborn, because similar device, in this age group can usually maintain the displaced hip in sufficient flexion and abduction to permit reduction and normal development. By 3 months of age, the nuclei of the pelvis and upper femur have ossified enough to permit radiologic diagnosis of CDH. Problems related to treatment increase as the child grows older. In infants up to 6 months of age, closed methods with a harness usually succeed. Beyond 6 months, the soft tissues shorten and prevent easy reduction. These patients almost always require pre-reduction traction. An adductor tenotomy also facilitates reduction and apparently lessens compressive forces on the femoral head, an important consideration in preventing avascular necrosis of the head. Children over 1 year old develop bony changes, such as excessive femoral valgus and anteversion and deformity of the acetabulum. Treatment in these patients requires realignment of bony deformities with femoral or pelvic osteotomies in addition to the measures noted previously. The gentleness and high success rate of early treatment make early diagnosis of CDH an important consideration in infants and newborns.

  12. 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.

  13. Void growth by dislocation-loop emission

    NASA Astrophysics Data System (ADS)

    Ahn, D. C.; Sofronis, P.; Kumar, M.; Belak, J.; Minich, R.

    2007-03-01

    Experimental results from spall tests on aluminum reveal the presence of a dense dislocation structure in an annulus around a void that grew under the tensile pulse when a shock wave was reflected at the free surface of the specimen. The proposition is that dislocation emission from the void surface under load is a viable mechanism for void growth. To understand void growth in the absence of diffusive effects, the interstitial-loop emission mechanism under tensile hydrostatic stress is investigated. First, the micromechanics of pile-up formation when interstitial loops are emitted from a void under applied macroscopic loading is reviewed. Demand for surface energy expenditure upon void-surface change is taken into consideration. It is demonstrated that in face-centered cubic metals loop emission from voids with a radius of ˜10 nm is indeed energetically possible in the hydrostatic stress environment generated by shock loading. On the other hand, the levels of hydrostatic stress prevalent in common structural applications are not sufficient to drive loops at equilibrium positions above a ˜10 nm void. However, for voids larger than about 100 nm, the energetics of loop emission are easily met as a necessary condition even under the low stress environment prevalent in structural applications.

  14. Extensor Mechanism Disruption in Knee Dislocation.

    PubMed

    O'Malley, Michael; Reardon, Patrick; Pareek, Ayoosh; Krych, Aaron; Levy, Bruce A; Stuart, Michael J

    2016-05-01

    Disruption of the knee extensor mechanism is a challenging injury with no clear consensus on optimal treatment. Although rare in the setting of knee dislocations, these injuries should not be overlooked. Acute, complete rupture of either the quadriceps or patellar tendon necessitates primary repair with or without augmentation. Surgical management may also be required in the setting of a partial tear if a significant extensor lag is present or nonoperative treatment has failed. Tendon augmentation is used during primary repair if the native tissue is inadequate or after a failed primary repair. The purpose of this study is to evaluate extensor mechanism disruption incidence, injury patterns, associated injuries, and surgical options, including a novel tendon augmentation technique. This procedure consists of primary patellar or quadriceps tendon repair with semitendinosus autograft augmentation utilizing a distal or proximal patellar socket. Advantages of repair with tendon augmentation include accelerated rehabilitation, decreased risk of patellar fracture from transverse or longitudinal bone tunnels, and less hardware complications. We recommend consideration of this technique for selected cases of acute extensor mechanism disruption in the setting of tibiofemoral dislocation. PMID:26636488

  15. 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.

  16. 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.

  17. 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.

  18. [Dislocation-disassembly of bipolar hip arthroplasty--case report].

    PubMed

    Gagała, Jacek; Blacha, Jan

    2005-01-01

    Bipolar hip arthroplasty dislocation is rare. A case of bipolar hip arthroplasty dislocation in patient treated because of femoral neck fracture was described. Patient had neurological problems. The arthroplasty was made with posterolateral approach. Disassembly of bipolar prosthesis occurred during closed reduction. Open reduction with bipolar head exchange was necessary. To avoid this complication reduction should be made in anesthesia with muscles relaxation.

  19. 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.

  20. 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

  1. Acute shoulder and elbow dislocations in the athlete.

    PubMed

    Burra, Giridhar; Andrews, James R

    2002-07-01

    Dislocations of the elbow are less common than shoulder dislocations. The primary treatment is conservative, with a conscious effort toward early mobilization. Recurrence is rare, and improvement in function and motion can be expected for up to 1 year. Operative treatment should be reserved for baseball pitchers and cases of complex instability.

  2. 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.

  3. 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.

  4. Dislocated ankle fracture complicated by near total distal ischaemia

    PubMed Central

    Duygun, Fatih; Sertkaya, Omer; Aldemir, Cengiz; Dogan, Ali

    2013-01-01

    Total arterial ischaemia is rarely seen following a dislocated ankle fracture but if it does and intervention is not made, it can lead to serious morbidity. We present a 39-year-old woman with almost total occlusion in the arteria tibialis and arteria dorsalis pedis following a dislocated ankle fracture as a result of a bicycle fall. PMID:24248319

  5. Moment tensors of a dislocation in a porous medium

    NASA Astrophysics Data System (ADS)

    Wang, Zhi; Hu, Hengshan

    2016-06-01

    A dislocation can be represented by a moment tensor for calculating seismic waves. However, the moment tensor expression was derived in an elastic medium and cannot completely describe a dislocation in a porous medium. In this paper, effective moment tensors of a dislocation in a porous medium are derived. It is found that the dislocation is equivalent to two independent moment tensors, i.e., the bulk moment tensor acting on the bulk of the porous medium and the isotropic fluid moment tensor acting on the pore fluid. Both of them are caused by the solid dislocation as well as the fluid-solid relative motion corresponding to fluid injection towards the surrounding rocks (or fluid outflow) through the fault plane. For a shear dislocation, the fluid moment tensor is zero, and the dislocation is equivalent to a double couple acting on the bulk; for an opening dislocation or fluid injection, the two moment tensors are needed to describe the source. The fluid moment tensor only affects the radiated compressional waves. By calculating the ratio of the radiation fields generated by unit fluid moment tensor and bulk moment tensor, it is found that the fast compressional wave radiated by the bulk moment tensor is much stronger than that radiated by the fluid moment tensor, while the slow compressional wave radiated by the fluid moment tensor is several times stronger than that radiated by the bulk moment tensor.

  6. 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

  7. Dislocation of the distal radioulnar joint associated with a transstyloid radiocarpal fracture dislocation. A case report and review of the literature.

    PubMed

    Stoffelen, D; Fortems, Y; De Smet, L; Broos, P

    1996-03-01

    Dislocations of the distal radio-ulnar joint (DRUJ) can be isolated or combined with fractures. Cases of DRUJ dislocations have been described with Galleazi fractures, open radius and ulna fractures and intraarticular fractures of the distal radius. We report a case of a volar DRUJ dislocation combined with a transstyloid radio-carpal dislocation. Because of severe instability of the wrist, open reduction of the radial styloid combined with an open reduction of the dislocated DRUJ is advised. PMID:8669257

  8. 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.

  9. Dislocation injection in strontium titanate by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Titus, Michael S.; Echlin, McLean P.; Gumbsch, Peter; Pollock, Tresa M.

    2015-08-01

    Femtosecond laser ablation is used in applications which require low damage surface treatments, such as serial sectioning, spectroscopy, and micromachining. However, dislocations are generated by femtosecond laser-induced shockwaves and consequently have been studied in strontium titanate (STO) using transmission electron microscopy (TEM) and electron backscatter diffraction analysis. The laser ablated surfaces in STO exhibit dislocation structures that are indicative of those produced by uniaxial compressive loading. TEM analyses of dislocations present just below the ablated surface confirm the presence of ⟨110 ⟩ dislocations that are of approximately 35° mixed character. The penetration depth of the dislocations varied with grain orientation relative to the surface normal, with a maximum depth of 1.5 μm. Based on the critical resolved shear stress of STO crystals, the approximate shockwave pressures experienced beneath the laser irradiated surface are reported.

  10. Charge accumulation at a threading edge dislocation in gallium nitride

    SciTech Connect

    Leung, K.; Wright, A.F.; Stechel, E.B.

    1999-04-01

    We have performed Monte Carlo calculations to determine the charge accumulation on threading edge dislocations in GaN as a function of the dislocation density and background dopant density. Four possible core structures have been examined, each of which produces defect levels in the gap and may therefore act as electron or hole traps. Our results indicate that charge accumulation, and the resulting electrostatic interactions, can change the relative stabilities of the different core structures. Structures having Ga and N vacancies at the dislocation core are predicted to be stable under nitrogen-rich and gallium-rich growth conditions, respectively. Due to dopant depletion at high dislocation density and the multitude of charge states, the line charge exhibits complex crossover behavior as the dopant and dislocation densities vary. {copyright} {ital 1999 American Institute of Physics.}

  11. Scapular dislocation from trivial trauma: a rare case.

    PubMed

    Landge, Vikrant; Vaishya, Raju; Aggarwal, Anurag

    2012-01-01

    Dislocation of the scapula between the ribs and into the thoracic cage is a very rare event. Scapulothoracic dissociation though has been reported, usually occurs after a severe injury and is often associated with other serious injuries like brachial plexus or chest injury, etc. Ainscow has described a rare type that may occur due to slight violence with a pre-existing condition. Cases of isolated scapular dislocation after minor trauma have not been reported frequently in the literature. It is a distinct clinical entity and needs to be differentiated from other similar conditions. Here, we present a case of painless scapular dislocation associated with trivial trauma followed by spontaneous reduction in a 10 years old girl. The patient had a recurrence of the dislocation before presenting to us. But she did not have any pre-existing condition for scapular dislocation.

  12. 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

  13. Second yield via dislocation-induced premelting in copper

    NASA Astrophysics Data System (ADS)

    Wang, L.; Cai, Y.; He, A. M.; Luo, S. N.

    2016-05-01

    Premelting or virtual melting was proposed previously as an important deformation mechanism for high strain-rate loading. However, two questions remain outstanding: how premelting occurs exactly, and whether it plays a role in plastic deformation independent of, parasitic on, or synergetic with, dislocation motion. By virtue of double-shock compression, our large-scale molecular dynamics simulations reveal two yields in single-crystal copper, with the first yield achieved via dislocation motion, and the second, via dislocation-induced premelting as well. The clean capture of melting during dislocation motion suggests that premelting occurs on slip planes and at their intersections, facilitating gliding and leading to yield together with dislocation motion.

  14. Ripple dislocation slip in wrinkled gold film deposited on polydimethylsiloxane

    NASA Astrophysics Data System (ADS)

    Lin, C. B.; Chuang, Y. F.; Liu, Y. H.; Lee, Sanboh; Chou, Y. T.

    2011-07-01

    The motion of ripple dislocations in a wrinkled thin film of gold deposited on polydimethylsiloxane (PDMS) was investigated. The deposition was made under tensile load along the first direction on the PDMS plate. After the tensile load was released, a ripple pattern and ripple dislocations were formed on the surface. Upon reloading in the second direction, these ripple dislocations were able to slip. At a given tensile load, the speed of slip decreased as the loading time increased, and finally reached a constant value, which was increasing with the applied load. The measured data were interpreted with a dynamic model based on Newton's law of motion. Interaction of ripple dislocations was also observed. It was shown that a pair of positive and negative ripple dislocations of equal strength could annihilate each other or form a dipole, depending on the magnitude of the applied load.

  15. Neglected Posterior Dislocation of Hip in Children - A Case Report

    PubMed Central

    Pal, Chandra Prakash; Kumar, Deepak; Sadana, Ashwani; Dinkar, Karuna Shankar

    2014-01-01

    Introduction: Traumatic dislocation of the hip in children is a rare injury. We report the outcome of 2 patients of neglected hip dislocation which were treated by open reduction and internal fixation by k-wires. Case Report: We treat 2 children both girls (one was of 4 years and other was 7 years of age). In both cases dislocation was unilateral and was not associated with any facture. Both cases were of posterior dislocation. in both cases open reduction and internal fixation was done by k wires. Hip spica was applied post operatively in both cases. The k wire was removed at 3 to 4 weeks. Patients were allowed to bear weight from gradual to full weight bearing after 6 weeks. Conclusion: We conclude that open reduction is a satisfactory treatment for neglected hip dislocation. It prevents not only deformity but also maintains limb length. PMID:27298953

  16. 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 "Center for Research and…

  17. 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; 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 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

  18. 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

  19. CTE's Role in Worker Retraining. Issue Brief

    ERIC Educational Resources Information Center

    Association for Career and Technical Education (NJ1), 2010

    2010-01-01

    This Issue Brief will explore the essential role that career and technical education programs play in addressing many of the issues faced by unemployed and underemployed workers. These programs target the adult learner through short-term and accelerated courses; utilize flexible learning approaches to account for students' other responsibilities;…

  20. 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…

  1. Dislocation-induced chirality of semiconductor nanocrystals.

    PubMed

    Baimuratov, Anvar S; Rukhlenko, Ivan D; Gun'ko, Yurii K; Baranov, Alexander V; Fedorov, Anatoly V

    2015-03-11

    Optical activity is a common natural phenomenon, which occurs in individual molecules, biomolecules, biological species, crystalline solids, liquid crystals, and various nanosized objects, leading to numerous important applications in almost every field of modern science and technology. Because this activity can hardly be altered, creation of artificial active media with controllable optical properties is of paramount importance. Here, for the first time to the best of our knowledge, we theoretically demonstrate that optical activity can be inherent to many semiconductor nanowires, as it is induced by chiral dislocations naturally developing during their growth. By assembling such nanowires in two- or three-dimensional periodic lattices, one can create optically active quantum supercrystals whose activity can be varied in many ways owing to the size quantization of the nanowires' energy spectra. We believe that this research is of particular importance for the future development of semiconducting nanomaterials and their applications in nanotechnology, chemistry, biology, and medicine.

  2. 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

  3. 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...

  4. 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...

  5. 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.

  6. Period-doubling reconstructions of semiconductor partial dislocations

    DOE PAGES

    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;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

  7. On the electronic properties of a single dislocation

    SciTech Connect

    Reiche, Manfred Erfurth, Wilfried; Pippel, Eckhard; Sklarek, Kornelia; Blumtritt, Horst; Haehnel, Angelika; Kittler, Martin

    2014-05-21

    A detailed knowledge of the electronic properties of individual dislocations is necessary for next generation nanodevices. Dislocations are fundamental crystal defects controlling the growth of different nanostructures (nanowires) or appear during device processing. We present a method to record electric properties of single dislocations in thin silicon layers. Results of measurements on single screw dislocations are shown for the first time. Assuming a cross-section area of the dislocation core of about 1 nm{sup 2}, the current density through a single dislocation is J = 3.8 × 10{sup 12} A/cm{sup 2} corresponding to a resistivity of ρ ≅ 1 × 10{sup −8} Ω cm. This is about eight orders of magnitude lower than the surrounding silicon matrix. The reason of the supermetallic behavior is the high strain in the cores of the dissociated dislocations modifying the local band structure resulting in high conductive carrier channels along defect cores.

  8. EXTRA-ARTICULAR FRACTURE OF THE MEDIAL END OF THE CLAVICLE ASSOCIATED WITH TYPE IV ACROMIOCLAVICULAR DISLOCATION: CAAE REPORT

    PubMed Central

    Correa, Mário Chaves; Gonçalves, Lucas Braga Jacques; Vilela, Jose Carlos Souza; Leonel, Igor Lima; Costa, Lincoln Paiva; de Andrade, Ronaldo Percopi

    2015-01-01

    Fractures of the clavicle and acromioclavicular dislocations are very common injuries when they occur separately. The combination of an acromioclavicular dislocation and a fracture of the lateral third of the clavicle is not rare. However, there are very few reported cases of acromioclavicular dislocations associated with fractures of the middle third of the clavicle; those associated with fractures of the medial third are even rarer. We report the case of an adult male who suffered an acromioclavicular dislocation (type IV) associated with a displaced extra-articular fracture of the medial end of the clavicle (Almann group 3) in a cycling accident. The patient was treated during the acute phase with open reduction and internal fixation of the two lesions. At the clinical evaluation 12 months after the surgery, the patient was asymptomatic, with full active and passive mobility, and normal strength and endurance of the shoulder girdle. Radiographs and a three-dimensional CT scan showed persistent posterosuperior subluxation of the acromioclavicular joint and anatomical consolidation of the clavicular fracture. PMID:27027060

  9. Strength and Dislocation Structure Evolution of Small Metals under Vibrations

    NASA Astrophysics Data System (ADS)

    Ngan, Alfonso

    2015-03-01

    It is well-known that ultrasonic vibration can soften metals, and this phenomenon has been widely exploited in industrial applications concerning metal forming and bonding. In this work, we explore the effects of a superimposed small oscillatory load on metal plasticity, from the nano- to macro-size range, and from audible to ultrasonic frequency ranges. Macroscopic and nano-indentation were performed on aluminum, copper and molybdenum, and the results show that the simultaneous application of oscillatory stresses can lower the hardness of these samples. More interestingly, EBSD and TEM observations show that subgrain formation and reduction in dislocation density generally occurred when stress oscillations were applied. These findings point to an important knowledge gap in metal plasticity - the existing understanding of ultrasound softening in terms of the vibrations either imposing additional stress waves to augment the quasi-static applied load, or heating up the metal, whereas the metal's intrinsic deformation resistance or dislocation interactive processes are assumed unaltered by the ultrasound, is proven wrong by the present results. Furthermore, in the case of nanoindentation, the Continuous Stiffness Measurement technique for contact stiffness measurement assumes that the imposed signal-carrier oscillations do not intrinsically alter the material properties of the specimen, and again, the present results prove that this can be wrong. To understand the enhanced subgrain formation and dislocation annihilation, Discrete Dislocation Dynamics (DDD) simulations were carried out and these show that when an oscillatory stress is superimposed on a quasi-static applied stress, reversals of motion of dislocations may occur, and these allow the dislocations to revisit repeatedly suitable configurations for annihilation. DDD, however, was unable to predict the observed subgrain formation presumably because the number of dislocations that can be handled is not large

  10. Dislocation following total knee arthroplasty: A report of six cases

    PubMed Central

    Villanueva, Manuel; Ríos-Luna, Antonio; Pereiro, Javier; Fahandez-Saddi, Homid; Pérez-Caballer, Antonio

    2010-01-01

    Background: Dislocation following total knee arthroplasty (TKA) is the worst form of instability. The incidence is from 0.15 to 0.5%. We report six cases of TKA dislocation and analyze the patterns of dislocation and the factors related to each of them. Materials and Methods: Six patients with dislocation of knee following TKA are reported. The causes for the dislocations were an imbalance of the flexion gap (n=4), an inadequate selection of implants (n=1), malrotation of components (n=1) leading to incompetence of the extensor mechanism, or rupture of the medial collateral ligament (MCC). The patients presented complained of pain, giving way episodes, joint effusion and difficulty in climbing stairs. Five patients suffered posterior dislocation while one anterior dislocation. An urgent closed reduction of dislocation was performed under general anaesthesia in all patients. All patients were operated for residual instability by revision arthroplasty after a period of conservative treatment. Results: One patient had deep infection and knee was arthrodesed. Two patients have a minimal residual lag for active extension, including a patient with a previous patellectomy. Result was considered excellent or good in four cases and fair in one, without residual instability. Five out of six patients in our series had a cruciate retaining (CR) TKA designs: four were revised to a posterior stabilized (PS) TKA and one to a rotating hinge design because of the presence of a ruptured MCL. Conclusion: Further episodes of dislocation or instability will be prevented by identifying and treating major causes of instability. The increase in the level of constraint and correction of previous technical mistakes is mandatory. PMID:20924487

  11. 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…

  12. Galeazzi fracture with volar dislocation of the distal radioulnar joint.

    PubMed

    Kim, Suezie; Ward, James P; Rettig, Michael E

    2012-11-01

    Galeazzi fracture dislocations are fractures of the distal one-third of the radial diaphysis with traumatic disruption of the distal radioulnar joint (DRUJ). This injury results in subluxation or dislocation of the ulnar head. We present a case of a Galeazzi fracture with a volar dislocation of the DRUJ. Open reduction of the DRUJ with Kirschner wire fixation in pronation was necessary to reduce the joint and maintain anatomic alignment. Repair of the triangular fibrocartilage complex was also necessary to maintain stability of the DRUJ.

  13. 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.

  14. The dislocation free zone model of fracture by symbolic programming

    SciTech Connect

    Chang, Shih-Jung

    1997-09-01

    The dislocation free zone (DFZ) model of fracture was developed by Chang and Ohr after a series of experimental observations on the crack tip dislocation structures that invariably showed the existence of the dislocation free region. The DFZ model is a modified BCS crack model that is supplemented with the Rice-Thomson crack tip dislocation emission mechanism. This dislocation emission mechanism imposes a finite energy barrier to the crack tip for emitting dislocations into the plastic zone, in contrast to a zero energy barrier for the BCS model. This finite energy barrier results in the formation of the DFZ and a stress-singular crack tip region. This resistance was expressed in terms of a dislocation emission toughness K{sub e} as a material constant. Because of the emission toughness K{sub e} the crack tip has the choice either to emit dislocation or to fracture in brittle mode. The model, therefore, was first used to explain the fundamental phenomenon of brittle versus ductile fracture. Brittle fracture occurs if K{sub Ic} < K{sub e}, that is, the crack tip breaks before the dislocation can be emitted. Ductile fracture is possible if K{sub Ic} > K{sub e} so that dislocation will be generated before brittle fracture toughness K{sub Ic} is reached. The distribution function for the dislocations was solved from the dislocation pile-up equation. It was expressed in terms of the complete elliptic integrals. Although the analytical nature of the model is clear and precise, the numerical values of the model may not always be obtained readily. Attempts have been made to simplify and approximate the model by elementary mathematical functions. In this paper the distribution function is written in terms of a symbolic programming language MAPLE. The analytical and numerical manipulations can be made easily. An improvement of the program that accounts for the technique of calculating the elliptic integral of the third kind in different regions of the model is presented here.

  15. Role of oxygen at screw dislocations in GaN.

    PubMed

    Arslan, I; Browning, N D

    2003-10-17

    Here we report the first direct atomic scale experimental observations of oxygen segregation to screw dislocations in GaN using correlated techniques in the scanning transmission electron microscope. The amount of oxygen present in each of the three distinct types of screw dislocation core is found to depend on the evolution and structure of the core, and thus gives rise to a varying concentration of localized states in the band gap. Contrary to previous theoretical predictions, the substitution of oxygen for nitrogen is observed to extend over many monolayers for the open core dislocation. PMID:14611410

  16. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies

    DOE PAGES

    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 andmore » dynamics in these systems.« less

  17. 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.

  18. Discrete dislocation dynamics study of strained-layer relaxation.

    PubMed

    Schwarz, K W

    2003-10-01

    Numerical simulations are performed to follow the evolution of an initial density of dislocation loops in an infinite strained layer to the point where the dislocations have stopped moving. Several unexpected results are obtained. First, many of the threading arms are either annihilated or prematurely immobilized by hardening interactions such as jogging and junction formation. Second, the remaining dislocation arms are eventually trapped by stress fluctuations that arise more from local overrelaxation than from the blocking mechanisms usually considered. Third, the degree of relaxation that can be attained depends strongly on the initial density of threading arms. PMID:14611535

  19. Concentric reduction of the dislocated hip: computed tomographic evaluation

    SciTech Connect

    Hernandez, R.J.

    1984-01-01

    Concentric reduction of a dislocated hip can be evaluated by anteroposterior views or linear tomography. Anterior relationships, however, may be difficult to evaluate from a frontal radiograph despite good visibility. Computed tomography (CT), because of its cross-sectional imaging capabilities, is superior in demonstrating these relationships. The CT appearance of two types of dislocations (posterior and lateral ) is described. A posterior dislocation should be suspected if the femoral metaphysis approximates the acetabulum, a mass projects behind the ischium, or the fat plane anterior to the gluteus maximus is deformed or displaced posteriorly.

  20. Management of arterial and venous injuries in the dislocated knee.

    PubMed

    Gray, John L; Cindric, Matthew

    2011-06-01

    Although uncommonly encountered, knee dislocation is frequently associated with major vascular injury. Serious injuries resulting in ischemia demand prompt recognition and efficient management to prevent devastating long-term sequelae. In this review, we detail mechanisms of knee dislocation and associated popliteal vascular injuries. Diagnostic modalities used to evaluate the extent of vascular injury are individually discussed. Appropriate initial management of vascular injuries is crucial and an algorithm for diagnosis and management will be reviewed. We elaborate on the salient points of vascular reconstruction in the context of the dislocated knee: surgical approach, conduct of the procedure, and adjunctive maneuvers are described.

  1. Discrete Dislocation Dynamics Study of Strained-Layer Relaxation

    NASA Astrophysics Data System (ADS)

    Schwarz, K. W.

    2003-10-01

    Numerical simulations are performed to follow the evolution of an initial density of dislocation loops in an infinite strained layer to the point where the dislocations have stopped moving. Several unexpected results are obtained. First, many of the threading arms are either annihilated or prematurely immobilized by hardening interactions such as jogging and junction formation. Second, the remaining dislocation arms are eventually trapped by stress fluctuations that arise more from local overrelaxation than from the blocking mechanisms usually considered. Third, the degree of relaxation that can be attained depends strongly on the initial density of threading arms.

  2. Tibial-talar dislocation without fracture: treatment principles and outcome.

    PubMed

    Finkemeier, C; Engebretsen, L; Gannon, J

    1995-01-01

    The incidence of tibial-talar dislocations without fracture is unknown and has been sparsely reported in the literature. The diagnosis of the injury is straightforward with the appropriate examination and roentgenograms. Good to excellent results can be achieved with open or closed dislocations treated by closed reduction and immobilization for 4-6 weeks. Although open dislocations require irrigation, debridement, and possibly delayed closure, controversy exists with regard to acute ligament repair. Because good to excellent results are possible without acute ligament repair, and delayed repair on reconstruction can be accomplished with good outcomes, we recommend treating these injuries without ligament repair.

  3. Comparing social worker and non-social worker outcomes: a research review.

    PubMed

    Rubin, Allen; Parrish, Danielle E

    2012-10-01

    This article reports on a review of the literature comparing the outcomes of social workers with those of non-social workers. The review was commissioned by NASW's Texas Chapter to examine empirical evidence regarding the comparative effectiveness of social work to possibly support efforts to educate employers and the public about the value of social work. Because of the limited number of internally valid studies that have compared social workers and non-social workers on actual client outcomes, studies were also included if they examined practitioner variables that might be associated with client outcomes. The mixed findings point to a lack of compelling evidence supporting the superiority of social work in the child welfare field. However, in the mental health and aging fields, the limited evidence suggests that social workers do at least as well as non-social workers regarding practitioner retention, mental health court intervention, efforts to maintain older adult independence in the community, and attitudes toward evidence-based practice. Implications are presented to guide NASW in promoting rigorous research comparing social workers and non-social workers on actual client outcomes, especially in the field of child welfare.

  4. Worker honey bee pheromone regulation of foraging ontogeny

    NASA Astrophysics Data System (ADS)

    Pankiw, Tanya

    The evolution of sociality has configured communication chemicals, called primer pheromones, which play key roles in regulating the organization of social life. Primer pheromones exert relatively slow effects that fundamentally alter developmental, physiological, and neural systems. Here, I demonstrate how substances extracted from the surface of foraging and young pre-foraging worker bees regulated age at onset of foraging, a developmental process. Hexane-extractable compounds washed from foraging workers increased foraging age compared with controls, whereas extracts of young pre-foraging workers decreased foraging age. This represents the first known direct demonstration of primer pheromone activity derived from adult worker bees.

  5. 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.

  6. 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.

  7. 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).

  8. 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). PMID:25518804

  9. Quantifying dislocation microstructure evolution and cyclic hardening in fatigued face-centered cubic single crystals

    NASA Astrophysics Data System (ADS)

    Hussein, Ahmed M.; El-Awady, Jaafar A.

    2016-06-01

    Discrete dislocation dynamics simulations were performed to investigate the dislocation microstructure evolution and cyclic hardening during the early stages of fatigue loading in nickel single crystals. The effects of the crystal size and initial dislocation densities on both the mechanical response and the evolution of dislocation microstructure were quantified. Crystals having an initial dislocation density of 1012 m-2 and diameter less than 2.0 μm do not show any dislocation density multiplication or cyclic hardening. In contrast, crystals having the same initial dislocation density and diameters larger than 2.0 μm show a significant dislocation density accumulation in the form of dislocation cell-like structures, even after only a few number of loading cycles. This dislocation density accumulation was also accompanied by considerable cyclic hardening. The dislocation cell size and its wall thickness increase with increasing crystal size. With increasing dislocation density the critical crystal size, at which dislocation cell-structures form, decreases. The information theoretic entropy is utilized as a metric to quantify the extent of dislocation patterning and the formation and evolution of dislocation cell structures over time. Cross-slip was found to play a dominant role in the dislocation cell-structure formation. Further insights on the mechanisms contributing to the observed behavior are presented and discussed.

  10. 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.

  11. The effect of length scale on the determination of geometrically necessary dislocations via EBSD continuum dislocation microscopy.

    PubMed

    Ruggles, T J; Rampton, T M; Khosravani, A; Fullwood, D T

    2016-05-01

    Electron backscatter diffraction (EBSD) dislocation microscopy is an important, emerging field in metals characterization. Currently, calculation of geometrically necessary dislocation (GND) density is problematic because it has been shown to depend on the step size of the EBSD scan used to investigate the sample. This paper models the change in calculated GND density as a function of step size statistically. The model provides selection criteria for EBSD step size as well as an estimate of the total dislocation content. Evaluation of a heterogeneously deformed tantalum specimen is used to asses the method. PMID:26986021

  12. Microscopic Structure of Stepwise Threading Dislocation in 4H-SiC Substrate

    NASA Astrophysics Data System (ADS)

    Ishikawa, Yukari; Sugawara, Yoshihiro; Saitoh, Hiroaki; Danno, Katsunori; Suzuki, Hiroshi; Bessho, Takeshi; Kawai, Yoichiro; Shibata, Noriyoshi

    2012-04-01

    The dislocation structure that forms the caterpillar-shaped etch pit upon molten KOH etching is investigated by transmission electron microscopy employing a weak-beam dark-field method. The observed dislocation has the Burgers vector 1/3[bar 12bar 10], and its structure was transformed from a basal plane dislocation to a threading edge dislocation. In the basal plane dislocation region, it propagated parallel to the [10bar 10] direction. On the basis of the measured dislocation structure, the caterpillar pit formation is explained. The process of dislocation formation is discussed by analyzing the relationship between sample types and the detection of the caterpillar pits.

  13. Traumatic testicular dislocation a review of 36 cases.

    PubMed

    Kochakarn, W; Choonhaklai, V; Hotrapawanond, P; Muangman, V

    2000-02-01

    We retrospectively reviewed 36 patients who were treated in our institutes with traumatic testicular dislocation from 1975 to 1997. The mean patient age was 25 years old (18-38). Average time to present at the emergency room was 1 hour (0.5-6). Bilateral dislocation was found in thirty cases and unilateral dislocation was found in six cases. The sites of dislocation included: 34 cases (64 testes) at superficial inguinal area, one case (one testis) at acetabular area, and one case (one testis) at the perineal area. Closed reduction under general anesthesia was successful in 14 cases, open reduction after failed closed reduction in 10 cases, open exploration and repaired testis with reposition in 11 cases and orchiectomy only in one case. The overall results after treatment showed the normal size and position of the testis. PMID:10710892

  14. 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

  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. PMID:27494477

  16. Measuring surface dislocation nucleation in defect-scarce nanostructures.

    PubMed

    Chen, Lisa Y; He, Mo-rigen; Shin, Jungho; Richter, Gunther; Gianola, Daniel S

    2015-07-01

    Linear defects in crystalline materials, known as dislocations, are central to the understanding of plastic deformation and mechanical strength, as well as control of performance in a variety of electronic and photonic materials. Despite nearly a century of research on dislocation structure and interactions, measurements of the energetics and kinetics of dislocation nucleation have not been possible, as synthesizing and testing pristine crystals absent of defects has been prohibitively challenging. Here, we report experiments that directly measure the surface dislocation nucleation strengths in high-quality 〈110〉 Pd nanowhiskers subjected to uniaxial tension. We find that, whereas nucleation strengths are weakly size- and strain-rate-dependent, a strong temperature dependence is uncovered, corroborating predictions that nucleation is assisted by thermal fluctuations. We measure atomic-scale activation volumes, which explain both the ultrahigh athermal strength as well as the temperature-dependent scatter, evident in our experiments and well captured by a thermal activation model. PMID:25985457

  17. Atomistic Simulation of Dislocation-Defect Interactions in Cu

    SciTech Connect

    Wirth, B D; Bulatov, V V; Diaz de la Rubia, T

    2001-01-01

    The mechanisms of dislocation-defect interactions are of practical importance for developing quantitative structure-property relationships, mechanistic understanding of plastic flow localization and predictive models of mechanical behavior in metals under irradiation. In copper and other face centered cubic metals, high-energy particle irradiation produces hardening and shear localization. Post-irradiation microstructural examination in Cu reveals that irradiation has produced a high number density of nanometer sized stacking fault tetrahedra. Thus, the resultant irradiation hardening and shear localization is commonly attributed to the interaction between stacking fault tetrahedra and mobile dislocations, although the mechanism of this interaction is unknown. In this work, we present a comprehensive molecular dynamics simulation study that characterizes the interaction and fate of moving dislocations with stacking fault tetrahedra in Cu using an EAM interatomic potential. This work is intended to produce atomistic input into dislocation dynamics simulations of plastic flow localization in irradiated materials.

  18. In-game Management of Common Joint Dislocations

    PubMed Central

    Skelley, Nathan W.; McCormick, Jeremy J.; Smith, Matthew V.

    2014-01-01

    Context: Sideline management of sports-related joint dislocations often places the treating medical professional in a challenging position. These injuries frequently require prompt evaluation, diagnosis, reduction, and postreduction management before they can be evaluated at a medical facility. Our objective is to review the mechanism, evaluation, reduction, and postreduction management of sports-related dislocations to the shoulder, elbow, finger, knee, patella, and ankle joints. Evidence Acquisition: A literature review was performed using the PubMed database to evaluate previous and current publications focused on joint dislocations. This review focused on articles published between 1980 and 2013. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinician should weigh the benefits and risks of on-field reduction based on their knowledge of the injury and the presence of associated injuries. Conclusion: When properly evaluated and diagnosed, most sports-related dislocations can be reduced and initially managed at the game. PMID:24790695

  19. Arytenoid dislocation after uneventful endotracheal intubation: a case report

    PubMed Central

    Oh, Tak Kyu; Ryu, Chang Hwan; Park, Yu Na; Kim, Nam Woo

    2016-01-01

    Arytenoid dislocation is an unusual complication of endotracheal intubation. We reported a case of a 48-year-old female with arytenoid dislocation after uneventful endotracheal intubation, which was successfully treated with arytenoid reduction. The patient complained of persistent hoarseness until the fourth day after an uneventful gynecologic surgery under general anesthesia. On laryngoscopic examination, paralyzed left vocal cord with minimal arytenoid movement was observed. An anteromedial dislocation of the left arytenoid cartilage was suspected and surgical reduction was performed by the laryngologist. The hoarseness was immediately resolved after surgical intervention. Anesthesiologists should be careful not to cause laryngeal trauma in anesthetized patients. In addition, early diagnosis and prompt surgical reduction are essential for a better prognosis for arytenoid dislocation. PMID:26885311

  20. Dislocation Structure and Mobility in hcp 4He

    NASA Astrophysics Data System (ADS)

    Landinez Borda, Edgar Josué; Cai, Wei; de Koning, Maurice

    2016-07-01

    Using path-integral Monte Carlo simulations, we assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp 4He. 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.

  1. 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.

  2. Dislocation Interactions with Voids and Helium Bubbles in FCC Metals

    SciTech Connect

    Robertson, I; Robach, J; Wirth, B; Young, J

    2003-11-18

    The formation of a high number density of helium bubbles in FCC metals irradiated within the fusion energy environment is well established. Yet, the role of helium bubbles in radiation hardening and mechanical property degradation of these steels remains an outstanding issue. In this paper, we present the results of a combined molecular dynamics simulation and in-situ straining transmission electron microscopy study, which investigates the interaction mechanisms between glissile dislocations and nanometer-sized helium bubbles. The molecular dynamics simulations, which directly account for dislocation core effects through semi-empirical interatomic potentials, provide fundamental insight into the effect of helium bubble size and internal gas pressure on the dislocation/bubble interaction and bypass mechanisms. The combination of simulation and in-situ straining experiments provides a powerful approach to determine the atomic to microscopic mechanisms of dislocation-helium bubble interactions, which govern the mechanical response of metals irradiated within the fusion environment.

  3. Dislocation processes and deformation twinning in nanocrystalline Al.

    SciTech Connect

    Yamakov, V.; Wolf, D.; Phillpot, S.R.; Gleiter, H.

    2002-01-29

    Using a recently developed, massively parallel molecular-dynamics (MD) code for the simulation of polycrystal plasticity, we analyze for the case of nanocrystalline Al the complex interplay among various dislocation and grain-boundary processes during low-temperature deformation. A unique aspect of this work, arising from our ability to deform to rather large plastic strains and to consider a rather large grain size, is the observation of deformation under very high grain-boundary and dislocation densities, i.e., in a deformation regime where they compete on an equal footing. We are thus able to identify the intra- and intergranular dislocation and grain-boundary processes responsible for the extensive deformation twinning observed in our simulations. This illustrates the ability of this type of simulations to capture novel atomic-level insights into the underlying deformation mechanisms not presently possible experimentally. smaller grain size, mobile dislocations must be nucleated from other sources, such as the GBs or grain junctions.

  4. 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

  5. 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.

  6. Theoretical investigations of compositional inhomogeneity around threading dislocations in III-nitride semiconductor alloys

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Ryohei; Akiyama, Toru; Nakamura, Kohji; Ito, Tomonori

    2016-05-01

    The compositional inhomogeneity of group III elements around threading dislocations in III-nitride semiconductors are theoretically investigated using empirical interatomic potentials and Monte Carlo simulations. We find that the calculated atomic arrangements around threading dislocations in Al0.3Ga0.7N and In0.2Ga0.8N depend on the lattice strain around dislocation cores. Consequently, compositional inhomogeneity arises around edge dislocation cores to release the strain induced by dislocation cores. In contrast, the compositional inhomogeneity in screw dislocation is negligible owing to relatively small strain induced by dislocation cores compared with edge dislocation. These results indicate that the strain relief around dislocation cores is decisive in determining the atomic arrangements and resultant compositional inhomogeneity around threading dislocations in III-nitride semiconductor alloys.

  7. Unusual upward closed tibiotalar dislocation without fracture: A case report.

    PubMed

    Lamraski, Guyve; Clegg, Emilie

    2010-06-01

    Pure tibiotalar dislocations without associated fracture are rare. The authors report a case of an unusual closed tibiotalar dislocation without fracture, involving proximal ascension of the talus. Despite immediate closed reduction, a tibiofibular diastasis remained, therefore two syndesmosis screws were inserted, followed by six weeks of plaster casting. After 5 years of follow-up, functional results were excellent, MRI showed slight arthritic degenerative changes. PMID:20483130

  8. Plastic dislocation motion via nonequilibrium molecular and continuum dynamics

    SciTech Connect

    Hoover, W.G.; Ladd, A.J.C.; Hoover, N.E.

    1980-09-29

    The classical two-dimensional close-packed triangular lattice, with nearest-neighbor spring forces, is a convenient standard material for the investigation of dislocation motion and plastic flow. Two kinds of calculations, based on this standard material, are described here: (1) Molecular Dynamics simulations, incorporating adiabatic strains described with the help of Doll's Tensor, and (2) Continuum Dynamics simulations, incorporating periodic boundaries and dislocation interaction through stress-field superposition.

  9. Posterior dislocation of the hip while playing basketball.

    PubMed

    Tennent, T D; Chambler, A F; Rossouw, D J

    1998-12-01

    Injuries in basketball are usually to the ankles and knees. Dislocation of the hip is usually associated with severe trauma--for example, road traffic accidents. A case is reported here in which a 22 year old club basketball player slipped on landing from a jump shot, forcing him into a side splits position from which he sustained a posterior dislocation of the hip resulting in a sciatic nerve palsy.

  10. Pure closed posteromedial dislocation of the tibiotalar joint without fracture.

    PubMed

    Wang, Yun-tao; Wu, Xiao-tao; Chen, Hui

    2013-08-01

    Pure tibiotalar dislocation without an associated fracture is an extremely rare injury. We present three cases of closed posteromedial tibiotalar dislocation without any associated fractures to the foot, ankle, or leg. All patients were treated conservatively with immediate closed reduction under general or local anaesthesia and immobilised in a short leg cast for six weeks without weight-bearing resulting in a satisfactory outcome at the final follow-up. A review of the literature is also presented in this paper.

  11. 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.

  12. 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.

  13. 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

  14. The energetics of dislocation array stability in strained epitaxial layers

    NASA Astrophysics Data System (ADS)

    Gosling, T. J.; Willis, J. R.; Bullough, R.; Jain, S. C.

    1993-06-01

    Two aspects of the energetics of dislocation array stability in lattice-mismatched strained layers are addressed. The first concerns criteria for determining equilibrium dislocation distributions in strained layers; the second concerns the difference between the energies of arrays of dislocations in which the Burgers vectors of all dislocations are identical, and those in which the screw components of the Burgers vectors alternate. The conclusions reached are at variance with those of recent work by Feng and Hirth on periodic arrays of dipoles in an infinite body [X. Feng and J. P. Hirth, J. Appl. Phys. 72, 1386 (1992); J. P. Hirth and X. Feng, J. Appl. Phys. 67, 3343 (1990)]. In particular, it is emphasized that if layers remain in equilibrium then there is always a residual mean strain; in other words, the mismatch strain is never completely relaxed. Also it is shown, via a direct calculation, that although alternating the screw components of the Burgers vectors of dislocations within a single array is energetically favorable, it is preferable to have all screw components of the same sign within an array if two orthogonal arrays are considered. Although for comparison with the work of Feng and Hirth arrays of dipoles in an infinite body are considered in more detail, the stated conclusions are also shown to hold for arrays of unpaired dislocations near a free surface.

  15. 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.

  16. 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.

  17. 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

  18. Material yielding and irreversible deformation mediated by dislocation motion

    NASA Astrophysics Data System (ADS)

    Miguel, M.-Carmen; Laurson, L.; Alava, M. J.

    2008-08-01

    We study the collective behavior of dislocation assemblies in simplified models of plastic deformation. We first review several numerical results on long range dislocation interactions with simplified dislocation motion constraints. These typically give rise to a yielding transition separating stationary and moving dislocation phases. Furthermore, we discuss the intermittent relaxation of the plastic strain-rate observed around this transition at mesoscopic scales, and how this intermittent behavior gives rise to an average slow power law relaxation in time known in the literature as Andrade’s creep. We analyze the coherent dynamics and the average stress-strain relationship in the steady regime of plastic deformation. In this steady regime, plastic deformation proceeds in the form of plastic avalanches whose size and duration are broadly distributed and statistically characterized. One signature of the time correlations of this heterogeneous collective dislocation dynamics is a power spectrum scaling with frequency as f - a with an exponent α close to 1.5. This feature appears to be peculiar of dislocation and grain boundary motion as has been observed in other physical situations in the vicinity of a yielding transition.

  19. Current concepts in the diagnosis and management of acromioclavicular dislocations.

    PubMed

    Post, M

    1985-11-01

    Not all complete dislocations of the acromioclavicular joint should be treated by one method alone. A classification of acromioclavicular dislocation is presented and is based upon the pathology of the injury. Grade I sprain results from a mild force that causes tearing of only a few fibers of the acromioclavicular joint. Grade II sprains are caused by a moderate force with a rupture of the capsule and acromioclavicular ligament. Grade III sprains result from a severe force that ruptures both the acromioclavicular and coracoclavicular ligaments and causes a dislocation of the joint. Grade IV dislocation may be associated with an avulsion fracture of the coracoclavicular ligament from the inferior lateral clavicle, severe tearing or other injury to the soft-tissue envelope about the lateral clavicle, or a buttonhole injury of the lateral clavicle. Grade V dislocation refers to a posterior displacement of the lateral clavicle from any cause, while Grade VI relates to an inferior lateral clavicle displacement. Grades I, II, and most Grade III injuries can be treated conservatively. The indications for open treatment of Grade III injuries are reviewed. It is recommended that Grade IV and most Grade V and VI dislocations be managed with open methods.

  20. 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.

  1. Dislocation characterization in cold rolled stainless steel using nonlinear ultrasonic techniques: A comprehensive model

    NASA Astrophysics Data System (ADS)

    Zhang, Jianfeng; Xuan, Fu-zhen; Xiang, Yanxun

    2013-09-01

    Both dislocation density and character in cold rolled stainless steel cause the change of acoustic nonlinearity. An analytical model considering the different oscillating motion of edge and screw dislocations is presented for the generation of ultrasonic harmonic wave during the process of multiplication and motion of dislocation. Results reveal that the edge dislocation induces stronger acoustic nonlinearity response than screw dislocation. The new model is certified by the application to the cold rolled stainless steel.

  2. 20 CFR 663.120 - Are displaced homemakers eligible for dislocated worker activities under WIA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... two significant differences from the eligibility requirements under the Job Training Partnership Act... with Dependent Children (AFDC) as well as those who had been dependent on the income of another...

  3. Social Support and the Impact of Job Loss in Dislocated Blue-Collar Workers.

    ERIC Educational Resources Information Center

    Mallinckrodt, Brent; Bennett, Jeanine

    1992-01-01

    Investigated direct and buffering effects of social support for 41 laid off timber industry employees. Found that financial concerns and several types of support had strong direct effects on symptoms of stress. Significant buffering effects were found for reassurance of worth support, which provided persons with sense that others acknowledge their…

  4. Traumatic cervical cord transection without facet dislocations--a proposal of combined hyperflexion-hyperextension mechanism: a case report.

    PubMed

    Cha, Yoo-Hyun; Cho, Tai-Hyoung; Suh, Jung-Keun

    2010-08-01

    A patient is presented with a cervical spinal cord transection which occurred after a motor vehicle accident in which the air bag deployed and the seat belt was not in use. The patient had complete quadriplegia below the C5 level and his imaging study showed cervical cord transection at the level of the C5/6 disc space with C5, C6 vertebral bodies and laminar fractures. He underwent a C5 laminectomy and a C4-7 posterior fusion with lateral mass screw fixation. Previous reports have described central cord syndromes occurring in hyperextension injuries, but in adults, acute spinal cord transections have only developed after fracture-dislocations of the spine. A case involving a post-traumatic spinal cord transection without any evidence of radiologic facet dislocations is reported. Also, we propose a combined hyperflexion-hyperextension mechanism to explain this type of injury.

  5. Detailed formation processes of stable dislocations in graphene

    NASA Astrophysics Data System (ADS)

    Lee, Gun-Do; Yoon, Euijoon; He, Kuang; Robertson, Alex W.; Warner, Jamie H.

    2014-11-01

    We use time-dependent HRTEM to reveal that stable dislocation pairs in graphene are formed from an initial complex multi-vacancy cluster that undergoes multiple bond rotations and adatom incorporation. In the process, it is found that the transformation from the formed complex multi-vacancy cluster can proceed without the increase of vacancy because many atoms and dimers are not only evaporated but also actively adsorbed. In tight-binding molecular dynamics simulations, it is confirmed that adatoms play an important role in the reconstruction of non-hexagonal rings into hexagonal rings. From density functional theory calculations, it is also found from simulations that there is a favorable distance between two dislocations pointing away from each other (i.e. formed from atom loss). For dislocation pairs pointing away from each other, the hillock-basin structure is more stable than the hillock-hillock structure for dislocation pairs pointing away from each other (i.e. formed from atom loss).We use time-dependent HRTEM to reveal that stable dislocation pairs in graphene are formed from an initial complex multi-vacancy cluster that undergoes multiple bond rotations and adatom incorporation. In the process, it is found that the transformation from the formed complex multi-vacancy cluster can proceed without the increase of vacancy because many atoms and dimers are not only evaporated but also actively adsorbed. In tight-binding molecular dynamics simulations, it is confirmed that adatoms play an important role in the reconstruction of non-hexagonal rings into hexagonal rings. From density functional theory calculations, it is also found from simulations that there is a favorable distance between two dislocations pointing away from each other (i.e. formed from atom loss). For dislocation pairs pointing away from each other, the hillock-basin structure is more stable than the hillock-hillock structure for dislocation pairs pointing away from each other (i.e. formed from

  6. Predictive Modeling in Adult Education

    ERIC Educational Resources Information Center

    Lindner, Charles L.

    2011-01-01

    The current economic crisis, a growing workforce, the increasing lifespan of workers, and demanding, complex jobs have made organizations highly selective in employee recruitment and retention. It is therefore important, to the adult educator, to develop models of learning that better prepare adult learners for the workplace. The purpose of…

  7. Adult Education in Australia.

    ERIC Educational Resources Information Center

    Whitelock, Derek A., Ed.

    This evaluative national survey begins with a brief historical review of Australian adult education, followed by its current (1968) profile and features of the overall educational system. The next six chapters consider the role played by universities, Federal and state governments, the Workers' Educational Association and other voluntary…

  8. Migration and Adult Education

    ERIC Educational Resources Information Center

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  9. 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.

  10. Migrating Professional Knowledge: Progressions, Regressions, and Dislocations

    ERIC Educational Resources Information Center

    Slade, Bonnie L.

    2015-01-01

    Drawing on practice-based learning theory, this chapter examines issues pertaining to the deskilling of immigrant professionals in Canada. It argues that adult educators need to have an awareness of transnational migration dynamics and work in meaningful ways to keep immigrant professionals connected to professional knowledge practices.

  11. Monteggia fracture-dislocation: a case report, its' initial management and review of bado's classification.

    PubMed

    Musa, Abdullahi Agaba-Idu

    2006-12-01

    Fracture of proximal ulna and dislocation of the proximal radio-ulna joint in the same arm is called Monteggia fracture- dislocation. Four clinical variants of this fracture- dislocation have been described in literature. This is a report and description of initial management of a fracture- dislocation, which was consequent to a sideswipe injury and consisted of a combination of the following injuries; lateral dislocation of the radial head, fractures of the olecranon and proximal ulna in the left forearm. The radial head dislocation and fracture of the olecranon were open. The head of the radius was exposed through the same wound. This fracture-dislocation resembled type 3 Bado's classification of Monteggia fracture-dislocation because of fracture of the olecranon close to the coronoid process and lateral dislocation of the head of radius.

  12. Germany's Guest Workers.

    ERIC Educational Resources Information Center

    Gupte, Pranay

    1984-01-01

    In wake of a recent recession, Turkish "guest workers" are beginning to feel less welcome in West Germany. Many have accepted government cash incentives to return to Turkey, but others have prospered and wish to stay. The Germans themselves are split over whether the Turks threaten job opportunities for native workers or provide crucial support to…

  13. 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…

  14. 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…

  15. Leaving No Worker Behind: Community Colleges Retrain the Michigan Workforce--and Themselves

    ERIC Educational Resources Information Center

    Hilliard, Tom

    2011-01-01

    In 2007, Michigan undertook a bold mission: to retrain tens of thousands of adults to qualify for jobs in emerging and expanding sectors of the economy. The state's proposal to jobless, dislocated, and low-income residents was simple but appealing: enroll in up to two years of postsecondary education, and Michigan would cover up to $5,000 in…

  16. Atomistically determined phase-field modeling of dislocation dissociation, stacking fault formation, dislocation slip, and reactions in fcc systems

    NASA Astrophysics Data System (ADS)

    Rezaei Mianroodi, Jaber; Svendsen, Bob

    2015-04-01

    The purpose of the current work is the development of a phase field model for dislocation dissociation, slip and stacking fault formation in single crystals amenable to determination via atomistic or ab initio methods in the spirit of computational material design. The current approach is based in particular on periodic microelasticity (Wang and Jin, 2001; Bulatov and Cai, 2006; Wang and Li, 2010) to model the strongly non-local elastic interaction of dislocation lines via their (residual) strain fields. These strain fields depend in turn on phase fields which are used to parameterize the energy stored in dislocation lines and stacking faults. This energy storage is modeled here with the help of the "interface" energy concept and model of Cahn and Hilliard (1958) (see also Allen and Cahn, 1979; Wang and Li, 2010). In particular, the "homogeneous" part of this energy is related to the "rigid" (i.e., purely translational) part of the displacement of atoms across the slip plane, while the "gradient" part accounts for energy storage in those regions near the slip plane where atomic displacements deviate from being rigid, e.g., in the dislocation core. Via the attendant global energy scaling, the interface energy model facilitates an atomistic determination of the entire phase field energy as an optimal approximation of the (exact) atomistic energy; no adjustable parameters remain. For simplicity, an interatomic potential and molecular statics are employed for this purpose here; alternatively, ab initio (i.e., DFT-based) methods can be used. To illustrate the current approach, it is applied to determine the phase field free energy for fcc aluminum and copper. The identified models are then applied to modeling of dislocation dissociation, stacking fault formation, glide and dislocation reactions in these materials. As well, the tensile loading of a dislocation loop is considered. In the process, the current thermodynamic picture is compared with the classical mechanical

  17. A parallel algorithm for 3D dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiang; Ghoniem, Nasr; Swaminarayan, Sriram; LeSar, Richard

    2006-12-01

    Dislocation dynamics (DD), a discrete dynamic simulation method in which dislocations are the fundamental entities, is a powerful tool for investigation of plasticity, deformation and fracture of materials at the micron length scale. However, severe computational difficulties arising from complex, long-range interactions between these curvilinear line defects limit the application of DD in the study of large-scale plastic deformation. We present here the development of a parallel algorithm for accelerated computer simulations of DD. By representing dislocations as a 3D set of dislocation particles, we show here that the problem of an interacting ensemble of dislocations can be converted to a problem of a particle ensemble, interacting with a long-range force field. A grid using binary space partitioning is constructed to keep track of node connectivity across domains. We demonstrate the computational efficiency of the parallel micro-plasticity code and discuss how O(N) methods map naturally onto the parallel data structure. Finally, we present results from applications of the parallel code to deformation in single crystal fcc metals.

  18. Irreducible Lateral Patellar Dislocation: A Case Report and Literature Review

    PubMed Central

    Grewal, Balvinder; Elliott, Devlin; Daniele, Luca; Reidy, James

    2016-01-01

    Background: Acute patellar dislocation is a common injury in young people, especially in adolescent females and athletes. Lateral dislocation is the most common form of patellar dislocation and often reduces spontaneously or with simple manipulation and closed reduction. We report a rare circumstance in which the patella was irreducible and required manipulation and closed reduction in the operating room. Case Report: While dancing, a 32-year-old female was knocked by a fellow dancer on her left knee, and she fell to the nightclub floor. She was unable to stand or bear weight because of the pain, and her knee was in fixed flexion with lateral displacement of the patella. Multiple attempts at closed reduction under sedation failed in the emergency department. Computed tomography (CT) images revealed a medial border patellar fracture and lipohemarthrosis that required closed reduction and manipulation in the operating room. The patient was placed in a Richards splint for follow-up and referred to a physiotherapist for conservative management. Conclusion: This case highlights the fact that some lateral patellar dislocations are irreducible on initial attempts, particularly if a fracture is present or another mechanism of impingement impedes relocation. CT imaging is a valuable diagnostic tool, and manipulation under anesthesia or open reduction in the operating room may be necessary. Our review of the literature further highlights the complexity and potential problems associated with treatment of locked lateral patellar dislocations. PMID:27303231

  19. Single crystal plasticity by modeling dislocation density rate behavior

    SciTech Connect

    Hansen, Benjamin L; Bronkhorst, Curt; Beyerlein, Irene; Cerreta, E. K.; Dennis-Koller, Darcie

    2010-12-23

    The goal of this work is to formulate a constitutive model for the deformation of metals over a wide range of strain rates. Damage and failure of materials frequently occurs at a variety of deformation rates within the same sample. The present state of the art in single crystal constitutive models relies on thermally-activated models which are believed to become less reliable for problems exceeding strain rates of 10{sup 4} s{sup -1}. This talk presents work in which we extend the applicability of the single crystal model to the strain rate region where dislocation drag is believed to dominate. The elastic model includes effects from volumetric change and pressure sensitive moduli. The plastic model transitions from the low-rate thermally-activated regime to the high-rate drag dominated regime. The direct use of dislocation density as a state parameter gives a measurable physical mechanism to strain hardening. Dislocation densities are separated according to type and given a systematic set of interactions rates adaptable by type. The form of the constitutive model is motivated by previously published dislocation dynamics work which articulated important behaviors unique to high-rate response in fcc systems. The proposed material model incorporates thermal coupling. The hardening model tracks the varying dislocation population with respect to each slip plane and computes the slip resistance based on those values. Comparisons can be made between the responses of single crystals and polycrystals at a variety of strain rates. The material model is fit to copper.

  20. Theoretical study of kinks on screw dislocation in silicon

    NASA Astrophysics Data System (ADS)

    Pizzagalli, L.; Pedersen, A.; Arnaldsson, A.; Jónsson, H.; Beauchamp, P.

    2008-02-01

    Theoretical calculations of the structure, formation, and migration of kinks on a nondissociated screw dislocation in silicon have been carried out using density functional theory calculations as well as calculations based on interatomic potential functions. The results show that the structure of a single kink is characterized by a narrow core and highly stretched bonds between some of the atoms. The formation energy of a single kink ranges from 0.9to1.36eV , and is of the same order as that for kinks on partial dislocations. However, the kinks migrate almost freely along the line of an undissociated dislocation unlike what is found for partial dislocations. The effect of stress has also been investigated in order to compare with previous silicon deformation experiments which have been carried out at low temperature and high stress. The energy barrier associated with the formation of a stable kink pair becomes as low as 0.65eV for an applied stress on the order of 1GPa , indicating that displacements of screw dislocations likely occur via thermally activated formation of kink pairs at room temperature.