A millimeter-wave tunneLadder TWT

NASA Technical Reports Server (NTRS)

Jacquez, A.; Karp, A.; Wilson, D.; Scott, A.

1988-01-01

A millimeter wave traveling wave tube was developed using a dispersive, high impedance forward interaction structure based on a ladder, with non-space harmonic interaction, for a tube with high gain per unit length and high efficiency. The TunneLadder interaction structure combines ladder properties modified to accommodate Pierce gun beam optics in a radially magnetized permanent magnet focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to diamond cubes which are in turn active-diffusion brazed to each ridge of a doubly ridged waveguide. Cold test data are presented, representing the omega-beta and impedance characteristics of the modified ladder circuit. These results were used in small and large signal computer programs to predict TWT gain and efficiency. Actual data from tested tubes verify the predicted performance while providing broader bandwidth than expected.

Shaping Tennessee's Career Ladder Program--1985. Part 2: Improving Teacher Quality through Incentives Project.

ERIC Educational Resources Information Center

Hadler, Janet R.; Carlson, Deborah L.

Outcomes of Tennessee's Career Ladder Program are presented in this report, with a focus on the early implementation stage and perceptions of teachers and administrators. Methodology involved two sets of interviews with participating teachers and administrators from 18 schools and a statewide survey of 1,039 out of 2,105 faculty from 54 schools.…

Development of Curriculum Content for a Unique Career Ladder Multi-Entry/Multi-Exit Nursing Program. Final Report.

ERIC Educational Resources Information Center

Rosbach, Ellen M.

A project was undertaken to develop the curriculum content for a unique career ladder multi-entry/multi-exit nursing program that would provide training for nurse aides, practical nurses, and registered nurses. The major objectives of the project were to conduct a review of the literature on curriculum materials presently in use, to develop 11…

A millimeter-wave tunneladder TWT

NASA Technical Reports Server (NTRS)

Wilson, D.

1988-01-01

A millimeter-wave traveling wave tube (TWT) was developed using a dispersive, high-impedance forward wave interaction structure based on a ladder, with non-space-harmonic interaction, for a tube with high gain per inch and high efficiency. The 'TunneLadder' interaction structure combines ladder properties modified to accommodate Pierce gun beam optics in a radially magnetized PM focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to diamond cubes which are in turn active diffusion brazed to each ridge of a doubly ridged waveguide. Cold-test data, representing the (omega)(beta) and and impedance characteristics of the modified ladder circuit, were used in small and large-signal computer programs to predict TWT gain and efficiency. The structural design emphasizes ruggedness and reliability. Actual data from tested tubes verify the predicted performance while providing broader bandwidth than expected.

Implementation of Evidence-Based Practice in Relation to a Clinical Nursing Ladder System: A National Survey in Taiwan

PubMed Central

Weng, Yi-Hao; Chen, Chiehfeng; Kuo, Ken N; Yang, Chun-Yuh; Lo, Heng-Lien; Chen, Kee-Hsin; Chiu, Ya-Wen

2015-01-01

Background Although evidence-based practice (EBP) has been widely investigated, few studies have investigated its correlation with a clinical nursing ladder system. The current national study evaluates whether EBP implementation has been incorporated into the clinical ladder system. Methods A cross-sectional questionnaire survey was conducted nationwide of registered nurses among regional hospitals of Taiwan in January to April 2011. Subjects were categorized into beginning nurses (N1 and N2) and advanced nurses (N3 and N4) by the clinical ladder system. Multivariate logistic regression model was used to adjust for possible confounding demographic factors. Results Valid postal questionnaires were collected from 4,206 nurses, including 2,028 N1, 1,595 N2, 412 N3, and 171 N4 nurses. Advanced nurses were more aware of EBP than beginning nurses (p < 0.001; 90.7% vs. 78.0%). In addition, advanced nurses were more likely to hold positive beliefs about and attitudes toward EBP (p < 0.001) and possessed more sufficient knowledge of and skills in EBP (p < 0.001). Furthermore, they more often implemented EBP principles (p < 0.001) and accessed online evidence-based retrieval databases (p < 0.001). The most common motivation for using online databases was self-learning for advanced nurses and positional promotion for beginning nurses. Multivariate logistic regression analyses showed advanced nurses were more aware of EBP, had higher knowledge and skills of EBP, and more often implemented EBP than beginning nurses. Linking Evidence to Action The awareness of, beliefs in, attitudes toward, knowledge of, skills in, and behaviors of EBP among advanced nurses were better than those among beginning nurses. The data indicate that a clinical ladder system can serve as a useful means to enhance EBP implementation. PMID:25588625

Critical thinking competence and disposition of clinical nurses in a medical center.

PubMed

Feng, Rung-Chuang; Chen, Mei-Jung; Chen, Mei-Chuan; Pai, Yu-Chu

2010-06-01

Critical thinking is essential in nursing practice. Promoting critical thinking competence in clinical nurses is an important way to improve problem solving and decision-making competence to further improve the quality of patient care. However, using an adequate tool to test nurses' critical thinking competence and disposition may provide the reference criteria for clinical nurse characterization, training planning, and resource allocation for human resource management. The purpose of this study was to measure the critical thinking competence and critical thinking disposition of clinical nurses as well as to explore the related factors of critical thinking competence. Clinical nurses from four different clinical ladders selected from one medical center were stratified randomly. All qualified subjects who submitted valid questionnaires were included in the study. A Taiwan version of the modified Watson-Glaser Critical Thinking Appraisal and Critical Thinking Disposition Inventory was developed to measure the critical thinking competence and critical thinking disposition of clinical nurses. Validity was evaluated using the professional content test (content validity index = .93). Reliability was assessed with a Cronbach's alpha coefficient of .85. Data were analyzed using the SPSS for Windows (Version 12.0; SPSS Inc., Chicago, IL). Results showed that competence of interpretation was the highest critical thinking competence factor. Inference was the lowest, and reflective thinking as a critical thinking disposition was more positive. In addition, age, years of nursing experience, and experiences in other hospitals significantly influenced critical thinking competence (p < .05). Factors of age, years of experience, and nurses clinical ladder were shown to affect critical thinking disposition scores. Clinical ladder N4 nurses had the highest scores in both competence and disposition. A significant relationship was found between critical thinking competence and disposition scores, with 29.3% of the variance in critical thinking competence potentially explained by total years of nurse hospital experience. Clinical ladder and age were predictive factors for critical thinking disposition. Commonality was 27.9%. Nursing experience and clinical ladders positively affect critical thinking competence and disposition. Issues of critical thinking competence increasingly need to be measured. Therefore, appropriate tools for nursing professions should be further developed and explored for specific areas of practice.

Teacher Attitudes toward Career Ladder.

ERIC Educational Resources Information Center

Dickson, LouAnn

An evaluation of teacher attitudes toward a public schools career ladder program is presented. Survey questionnaires mailed to 3,239 administrators, nonprogram teachers, and participating teachers elicited 1,683 returns for a 52 percent response rate. Findings indicate that the majority of teachers favored continuation of the career ladder…

Undergraduate Education: An Essential Rung on the Rehabilitation Career Ladder

ERIC Educational Resources Information Center

Evenson, Tom; Holloway, Linda

2007-01-01

This article presents the historical pertinence of undergraduate education to developing a career ladder within the field of vocational rehabilitation. Support for the relevance is presented through the results of an investigation of baccalaureate-level competence and preparation as perceived by graduates of rehabilitation services programs. Job…

Chutes and Ladders in Hepatitis C Nucleoside Drug Development§

PubMed Central

Coats, Steven J.; Garnier-Amblard, Ethel C.; Amblard, Franck; Ehteshami, Maryam; Amiralaei, Sheida; Zhang, Hongwang; Zhou, Longhu; Boucle, Sebastien R. L.; Lu, Xiao; Bondada, Lavanya; Shelton, Jadd R.; Li, Hao; Liu, Peng; Li, Chengwei; Cho, Jong Hyun; Chavre, Satish N.; Zhou, Shaoman; Mathew, Judy; Schinazi, Raymond F.

2014-01-01

Chutes and Ladders is an exciting up-and-down-again game in which players race to be the first to the top of the board. Along the way, they will find ladders to help them advance, and chutes that will cause them to move backwards. The development of nucleoside analogs for clinical treatment of hepatitis C presents a similar scenario in which taking shortcuts may help quickly advance a program, but there is always a tremendous risk of being sent backwards as one competes for the finish line. In recent years the treatment options for chronic hepatitis C virus (HCV) infection have expand due to the development of a replicon based in vitro evaluation system, allowing for the identification of multiple drugable viral targets along with a concerted and substantial drug discovery effort. Three major drug targets have reached clinical study for chronic HCV infection: the NS3/4A serine protease, the large phosphoprotein NS5A, and the NS5B RNA-dependent RNA polymerase. Recently, two oral HCV protease inhibitors were approved by the FDA and were the first direct acting anti-HCV agents to result from the substantial research in this area. There are currently many new chemical entities from several different target classes that are being evaluated worldwide in clinical trials for their effectiveness at achieving a sustained virologic response (SVR) (Pham et al., 2004; Radkowski et al., 2005). Clearly the goal is to develop therapies leading to a cure that are safe, widely accessible and available, and effective against all HCV genotypes (GT), and all stages of the disease. Nucleoside analogs that target the HCV NS5B polymerase that have reached human clinical trials is the focus of this review as they have demonstrated significant advantages in the clinic with broader activity against the various HCV GT and a higher barrier to the development of resistant viruses when compared to all other classes of HCV inhibitors. PMID:24275341

Development of a 39.5 GHz Karp traveling wave tube for use in space

NASA Technical Reports Server (NTRS)

Jacquez, A.; Wilson, D.

1988-01-01

A millimeter-wave TWT was developed using a dispersive, high-impedance forward wave interaction structure based on a ladder, with non-space-harmonic interaction, for a tube with high gain per inch and high efficiency. The 'Tunneladder' interaction structure combines ladder properties modified to accommodate Pierce gun beam optics on a radially magnetized PM focusing structure. The development involved the fabrication of chemically milled, shaped ladders diffusion brazed to each ridge of a double ridged waveguide. Cold-test data are presented, representing the omega-Beta and impedance characteristics of the modified ladder circuit These results were used in small and large-signal computer programs to predict TWT gain and efficiency. A laboratory model tube was designed and fabricated, including all major subassemblies.

Development and validation of a nursing professionalism evaluation model in a career ladder system.

PubMed

Kim, Yeon Hee; Jung, Young Sun; Min, Ja; Song, Eun Young; Ok, Jung Hui; Lim, Changwon; Kim, Kyunghee; Kim, Ji-Su

2017-01-01

The clinical ladder system categorizes the degree of nursing professionalism and rewards and is an important human resource tool for managing nursing. We developed a model to evaluate nursing professionalism, which determines the clinical ladder system levels, and verified its validity. Data were collected using a clinical competence tool developed in this study, and existing methods such as the nursing professionalism evaluation tool, peer reviews, and face-to-face interviews to evaluate promotions and verify the presented content in a medical institution. Reliability and convergent and discriminant validity of the clinical competence evaluation tool were verified using SmartPLS software. The validity of the model for evaluating overall nursing professionalism was also analyzed. Clinical competence was determined by five dimensions of nursing practice: scientific, technical, ethical, aesthetic, and existential. The structural model explained 66% of the variance. Clinical competence scales, peer reviews, and face-to-face interviews directly determined nursing professionalism levels. The evaluation system can be used for evaluating nurses' professionalism in actual medical institutions from a nursing practice perspective. A conceptual framework for establishing a human resources management system for nurses and a tool for evaluating nursing professionalism at medical institutions is provided.

South Dakota Statewide Core Curriculum, Career Ladder, and Challenge System. A Case History.

ERIC Educational Resources Information Center

Brekke, Donald G.; Gildseth, Wayne M.

The South Dakota Core Curriculum Project involving the career ladder approach to health manpower training, which began in 1970, had seven objectives including the following: (1) To organize a Health Manpower Council for the entire State; (2) to define the areas of basic commonality among the various training programs; and (3) to develop a core…

The power of engagement: implementation of a career ladder program.

PubMed

Bourgeault, Robert; Newmark, Jason

2012-01-01

At Baystate Health in Massachusetts, the development and implementation of a career ladder program was implemented to reduce turnover and to improve employee satisfaction, morale, and recruitment efforts. There was significant initial expenditure in the program, as a result of promoting the large number of employees with significant experience and seniority. A smaller number of staff are expected to apply for advancement during successive cycles, allowing for decreased incremental expense going forward. Critical to the success of the program was understanding the time commitment, getting senior organizational support and staff buy-in, and justifying the associated expenses. The development and initiation of the program has done much to support a positive work environment with increased morale and higher performance among significant numbers of staff at all levels.

Career Ladders and Teacher Incentives: The Utah Experiment. Part I: The Implementation. Final Report: Secretary's Discretionary Program Implementation Grant to Develop Teacher Incentive Structures.

ERIC Educational Resources Information Center

Peterson, Ken; Kauchak, Don

This volume, the first of two reports on development of teacher incentive structures, focuses on implementation of a career ladder design and teacher evaluation experiment in four Utah school districts. The report has five sections. Section 1 describes study background and implementation of an evaluation-reward system that featured data collection…

Hood River Production Master Plan.

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Toole, Patty

1991-07-01

The Northwest Power Planning Council's 1987 Columbia River Fish and Wildlife Program authorizes the development of artificial production facilities to raise chinook salmon and steelhead for enhancement in the Hood, Umatilla, Walla Walla, Grande Ronde and Imnaha rivers and elsewhere. On February 26, 1991 the Council agreed to disaggregate Hood River from the Northeast Oregon Hatchery Project, and instead, link the Hood River Master Plan (now the Hood River Production Plan) to the Pelton Ladder Project (Pelton Ladder Master Plan 1991).

Educating Medical Laboratory Technologists: Revisiting Our Assumptions in the Current Economic and Health-Care Environment

PubMed Central

Linder, Regina

2012-01-01

Health care occupies a distinct niche in an economy struggling to recover from recession. Professions related to the care of patients are thought to be relatively resistant to downturns, and thus become attractive to students typically drawn to more lucrative pursuits. Currently, a higher profile for clinical laboratory technology among college students and those considering career change results in larger and better prepared applicant pools. However, after decades of contraction marked by closing of programs, prospective students encounter an educational system without the capacity or vigor to meet their needs. Here discussed are some principles and proposals to allow universities, partnering with health-care providers, government agencies, and other stake-holders to develop new programs, or reenergize existing ones to serve our students and patients. Principles include academic rigor in biomedical and clinical science, multiple points of entry for students, flexibility in format, cost effectiveness, career ladders and robust partnerships. PMID:23653802

Building blocks for career advancement.

PubMed

Broomall, Thomas; Snyder, Bruce

2007-01-01

After attaining IAHSS certification, protective services officers at CCHMC continue on a Career Ladder Program designed to improve knowledge and performance and improve the chances of officer retention. That program is described in detail in this article.

The Charlotte-Mecklenburg Teacher Career Development Program.

ERIC Educational Resources Information Center

Schlechty, Phillip C.; And Others

1985-01-01

Effective training, evaluation, and incentives are key aspects of this school system's six-level career ladder program for teacher development. The three-pronged committee structure for planning and communication and the program's ownership by everyone involved have been vital to its successful planning and development. (DCS)

Howard University program for radiotherapeutic technology.

PubMed

Tabron, M J

1975-01-01

The Howard University program for radiotherapeutic technology provides for a career ladder with steps of two years. After the first two years everyone must take and pass examination in radiotherapeutic technology given by The American Registry of Radiologic Technologists. The candidate then can proceed with two years of university courses to a Bachelor of Science degree. Depending upon his interest, he can emphasize business, education, or science. The latter would qualify him for application medical school. The core of the curriculum for the first two years consists of clinical work in the radiotherapy department every morning and of two integrated multidisciplinary courses in the afternoon, namely, life sciences (anatomy, physiology, pathology and oncology) and natural sciences (mathematics, physics, radiation physics and treatment planning).

Strength Analysis on Ship Ladder Using Finite Element Method

NASA Astrophysics Data System (ADS)

Budianto; Wahyudi, M. T.; Dinata, U.; Ruddianto; Eko P., M. M.

2018-01-01

In designing the ship’s structure, it should refer to the rules in accordance with applicable classification standards. In this case, designing Ladder (Staircase) on a Ferry Ship which is set up, it must be reviewed based on the loads during ship operations, either during sailing or at port operations. The classification rules in ship design refer to the calculation of the structure components described in Classification calculation method and can be analysed using the Finite Element Method. Classification Regulations used in the design of Ferry Ships used BKI (Bureau of Classification Indonesia). So the rules for the provision of material composition in the mechanical properties of the material should refer to the classification of the used vessel. The analysis in this structure used program structure packages based on Finite Element Method. By using structural analysis on Ladder (Ladder), it obtained strength and simulation structure that can withstand load 140 kg both in static condition, dynamic, and impact. Therefore, the result of the analysis included values of safety factors in the ship is to keep the structure safe but the strength of the structure is not excessive.

Standard specification for light ladders

NASA Astrophysics Data System (ADS)

1980-11-01

Requirements are given for the construction, inspection, and testing of single ladders, extension ladders, step-ladders, extending step-ladders, trestle ladders, extending trestle ladders, and special purpose ladders. The composition of the aluminum alloys, and of the steels and glass fiber reinforced polyester components coming into contact with the aluminum are included. Coatings used to provide corrosion resistance are also specified.

The Pathway Program: How a Collaborative, Distributed Learning Program Showed Us the Future of Social Work Education

ERIC Educational Resources Information Center

Morris, Teresa; Mathias, Christine; Swartz, Ronnie; Jones, Celeste A; Klungtvet-Morano, Meka

2013-01-01

This paper describes a three-campus collaborative, distributed learning program that delivers social work education to remote rural and desert communities in California via distance learning modalities. This "Pathway Program" provides accredited social work education for a career ladder beginning with advising and developing an academic…

Clinical laboratory technician to clinical laboratory scientist articulation and distance learning.

PubMed

Crowley, J R; Laurich, G A; Mobley, R C; Arnette, A H; Shaikh, A H; Martin, S M

1999-01-01

Laboratory workers and educators alike are challenged to support access to education that is current and provides opportunities for career advancement in the work place. The clinical laboratory science (CLS) program at the Medical College of Georgia in Augusta developed a clinical laboratory technician (CLT) to CLS articulation option, expanded it through distance learning, and integrated computer based learning technology into the educational process over a four year period to address technician needs for access to education. Both positive and negative outcomes were realized through these efforts. Twenty-seven students entered the pilot articulation program, graduated, and took a CLS certification examination. Measured in terms of CLS certification, promotions, pay raises, and career advancement, the program described was a success. However, major problems were encountered related to the use of unfamiliar communication technology; administration of the program at distance sites; communication between educational institutions, students, and employers; and competition with CLT programs for internship sites. These problems must be addressed in future efforts to provide a successful distance learning program. Effective methods for meeting educational needs and career ladder expectations of CLTs and their employers are important to the overall quality and appeal of the profession. Educational technology that includes computer-aided instruction, multimedia, and telecommunications can provide powerful tools for education in general and CLT articulation in particular. Careful preparation and vigilant attention to reliable delivery methods as well as students' progress and outcomes is critical for an efficient, economically feasible, and educationally sound program.

Creating a Professional Ladder for Interpreters for Improvement of Care.

PubMed

Marshall, Lori; Fischer, Anna; Noyes Soeller, Allison; Cordova, Richard; Gutierrez, Yvonne R; Alford, Luis

2016-01-01

Children's Hospital Los Angeles (CHLA), a metropolitan academic medical center, recognized limitations in how the professional interpreters from the Diversity Services Department were used to support effective patient-provider communication across the organization. Given the importance of mitigating language and communication barriers, CHLA sought to minimize clinical and structural barriers to health care for limited English proficiency populations through a comprehensive restructuring of the Diversity Services Department. This approach entailed a new delivery model for hospital language assistance and cultural consultancy resources. The intervention focused on restructuring the Diversity Services Department, redefining priorities, reallocating resources, and redefining the roles of the language staff positions in the department. The language staff role was redesigned to fit a four-level professional career ladder modeled after the professional career ladders commonly used in hospitals for the RN role and other professional disciplines. The approach involved creating new levels of language specialist, each with progressive requirements for performance, leadership, and accountability for patient care outcomes. Language staff in the inpatient, clinic, and emergency department settings worked alongside nurses, physicians, and other disciplines to care for a specific set of patients. The result of this work was a positive culture change resulting in service efficiencies, care improvements, and improved access to language services. A professional career ladder for language staff contributed to improving the quality and access of language services and advancing the interpreting profession by incorporating care coordination support, vital document translation, and cultural consultancy.

Administration and Stenographic Career Ladders, AFS 702x0/A/B/C and 702X1.

DTIC Science & Technology

1980-04-01

MEN mIIIIIIIII hhhllllhlhhl UNITED STATES AIR FORCE _Si -j𔃽.- 0 ADMINISTRATION AND5$TENOGRAPHIC -CAREER LADDERS AIS 702XO/ A /B/C AND 702X1 -J AFPT- 9...7J2-389 ( ,/ " ’ _ LA. -IAPRI 180 This document has n a :’.-pro+ved1 + ,for pil s’ s ;i - , OqCUPATIONAL ANALYSIS PROGRAM USAF OCCUPATIONAL...79 APPENDIX A O--------------------------------------------- 80 Acc22~C~For 1 -* ii L PREFACE This report presents the results of a detailed Air

Leadership behaviors of frontline staff nurses.

PubMed

Fardellone, Christine; Musil, Carol M; Smith, Elaine; Click, Elizabeth R

2014-11-01

A recommendation in the Institute of Medicine's report, The Future of Nursing: Leading Change, Advancing Health, challenges the nursing profession to enhance nursing's leadership role in health care redesign. This descriptive, correlational, cross-sectional study examined the self-perceived leadership behaviors of RNs enrolled in a clinical ladder career pathway. A self-report survey was conducted using the Leadership Practice Inventory and a demographic questionnaire. Significant associations between continuous and categorical demographic factors and ladder levels were reported. Nurses with more experience showed fewer leadership behaviors. Leadership development is necessary for nurses in all areas of practice. The findings from this study provide evidence of the strengths and weaknesses in leadership behaviors of staff clinical RNs who often make frontline decisions for patients. Copyright 2014, SLACK Incorporated.

Attrition of Hmong Students in Teacher Education Programs.

ERIC Educational Resources Information Center

Root, Steven; Rudawski, Anthony; Taylor, Matthew; Rochon, Ronald

2003-01-01

A descriptive study addressed student attrition in two Title VII Bilingual Education Career Ladder Programs for Hmong paraprofessionals and traditional-age college students working toward teacher certification in Wisconsin. Surveys showed that dropouts were disproportionately male and nontraditional students; factors included financial problems,…

29 CFR 1917.119 - Portable ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Requirements for Portable Reinforced Plastic Ladders (d) Standards for job-made portable ladders. Job-made... usage. (1) Ladders made by fastening rungs or devices across a single rail are prohibited. (2) Ladders...

Facilitation Skills: The Catalyst for Increased Effectiveness in Consultant Practice and Clinical Systems Leadership

ERIC Educational Resources Information Center

Manley, Kim; Titchen, Angie

2017-01-01

Consultant practitioner is the pinnacle of the clinical career ladder for all health care disciplines in the United Kingdom. Consultant nurse, midwife and health visitor roles build on the clinical credibility and expertise characteristic of advanced level practice, but also possess expertise in: clinical systems leadership and the facilitation of…

29 CFR 1918.23 - Jacob's ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ladder. (d) When a Jacob's ladder is being used so that there is a danger of an employee falling or being... ladders. (a) Jacob's ladders shall be of the double rung or flat tread type. They shall be well maintained... pulled up entirely. (c) When a Jacob's ladder is used as the means of access to a barge being worked...

Hood River and Pelton Ladder Evaluation Studies : Annual Report 1994.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olsen, Erik A.; French, Rod A.; Ritchey, Alan D.

1995-09-01

In 1992, the Northwest Power Planning Council approved the Hood River and Pelton ladder master plans within the framework of the Columbia River Basin Fish and Wildlife Program. The master plans define an approach for implementing a hatchery supplementation program in the Hood River subbasin. The hatchery program as defined in the master plans is called the Hood River Hatchery Production Program (HRPP). The HRPP will be phased in over several years and will be jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Warm Springs (CTWS) Reservation. In December 1991, amore » monitoring and evaluation program was implemented in the Hood River subbasin to collect life history and production information on stocks of anadromous salmonids returning to the Hood River subbasin. The program was implemented to provide the baseline information needed to: (1) evaluate various management options for implementing the HRPP and (2) determine any post-project impacts the HRPP has on indigenous populations of resident fish. Information collected during the 1992-94 fiscal years will also be used to prepare an environmental impact statement (EIS) evaluating the program`s impact on the human environment. To begin construction on project facilities, it was proposed that the HRPP be implemented in two phases. Phase I would include work that would fall under a {open_quotes}categorical exclusion{close_quotes} from NEPA, and Phase II would include work requiring an EIS prior to implementation. This report summarizes the life history and escapement data collected in the Hood River subbasin and the status work of implemented under Phase I of the HR Life history and escapement data will be used to: (1) test the assumptions on which harvest and escapement goals for the Hood River and Pelton ladder master plans are based and (2) develop biologically based management recommendations for implementing the HRPP.« less

A Touch of...Class!

ERIC Educational Resources Information Center

Tweedie, Karen, Ed.

1987-01-01

Games for use in the second-language classroom are suggested, including variations on tic-tac-toe and snakes and ladders, races, board games based on American television programs, math activities, and a classroom mystery. (MSE)

29 CFR 1917.118 - Fixed ladders.

Code of Federal Regulations, 2014 CFR

2014-07-01

... tubular scaffold framing; and (4) Ladders used only for fire-fighting or emergency purposes. (b... a ladder, including individual rung ladders, permanently attached to a structure, building or piece... walls of the well. (c) Defects. (1) Ladders with broken, split or missing rungs, steps or rails, broken...

29 CFR 1917.118 - Fixed ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

... tubular scaffold framing; and (4) Ladders used only for fire-fighting or emergency purposes. (b... a ladder, including individual rung ladders, permanently attached to a structure, building or piece... walls of the well. (c) Defects. (1) Ladders with broken, split or missing rungs, steps or rails, broken...

29 CFR 1917.118 - Fixed ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

... tubular scaffold framing; and (4) Ladders used only for fire-fighting or emergency purposes. (b... a ladder, including individual rung ladders, permanently attached to a structure, building or piece... walls of the well. (c) Defects. (1) Ladders with broken, split or missing rungs, steps or rails, broken...

Effects of foot placement, hand positioning, age and climbing biodynamics on ladder slip outcomes.

PubMed

Pliner, Erika M; Campbell-Kyureghyan, Naira H; Beschorner, Kurt E

2014-01-01

Ladder falls frequently cause severe injuries; yet the factors that influence ladder slips/falls are not well understood. This study aimed to quantify (1) the effects of restricted foot placement, hand positioning, climbing direction and age on slip outcomes, and (2) differences in climbing styles leading to slips versus styles leading to non-slips. Thirty-two occupational ladder users from three age groups (18-24, 25-44 and 45-64 years) were unexpectedly slipped climbing a vertical ladder, while being assigned to different foot placement conditions (unrestricted vs. restricted toe clearance) and different hand positions (rails vs. rungs). Constraining foot placement increased the climber's likelihood of slipping (p < 0.01), while younger and older participants slipped more than the middle-aged group (p < 0.01). Longer double stance time, dissimilar and more variable foot and body positioning were found in styles leading to a slip. Maintaining sufficient toe clearance and targeting ladder safety training to younger and older workers may reduce ladder falls. Practitioner Summary: Ladder falls frequently cause severe occupational fall injuries. This study aims to identify safer ladder climbing techniques and individuals at risk of falling. The results suggest that ladders with unrestricted toe clearance and ladder climbing training programmes, particularly for younger and older workers, may reduce ladder slipping risk.

A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

USGS Publications Warehouse

Welsh, Stuart A.; Aldinger, Joni L.

2014-01-01

Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

Ladder Safety Live #12985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chochoms, Michael

2017-02-23

This course presents information for working safely with portable ladders: specifically, stepladders, extensions ladders, and their derivations. Additionally, this course provides limited information on the safe use of stepstools and fixed ladders. The skills, techniques, and good practices needed for selecting, inspecting, setting up and securing, and using ladders are presented in this course.

Ladder polymers for use as high temperature stable resins or coatings

NASA Technical Reports Server (NTRS)

Meador, Mary Ann (Inventor)

1990-01-01

An object of the invention is to synthesize a new class of ladder and partial ladder polymers. In accordance with the invention, the new class of ladder and partial ladder polymers are synthesized by polymerizing a bis-dienophile with a bis-diene. Another object of the invention is to provide a fabricated, electrically conducting, void free composite comprising the new class of the ladder and partial ladder polymers described above. The novelty of the invention relates to a new class of ladder and partial ladder polymers and a process for synthesizing these polymers. These polymers are soluble in common organic solvents and are characterized with a unique dehydration property at temperatures of 300 to 400 C to provide thermo-oxidatively stable pentiptycene units along the polymeric backbone. These polymers are further characterized with high softening points and good thermo-oxidative stability properties. Thus these polymers have potential as processable, matrix resins for high temperature composite applications.

Lessons in Leadership: Executive Leadership Programs for Advancing Diversity in Higher Education. Diversity in Higher Education. Volume 5

ERIC Educational Resources Information Center

Leon, David, Ed.

2005-01-01

A largely unseen phenomenon is shaping the direction of higher education today: the growth of leadership programs. These programs are hidden ladders that help the talented move up toward university presidencies. Their number and importance are rapidly increasing, and they will more and more determine who makes decisions in higher education. More…

29 CFR 1917.119 - Portable ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.119 Portable ladders. (a) Scope and applicability... Requirements for Portable Reinforced Plastic Ladders (d) Standards for job-made portable ladders. Job-made...

Pruritus: Management Algorithms and Experimental Therapies

PubMed Central

Steinhoff, Martin; Cevikbas, Ferda; Ikoma, Akihiko; Berger, Timothy G.

2013-01-01

Pruritus (itch) is a major symptom in many dermatologic as well as systemic diseases and has a dramatic impact on the quality of life in these patients. The symptom of itch has to be treated on the basis of its pathophysiology and its underlying disease. In daily practice, a “quick” diagnosis of the underlying disease is often difficult, although a rapid relief of the itch is desired. We often treat patients on the basis of the symptomatology. A rational therapeutic ladder for a symptomatic therapy is useful until the final diagnosis has been confirmed. There are probably many subtypes of pruritus, just as there are many diseases that cause itch. The pathophysiology in many subtypes of pruritus is still poorly understood, hindering a rapid and targeted treatment strategy. An extensive diagnostic workup is often required to determine the final cause(s) of the itch. Thus, in daily life, physicians often start with a more or less rational therapeutic strategy to combat the debilitating itch. We present possible therapeutic ladders that form the basis for effective therapeutic itch strategies in various diseases. On the basis of our current knowledge about the different pathophysiologies of itch, on clinical trials or case reports, and our own clinical experience, we aim to present therapeutic ladders for the rapid as well as long-term management of itch. Finally, we summarize current exciting developments of experimental strategies in itch research and in clinical development for itch therapy. PMID:21767775

A High Efficiency, Miniaturized Ka Band Traveling Wave Tube Based on a Novel Finned Ladder RF Circuit Design

NASA Technical Reports Server (NTRS)

Wintucky, E. G.; Wilson, J. D.; Vaden, K. R.; Force, D. A.; Freeman, J. C.; Lesny, G. G.; Kory, C. L.; Chevalier, C. T.; Ebihara, B.; Dayton, J. A.;

Work-related ladder fall fractures: identification and diagnosis validation using narrative text.

PubMed

Smith, Gordon S; Timmons, Robert A; Lombardi, David A; Mamidi, Dheeresh K; Matz, Simon; Courtney, Theodore K; Perry, Melissa J

2006-09-01

To identify ladder-related fracture injuries and determine how ladder fall fractures differ from other ladder-related injuries. Ladder-related fracture cases were identified using narrative text and coded data from workers' compensation claims. Potential cases were identified by text searches and verified with claim records. Injury characteristics were compared using proportionate injury ratios. Of 9826 ladder-related injuries, 7% resulted in fracture cases. Falls caused 89% of fractures and resulted in more medical costs and disability days than other injuries. Frequent mechanisms were ladder instability (22%) and lost footing (22%). Narrative text searches identified 17% more fractures than injury codes alone. Males were more likely to sustain a fall fracture than other injuries; construction workers were most likely, and retail workers were the least likely to sustain fractures. Fractures are an important injury from ladder falls, resulting more serious consequences than other ladder-related injuries. Text analysis can improve the quality and utility of workers compensation data by identifying and understanding injury causes. Proportionate injury ratios are also useful for making cross-group comparisons of injury experience when denominator data are not available. Greater attention to risk factors for ladder falls is needed for targeting interventions.

The Causes and Costs of Promotion Trauma.

ERIC Educational Resources Information Center

Darling, Lu Ann W.; McGrath, Loraine G.

1983-01-01

Minimizing the stress that nurses experience after a promotion requires an understanding of the factors associated with moving up the managerial ladder. Knowing these factors, nursing administrators can plan their programs to support their managers in transition. (SSH)

46 CFR 108.160 - Vertical ladders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Construction and Arrangement Means of Escape § 108.160 Vertical ladders. (a) Each vertical ladder must have... vertical fixed ladders may be made of wood. [CGD 73-251, 43 FR 56808, Dec. 4, 1978, as amended by USCG-2002...

California School Paraprofessional Teacher Training Program. An Annual Report to the Legislature as Required by SB 1636 (Chap. 1444, Stats. 1990)

ERIC Educational Resources Information Center

California Commission on Teacher Credentialing, 2015

2015-01-01

The primary purpose of the California School Paraprofessional Teacher Training Program (PTTP) was to create local career ladders that enable school paraprofessionals--including teacher assistants, library-media aides, and instructional assistants--to become certificated classroom teachers in K-12 public schools. This pathway to teaching program…

The College Ladder: Linking Secondary and Postsecondary Education for Success for All Students

ERIC Educational Resources Information Center

Lerner, Jennifer Brown; Brand, Betsy

2006-01-01

This compendium identifies and describes schools, programs, and policies that link secondary and postsecondary education to help students earn college credit or take college-level courses while in high school. It raises issues for practitioners and policymakers to consider as these program grow and target a wider range of students. This compendium…

Insider's Guide to Community College Administration.

ERIC Educational Resources Information Center

Jensen, Robert; Giles, Ray; Kirklin, Pat

This book offers advice on the skills and attitudes needed to succeed as a community college leader. As one begins to move up the organizational ladder from program director or assistant dean to dean or vice president, the sphere of influence expands dramatically. There is a greater need to be able to see how programs and decisions affect the…

Ladders to Success: Enhancing Transfer from Technical Associate in Science Degrees to Baccalaureates. AIR 1999 Annual Forum Paper.

ERIC Educational Resources Information Center

Pitter, Gita Wijesinghe

This paper describes the collaborative activities which have developed since 1998 Florida legislation that required stronger articulation between Associate in Science (AS) programs at state community colleges and baccalaureate programs at universities. Three major models of AS to baccalaureate articulation are evaluated: (1) a statewide career…

AACJC/Metropolitan Life Foundation Registered Nurse Shortage Project: Final Report.

ERIC Educational Resources Information Center

Hawaii Univ., Lihue. Kauai Community Coll.

In an effort to increase the number of graduating Kauai High School (KHS) seniors prepared to enter the Kauai Community College (KCC) Career Ladder Nursing Program, a special 2 + 2 program was initiated involving college/high school curriculum articulation, academic and career counseling, and early admission to KCC. At the outset of the project,…

Phonon and magnon dispersions of incommensurate spin ladder compound Sr14Cu24O41

NASA Astrophysics Data System (ADS)

Chen, Xi; Bansal, Dipanshu; Sullivan, Sean; Zhou, Jianshi; Delaire, Olivier; Shi, Li

There are a variety of compounds consisting of two or more interpenetrating sublattices with lattice periods incommensurate at least along one crystal axis. One example is spin ladder compound Sr14Cu24O41 consisting of incommensurate spin ladder and spin chain sublattices. It has been predicted that unique phonon modes occur in these compounds due to the relative motion of the sublattices. In the low-wavelength limit, there is only one longitudinal acoustic mode due to the rigid translation of both sublattices. In addition, one extra pseudo-acoustic mode is present due to relative sliding motions of the two sublattices. Although the theoretical aspects of the lattice dynamics of incommensurate compounds have been studied, there have been few experimental investigations on their phonon dynamics. In this work, single crystals of Sr14Cu24O41are grown by the traveling solvent floating zone method. The phonon dispersion of Sr14Cu24O41 is studied through inelastic neutron scattering measurements in order to better understand its phonon dynamics. In addition, its magnon dispersion is investigated and correlated to the large directional magnon thermal conductivity. The measurements reveal a wealth of intriguing features on phonons and magnons in the spin ladder compound. This work is supported by ARO MURI program under Award # W911NF-14-1-0016.

30 CFR 56.11006 - Fixed ladder landings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fixed ladder landings. 56.11006 Section 56....11006 Fixed ladder landings. Fixed ladders shall project at least 3 feet above landings, or subtantial handholds shall be provided above the landings. ...

30 CFR 56.11006 - Fixed ladder landings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fixed ladder landings. 56.11006 Section 56....11006 Fixed ladder landings. Fixed ladders shall project at least 3 feet above landings, or subtantial handholds shall be provided above the landings. ...

29 CFR 1910.25 - Portable wood ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.25 Portable wood ladders. (a... safety under normal conditions of usage. Other types of special ladders, fruitpicker's ladders...

Plumbing Career Ladder AFSC 552X5 and Occupational Series WG-4206.

DTIC Science & Technology

1987-12-01

41 APPENDIX A ........................................................... 42 APPENDIX C ...43 Jl APPENDIX C ............................................................ o. PREFACE This report...instrument was developed by 14r William C . Cosgrove, Inventory Development Specialist, with computer programming support furnished by Ms Rebecca Hernandez

Multimode and multistate ladder oscillator and frequency recognition device

NASA Technical Reports Server (NTRS)

Aumann, Herbert M. (Inventor)

1976-01-01

A ladder oscillator composed of capacitive and inductive impedances connected together to form a ladder network which has a chosen number N oscillation modes at N different frequencies. Each oscillation mode is characterized by a unique standing wave voltage pattern along the nodes of the ladder oscillator, with the mode in which the ladder oscillator is oscillating being determinable from the amplitudes or phase of the oscillations at the nodes. A logic circuit may be connected to the nodes of the oscillator to compare the phases of selected nodes and thereby determine which mode the oscillator is oscillating in. A ladder oscillator composed of passive capacitive and inductive impedances can be utilized as a frequency recognition device, since the passive ladder oscillator will display the characteristic standing wave patterns if an input signal impressed upon the ladder oscillator is close to one of the mode frequencies of the oscillator. A CL ladder oscillator having series capacitive impedances and shunt inductive impedances can exhibit sustained and autonomous oscillations if active nonlinear devices are connected in parallel with the shunt inductive impedances. The active CL ladder oscillator can be synchronized to input frequencies impressed upon the oscillator, and will continue to oscillate after the input signal has been removed at a mode frequency which is, in general, nearest to the input signal frequency. Autonomous oscillations may also be obtained as desired from the active CL ladder oscillator at the mode frequencies.

Creating Career Ladders in University Systems: The Accelerated Associate's Degree Program for Unemployed Licensed Nurses at the Inter-American University of Puerto Rico.

ERIC Educational Resources Information Center

Melendez, Edwin; Suarez, Carlos

This document describes the Accelerated Associate's Degree Program for Licensed Practical Nurses (LPN) at the Inter-American University of Puerto Rico. The program, targeting unemployed LPNs living in San Juan, Puerto Rico, allows students to complete an associate's degree in one year. Fifty-four students enrolled during the first year and 50% of…

Puerto Rico Experimental Model Dental Auxiliary Training Program. The Comprehensive Report, October 22, 1976-February 24, 1980.

ERIC Educational Resources Information Center

Puerto Rico Univ., San Juan. School of Dentistry.

The Dental Auxiliary Department of the University of Puerto Rico designed a career option dental auxiliary training program which is a step ladder program with three exit points over a period of two academic years. The first option is a six-month track to train a traditional chairside dental auxiliary. The second option is a nine-month track to…

Developing a career advancement program.

PubMed

Pinette, Shirley L

2003-01-01

Have you ever asked yourself, "What will I be doing five or ten years from now?" "Will I be doing the same thing I'm doing right now?" How would you feel if the answer were "yes"? I often wonder if any of my employees think the same thing. If they do, and the answer is "yes," just how does that make them feel? A day's work for managers can run the gamut--from billing and coding, to patient issues, to staff performance reviews, to CQI, to JCAHO-just to name a few. We're NEVER bored. Can we say the same of our employees, or do they do the same thing day in and day out? If so, it's no wonder that attitudes may become negative and motivation and productivity may decline. What are we as healthcare managers and administrators doing to value and continually train our employees so that staff morale, productivity and patient satisfaction remain high? What are we doing to keep those highly motivated employees motivated and challenged so that they don't get bored and want to move across town to our neighboring hospital or healthcare center? What are we doing to stop our employees from developing the "same job, different day" attitude? A Career Ladder program holds many benefits and opportunities for the motivated employee who seeks and needs additional challenges on the job. It affords them opportunities to learn new skills, demonstrate initiative, accept additional responsibilities and possibly advance into new positions. It also affords them opportunities to grow, to be challenged and to feel like an important and valued member of the radiology team and radiology department. For the manager, a Career Ladder program affords opportunities to retain valuable employees, attract new high-quality employees and maintain a workforce of well-trained highly motivated employees, which in turn will provide high quality products and services to our customers. A Career Ladder program is a "win-win" situation for everyone. For the last twelve months, I have been working with other managers in the department of diagnostic imaging at Yale-New Haven Hospital in New Haven, Conn., to develop a Career Ladder for all diagnostic imaging staff members, called the Career Advancement Program (CAP). The process has been time consuming and has required intense discussion and debate. The draft plan is for one CAP with multiple tracks to be used by all staff, both technical and support. A copy of the draft plan is included in this article.

30 CFR 57.11006 - Fixed ladder landings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fixed ladder landings. 57.11006 Section 57... Escapeways Travelways-Surface and Underground § 57.11006 Fixed ladder landings. Fixed ladders shall project at least 3 feet above landings, or substantial handholds shall be provided above the landings. ...

30 CFR 57.11006 - Fixed ladder landings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fixed ladder landings. 57.11006 Section 57... Escapeways Travelways-Surface and Underground § 57.11006 Fixed ladder landings. Fixed ladders shall project at least 3 feet above landings, or substantial handholds shall be provided above the landings. ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

46 CFR 108.167 - Weather deck ladders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Weather deck ladders. 108.167 Section 108.167 Shipping... EQUIPMENT Construction and Arrangement Means of Escape § 108.167 Weather deck ladders. Each unit must have at least one permanent, inclined ladder between each weather deck. Classified Locations ...

29 CFR 1910.25 - Portable wood ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 5 2013-07-01 2013-07-01 false Portable wood ladders. 1910.25 Section 1910.25 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.25 Portable wood ladders. (a... for the construction, care, and use of the common types of portable wood ladders, in order to insure...

29 CFR 1910.25 - Portable wood ladders.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 5 2014-07-01 2014-07-01 false Portable wood ladders. 1910.25 Section 1910.25 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.25 Portable wood ladders. (a... for the construction, care, and use of the common types of portable wood ladders, in order to insure...

30 CFR 56.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fixed ladder anchorage and toe clearance. 56.11005 Section 56.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Travelways § 56.11005 Fixed ladder anchorage and toe clearance. Fixed ladders shall be anchored securely and...

30 CFR 56.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fixed ladder anchorage and toe clearance. 56.11005 Section 56.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Travelways § 56.11005 Fixed ladder anchorage and toe clearance. Fixed ladders shall be anchored securely and...

30 CFR 56.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fixed ladder anchorage and toe clearance. 56.11005 Section 56.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Travelways § 56.11005 Fixed ladder anchorage and toe clearance. Fixed ladders shall be anchored securely and...

30 CFR 56.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fixed ladder anchorage and toe clearance. 56.11005 Section 56.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Travelways § 56.11005 Fixed ladder anchorage and toe clearance. Fixed ladders shall be anchored securely and...

30 CFR 56.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fixed ladder anchorage and toe clearance. 56.11005 Section 56.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Travelways § 56.11005 Fixed ladder anchorage and toe clearance. Fixed ladders shall be anchored securely and...

29 CFR 1915.72 - Ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

...). (b) Construction of portable wood cleated ladders up to 30 feet in length. (1) Wood side rails shall... shall be at least 25/32×33/4 inches in cross section. (c) Construction of portable wood cleated ladders... split side rails, or other faulty or defective construction is prohibited. When ladders with such...

46 CFR 190.10-15 - Vertical ladders not accepted.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Vertical ladders not accepted. 190.10-15 Section 190.10-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-15 Vertical ladders not accepted. (a) Vertical ladders...

5 CFR 335.104 - Eligibility for career ladder promotion.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Eligibility for career ladder promotion... REGULATIONS PROMOTION AND INTERNAL PLACEMENT General Provisions § 335.104 Eligibility for career ladder promotion. No employee shall receive a career ladder promotion unless his or her current rating of record...

Toward a Career Ladder in Nursing: Upgrading Nurse's Aides to LPNs Through a Work-Study Program. Final Progress Report.

ERIC Educational Resources Information Center

Medical and Health Research Association of New York City, Inc., NY.

To arrange a program that would enable nurse's aides to undertake licensed practical nurse (LPN) training without financial sacrifice, a 3-year experimental and demonstration project, funded by the Manpower Administration, was conducted in New York City between October 1967 and September 1969. Through a work-study arrangement, 422 nurse's aides in…

Subjective Social Status and Health Behaviors Among African Americans

PubMed Central

Reitzel, Lorraine R.; Nguyen, Nga; Strong, Larkin L.; Wetter, David W.; McNeill, Lorna H.

2012-01-01

Objectives To examine associations of the US and community subjective social status (SSS) ladders with smoking status, at-risk drinking, fruit and vegetable intake, physical activity, and body mass index among 1467 church-going African American adults from a larger cohort study. Methods Regression analyses, adjusted for sociodemographics, examined associations between SSS ladders and health behaviors. Results The SSS-US ladder was significantly associated with fruit and vegetable consumption (p = .007) and physical activity (p = .005). The SSS-community ladder was not significantly associated with any health behaviors. Conclusions Among this sample of African Americans, the SSS-US ladder is more predictive of some health behaviors than is the SSS-community ladder. PMID:22943107

29 CFR 1926.1053 - Ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... plastic ladder shall sustain at least 3.3 times the maximum intended load. The ability of a ladder to... that each extra-heavy-duty type 1A metal or plastic ladders shall sustain at least 3.3 times the... parapet is cut to permit passage through the parapet; if the parapet is continuous, the access level shall...

Effect of risk ladder format on risk perception in high- and low-numerate individuals.

PubMed

Keller, Carmen; Siegrist, Michael; Visschers, Vivianne

2009-09-01

Utilizing a random sample from the general population (N= 257), we examined the effect of the radon risk ladder on risk perception, as qualified by respondents' numeracy. The radon risk ladder provides comparative risk information about the radon equivalent of smoking risk. We compared a risk ladder providing smoking risk information with a risk ladder not providing this information. A 2 (numeracy; high, low) x 3 (risk level; high, medium, low) x 2 (smoking risk comparison: with/without) between subjects experimental design was used. A significant (p < 0.045) three-way interaction between format, risk level, and numeracy was identified. Participants with low numeracy skills, as well as participants with high numeracy skills, generally distinguished between low, medium, and high risk levels when the risk ladder with comparative smoking risk information was presented. When the risk ladder without the comparative information about the smoking risk was presented, low-numerate individuals differentiated between risk levels to a much lesser extent than high-numerate individuals did. These results provide empirical evidence that the risk ladder can be a useful tool in enabling people to interpret various risk levels. Additionally, these results allow us to conclude that providing comparative information within a risk ladder is particularly helpful to the understanding of different risk levels by people with low numeracy skills.

Role of Structural Asymmetry in Controlling Drop Spacing in Microfluidic Ladder Networks

NASA Astrophysics Data System (ADS)

Wang, William; Maddala, Jeevan; Vanapalli, Siva; Rengasamy, Raghunathan

2012-02-01

Manipulation of drop spacing is crucial to many processes in microfluidic devices including drop coalescence, detection and storage. Microfluidic ladder networks ---where two droplet-carrying parallel channels are connected by narrow bypass channels through which the motion of drops is forbidden---have been proposed as a means to control relative separation between pairs of drops. Prior studies in microfluidic ladder networks with vertical bypasses, which possess fore-aft structural symmetry, have revealed that pairs of drops can only undergo reduction in drop spacing at the ladder exit. We investigate the dynamics of drops in microfluidic ladder networks with both vertical and slanted bypasses. Our analytical results indicate that unlike symmetric ladder networks, structural asymmetry introduced by a single slanted bypass can be used to modulate the relative spacing between drops, enabling them to contract, synchronize, expand or even flip at the ladder exit. Our experiments confirm all the behaviors predicted by theory. Numerical analysis further shows that ladders containing several identical bypasses can only linearly transform the input drop spacing. Finally, we find that ladders with specific combinations of vertical and slanted bypasses can generate non-linear transformation of input drop spacing, despite the absence of drop decision-making events at the bypass junctions.

Evaluation Procedures in the Charlotte-Mecklenburg Career Ladder Plan.

ERIC Educational Resources Information Center

Schlechty, Phillip C.

1985-01-01

Describes faculty evaluation procedures used in the Charlotte-Mecklenburg (North Carolina) Public Schools in conjunction with career development. Covers the program's philosophy, purposes, and special characteristics; expectations set and competencies sought; the areas evaluation; evaluator characteristics; the observation process; teachers'…

White sturgeon (Acipenser transmontanus) passage at the Dalles Dam, Columbia River, USA

USGS Publications Warehouse

Parsley, M.J.; Wright, C.D.; Van Der Leeuw, B. K.; Kofoot, E.E.; Peery, C.A.; Moser, M.L.

2007-01-01

White sturgeon (Acipenser transmontanus) ???95 cm TL were monitored using acoustic and radio telemetry at a large hydroelectric dam (the Dalles Dam) on the Columbia River, during March 2004 through November 2005 to determine timing and routes of passage and to characterize general movements. Transmitters were surgically implanted into 148 fish during the study; 90 were released into the tailrace and 58 into the forebay. We documented 26 passage events by 19 tagged fish: eight upstream via fish ladders and 18 downstream, mostly through open spill gates. During the study 17 fish entered the two ladders one or more times; 11 entered only the east ladder, three entered only the north ladder, and three entered both ladders at sometime. Residence time within the ladders by individual fish was variable, ranging from about 1 min to nearly 6 months (median = 7.7 h). Only six fish successfully ascended the east ladder, one fish twice. We could not unequivocally determine which fish ladder one fish used to pass upstream. Differences in construction between the north and east fish ladders may account for the greater success of the east fish ladder in passing sturgeon upstream. Changes to operations at hydroelectric dams to benefit migrating anadromous salmonids may influence upstream or downstream passage by white sturgeon. Altering patterns and timing of spill discharge, altering fish ladder entrance attraction flows, and the use of lights, sound, and partial barriers to direct other species of fish to preferred passage routes have unknown effects on sturgeon passage. A better understanding of the consequences to the metapopulation of increasing or precluding upstream or downstream passage is needed. ?? 2007 The Authors.

Work-related falls from ladders--a follow-back study of US emergency department cases.

PubMed

Lombardi, David A; Smith, Gordon S; Courtney, Theodore K; Brennan, Melanye J; Kim, Jae Young; Perry, Melissa J

2011-11-01

Ladder falls comprise 16% of all US workplace fall-related fatalities, and ladder use may be particularly hazardous among older workers. This follow-back study of injured workers from a nationally representative sample of US emergency departments (ED) focused on factors related to ladder falls in three domains of the work environment: work equipment, work practices, and worker-related factors. Risk factors for fractures, the most frequent and severe outcome, were also evaluated. Workers injured from a ladder fall, treated in one of the 65 participating ED in the occupational National Electronic Injury Surveillance System (NEISS) were asked to participate. The questionnaire included worker demographics, injury, ladder and work equipment and environment characteristics, work tasks, and activities. Multivariate logistic regression models estimated odds ratios and 95% confidence intervals of a work-related fracture. Three-hundred and six workers experiencing an injury from an--on average--7.5-foot-fall from a step, extension, or straight ladder were interviewed primarily from construction, installation, maintenance, and repair professions. Injuries were most frequently to the arm, elbow or shoulder; head, neck, or face with diagnoses were primarily fracture, strain, sprain, contusion or abrasion. Workers were most frequently standing or sitting on the ladder while installing, hanging an item, or performing a repair when they fell. Ladder movement was the mechanism in 40% of falls. Environmental conditions played a role in <10% of cases. There was a significant association between fracture risk and fall height while working on the ladder that was also influenced by older work age. This study advances knowledge of falls from ladders to support those who specify means and methods, select equipment, and plan, supervise, or manage the performance of employees working at heights.

Passage and behaviour of cultured Lake Sturgeon in a prototype side-baffle fish ladder: I. Ladder hydraulics and fish ascent

USGS Publications Warehouse

Kynard, B.; Pugh, D.; Parker, T.

2011-01-01

Research and development of a fish ladder for sturgeons requires understanding ladder hydraulics and sturgeon behaviour in the ladder to insure the ladder is safe and provides effective passage. After years of research and development, we designed and constructed a full-scale prototype side-baffle ladder inside a spiral flume (38.3m long??1m wide??1m high) on a 6% (1:16.5) slope with a 1.92-m rise in elevation (bottom to top) to test use by sturgeons. Twenty-eight triangular side baffles, each extending part way across the flume, alternated from inside wall to outside wall down the ladder creating two major flow habitats: a continuous, sinusoidal flow down the ladder through the vertical openings of side-baffles and an eddy below each side baffle. Ascent and behaviour was observed on 22 cultured Lake Sturgeon=LS (Acipenser fulvescens) repeatedly tested in groups as juveniles (as small as 105.1cm TL, mean) or as adults (mean TL, 118cm) during four periods (fall 2002 and 2003; spring 2003 and 2007). Percent of juveniles entering the ladder that ascended to the top was greater in spring (72.7%) than in fall (40.9-45.5%) and 90.9% of 11 adults, which ascended as juveniles, ascended to the top. Six LS (27.3%) never swam to the top and seven (31.8%) swam to the top in all tests, indicating great variability among individuals for ascent drive. Some LS swam directly to the top in <1min, but most rested in an eddy during ascent. Juveniles swimming through outside wall baffle slots (mean velocity, 1.2ms-1) swam at 1.8-2.2body lengthss-1 and 3.2-3.3tail beatss-1, either at or approaching prolonged swimming speed. The side-baffle ladder was stream-like and provided key factors for a sturgeon ladder: a continuous flow and no full cross-channel walls, abundant eddies for resting, an acceptable water depth, and a water velocity fish could ascend swimming 2bls-1. A side-baffle ladder passes LS and other moderate-swimming fishes. ?? 2011 Blackwell Verlag, Berlin.

Getting Clever with the Sliding Ladder

ERIC Educational Resources Information Center

De, Subhranil

2014-01-01

The familiar system involving a uniform ladder sliding against a vertical wall and a horizontal floor is considered again. The floor is taken to be smooth and the wall to be possibly rough--a situation where no matter how large the static friction coefficient between the ladder and the wall, the ladder cannot lean at rest and must slide down.…

Quantifying Ladder Fuels: A New Approach Using LiDAR

Treesearch

Heather Kramer; Brandon Collins; Maggi Kelly; Scott Stephens

2014-01-01

We investigated the relationship between LiDAR and ladder fuels in the northern Sierra Nevada, California USA. Ladder fuels are often targeted in hazardous fuel reduction treatments due to their role in propagating fire from the forest floor to tree crowns. Despite their importance, ladder fuels are difficult to quantify. One common approach is to calculate canopy base...

29 CFR Appendix A to Subpart X of... - Ladders

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 8 2013-07-01 2013-07-01 false Ladders A Appendix A to Subpart X of Part 1926 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders Pt. 1926, Subpt. X, App. A Appendix A to Subpart X of Part 1926—Ladders This appendix serves as a non-mandatory guideline to assist...

29 CFR Appendix A to Subpart X of... - Ladders

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 8 2014-07-01 2014-07-01 false Ladders A Appendix A to Subpart X of Part 1926 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders Pt. 1926, Subpt. X, App. A Appendix A to Subpart X of Part 1926—Ladders This appendix serves as a non-mandatory guideline to assist...

29 CFR Appendix A to Subpart X of... - Ladders

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Ladders A Appendix A to Subpart X of Part 1926 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders Pt. 1926, Subpt. X, App. A Appendix A to Subpart X of Part 1926—Ladders This appendix serves as a non-mandatory guideline to assist...

29 CFR Appendix A to Subpart X of... - Ladders

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Ladders A Appendix A to Subpart X of Part 1926 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders Pt. 1926, Subpt. X, App. A Appendix A to Subpart X of Part 1926—Ladders This appendix serves as a non-mandatory guideline to assist...

29 CFR Appendix A to Subpart X of... - Ladders

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 8 2012-07-01 2012-07-01 false Ladders A Appendix A to Subpart X of Part 1926 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders Pt. 1926, Subpt. X, App. A Appendix A to Subpart X of Part 1926—Ladders This appendix serves as a non-mandatory guideline to assist...

Fall Prevention in Apprentice Carpenters

PubMed Central

Kaskutas, Vicki; Dale, Ann Marie; Lipscomb, Hester; Gaal, John; Fuchs, Mark; Evanoff, Bradley; Faucette, Julia; Gillen, Marion; Deych, Elena

2013-01-01

Objectives Falls from heights are a leading cause of mortality and morbidity in the construction industry, especially among inexperienced workers. We surveyed apprentice carpenters to identify individual and organizational factors associated with falls from heights. Methods We developed a 72-item fall prevention survey with multiple domains including fall experience, fall prevention knowledge, risk perceptions, confidence in ability to prevent falls, training experience, and perceptions of the safety climate and crew safety behaviors. We administered the questionnaire to apprentice carpenters in this cross-sectional study. Results Of the 1,025 respondents, 51% knew someone who had fallen from height at work and 16% had personally fallen in the past year, with ladders accounting for most of the falls. Despite participation in school-based and on-the-job training, fall prevention knowledge was poor. Ladders were perceived as low risk and ladder training was rare. Apprentices reported high levels of unsafe fall-related behaviors on their work crews. Apprentices working residential construction were more likely to fall than those working commercial construction, as were apprentices working on crews with fewer senior carpenters to provide mentorship, and those reporting more unsafe behaviors among fellow workers. Conclusions Despite participation in a formal apprenticeship program, many apprentices work at heights without adequate preparation and subsequently experience falls. Apprenticeship programs can improve the timing and content of fall prevention training. This study suggests that organizational changes in building practices, mentorship, and safety culture must also occur in order to decrease worker falls from heights. PMID:19953214

Strategies to Increase Teacher Supply and Quality: Related Policy Issues.

ERIC Educational Resources Information Center

Raizen, Senta

1986-01-01

"Quick fixes" and over-reactive policy mandates don't clearly anticipate long-term implications. Examples are given of the negative effects of scholarship/loan programs, career ladders, changing credentialing requirements, and teacher competency testing, originally devised to avoid teacher shortages. (Author/CB)

10 CFR 1042.520 - Job classification and structure.

Code of Federal Regulations, 2011 CFR

2011-01-01

....520 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex... establish separate lines of progression, seniority lists, career ladders, or tenure systems based on sex; or...

Practical solutions for staff recruitment & retention.

PubMed

Vander Hoek, N

2001-01-01

There are three essential topics for radiology managers to consider in light of persistent staffing shortages: support of the profession and educational programs, perks as recruitment tools and incentives as retention tools. Some activities that can help support departments and educational programs for radiologic technologists are job shadowing, training for volunteer services, advanced placement for school applicants, sponsoring an educational program or clinical training site, creating a positive work environment and supporting outreach projects geared to local high schools. Traditional perks used in recruitment efforts have included relocation assistance, travel and lodging expenses during the interview process, loan repayment, scholarships and sign-on bonuses. Some common incentives for retaining employees are tuition reimbursement, cross training, availability of educational resources, continuing education opportunities, professional development and incremental increases in salary. There are many other tools that can be used, such as career ladders, creating an environment conducive to teamwork or a more personal atmosphere and showcasing talents of various staff members. There is much overlap among these suggestions in support of the profession and educational programs, recruitment and retention of qualified staff radiologic technologists. Radiology managers can and should be creative in developing different programs to build loyalty and commitment to a radiology department.

Allowable bending stresses of wood for use in portable wood ladders

Treesearch

Fred Werren

1975-01-01

A standard for portable wood ladders has been in effect since 1923, and has been revised several times since then. The most recent publication is "American National Standard Safety Standard for Portable Wood Ladders," A14.1-1975, from American National Standards Institute, Inc. Methods of arriving at allowable stresses for wood ladder parts have never been...

Building New Career Ladders in Clerical Occupations: Final Report for the Period July 1, 1974-June 30, 1975.

ERIC Educational Resources Information Center

National Council of Negro Women, New York, NY.

A project by the National Council of Negro Women called "Building New Career Ladders in Clerical Occupations" has five components. Two of these are: (1) development of career ladders on the job; and (2) testing, evaluation, and dissemination. In the career ladder component, 33 companies participated through financial contributions; giving…

Corrosion Control Specialist Career Ladder AFSC 53530, 53550, 53570, and 53690. Occupational Survey Report.

ERIC Educational Resources Information Center

Air Force Occupational Measurement Center, Lackland AFB, TX.

The report describes the results of a detailed occupational survey of the corrosion control career ladder. Responses to a 457-task, time rating inventory from 1,015 personnel (representing 64 percent of the career field) were analyzed to produce seven specific findings and the career ladder structure. The career ladder includes a variety of jobs…

Giant Stark effect in double-stranded porphyrin ladder polymers

NASA Astrophysics Data System (ADS)

Pramanik, Anup; Kang, Hong Seok

2011-03-01

Using the first-principles calculations, we have investigated the stability and the electronic structure of two types of recently synthesized one-dimensional nanoribbons, i.e., double-stranded zinc(II) porphyrin ladder polymer (LADDER) arrays. First, electronic structure calculations were used to show that the LADDER is a semiconductor. Most importantly, the application of a transverse electric field significantly reduces the band gap of the LADDER, ultimately converting the LADDER to a metal at a field strength of 0.1 V/Å. The giant Stark effect in this case is almost as strong as that in boron nitride nanotubes and nanoribbons. In the presence of an electric field, hole conduction and electronic conduction will occur entirely through spatially separated strands, rendering these materials useful for nanoelectronic devices. Second, the substitution of hydrogen atoms in the porphyrin units or that of zinc ions with other kinds of chemical species is found to increase the binding strength of the LADDER and reduce the band gap.

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

NASA Astrophysics Data System (ADS)

Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

2016-12-01

We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13472 and #13691.

A balanced intervention ladder: promoting autonomy through public health action.

PubMed

Griffiths, P E; West, C

2015-08-01

The widely cited Nuffield Council on Bioethics 'Intervention Ladder' structurally embodies the assumption that personal autonomy is maximized by non-intervention. Consequently, the Intervention Ladder encourages an extreme 'negative liberty' view of autonomy. Yet there are several alternative accounts of autonomy that are both arguably superior as accounts of autonomy and better suited to the issues facing public health ethics. We propose to replace the one-sided ladder, which has any intervention coming at a cost to autonomy, with a two-sided 'Balanced Intervention Ladder,' where intervention can either enhance or diminish autonomy. We show that not only the alternative, richer accounts of autonomy but even Mill's classic version of negative liberty puts some interventions on the positive side of the ladder. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Dental Laboratory Career Ladder AFS 982X0.

DTIC Science & Technology

1982-09-01

7ADA120 102 AIR FORCE OCCUPATIONAL MEASUREMENT CENTER RANDOLPH AFB TX F/6 Ri9 DENTAL LABORATORY CAREER LADDER AFS 982XO.(U) UNCLASSIFIED NLEEEili E...Eli E~lllllllllEEE EEEEEIIIEEEEEE EIEEEEIIEEEEEE IIIIIIIIIIIIIIlLZ UNITED STATES AIR FORCE 0! DENTAL LABORATORY CAREER LADDER DTlC AFS 982X0 ELEr.L_...LADDER STRUCTURE GROUPS ----------------------------------- 57 APPENDIX B - JOB DESCRIPTIONS FOR BASE AND AREA DENTAL LABORATORY PERSONNEL

29 CFR 36.520 - Job classification and structure.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in... progression, seniority lists, career ladders, or tenure systems based on sex; or (c) Maintain or establish...

29 CFR 36.520 - Job classification and structure.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in... progression, seniority lists, career ladders, or tenure systems based on sex; or (c) Maintain or establish...

Use of portable ladders - field observations and self-reported safety performance in the cable TV industry.

PubMed

Chang, Wen-Ruey; Huang, Yueng-Hsiang; Brunette, Christopher; Lee, Jin

2017-11-01

Portable ladders incidents remain a major cause of falls from heights. This study reported field observations of environments, work conditions and safety behaviour involving portable ladders and their correlations with self-reported safety performance. Seventy-five professional installers of a company in the cable and other pay TV industry were observed for 320 ladder usages at their worksites. The participants also filled out a questionnaire to measure self-reported safety performance. Proper setup on slippery surfaces, correct method for ladder inclination setup and ladder secured at the bottom had the lowest compliance with best practices and training guidelines. The observation compliance score was found to have significant correlation with straight ladder inclined angle (Pearson's r = 0.23, p < 0.0002) and employees' self-reported safety participation (r = 0.29, p < 0.01). The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours. Practitioner Summary: A checklist was used while observing professional installers of a cable company for portable ladder usage at their worksites. Items that had the lowest compliance with best practices and training guidelines were identified. The results provide a broad perspective on employees' safety compliance and identify areas for improving safety behaviours.

The reconstructive microsurgery ladder in orthopaedics.

PubMed

Tintle, Scott M; Levin, L Scott

2013-03-01

Since the advent of the operating microscope by Julius Jacobson in 1960, reconstructive microsurgery has become an integral part of extremity reconstruction and orthopaedics. During World War I, with the influx of severe extremity trauma Harold Gillies introduced the concept of the reconstructive ladder for wound closure. The concept of the reconstructive ladder goes from simple to complex means of attaining wound closure. Over the last half century microsurgery has continued to evolve and progress. We now have a microsurgical reconstructive ladder. The microsurgical reconstruction ladder is based upon the early work on revascularization and replantation extending through the procedures that are described in this article. Copyright © 2013. Published by Elsevier Ltd.

Directory of Credit-Granting Policies in Medical Laboratory Education.

ERIC Educational Resources Information Center

National Committee for Careers in Medical Technology, Bethesda, MD.

Ways now exist for medical laboratory workers to advance up the educational career ladder, gaining credit for prior training and/or experience. A total of 369 Certified Medical Laboratory Assistant Schools, colleges with Associate Degree Medical Laboratory Technicians programs, schools of Medical Technology, and colleges with baccalaureate Medical…

Teacher-Controlled Evaluation in a Career Ladder Program.

ERIC Educational Resources Information Center

Peterson, Ken; Mitchell, Anthony

1985-01-01

Teachers in Utah's Park City School District select which of several types of information they wish to gather as evidence of their own teaching ability and effectiveness. The teachers are trained in information gathering methods, and the dossiers they develop serve as the basis for evaluations and promotions. (PGD)

24. DETAIL EXTERIOR VIEW LOOKING EAST, SHOWING FISH LADDER AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. DETAIL EXTERIOR VIEW LOOKING EAST, SHOWING FISH LADDER AT NORTH END OF DAM/SPILLWAY; WATER FLOWING THROUGH FISH LADDER IS VISIBLE AT BOTTOM. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

Topological phases in frustrated synthetic ladders with an odd number of legs

NASA Astrophysics Data System (ADS)

Barbarino, Simone; Dalmonte, Marcello; Fazio, Rosario; Santoro, Giuseppe E.

2018-01-01

The realization of the Hofstadter model in a strongly anisotropic ladder geometry has now become possible in one-dimensional optical lattices with a synthetic dimension. In this work, we show how the Hofstadter Hamiltonian in such ladder configurations hosts a topological phase of matter which is radically different from its two-dimensional counterpart. This topological phase stems directly from the hybrid nature of the ladder geometry and is protected by a properly defined inversion symmetry. We start our analysis by considering the paradigmatic case of a three-leg ladder which supports a topological phase exhibiting the typical features of topological states in one dimension: robust fermionic edge modes, a degenerate entanglement spectrum, and a nonzero Zak phase; then, we generalize our findings—addressable in the state-of-the-art cold-atom experiments—to ladders with a higher number of legs.

Ladder operators for the Klein-Gordon equation with a scalar curvature term

NASA Astrophysics Data System (ADS)

Mück, Wolfgang

2018-01-01

Recently, Cardoso, Houri and Kimura constructed generalized ladder operators for massive Klein-Gordon scalar fields in space-times with conformal symmetry. Their construction requires a closed conformal Killing vector, which is also an eigenvector of the Ricci tensor. Here, a similar procedure is used to construct generalized ladder operators for the Klein-Gordon equation with a scalar curvature term. It is proven that a ladder operator requires the existence of a conformal Killing vector, which must satisfy an additional property. This property is necessary and sufficient for the construction of a ladder operator. For maximally symmetric space-times, the results are equivalent to those of Cardoso, Houri and Kimura.

A Simulator for the Respiratory Tree in Healthy Subjects Derived from Continued Fractions Expansions

NASA Astrophysics Data System (ADS)

Muntean, Ionuţ; Ionescu, Clara; Naşcu, Ioan

2009-04-01

Taking into account the self-similar recurrent geometrical structure of the human respiratory tree, the total respiratory impedance can be represented using an electrical equivalent of a ladder network model. In this paper, the parameters of the respiratory tree are employed in simulation, based on clinical insight and morphology. Once the transfer function of the total input impedance model is calculated, it is further interpreted in its continued fraction expansion form. The purpose is to compare the ladder network structure with the continuous fraction expansion form of the impedance. The results are supporting the theory of fractional-order impedance appearance (also known as constant-phase behaviour) and help understanding the mathematical and morphological basis for constructing a physiology-based simulator of the human lungs.

29 CFR 1910.27 - Fixed ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.27 Fixed ladders. (a) Design... fraction thereof, except that, where no cage, well, or ladder safety device is provided, landing platforms...

22. DETAIL EXTERIOR VIEW LOOKING NORTHWEST, SHOWING FISH LADDER AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. DETAIL EXTERIOR VIEW LOOKING NORTHWEST, SHOWING FISH LADDER AT NORTH END OF DAM/SPILLWAY; VIEW SHOWS SECTION OF FISH LADDER NEAR WHERE IT ENTERS THE COLUMBIA RIVER. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

Instabilities of coupled Cu2O5 ladders

NASA Astrophysics Data System (ADS)

Schuetz, Florian; Marston, Brad

2008-03-01

The spin-ladder compound Sr14-xCaxCu24O41 has a complex phase diagram including charge-density-wave order as well as unconventional superconductivity under high pressure. Due to its quasi-one-dimensional natureootnotetextS. Lee, J. B. Marston, J. O. Fjaerestad, Phys. Rev. B 72, 075126. fundamental questions about the high-Tc cuprates might be more easily addressed in this context. However, due to the spatial proximity of neighboring ladders inter-ladder Coulomb repulsion as well as hopping between ladders might still be important. Using the functional renormalization groupootnotetextM. Salmhofer and C. Honerkamp, Prog. Theor. Physics 105, 1 (2001). and an analysis of generalized susceptibilities ootnotetextD. Zanchi and H. J. Schulz, Phys. Rev. B 61, 13609 (2000); C. J. Halboth and W. Metzner, Phys. Rev. Lett. 85, 5162 (2000)., we study a model of coupled Cu2O5 ladders ootnotetextK. Wohlfeld, A. M. Oles, and G. A. Sawatzky, Phys. Rev. B 75, 180501(R) (2007).. We investigate instabilities towards charge, spin, and pairing order as a function of hole doping, inter-ladder hopping, and interaction strength starting from experimentally relevant hopping parametersootnotetextT. F. A. Müller, et al., Phys. Rev. B 57, R12655 (1998)..

7. DETAIL VIEW OF LOWER MOUTH OF FISH LADDER AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. DETAIL VIEW OF LOWER MOUTH OF FISH LADDER AT ROCK OUTCROPPING, SHOWING NATURAL CARVED ROCK POOLS, UPPER PORTION OF FISH LADDER VISIBLE IN DISTANCE, LOOKING SOUTHWEST (UPSTREAM) - Van Arsdale Dam, South Fork of Eel River, Ukiah, Mendocino County, CA

Stennis acquires new ladder truck

NASA Image and Video Library

2009-10-20

The Stennis Space Center Fire Department added to its fire-fighting capabilities with acquisition of a new emergency response vehicle, Ladder-1, for use on-site. The E-One HP78 Aerial Truck is a combination aerial ladder and fire suppression unit and is designed with the latest safety technology. Featuring a 78-foot ladder and a pumping capability of 1,500 gallons per minute, the new truck provides firefighters with a tremendous rescue and fire suppression tool, Stennis Fire Chief Clark Smith said.

Understanding phylogenies in biology: the influence of a Gestalt Perceptual Principle.

PubMed

Novick, Laura R; Catley, Kefyn M

2007-12-01

Cladograms, hierarchical diagrams depicting evolutionary histories among (groups of) species, are commonly drawn in 2 informationally equivalent formats--tree and ladder. The authors hypothesize that these formats are not computationally equivalent because the Gestalt principle of good continuation obscures the hierarchical structure of ladders. Experimental results confirmed that university students (N = 44) prefer to subdivide ladders in accordance with good continuation rather than with the underlying hierarchical structure. Two subsequent experiments (N = 164) investigated cladogram understanding by examining students' ability to translate between formats (e.g., from tree to ladder). As predicted, students had greater difficulty understanding ladders than trees. This effect was larger for students with weaker backgrounds in biology. These results have important implications for evolution education reform.

2 (Secondary) + 2 (Postsecondary) Articulated Curriculum for Health Occupations: A How-To-Manual.

ERIC Educational Resources Information Center

Lovelace, Bill E.; And Others

This manual addresses specific aspects of the development and implementation of articulated vocational programs between high schools and colleges. The approach presented in the manual was derived from research and the experiences of the Paris Junior College (Texas) project staff who developed a "2 + 2" articulated career ladder curriculum for…

Bridging Silos: Novices Partner with Veteran Teachers on the Path to Board Certification

ERIC Educational Resources Information Center

Gilrein, Erin; Wolfe, Jennifer

2016-01-01

To stem the tide of new professionals leaving teaching, the Oceanside School District in New York created a program that sees teaching as a six-year career ladder beginning with an internship and ending with National Board Certification, with board-certified teachers supporting new interns and residents.

Programmed cell death progressively models the development of anther sporophytic tissues from the tapetum and is triggered in pollen grains during maturation.

PubMed

Varnier, Anne-Lise; Mazeyrat-Gourbeyre, Florence; Sangwan, Rajbir S; Clément, Christophe

2005-11-01

To characterize the spatial and temporal occurrence of programmed cell death (PCD) in Lilium anther tissues, we used both microscopical and molecular markers of apoptosis for developmental stages from meiosis to pollen release. The first hallmarks of PCD include cell condensation and shrinkage of the cytoplasm, separation of chromatin into delineated masses, and DNA fragmentation in the tapetum as early as the premeiosis stage. PCD then extended to other anther sporophytic tissues, leading to anther dehiscence. Although the PCD clearly affected the endothecium and the epidermis, these two cell layers remained alive until anther dehiscence. In pollen, no sign of PCD was found until pollen mitosis I, after what apoptotic features developed progressively in the vegetative cell. In addition, DNA ladders were detected in all sporophytic tissues and cell types throughout pollen development, whereas in the male gametophyte DNA ladders were only detected during pollen maturation. Our data suggest that PCD is a progressive and active process affecting all the anther tissues, first being triggered in the tapetum.

Effects of ladder parameters on asymmetric patterns of force exertion during below-knee amputees climbing ladders.

PubMed

Li, Weidong; Li, Shiqi; Fu, Yan; Chen, Jacon

2017-03-01

Different from walking, ladder climbing requires four-limb coordination and more energy exertion for below-knee amputees (BKAs). We hypothesized that functional deficiency of a disabled limb shall be compensated by the other three intact limbs, showing an asymmetry pattern among limbs. Hand and foot forces of six below-knee amputees and six able-bodied people were collected. Hand, foot and hand/foot sum force variances between groups (non-BKA, intact side and prosthetic side) were carefully examined. Our hypothesis was validated that there is asymmetry between prosthetic and intact side. Results further showed that the ipsilateral hand of the prosthetic leg is stronger than the hand on the intact side, compensating weakness of the prosthetic leg. Effects of ladder rung separations and ladder slant on asymmetric force distribution of BKAs were evaluated, indicating that rung separation has a more significant interactive effect on hand/foot force of BKAs than ladder slant.

Adaptation of a ladder beam walking task to assess locomotor recovery in mice following spinal cord injury.

PubMed

Cummings, Brian J; Engesser-Cesar, Christie; Cadena, Gilbert; Anderson, Aileen J

2007-02-27

Locomotor impairments after spinal cord injury (SCI) are often assessed using open-field rating scales. These tasks have the advantage of spanning the range from complete paralysis to normal walking; however, they lack sensitivity at specific levels of recovery. Additionally, most supplemental assessments were developed in rats, not mice. For example, the horizontal ladder beam has been used to measure recovery in the rat after SCI. This parametric task results in a videotaped archival record of the event, is easily administered, and is unambiguously scored. Although a ladder beam apparatus for mice is available, its use in the assessment of recovery in SCI mice is rare, possibly because normative data for uninjured mice and the type of step misplacements injured mice exhibit is lacking. We report the development of a modified ladder beam instrument and scoring system to measure hindlimb recovery in vertebral T9 contusion spinal cord injured mice. The mouse ladder beam allows for the use of standard parametric statistical tests to assess locomotor recovery. Ladder beam performance is consistent across four strains of mice, there are no sex differences, and inter-rater reliability between observers is high. The ladder beam score is proportional to injury severity and can be used to easily separate mice capable of weight-supported stance up to mice with consistent forelimb to hindlimb coordination. Critically, horizontal ladder beam testing discriminates between mice that score identically in terms of stepping frequency in open-field testing.

Adaptation of a ladder beam walking task to assess locomotor recovery in mice following spinal cord injury

PubMed Central

Cummings, Brian J.; Engesser-Cesar, Christie; Anderson, Aileen J.

2007-01-01

Locomotor impairments after spinal cord injury (SCI) are often assessed using open-field rating scales. These tasks have the advantage of spanning the range from complete paralysis to normal walking; however, they lack sensitivity at specific levels of recovery. Additionally, most supplemental assessments were developed in rats, not mice. For example, the horizontal ladder beam has been used to measure recovery in the rat after SCI. This parametric task results in a videotaped archival record of the event, is easily administered, and is unambiguously scored. Although a ladder beam apparatus for mice is available, its use in the assessment of recovery in SCI mice is rare, possibly because normative data for uninjured mice and the type of step misplacements injured mice exhibit is lacking. We report the development of a modified ladder beam instrument and scoring system to measure hindlimb recovery in vertebral T9 contusion spinal cord injured mice. The mouse ladder beam allows for the use of standard parametric statistical tests to assess locomotor recovery. Ladder beam performance is consistent across four strains of mice, there are no sex differences, and inter-rater reliability between observers is high. The ladder beam score is proportional to injury severity and can be used to easily separate mice capable of weight-supported stance up to mice with consistent forelimb to hindlimb coordination. Critically, horizontal ladder beam testing discriminates between mice that score identically in terms of stepping frequency in open-field testing. PMID:17197044

Nurse retention in a correctional facility: a study of the relationship between the nurses' perceived barriers and benefits.

PubMed

Chafin, W Sue; Biddle, Wendy L

2013-04-01

Retention of nursing staff is more complex in a correctional facility. After a period of 3 years, only 20% of the staff remained employed at this study facility. Without retention of qualified correctional nurses, there are decreases in access to care, gaps in continuity of care, and less time for mentorship. Trained correctional nurses improve patient and staff safety, provide more education, and are more team-oriented. The purpose of this study was to identify barriers and benefits to nursing staff satisfaction with their job and the likelihood that they will continue to work in correctional settings. Practice and patient care will be favorably impacted if correctional nurses are provided with services such as new hire orientation, clinical ladder programs to recruit and retain nursing staff, and teambuilding.

Designing and Implementing Performance-Based Career Ladder Plans.

ERIC Educational Resources Information Center

Hawley, Willis D.

1985-01-01

Reviews the factors that any teacher motivation plan must incorporate to be effective and outlines 11 principles that should be followed in designing career ladder plans to meet teacher needs, increase teacher competence, and facilitate effective instruction. Warns against potential pitfalls in career ladder plans. (PGD)

KSC-2012-3995

NASA Image and Video Library

2012-07-20

CAPE CANAVERAL, Fla. – Inside the RLV Hangar near NASA Kennedy Space Center’s Shuttle Landing Facility, or SLF, in Florida, Florida Tech, or FIT, Aviation Program Supervisor Tennesse Garvey, at left on the ladder, and several students view an F104 Starfighter. At right, on the ladder is Starfighter Director Rick Svetkoff. The FIT aviation instructors and their students arrived at the SLF in Cherokee Warrior and Cessna 172S lightweight aircraft. The middle and high school students are participating in FIT’s Av/Aero summer camp experience. They and their flight instructors toured the SLF midfield control tower, viewed F104 Starfighters and NASA Huey helicopters in the RLV Hangar, viewed the runway plaques marking wheels stop for each of the three space shuttles, and toured the Vehicle Assembly Building where space shuttle Atlantis currently is stored. Photo credit: NASA/Kim Shiflett

30 CFR 57.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fixed ladder anchorage and toe clearance. 57.11005 Section 57.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... MINES Travelways and Escapeways Travelways-Surface and Underground § 57.11005 Fixed ladder anchorage and...

30 CFR 57.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fixed ladder anchorage and toe clearance. 57.11005 Section 57.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... MINES Travelways and Escapeways Travelways-Surface and Underground § 57.11005 Fixed ladder anchorage and...

30 CFR 57.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fixed ladder anchorage and toe clearance. 57.11005 Section 57.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... MINES Travelways and Escapeways Travelways-Surface and Underground § 57.11005 Fixed ladder anchorage and...

30 CFR 57.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fixed ladder anchorage and toe clearance. 57.11005 Section 57.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... MINES Travelways and Escapeways Travelways-Surface and Underground § 57.11005 Fixed ladder anchorage and...

30 CFR 57.11005 - Fixed ladder anchorage and toe clearance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fixed ladder anchorage and toe clearance. 57.11005 Section 57.11005 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... MINES Travelways and Escapeways Travelways-Surface and Underground § 57.11005 Fixed ladder anchorage and...

29 CFR 1910.29 - Manually propelled mobile ladder stands and scaffolds (towers).

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (stress grade) construction grade lumber or equivalent. (vi) All scaffold work levels 10 feet or higher... (towers). 1910.29 Section 1910.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND..., construction, and use of mobile work platforms (including ladder stands but not including aerial ladders) and...

29 CFR 1910.29 - Manually propelled mobile ladder stands and scaffolds (towers).

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (stress grade) construction grade lumber or equivalent. (vi) All scaffold work levels 10 feet or higher... (towers). 1910.29 Section 1910.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND..., construction, and use of mobile work platforms (including ladder stands but not including aerial ladders) and...

29 CFR 1910.29 - Manually propelled mobile ladder stands and scaffolds (towers).

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (stress grade) construction grade lumber or equivalent. (vi) All scaffold work levels 10 feet or higher... (towers). 1910.29 Section 1910.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND..., construction, and use of mobile work platforms (including ladder stands but not including aerial ladders) and...

29 CFR 1910.29 - Manually propelled mobile ladder stands and scaffolds (towers).

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (stress grade) construction grade lumber or equivalent. (vi) All scaffold work levels 10 feet or higher... (towers). 1910.29 Section 1910.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND..., construction, and use of mobile work platforms (including ladder stands but not including aerial ladders) and...

29 CFR 1910.29 - Manually propelled mobile ladder stands and scaffolds (towers).

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (stress grade) construction grade lumber or equivalent. (vi) All scaffold work levels 10 feet or higher... (towers). 1910.29 Section 1910.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND..., construction, and use of mobile work platforms (including ladder stands but not including aerial ladders) and...

46 CFR 163.003-13 - Construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

... that can be used for attaching additional ladder sections. (c) Steps. Pilot ladder steps must meet the... instead of the orange color required under paragraph (c)(8) of this section, and must have the special.... A pilot ladder must not have splinters, burrs, sharp edges, corners, projections, or other defects...

Understanding the Behaviour of Infinite Ladder Circuits

ERIC Educational Resources Information Center

Ucak, C.; Yegin, K.

2008-01-01

Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

29 CFR 1926.1053 - Ladders.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Stairways and Ladders § 1926.1053 Ladders. Link to an... structural defects, such as, but not limited to, broken or missing rungs, cleats, or steps, broken or split..., such as, but not limited to, broken or missing rungs, cleats, or steps, broken or split rails, or...

An Evolving Model for Capacity Building with Earth Observation Imagery

NASA Astrophysics Data System (ADS)

Sylak-Glassman, E. J.

2015-12-01

For the first forty years of Earth observation satellite imagery, all imagery was collected by civilian or military governmental satellites. Over this timeframe, countries without observation satellite capabilities had very limited access to Earth observation data or imagery. In response to the limited access to Earth observation systems, capacity building efforts were focused on satellite manufacturing. Wood and Weigel (2012) describe the evolution of satellite programs in developing countries with a technology ladder. A country moves up the ladder as they move from producing satellites with training services to building satellites locally. While the ladder model may be appropriate if the goal is to develop autonomous satellite manufacturing capability, in the realm of Earth observation, the goal is generally to derive societal benefit from the use of Earth observation-derived information. In this case, the model for developing Earth observation capacity is more appropriately described by a hub-and-spoke model in which the use of Earth observation imagery is the "hub," and the "spokes" describe the various paths to achieving that imagery: the building of a satellite (either independently or with assistance), the purchase of a satellite, participation in a constellation of satellites, and the use of freely available or purchased satellite imagery. We discuss the different capacity-building activities that are conducted in each of these pathways, such as the "Know-How Transfer and Training" program developed by Surrey Satellite Technology Ltd. , Earth observation imagery training courses run by SERVIR in developing countries, and the use of national or regional remote sensing centers (such as those in Morocco, Malaysia, and Kenya) to disseminate imagery and training. In addition, we explore the factors that determine through which "spoke" a country arrives at the ability to use Earth observation imagery, and discuss best practices for achieving the capability to use imagery.

29 CFR 1926.1053 - Ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

... spreader or locking device shall be provided on each stepladder to hold the front and back sections in an... ascend or descend without continually having to hold, push or pull any part of the device, leaving both... degrees from the horizontal, as measured to the back side of the ladder. (6) Ladders shall be used only on...

Discussing Laddering Application by the Means-End Chain Theory

ERIC Educational Resources Information Center

Veludo-de-Oliveira, Tania Modesto; Ikeda, Ana Akemi; Campomar, Marcos Cortez

2006-01-01

This article aims at analyzing laddering as a technique of qualitative research, emphasizing the procedures for data collection, analysis and interpretation, and its main limitations as well. "Laddering refers to an in-depth, one-on-one interviewing technique used to develop an understanding of how consumers translate the attributes of products…

Perspective on rainbow-ladder truncation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eichmann, G.; Institut fuer Physik, Karl-Franzens-Universitaet Graz, A-8010 Graz; Alkofer, R.

2008-04-15

Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light.

Modeling the Sliding/Falling Ladder Paradox

ERIC Educational Resources Information Center

Fox, William P.; Fox, James B.

2003-01-01

Recently we were presented with an interesting twist to the sliding ladder problem viewed in the related rates section of most calculus textbooks. Our problem concerning a sliding ladder that eventually hits the ground. At first, those attempting this problem fell into the calculus trap using only related rates. Previous work for this problem…

46 CFR 163.002-5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... load means the sum of the weights of— (1) The rigid ladder or lift platform, the suspension cables (if... persons capacity of the hoist; (c) Lift height means the distance from the lowest step of the pilot ladder... (2) If the hoist does not have suspension cables, the ladder or lift platform is in its lowest...

46 CFR 163.002-21 - Approval tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... must not break or crack during these tests. (2) Platform strength. If the pilot hoist has a lift... deck interlock must prevent movement of the ladder or lift platform when the lever is activated. (4... of the hoist is placed on its ladder or lift platform. The ladder or lift platform is repeatedly...

46 CFR 163.002-5 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... load means the sum of the weights of— (1) The rigid ladder or lift platform, the suspension cables (if... persons capacity of the hoist; (c) Lift height means the distance from the lowest step of the pilot ladder... (2) If the hoist does not have suspension cables, the ladder or lift platform is in its lowest...

Teacher Career Ladders in Utah: Perspectives on Early Stages.

ERIC Educational Resources Information Center

Peterson, Ken, Ed.; And Others

The status of teacher career ladders in Utah is discussed from five different perspectives. Jim Wilson, representing the Legislative Research Analyst's Office and General Counsel of the Legislature, speaks about legislative intent from the past year and what legislators thought would happen and wanted to happen regarding career ladder bills which…

49 CFR 214.519 - Floors, decks, stairs, and ladders of on-track roadway maintenance machines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... roadway maintenance machines. 214.519 Section 214.519 Transportation Other Regulations Relating to... SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.519 Floors, decks, stairs, and ladders of on-track roadway maintenance machines. Floors, decks, stairs, and ladders of on-track roadway...

49 CFR 214.519 - Floors, decks, stairs, and ladders of on-track roadway maintenance machines.

Code of Federal Regulations, 2011 CFR

2011-10-01

... roadway maintenance machines. 214.519 Section 214.519 Transportation Other Regulations Relating to... SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.519 Floors, decks, stairs, and ladders of on-track roadway maintenance machines. Floors, decks, stairs, and ladders of on-track roadway...

Perspective on rainbow-ladder truncation

NASA Astrophysics Data System (ADS)

Eichmann, G.; Alkofer, R.; Cloët, I. C.; Krassnigg, A.; Roberts, C. D.

2008-04-01

Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light.

77 FR 15839 - Culturally Significant Objects Imported for Exhibition Determinations: “Joan Miró: the Ladder of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-16

... DEPARTMENT OF STATE [Public Notice 7827] Culturally Significant Objects Imported for Exhibition Determinations: ``Joan Mir[oacute]: the Ladder of Escape'' SUMMARY: Notice is hereby given of the following... exhibition ``Joan Mir[oacute]: the Ladder of Escape,'' imported from abroad for temporary exhibition within...

The pPSU Plasmids for Generating DNA Molecular Weight Markers.

PubMed

Henrici, Ryan C; Pecen, Turner J; Johnston, James L; Tan, Song

2017-05-26

Visualizing nucleic acids by gel electrophoresis is one of the most common techniques in molecular biology, and reference molecular weight markers or ladders are commonly used for size estimation. We have created the pPSU1 & pPSU2 pair of molecular weight marker plasmids which produce both 100 bp and 1 kb DNA ladders when digested with two common restriction enzymes. The 100 bp ladder fragments have been optimized to migrate appropriately on both agarose and native polyacrylamide, unlike many currently available DNA ladders. Sufficient plasmid DNA can be isolated from 100 ml E. coli cultures for the two plasmids to produce 100 bp or 1 kb ladders for 1000 gels. As such, the pPSU1 and pPSU2 plasmids provide reference fragments from 50 to 10000 bp at a fraction of the cost of commercial DNA ladders. The pPSU1 and pPSU2 plasmids are available without licensing restrictions to nonprofit academic users, affording freely available high-quality, low-cost molecular weight standards for molecular biology applications.

From Mountaintop to Corporate Ladder--What New Professionals Really Really Want in a Capstone Experience!

ERIC Educational Resources Information Center

French, Erica; Bailey, Janis; van Acker, Elizabeth; Wood, Leigh

2015-01-01

Capstone subjects are increasingly used in Universities worldwide to complete the undergraduate program experience and to transition graduates into the workplace. As such, capstones fulfil a large role consolidating one experience and traversing the gap to another. Yet, little is known or understood about their design, their implementation or…

Development of a Goal Setting Process and Instrumentation for Teachers and Principals.

ERIC Educational Resources Information Center

Minix, Nancy; And Others

A pilot program, the Career Ladder Plan, was developed in Kentucky to evaluate a teacher's performance in terms of professional growth and development and professional leadership/initiative based on that teacher's performance on a setting/goal attainment process. Goals jointly selected by the teacher and his/her principal must contribute to school…

Impacts of the School Social Unit on Teacher Authority during Work Redesign.

ERIC Educational Resources Information Center

Hart, Ann Weaver

1990-01-01

Work redesign to facilitate teacher empowerment was studied in a year-long comparative case study in two junior-high schools implementing a career-ladder program. Journals of 6 teacher leaders (TLs), 23 teachers, and 3 teacher-specialists; TLs' and novice teachers' midyear surveys; and 61 classroom observations by TLs and principals were analyzed.…

Moving up the Ladder: How Do States Deliver Quality Improvement Supports within Their Quality Rating and Improvement Systems? Brief

ERIC Educational Resources Information Center

Holod, Aleksandra; Faria, Ann-Marie; Weinberg, Emily; Howard, Eboni

2015-01-01

As national attention has increasingly focused on the potential for high-quality early childhood education (ECE) to improve children's school readiness, states have developed quality rating and improvement systems (QRISs) to document the quality of ECE programs, support systematic quality improvement, and provide clear information to families…

Chutes or Ladders? Creating Support Services to Help Early Childhood Students Succeed in Higher Education

ERIC Educational Resources Information Center

Dukakis, Kara; Bellm, Dan; Seer, Natalie; Lee, Yuna

2007-01-01

This report explores efforts in California to generally support nontraditional students, and early care and education (ECE) nontraditional students in particular. It is recommended that institutions of higher education and local planners work together to assess the needs of nontraditional students in their ECE programs, the adequacy of existing…

Edge currents in frustrated Josephson junction ladders

NASA Astrophysics Data System (ADS)

Marques, A. M.; Santos, F. D. R.; Dias, R. G.

2016-09-01

We present a numerical study of quasi-1D frustrated Josephson junction ladders with diagonal couplings and open boundary conditions, in the large capacitance limit. We derive a correspondence between the energy of this Josephson junction ladder and the expectation value of the Hamiltonian of an analogous tight-binding model, and show how the overall superconducting state of the chain is equivalent to the minimum energy state of the tight-binding model in the subspace of one-particle states with uniform density. To satisfy the constraint of uniform density, the superconducting state of the ladder is written as a linear combination of the allowed k-states of the tight-binding model with open boundaries. Above a critical value of the parameter t (ratio between the intra-rung and inter-rung Josephson couplings) the ladder spontaneously develops currents at the edges, which spread to the bulk as t is increased until complete coverage is reached. Above a certain value of t, which varies with ladder size (t = 1 for an infinite-sized ladder), the edge currents are destroyed. The value t = 1 corresponds, in the tight-binding model, to the opening of a gap between two bands. We argue that the disappearance of the edge currents with this gap opening is not coincidental, and that this points to a topological origin for these edge current states.

Helping early career research scientists ascend the professional ladder.

PubMed

King, Laina

2013-08-01

The Keystone Symposia Early Career Investigator Travel Award initiative is a unique successful research mentoring program tailored for 'end of the pipeline' life and biomedical scientists from academia and industry. Using targeted educational, mentoring, and networking activities, the program benefits early career scientists in solving a specific laboratory-based research question that is limiting their evolving research and could increase their ability to obtain new grants and improve their career progression. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dissipation, Voltage Profile and Levy Dragon in a Special Ladder Network

ERIC Educational Resources Information Center

Ucak, C.

2009-01-01

A ladder network constructed by an elementary two-terminal network consisting of a parallel resistor-inductor block in series with a parallel resistor-capacitor block sometimes is said to have a non-dispersive dissipative response. This special ladder network is created iteratively by replacing the elementary two-terminal network in place of the…

Getting to the Bottom of a Ladder Problem

ERIC Educational Resources Information Center

McCartney, Mark

2002-01-01

In this paper, the author introduces a simple problem relating to a pair of ladders. A mathematical model of the problem produces an equation which can be solved in a number of ways using mathematics appropriate to "A" level students or first year undergraduates. The author concludes that the ladder problem can be used in class to develop and…

46 CFR 163.002-13 - Construction.

Code of Federal Regulations, 2011 CFR

2011-10-01

... a rigid ladder or a lift platform on which a person being raised or lowered may stand. (b) Spreader. Each hoist must have a spreader or other device to prevent twisting of its ladder or lift platform. If.... The rigid ladder or lift platform on a pilot hoist and the ends of its spreader (if a spreader is...

46 CFR 163.002-13 - Construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

... a rigid ladder or a lift platform on which a person being raised or lowered may stand. (b) Spreader. Each hoist must have a spreader or other device to prevent twisting of its ladder or lift platform. If.... The rigid ladder or lift platform on a pilot hoist and the ends of its spreader (if a spreader is...

Revisiting the Ladder on a Wall Problem

ERIC Educational Resources Information Center

Salu, Yehuda

2011-01-01

The problem of a ladder leaning on a wall has been a staple of introductory physics for years. It is discussed in numerous physics textbooks and in journals. Now, it even has an Internet presence. Postings from students seek help for "ladder on a wall" problems. A quick review of those postings would show that they all deal with frictionless…

Experimental ladder proof of Hardy's nonlocality for high-dimensional quantum systems

NASA Astrophysics Data System (ADS)

Chen, Lixiang; Zhang, Wuhong; Wu, Ziwen; Wang, Jikang; Fickler, Robert; Karimi, Ebrahim

2017-08-01

Recent years have witnessed a rapidly growing interest in high-dimensional quantum entanglement for fundamental studies as well as towards novel applications. Therefore, the ability to verify entanglement between physical qudits, d -dimensional quantum systems, is of crucial importance. To show nonclassicality, Hardy's paradox represents "the best version of Bell's theorem" without using inequalities. However, so far it has only been tested experimentally for bidimensional vector spaces. Here, we formulate a theoretical framework to demonstrate the ladder proof of Hardy's paradox for arbitrary high-dimensional systems. Furthermore, we experimentally demonstrate the ladder proof by taking advantage of the orbital angular momentum of high-dimensionally entangled photon pairs. We perform the ladder proof of Hardy's paradox for dimensions 3 and 4, both with the ladder up to the third step. Our paper paves the way towards a deeper understanding of the nature of high-dimensionally entangled quantum states and may find applications in quantum information science.

Estimating ladder fuels: a new approach combining field photography with LiDAR

Treesearch

Heather Kramer; Brandon Collins; Frank Lake; Marek Jakubowski; Scott Stephens; Maggi Kelly

2016-01-01

Forests historically associated with frequent fire have changed dramatically due to fire suppression and past harvesting over the last century. The buildup of ladder fuels, which carry fire from the surface of the forest floor to tree crowns, is one of the critical changes, and it has contributed to uncharacteristically large and severe fires. The abundance of ladder...

Polarization-dependent infrared reflectivity study of Sr 2.5 Ca 11.5 Cu 24 O 41 under pressure: Charge dynamics, charge distribution, and anisotropy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, S.; Huber, A.; Ammerahl, U.

2014-12-18

We present a polarization-dependent infrared reflectivity study of the spin-ladder compound Sr₂̣₅Ca₁₁̣₅Cu₂₄O₄₁ under pressure. The optical response is strongly anisotropic, with the highest reflectivity along the ladders/chains ( E∥c) revealing a metallic character. For the polarization direction perpendicular to the ladder plane, an insulating behavior is observed. With increasing pressure the optical conductivity for E∥c shows a strong increase, which is most pronounced below 2000cm⁻¹. According to the spectral weight analysis of the E∥c optical conductivity the hole concentration in the ladders increases with increasing pressure and tends to saturate at high pressure. At ~7.5 GPa the number of holesmore » per Cu atom in the ladders has increased by Δδ=0.09(±0.01), and the Cu valence in the ladders has reached the value +2.33. Thus, the optical data suggest that Sr₂̣₅Ca₁₁̣₅Cu₂₄O₄₁ remains electronically highly anisotropic up to high pressure, also at low temperatures.« less

Biomechanical analysis of loading/unloading a ladder on a truck.

PubMed

Moriguchi, Cristiane Shinohara; Carnaz, Leticia; de Miranda, Luiz Carlos; Marklin, Richard William; Coury, Helenice Jane Cote Gil

2012-01-01

Loading/unloading a ladder on vehicles are frequent tasks and involve overhead handling that may expose workers to risk factors of shoulder musculoskeletal disorders. The objective of the present study was to evaluate posture, forces required and perceived exertion when loading and unloading the ladder on a utility truck. Thirteen male overhead line workers from an electric utility in Brazil participated in this study. Shoulder elevation angle was measured using inclinometers. The required force to load/unload the ladder was measured by dynamometer. Subjective assessment of the perceived exertion was recorded to compare the exertion reported during the test conditions to the field conditions. The task of loading/unloading the ladder presented risks of shoulder musculoskeletal disorders (MSDs) to workers because it requires high levels of force (approximately 60% of the maximal force) combined with overhead posture of the shoulders (more than 100° from the neutral posture). Age and height presented to interfere in biomechanical risks presented in load/unload task. There was no significant difference between the subjective exertion during the test conditions and handling the ladder in the field. Ergonomic intervention is recommended to reduce these risks for shoulder MSDs.

New insights into the origin of ladder dikes: Implications for punctuated growth and crystal accumulation in the Cathedral Peak granodiorite

NASA Astrophysics Data System (ADS)

Wiebe, R. A.; Jellinek, A. M.; Hodge, K. F.

2017-04-01

Ladder dikes are steep tabular bodies, typically a meter or less thick, composed of moderately dipping, concave upward, alternating dark (i.e. schlieren) and light bands oriented roughly perpendicular to the ladder dike margins. These structures occur widely but sparsely in granitic rocks and are found prominently in the Cathedral Peak granodiorite (CPG) of the Tuolumne Intrusive suite. Previous studies have interpreted that ladder dikes form as a result of processes including the downward flow of crystal mush in cracks within strong crystal mush or by upward flow in steep tubes that migrate within a strong crystal mush. Our new observations indicate that ladder dikes formed by downward flow of crystal mush in troughs or valleys, in a manner potentially comparable to trough bands in mafic layered intrusions. Extensions of the schlieren outward and upward away from the ladder dike margins into the host granite demonstrate that the host granite was deposited as mounds on both sides at the same time as the ladder dikes. Ladder dikes, therefore, record lateral flows of crystal mush on a magma chamber floor. Vertical exposures suggest these flows are on the order of ten meters thick. Some steep exposures on granite domes indicate multiple ladder dikes (and flows) over a stratigraphic height of 80-100 m. Later (stratigraphically higher) flows commonly deform and erode the top of an earlier flow, and granitic material rich in K-feldspar megacrysts has locally engulfed large blocks of ladder dikes, demonstrating that the megacrysts were also transported in flows. Flows in the CPG are directed away from the center of the pluton toward the western and eastern margins and apparently spread along a strong crystal mush floor and into a rheologically complex CPG magma. Whereas established dynamical models for spreading (single phase) gravity currents with simple and complex rheologies explain the elongate geometry, spacing and orientation of the tabular bodies, the origin and character of the downward flows required to explain the trough band schlieren structures is challenging. However, an intermittent and progressive deposition of trough bands, consistent with field observations, is potentially explained if the two-phase (crystals and melt) dynamics governing the response of the CPG magma to a new injection are considered.

Laser mass spectrometry for DNA sequencing, disease diagnosis, and fingerprinting

NASA Astrophysics Data System (ADS)

Chen, C. H. Winston; Taranenko, N. I.; Zhu, Y. F.; Chung, C. N.; Allman, S. L.

1997-05-01

Since laser mass spectrometry has the potential for achieving very fast DNA analysis, we recently applied it to DNA sequencing, DNA typing for fingerprinting, and DNA screening for disease diagnosis. Two different approaches for sequencing DNA have been successfully demonstrated. One is to sequence DNA with DNA ladders produced from Sanger's enzymatic method. The other is to do direct sequencing without DNA ladders. The need for quick DNA typing for identification purposes is critical for forensic application. Our preliminary results indicate laser mass spectrometry can possible be used for rapid DNA fingerprinting applications at a much lower cost than gel electrophoresis. Population screening for certain genetic disease can be a very efficient step to reducing medical costs through prevention. Since laser mass spectrometry can provide very fast DNA analysis, we applied laser mass spectrometry to disease diagnosis. Clinical samples with both base deletion and point mutation have been tested with complete success.

Made for Leadership: The Tools and Tips You Need to Effectively Climb the College Ladder

ERIC Educational Resources Information Center

Ullman, Ellen

2015-01-01

Good leaders need to develop and improve their skills. That's why the American Association of Community Colleges (AACC) created a set of competencies for community college leaders that has served as the foundation for informal and doctoral-level training programs. When the original competencies were revised in 2012, AACC sought input from a number…

Gluing Ladder Feynman Diagrams into Fishnets

DOE PAGES

Basso, Benjamin; Dixon, Lance J.

2017-08-14

We use integrability at weak coupling to compute fishnet diagrams for four-point correlation functions in planar Φ 4 theory. Our results are always multilinear combinations of ladder integrals, which are in turn built out of classical polylogarithms. The Steinmann relations provide a powerful constraint on such linear combinations, which leads to a natural conjecture for any fishnet diagram as the determinant of a matrix of ladder integrals.

Fluxoids configurations in finite superconducting networks

NASA Astrophysics Data System (ADS)

Sharon, Omri J.; Haham, Noam; Shaulov, Avner A.; Yeshurun, Yosef

2017-12-01

Analysis of superconducting ladders consisting of rectangular loops, yields an Ising like expression for the total energy of the ladders as a function of the loops vorticities and the applied magnetic field. This expression shows that fluxoids can be treated as repulsively interacting objects driven towards the ladder center by the applied field. Distinctive repulsive interactions between fluxoids are obtained depending on the ratio l between the loops length and the common width of adjacent loops. A 'short range' and a 'long range' interactions obtained for l ≳ 1 and l ≪ 1, respectively, give rise to remarkably different fluxoid configurations. The different configurations of fluxoids in different types of ladders are illustrated by simulations.

Dental Assistant, AFSC 981X0

DTIC Science & Technology

1989-03-01

career ladder assist dental officers in the performance of restorative, endodontic, orthodontic , pedodontic, periodontic, prosthodontic, and dental...representative location for orthodontic , pedodontic, and medi- cal readiness functions Randolph AFB TX Typical USAF Clinic In addition to interviews at the...the 2,230 personnel surveyed and are listed below. The relative time spent by respondents in each duty is pre - sented in Table 3. Selected background

Design concepts for a high-impedance narrow-band 42 GHz power TWT using a fundamental/forward ladder-based circuit

NASA Technical Reports Server (NTRS)

Karp, A.

1980-01-01

A low-cost, narrowband, millimeter wave space communications TWT design was studied. Cold test interaction structure scale models were investigated and analyses were undertaken to predict the electrical and thermal response of the hypothetical 200 W TWT at 42 GHz and 21 kV beam voltage. An intentionally narrow instantaneous bandwidth (1%, with the possibility of electronic tuning of the center frequency over several percent) was sought with a highly dispersive, high impedance "forward wave' interaction structure based on a ladder (for economy in fabrication) and nonspace harmonic interaction, for a high gain rate and a short, economically focused tube. The "TunneLadder' interaction structure devised combines ladder properties with accommodation for a pencil beam. Except for the impedance and bandwidth, there is much in common with the millimeter wave helix TWTs which provided the ideal of diamond support rods. The benefits of these are enhanced in the TunneLadder case because of spatial separation of beam interception and RF current heating.

Ladder Climbing and Autoresonant Acceleration of Plasma Waves

NASA Astrophysics Data System (ADS)

Barth, Ido; Dodin, Ilya; Fisch, Nathaniel

2015-11-01

When the background density in a bounded plasma is modulated in time, discrete modes become coupled. Interestingly, for appropriately chosen modulations, the average plasmon energy might be made to grow in a ladder-like manner, achieving up-conversion or down-conversion of the plasmon energy. This reversible process is identified as a classical analog of the effect known as quantum ladder climbing, so that the efficiency and the rate of this process can be written immediately by analogy to a quantum particle in a box. In the limit of densely spaced spectrum, ladder climbing transforms into continuous autoresonance; plasmons may then be manipulated by chirped background modulations much like electrons are autoresonantly manipulated by chirped fields. By formulating the wave dynamics within a universal Lagrangian framework, similar ladder climbing and autoresonance effects are predicted to be achievable with general linear waves in both plasma and other media. Supported by NNSA grant DE274-FG52-08NA28553, DOE contract DE-AC02-09CH11466, and DTRA grant HDTRA1-11-1-0037.

Ladder-structured photonic variable delay device

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

1998-01-01

An ladder-structured variable delay device for providing variable true time delay to multiple optical beams simultaneously. The device comprises multiple basic units stacked on top of each other resembling a ladder. Each basic unit comprises a polarization sensitive corner reflector formed by two polarization beamsplitters and a polarization rotator array placed parallel to the hypotenuse of the corner reflector. Controlling an array element of the polarization rotator array causes an optical beam passing through the array element to either go up to a basic unit above it or reflect back towards output. The beams going higher on the ladder experience longer optical path delay. Finally, the ladder-structured variable device can be cascaded with another multi-channel delay device to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Reconfigurable Analog PDE computation for Baseband and RFComputation

DTIC Science & Technology

2017-03-01

waveguiding PDEs. One-dimensional ladder topologies enable linear delays, linear-phase analog filters , as well as analog beamforming, potentially at RF...performance. This discussion focuses on ODE / PDE analog computation available in SoC FPAA structures. One such computation is a ladder filter (Fig...Implementation of a one-dimensional ladder filter for computing inductor (L) and capacitor (C) lines. These components can be implemented in CABs or as

Research of vibration controlling based on programmable logic controller for electrostatic precipitator

NASA Astrophysics Data System (ADS)

Zhang, Zisheng; Li, Yanhu; Li, Jiaojiao; Liu, Zhiqiang; Li, Qing

2013-03-01

In order to improve the reliability, stability and automation of electrostatic precipitator, circuits of vibration motor for ESP and vibration control ladder diagram program are investigated using Schneider PLC with high performance and programming software of Twidosoft. Operational results show that after adopting PLC, vibration motor can run automatically; compared with traditional control system of vibration based on single-chip microcomputer, it has higher reliability, better stability and higher dust removal rate, when dust emission concentrations <= 50 mg m-3, providing a new method for vibration controlling of ESP.

Ladder operators and coherent states for the Jaynes-Cummings model in the rotating-wave approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hussin, V.; Nieto, L.M.

2005-12-15

Using algebraic techniques, we realize a systematic search of different types of ladder operators for the Jaynes-Cummings model in the rotating-wave approximation. The link between our results and previous studies on the diagonalization of the associated Hamiltonian is established. Using some of the ladder operators obtained before, examples are given on the possibility of constructing a variety of interesting coherent states for this Hamiltonian.

The Health Services Mobility Study Method of Task Analysis and Curriculum Design. Research Report No. 11. Volume 3: Using the Computer to Develop Job Ladders.

ERIC Educational Resources Information Center

Gilpatrick, Eleanor

This document is volume 3 of a four-volume report which describes the components of the Health Services Mobility Study (HSMS) method of task analysis, job ladder design, and curriculum development. Divided into four chapters, volume 3 is a manual for using HSMS computer based statistical procedures to design job structures and job ladders. Chapter…

Pain in Patients with Pancreatic Cancer: Prevalence, Mechanisms, Management and Future Developments.

PubMed

Koulouris, Andreas I; Banim, Paul; Hart, Andrew R

2017-04-01

Pain affects approximately 80% of patients with pancreatic cancer, with half requiring strong opioid analgesia, namely: morphine-based drugs on step three of the WHO analgesic ladder (as opposed to the weak opioids: codeine and tramadol). The presence of pain is associated with reduced survival. This article reviews the literature regarding pain: prevalence, mechanisms, pharmacological, and endoscopic treatments and identifies areas for research to develop individualized patient pain management pathways. The online literature review was conducted through: PubMed, Clinical Key, Uptodate, and NICE Evidence. There are two principal mechanisms for pain: pancreatic duct obstruction and pancreatic neuropathy which, respectively, activate mechanical and chemical nociceptors. In pancreatic neuropathy, several histological, molecular, and immunological changes occur which correlate with pain including: transient receptor potential cation channel activation and mast cell infiltration. Current pain management is empirical rather etiology-based and is informed by the WHO analgesic ladder for first-line therapies, and then endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) in patients with resistant pain. For EUS-CPN, there is only one clinical trial reporting a benefit, which has limited generalizability. Case series report pancreatic duct stenting gives effective analgesia, but there are no clinical trials. Progress in understanding the mechanisms for pain and when this occurs in the natural history, together with assessing new therapies both pharmacological and endoscopic, will enable individualized care and may improve patients' quality of life and survival.

49 CFR 180.403 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to appurtenances, such as fender attachments, lighting brackets, ladder brackets; and (2) Replacement..., lighting brackets, ladder brackets; and (2) Replacement of components such as valves, vents, and fittings...

Doping evolution of charge and spin excitations in two-leg Hubbard ladders: Comparing DMRG and FLEX results [Doping evolution of charge and spin excitations in two-leg Hubbard ladders: Comparing DMRG and RPA+FLEX results

DOE PAGES

Nocera, Alberto; Wang, Yan; Patel, Niravkumar D.; ...

2018-05-31

Here, we study the magnetic and charge dynamical response of a Hubbard model in a two-leg ladder geometry using the density matrix renormalization group (DMRG) method and the random phase approximation within the fluctuation-exchange approximation (FLEX). Our calculations reveal that FLEX can capture the main features of the magnetic response from weak up to intermediate Hubbard repulsion for doped ladders, when compared with the numerically exact DMRG results. However, while at weak Hubbard repulsion both the spin and charge spectra can be understood in terms of weakly interacting electron-hole excitations across the Fermi surface, at intermediate coupling DMRG shows gappedmore » spin excitations at large momentum transfer that remain gapless within the FLEX approximation. For the charge response, FLEX can only reproduce the main features of the DMRG spectra at weak coupling and high doping levels, while it shows an incoherent character away from this limit. Overall, our analysis shows that FLEX works surprisingly well for spin excitations at weak and intermediate Hubbard U values even in the difficult low-dimensional geometry such as a two-leg ladder. Finally, we discuss the implications of our results for neutron scattering and resonant inelastic x-ray scattering experiments on two-leg ladder cuprate compounds.« less

Doping evolution of charge and spin excitations in two-leg Hubbard ladders: Comparing DMRG and FLEX results [Doping evolution of charge and spin excitations in two-leg Hubbard ladders: Comparing DMRG and RPA+FLEX results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nocera, Alberto; Wang, Yan; Patel, Niravkumar D.

Here, we study the magnetic and charge dynamical response of a Hubbard model in a two-leg ladder geometry using the density matrix renormalization group (DMRG) method and the random phase approximation within the fluctuation-exchange approximation (FLEX). Our calculations reveal that FLEX can capture the main features of the magnetic response from weak up to intermediate Hubbard repulsion for doped ladders, when compared with the numerically exact DMRG results. However, while at weak Hubbard repulsion both the spin and charge spectra can be understood in terms of weakly interacting electron-hole excitations across the Fermi surface, at intermediate coupling DMRG shows gappedmore » spin excitations at large momentum transfer that remain gapless within the FLEX approximation. For the charge response, FLEX can only reproduce the main features of the DMRG spectra at weak coupling and high doping levels, while it shows an incoherent character away from this limit. Overall, our analysis shows that FLEX works surprisingly well for spin excitations at weak and intermediate Hubbard U values even in the difficult low-dimensional geometry such as a two-leg ladder. Finally, we discuss the implications of our results for neutron scattering and resonant inelastic x-ray scattering experiments on two-leg ladder cuprate compounds.« less

Real-space localization and quantification of hole distribution in chain-ladder Sr3Ca11Cu24O41 superconductor.

PubMed

Bugnet, Matthieu; Löffler, Stefan; Hawthorn, David; Dabkowska, Hanna A; Luke, Graeme M; Schattschneider, Peter; Sawatzky, George A; Radtke, Guillaume; Botton, Gianluigi A

2016-03-01

Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and ladders and to unravel the hole distribution from the atomic scale variations of the O-K near-edge structures. The experimental data unambiguously demonstrate that most of the holes lie within the chain layers. A quantitative interpretation supported by inelastic scattering calculations shows that about two holes are located in the ladders, and about four holes in the chains, shedding light on the electronic structure of Sr3Ca11Cu24O41. Combined atomic resolution STEM-EELS and inelastic scattering calculations is demonstrated as a powerful approach toward a quantitative understanding of the electronic structure of cuprate superconductors, offering new possibilities for elucidating their physical properties.

ABC of ladder operators for rationally extended quantum harmonic oscillator systems

NASA Astrophysics Data System (ADS)

Cariñena, José F.; Plyushchay, Mikhail S.

2017-07-01

The problem of construction of ladder operators for rationally extended quantum harmonic oscillator (REQHO) systems of a general form is investigated in the light of existence of different schemes of the Darboux-Crum-Krein-Adler transformations by which such systems can be generated from the quantum harmonic oscillator. Any REQHO system is characterized by the number of separated states in its spectrum, the number of ‘valence bands’ in which the separated states are organized, and by the total number of the missing energy levels and their position. All these peculiarities of a REQHO system are shown to be detected and reflected by a trinity (A^+/- , B^+/- , C^+/-) of the basic (primary) lowering and raising ladder operators related between themselves by certain algebraic identities with coefficients polynomially-dependent on the Hamiltonian. We show that all the secondary, higher-order ladder operators are obtainable by a composition of the basic ladder operators of the trinity which form the set of the spectrum-generating operators. Each trinity, in turn, can be constructed from the intertwining operators of the two complementary minimal schemes of the Darboux-Crum-Krein-Adler transformations.

Real-space localization and quantification of hole distribution in chain-ladder Sr3Ca11Cu24O41 superconductor

PubMed Central

Bugnet, Matthieu; Löffler, Stefan; Hawthorn, David; Dabkowska, Hanna A.; Luke, Graeme M.; Schattschneider, Peter; Sawatzky, George A.; Radtke, Guillaume; Botton, Gianluigi A.

2016-01-01

Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and ladders and to unravel the hole distribution from the atomic scale variations of the O-K near-edge structures. The experimental data unambiguously demonstrate that most of the holes lie within the chain layers. A quantitative interpretation supported by inelastic scattering calculations shows that about two holes are located in the ladders, and about four holes in the chains, shedding light on the electronic structure of Sr3Ca11Cu24O41. Combined atomic resolution STEM-EELS and inelastic scattering calculations is demonstrated as a powerful approach toward a quantitative understanding of the electronic structure of cuprate superconductors, offering new possibilities for elucidating their physical properties. PMID:27051872

34. Attic, from folding ladder, looking north Veterans Administration ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

34. Attic, from folding ladder, looking north - Veterans Administration Center, Officers Duplex Quarters, 5302 East Kellogg (Legal Address); 5500 East Kellogg (Common Address), Wichita, Sedgwick County, KS

Development and Use of a Goal Setting/Attainment Process Designed To Measure a Teacher's Ability To Engage in Professional Growth and Leadership Initiatives.

ERIC Educational Resources Information Center

Minix, Nancy; And Others

The process used to evaluate progress in identifying the goals to be used in evaluating teacher performance under the Kentucky Career Ladder Program is described. The process pertains to two areas of teacher development: (1) professional growth and development, and (2) professional leadership and initiative. A total of 1,650 individuals were asked…

Ergonomics in designing process: dialogue between designers, executors and users in the maintenance activity of radars in an oil refinery.

PubMed

Menegon, Fabrício Augusto; Rodrigues, Daniela da Silva; Fontes, Andréa Regina Martins; Menegon, Nilton Luiz

2012-01-01

This paper aims to discuss the role of ergonomics in design process using the dialogue developed by designers, implementers and users in an oil refinery. It was possible to identify the need of minimizing the postural constraints, risk of accidents, mechanical shocks and to enlarge safety perception in the access and permanency of the users at the workspace. It has been determined and validated by workers and managers to implement different deadlines depending on programming, viability and execution time for the improvements proposed. In a long-term: it was proposed the substitution of the ladders with time planning according to the maintenance program of the tanks; in a short-time: it was suggested the expansion of the existing platforms, implementation of a walkway connection provided with guardrails between the upper access of the side ladder and the repositioning of radar set and aerial aiming at the usage by workers at the workstation of the new platform. It was also elaborated eight typologies of intervention, according to the request, type of tank, material stored, and its setting place. The design process arises from ergonomics workplace analysis that presents concepts for solutions which was a mediator tool to be settled between users and implementers.

Piezoelectric biosensor with a ladder polymer substrate coating

DOEpatents

Renschler, Clifford L.; White, Christine A.; Carter, Robert M.

1998-01-01

A piezoelectric biosensor substrate useful for immobilizing biomolecules in an oriented manner on the surface of a piezoelectric sensor has a ladder polymer of polyacrylonitrile. To make the substrate, a solution of an organic polymer, preferably polyacrylonitrile, is applied to the surface of a piezoelectric sensor. The organic polymer is modifying by heating the polymer in a controlled fashion in air such that a ladder polymer is produced which, in turn, forms the attachment point for the biomolecules comprising the piezoelectric biosensor.

Piezoelectric biosensor with a ladder polymer substrate coating

DOEpatents

Renschler, C.L.; White, C.A.; Carter, R.M.

1998-09-29

A piezoelectric biosensor substrate useful for immobilizing biomolecules in an oriented manner on the surface of a piezoelectric sensor has a ladder polymer of polyacrylonitrile. To make the substrate, a solution of an organic polymer, preferably polyacrylonitrile, is applied to the surface of a piezoelectric sensor. The organic polymer is modifying by heating the polymer in a controlled fashion in air such that a ladder polymer is produced which, in turn, forms the attachment point for the biomolecules comprising the piezoelectric biosensor. 3 figs.

7. DETAIL, WINDOWS AND SAFETY LADDER AT RECEIVING DEPARTMENT, NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. DETAIL, WINDOWS AND SAFETY LADDER AT RECEIVING DEPARTMENT, NORTH SIDE, NEAR WEST END. - United Engineering Company Shipyard, Inspection & Repair Shops, 2900 Main Street, Alameda, Alameda County, CA

The incidence and burden of ladder, structure, and scaffolding falls.

PubMed

Diggs, Brian S; Lenfesty, Barbara; Arthur, Melanie; Hedges, Jerris R; Newgard, Craig D; Mullins, Richard J

2005-03-01

The national morbidity and mortality associated with falls from a height is incompletely described. The authors estimated the rates of injury, hospitalization, and mortality due to these falls for subgroups of the U.S. population. Administrative databases (1995-2000) provided national samples of patients treated for injuries following a fall from a height (ICD-9-CM E-codes E881.0, E881.1, or E882). Inpatient data are from the Nationwide Inpatient Sample, and emergency department data are from the National Hospital Ambulatory Medical Care Survey. A total of 347,484 (95% confidence interval = 308,417 to 386,551) emergency department presentations occur annually for injuries following a fall. Hospitalized patients older than 75 years of age had a 3.3% case fatality, and 42% were discharged to a skilled nursing facility. For patients older than 55 years of age, 86% of falls were not work related. Ladder and structure falls by elders are a substantial emergency department problem warranting thorough clinical evaluation and injury prevention efforts.

Delayed rectifier potassium channels are involved in SO2 derivative-induced hippocampal neuronal injury.

PubMed

Li, Guangke; Sang, Nan

2009-01-01

Recent studies implicate the possible neurotoxicity of SO(2), however, its mechanisms remain unclear. In the present study, we investigated SO(2) derivative-induced effect on delayed rectifier potassium channels (I(K)) and cellular death/apoptosis in primary cultured hippocampal neurons. The results demonstrate that SO(2) derivatives (NaHSO(3) and Na(2)SO(3), 3:1M/M) effectively augmented I(K) and promoted the activation of delayed rectifier potassium channels. Also, SO(2) derivatives increased neuronal death percentage and contributed to the formation of DNA ladder in concentration-dependent manners. Interestingly, the neuronal death and DNA ladder formation, caused by SO(2) derivatives, could be attenuated by the delayed rectifier potassium channel blocker (tetraethylammonium, TEA), but not by the transient outward potassium channel blocker (4-aminopyridine, 4-AP). It implies that stimulating delayed rectifier potassium channels were involved in SO(2) derivative-caused hippocampal neuronal insults, and blocking these channels might be one of the possibly clinical treatment for SO(2)-caused neuronal dysfunction.

29 CFR 1910.25 - Portable wood ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... library ladders are not specifically covered by this section. (b) Materials—(1) Requirements applicable to... device of sufficient size and strength to securely hold the front and back sections in open positions...

29 CFR 1910.25 - Portable wood ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

... library ladders are not specifically covered by this section. (b) Materials—(1) Requirements applicable to... device of sufficient size and strength to securely hold the front and back sections in open positions...

29 CFR 1910.26 - Portable metal ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of ladder equipment must be employed by the users. The following rules and regulations are essential... to oil and grease, equipment should be cleaned of oil, grease, or slippery materials. This can easily...

29 CFR 1910.26 - Portable metal ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

... of ladder equipment must be employed by the users. The following rules and regulations are essential... to oil and grease, equipment should be cleaned of oil, grease, or slippery materials. This can easily...

29 CFR 1910.26 - Portable metal ladders.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of ladder equipment must be employed by the users. The following rules and regulations are essential... to oil and grease, equipment should be cleaned of oil, grease, or slippery materials. This can easily...

Interplay of localized pyrene chromophores and π-conjugation in novel poly(2,7-pyrene) ladder polymers

NASA Astrophysics Data System (ADS)

Rudnick, Alexander; Kass, Kim-Julia; Preis, Eduard; Scherf, Ullrich; Bässler, Heinz; Köhler, Anna

2017-05-01

We present a detailed spectroscopic study, along with the synthesis, of conjugated, ladder-type 2,7-linked poly(pyrene)s. We observe a delocalization of the first singlet excited state along the polymer backbone, i.e., across the 2,7 linkage in the pyrene moiety, in contrast to earlier studies on conjugated 2,7-linked poly(pyrene)s without ladder structure. The electronic signature of the pyrene unit is, however, manifested in an increased lifetime and reduced oscillator strength as well as a modified vibronic progression in absorption of the singlet state compared to a ladder-type poly(para-phenylene) (MeLPPP). Furthermore, the reduced oscillator strength and increased lifetime slow down Förster-type energy transfer in films, where this transfer occurs to sites with increasing inter-chain coupling of H-type nature.

Occupational ladder fall injuries - United States, 2011.

PubMed

Socias, Christina M; Chaumont Menéndez, Cammie K; Collins, James W; Simeonov, Peter

2014-04-25

Falls remain a leading cause of unintentional injury mortality nationwide [corrected].Among workers, approximately 20% of fall injuries involve ladders. Among construction workers, an estimated 81% of fall injuries treated in U.S. emergency departments (EDs) involve a ladder. To fully characterize fatal and nonfatal injuries associated with ladder falls among workers in the United States, CDC's National Institute for Occupational Safety and Health (NIOSH) analyzed data across multiple surveillance systems: 1) the Census of Fatal Occupational Injuries (CFOI), 2) the Survey of Occupational Injuries and Illnesses (SOII), and 3) the National Electronic Injury Surveillance System-occupational supplement (NEISS-Work). In 2011, work-related ladder fall injuries (LFIs) resulted in 113 fatalities (0.09 per 100,000 full-time equivalent [FTE] workers), an estimated 15,460 nonfatal injuries reported by employers that involved ≥1 days away from work (DAFW), and an estimated 34,000 nonfatal injuries treated in EDs. Rates for nonfatal, work-related, ED-treated LFIs were higher (2.6 per 10,000 FTE) than those for such injuries reported by employers (1.2 per 10,000 FTE). LFIs represent a substantial public health burden of preventable injuries for workers. Because falls are the leading cause of work-related injuries and deaths in construction, NIOSH, the Occupational Safety and Health Administration, and the Center for Construction Research and Training are promoting a national campaign to prevent workplace falls. NIOSH is also developing innovative technologies to complement safe ladder use.

The effects of Navy ship ladder descent on the knee internal joint reaction forces

NASA Astrophysics Data System (ADS)

Coulter, Jonathan D.; Weinhandl, Joshua T.; Bawab, Sebastian Y.; Ringleb, Stacie I.

2017-02-01

Military populations may be at risk for developing knee osteoarthritis and other knee problems when descending a Navy ship ladder, which differs from traditional stairs due to non-overlapping treads, a larger rise and a steeper inclination angle. The purpose of this study was to develop a forward dynamic model of the descent of a Navy ship ladder to determine how this motion affects the internal knee reaction forces and how altering the hamstring/quadriceps ratio affects the internal joint reaction forces in the knee. Kinematic and kinetic data were collected from three male sailors descending a replica of a Navy ship ladder and were used as input into a model constructed in OpenSim. The peak resultant joint reaction force was 6.6 × BW, which was greater than values reported in the literature in traditional stairs. Peak compressive and anterior joint reaction forces, 4.05 × BW and 5.46 × BW, respectively, were greater than reported values for a squat, a motion similar to descending a ship ladder. The average peak vertical and anterior internal joint reaction force at the knee were 4.05 × BW and 5.46 × BW, respectively. The resultant joint reaction forces calculated from the ladder descent were greater than stair descent and squatting. Little effects were found in the joint reaction forces after adjusting the quadriceps to hamstring muscle strength ratios, possibly because these ratios might change the distribution of the contact forces across the joint, not the resultant forces.

Synthesis of dibenzothiophene-containing ladder polysilsesquioxane as a blue phosphorescent host material.

PubMed

Ren, Zhongjie; Sun, Dianming; Li, Huihui; Fu, Qiang; Ma, Dongge; Zhang, Jianming; Yan, Shouke

2012-03-26

A ladder polysilsesquioxanes with side chain of dibenzothiophene groups (BS-LPSQ) was successfully synthesized. The ladder structure of BS-LPSQ was characterized by MALDI-TOF MS, XRD, and (1)H NMR spectroscopy. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and spectroscopic analyses revealed that the BS-LPSQ has good film-forming ability, high thermal and morphological stability, and good miscibility to the dopant iridium bis(4,6-difluorophenyl)pyridinato-N,C(2)-picolinate (FIrpic), high triplet energy, and a wide bandgap. In addition, compared with the ringed polysiloxane BS-PSQ phosphorescent host material reported previously, the ladder structure of BS-LPSQ has not only a higher thermal resistance, but also could prevent molecular aggregation and effectively avoid quenching of fluorescence. Thus, the BS-LPSQ may be used as a better host for the blue-light-emitting iridium complex FIrpic. The performance of the electrophosphorescent device, based on the ladder BS-LPSQ as the active layer, is superior to that of ringed BS-PSQ and any other polyhedral oligomeric silsesquioxane (POSS)-based or polymer host materials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

46 CFR 163.003-1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... production tests for a pilot ladder used on a merchant vessel to embark and disembark pilots and other persons when away from the dock. (b) The requirements in this subpart apply to a pilot ladder designed for...

1. OVERALL VIEW SHOWING FACE OF CONCRETE GRAVITY DAM AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. OVERALL VIEW SHOWING FACE OF CONCRETE GRAVITY DAM AND FISH LADDER, LOOKING SOUTHWEST (UPSTREAM) FROM SNORE OPPOSITE FISH LADDER - Van Arsdale Dam, South Fork of Eel River, Ukiah, Mendocino County, CA

Partnering on a Curriculum To Address the Dental Care Crisis in a Rural Island Community: The First Step of a Career Ladder Program in Dental Assisting.

ERIC Educational Resources Information Center

Pezzoli, J. A.; Johnson, Nancy

This document describes the curriculum and objectives of the Certificate of Completion in Dental Assisting at Maui Community College, Hawaii. Hawaii is below the national average in oral health care, with as many as 40% of Maui residents being underserved. Dental disease among the uninsured and underinsured in Hawaii is three times the national…

Observation hall along west side. Looking south to escape ladder. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Observation hall along west side. Looking south to escape ladder. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

46 CFR 160.017-1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... approval and production tests for chain ladders used on a merchant vessel to get on and off the vessel in an emergency. (b) The requirements in this subpart apply to a chain ladder designed for use along a...

Controlled parity switch of persistent currents in quantum ladders

NASA Astrophysics Data System (ADS)

Filippone, Michele; Bardyn, Charles-Edouard; Giamarchi, Thierry

2018-05-01

We investigate the behavior of persistent currents for a fixed number of noninteracting fermions in a periodic quantum ladder threaded by Aharonov-Bohm and transverse magnetic fluxes Φ and χ . We show that the coupling between ladder legs provides a way to effectively change the ground-state fermion-number parity, by varying χ . Specifically, we demonstrate that varying χ by 2 π (one flux quantum) leads to an apparent fermion-number parity switch. We find that persistent currents exhibit a robust 4 π periodicity as a function of χ , despite the fact that χ →χ +2 π leads to modifications of order 1 /N of the energy spectrum, where N is the number of sites in each ladder leg. We show that these parity-switch and 4 π periodicity effects are robust with respect to temperature and disorder, and outline potential physical realizations using cold atomic gases and photonic lattices, for bosonic analogs of the effects.

Phase diagram and re-entrant fermionic entanglement in a hybrid Ising-Hubbard ladder

NASA Astrophysics Data System (ADS)

Sousa, H. S.; Pereira, M. S. S.; de Oliveira, I. N.; Strečka, J.; Lyra, M. L.

2018-05-01

The degree of fermionic entanglement is examined in an exactly solvable Ising-Hubbard ladder, which involves interacting electrons on the ladder's rungs described by Hubbard dimers at half-filling on each rung, accounting for intrarung hopping and Coulomb terms. The coupling between neighboring Hubbard dimers is assumed to have an Ising-like nature. The ground-state phase diagram consists of four distinct regions corresponding to the saturated paramagnetic, the classical antiferromagnetic, the quantum antiferromagnetic, and the mixed classical-quantum phase. We have exactly computed the fermionic concurrence, which measures the degree of quantum entanglement between the pair of electrons on the ladder rungs. The effects of the hopping amplitude, the Coulomb term, temperature, and magnetic fields on the fermionic entanglement are explored in detail. It is shown that the fermionic concurrence displays a re-entrant behavior when quantum entanglement is being generated at moderate temperatures above the classical saturated paramagnetic ground state.

Fractal ladder models and power law wave equations

PubMed Central

Kelly, James F.; McGough, Robert J.

2009-01-01

The ultrasonic attenuation coefficient in mammalian tissue is approximated by a frequency-dependent power law for frequencies less than 100 MHz. To describe this power law behavior in soft tissue, a hierarchical fractal network model is proposed. The viscoelastic and self-similar properties of tissue are captured by a constitutive equation based on a lumped parameter infinite-ladder topology involving alternating springs and dashpots. In the low-frequency limit, this ladder network yields a stress-strain constitutive equation with a time-fractional derivative. By combining this constitutive equation with linearized conservation principles and an adiabatic equation of state, a fractional partial differential equation that describes power law attenuation is derived. The resulting attenuation coefficient is a power law with exponent ranging between 1 and 2, while the phase velocity is in agreement with the Kramers–Kronig relations. The fractal ladder model is compared to published attenuation coefficient data, thus providing equivalent lumped parameters. PMID:19813816

Pressure-induced superconductivity in the iron-based ladder material BaFe2S3.

PubMed

Takahashi, Hiroki; Sugimoto, Akira; Nambu, Yusuke; Yamauchi, Touru; Hirata, Yasuyuki; Kawakami, Takateru; Avdeev, Maxim; Matsubayashi, Kazuyuki; Du, Fei; Kawashima, Chizuru; Soeda, Hideto; Nakano, Satoshi; Uwatoko, Yoshiya; Ueda, Yutaka; Sato, Taku J; Ohgushi, Kenya

2015-10-01

All the iron-based superconductors identified so far share a square lattice composed of Fe atoms as a common feature, despite having different crystal structures. In copper-based materials, the superconducting phase emerges not only in square-lattice structures but also in ladder structures. Yet iron-based superconductors without a square-lattice motif have not been found, despite being actively sought out. Here, we report the discovery of pressure-induced superconductivity in the iron-based spin-ladder material BaFe2S3, a Mott insulator with striped-type magnetic ordering below ∼120 K. On the application of pressure this compound exhibits a metal-insulator transition at about 11 GPa, followed by the appearance of superconductivity below Tc = 14 K, right after the onset of the metallic phase. Our findings indicate that iron-based ladder compounds represent promising material platforms, in particular for studying the fundamentals of iron-based superconductivity.

Staggered Orbital Currents in the Half-Filled Two-Leg Ladder

NASA Astrophysics Data System (ADS)

Fjaerestad, J. O.; Marston, Brad; Sudbo, A.

2002-03-01

We present strong analytical and numerical evidence for the existence of a staggered flux (SF) phase in the half-filled two-leg ladder, with true long-range order in the counter-circulating currents. Using abelian bosonization with a careful treatment of the Klein factors, we show that a certain phase of the half-filled ladder, previously identified as having spin-Peierls order, instead exhibits staggered orbital currents with no dimerization.(J. O. Fjærestad and J. B. Marston, cond- mat/0107094.) This result, combined with a weak-coupling renormalization-group analysis, implies that the SF phase exists in a region of the phase diagram of the half-filled t-U-V-J ladder. Using the density-matrix renormalization-group (DMRG) approach generalized to complex-valued wavefunctions, we demonstrate that the SF phase exhibits robust currents at intermediate values of the interaction strengths.

Magnetic properties and pairing tendencies of the iron-based superconducting ladder BaFe 2 S 3 : Combined ab initio and density matrix renormalization group study

DOE PAGES

Patel, Niravkumar D.; Nocera, Alberto; Alvarez, Gonzalo; ...

2016-08-10

The recent discovery of superconductivity under high pressure in the two-leg ladder compound BaFe 2S 3 [H. Takahashi et al., Nat. Mater. 14, 1008 (2015)] opens a broad avenue of research, because it represents the first report of pairing tendencies in a quasi-one-dimensional iron-based high-critical-temperature superconductor. Similarly, as in the case of the cuprates, ladders and chains can be far more accurately studied using many-body techniques and model Hamiltonians than their layered counterparts, particularly if several orbitals are active. In this publication, we derive a two-orbital Hubbard model from first principles that describes individual ladders of BaFe 2S 3. Themore » model is studied with the density matrix renormalization group. These first reported results are exciting for two reasons: (i) at half-filling, ferromagnetic order emerges as the dominant magnetic pattern along the rungs of the ladder, and antiferromagnetic order along the legs, in excellent agreement with neutron experiments; and (ii) with hole doping, pairs form in the strong coupling regime, as found by studying the binding energy of two holes doped on the half-filled system. In addition, orbital selective Mott phase characteristics develop with doping, with only oneWannier orbital receiving the hole carriers while the other remains half-filled. Lastly, these results suggest that the analysis of models for iron-based two-leg ladders could clarify the origin of pairing tendencies and other exotic properties of iron-based high-critical-temperature superconductors in general.« less

Climbing the Cosmic Distance Ladder Artist Concept

NASA Image and Video Library

2012-10-03

Astronomers using NASA Spitzer Space Telescope have greatly improved the cosmic distance ladder used to measure the expansion rate of the universe, its size and age. This artist concept symbolically shows a series of stars that have known distances.

LEANTO INTERIOR, LOOKING EAST. Image shows: ladder attached to south ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LEAN-TO INTERIOR, LOOKING EAST. Image shows: ladder attached to south façade, gate separating hay storage from animal pens, and east wall construction. - Boyer Farm, Barn, 711 South Fort Casey Road, Coupeville, Island County, WA

46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (1) Stairways, stairtowers, ladders, elevators, and landings must be designed with sufficient... accommodation spaces: Designed capacity; (ii) Accommodation spaces having fixed seating for passengers: Maximum seating capacity; (iii) Public spaces, including spaces such as casinos, restaurants, club rooms, and...

Ladder Operators for Some Spherically Symmetric Potentials in Quantum Mechanics

ERIC Educational Resources Information Center

Newmarch, J. D.; Golding, R. M.

1978-01-01

The energy levels of the free field, Coulomb potential, and the three-dimensional harmonic oscillator are found using the Dirac operator formalism by the construction of suitable ladder operators. The degeneracy of each level is also discussed. (Author/GA)

"Ladder" structure in tonal noise generated by laminar flow around an airfoil.

PubMed

Chong, Tze Pei; Joseph, Phillip

2012-06-01

The presence of a "ladder" structure in the airfoil tonal noise was discovered in the 1970s, but its mechanism hitherto remains a subject of continual investigation in the research community. Based on the measured noise results and some numerical analysis presented in this letter, the variations of four types of airfoil tonal noise frequencies with the flow velocity were analyzed individually. The ladder structure is proposed to be caused by the acoustic/hydrodynamic frequency lag between the scattering of the boundary layer instability noise and the discrete noise produced by an aeroacoustic feedback loop.

Analytical recursive method to ascertain multisite entanglement in doped quantum spin ladders

NASA Astrophysics Data System (ADS)

Roy, Sudipto Singha; Dhar, Himadri Shekhar; Rakshit, Debraj; SenDe, Aditi; Sen, Ujjwal

2017-08-01

We formulate an analytical recursive method to generate the wave function of doped short-range resonating valence bond (RVB) states as a tool to efficiently estimate multisite entanglement as well as other physical quantities in doped quantum spin ladders. We prove that doped RVB ladder states are always genuine multipartite entangled. Importantly, our results show that within specific doping concentration and model parameter regimes, the doped RVB state essentially characterizes the trends of genuine multiparty entanglement in the exact ground states of the Hubbard model with large on-site interactions, in the limit that yields the t -J Hamiltonian.

Simulation of TunneLadder traveling-wave tube cold-test characteristics: Implementation of the three-dimensional, electromagnetic circuit analysis code micro-SOS

NASA Technical Reports Server (NTRS)

Kory, Carol L.; Wilson, Jeffrey D.

1993-01-01

The three-dimensional, electromagnetic circuit analysis code, Micro-SOS, can be used to reduce expensive time-consuming experimental 'cold-testing' of traveling-wave tube (TWT) circuits. The frequency-phase dispersion characteristics and beam interaction impedance of a TunneLadder traveling-wave tube slow-wave structure were simulated using the code. When reasonable dimensional adjustments are made, computer results agree closely with experimental data. Modifications to the circuit geometry that would make the TunneLadder TWT easier to fabricate for higher frequency operation are explored.

Majorana spin liquids, topology, and superconductivity in ladders

NASA Astrophysics Data System (ADS)

Le Hur, Karyn; Soret, Ariane; Yang, Fan

2017-11-01

We theoretically address spin chain analogs of the Kitaev quantum spin model on the honeycomb lattice. The emergent quantum spin-liquid phases or Anderson resonating valence-bond (RVB) states can be understood, as an effective model, in terms of p -wave superconductivity and Majorana fermions. We derive a generalized phase diagram for the two-leg ladder system with tunable interaction strengths between chains allowing us to vary the shape of the lattice (from square to honeycomb ribbon or brickwall ladder). We evaluate the winding number associated with possible emergent (topological) gapless modes at the edges. In the Az phase, as a result of the emergent Z2 gauge fields and π -flux ground state, one may build spin-1/2 (loop) qubit operators by analogy to the toric code. In addition, we show how the intermediate gapless B phase evolves in the generalized ladder model. For the brick-wall ladder, the B phase is reduced to one line, which is analyzed through perturbation theory in a rung tensor product states representation and bosonization. Finally, we show that doping with a few holes can result in the formation of hole pairs and leads to a mapping with the Su-Schrieffer-Heeger model in polyacetylene; a superconducting-insulating quantum phase transition for these hole pairs is accessible, as well as related topological properties.

Automated Translation of Safety Critical Application Software Specifications into PLC Ladder Logic

NASA Technical Reports Server (NTRS)

Leucht, Kurt W.; Semmel, Glenn S.

2008-01-01

The numerous benefits of automatic application code generation are widely accepted within the software engineering community. A few of these benefits include raising the abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at the NASA Kennedy Space Center (KSC) recognized the need for PLC code generation while developing their new ground checkout and launch processing system. They developed a process and a prototype software tool that automatically translates a high-level representation or specification of safety critical application software into ladder logic that executes on a PLC. This process and tool are expected to increase the reliability of the PLC code over that which is written manually, and may even lower life-cycle costs and shorten the development schedule of the new control system at KSC. This paper examines the problem domain and discusses the process and software tool that were prototyped by the KSC software engineers.

The transport dynamics of chloride and sodium in a ladder fen during a continuous wastewater polishing experiment

NASA Astrophysics Data System (ADS)

McCarter, Colin P. R.; Price, Jonathan S.

2017-06-01

Ladder fen peatlands have excellent potential for wastewater polishing as they naturally contain both open water (pools) and subsurface (peat) treatment landforms; however, there is a poor understanding of solute transport in ladder fens with and without the increased hydrological load imposed by wastewater discharge. To better understand solute transport in ladder fens under wastewater polishing conditions a continuous solute (NaCl) tracer experiment (38 m3 day-1 of water, chloride - 47.2 mg L-1, and sodium - 25.3 mg L-1) was conducted during the summer of 2014 (day of year 192-243) in a small ladder fen in the James Bay Lowland. The transmissivity distribution and effective porosity (average 0.5) of the peat ribs were determined through repeated bail tests and the drainable porosity of 18 peat cores at -100 mb, respectively. Water samples were taken at least every 7 days to capture the solute (sodium and chloride) plumes. Both solute plumes never reached the site outflow (∼250 m downgradient) and displayed complex plume morphology, typically following the patterns of higher hydraulic conductivity within the upper 0.1 m of the saturated peat, rather than the microtopography. Based on the 50% breakthrough isotherms, sodium and chloride were transported at an average solute velocity of 1.9 and 1.1 m day-1, respectively (average linear groundwater velocity = 2.1 m day-1); thus, the solutes were retarded by a factor of 2.1 and 1.2 for sodium and chloride, respectively. Due to the inherent retardation of solutes into inactive pores and relatively high solute residence times, this study demonstrates the potential for wastewater polishing in ladder fens.

Poly[[sesqui[mu2-1,4-bis(imidazol-1-ylmethyl)benzene-kappa(2)N:N'](carbonato-kappa(2)O,O')copper(II)] 1,4-bis(imidazol-1-ylmethyl)benzene hemisolvate pentahydrate].

PubMed

Dai, Yu-Mei; Tang, En; Huang, Jin-Feng; Yang, Qiu-Yan

2008-10-01

The asymmetric unit of the title compound, {[Cu(CO(3))(C(14)H(14)N(4))(1.5)] x 0.5 C(14)H(14)N(4) x 5 H(2)O}(n), contains one Cu(II) cation in a slightly distorted square-pyramidal coordination environment, one CO(3)(2-) anion, one full and two half 1,4-bis(imidazol-1-ylmethyl)benzene (bix) ligands, one half-molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)(1.5)](n) molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 A. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu(II) atom is completed by two O atoms of the CO(3)(2-) anion. The framework is further strengthened by extensive O-H...O and O-H...N hydrogen bonds involving the water molecules, the O atoms of the CO(3)(2-) anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.

29 CFR 1917.118 - Fixed ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... bolts or structural members of tanks and towers; (3) Ladders built into or vertically attached to..., microwave communications, electrical power and similar towers, poles and structures, including stacks and... consisting of individual rungs that are attached to walls, conical manhole sections or river cells shall: (1...

29 CFR 1917.118 - Fixed ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

... bolts or structural members of tanks and towers; (3) Ladders built into or vertically attached to..., microwave communications, electrical power and similar towers, poles and structures, including stacks and... consisting of individual rungs that are attached to walls, conical manhole sections or river cells shall: (1...

46 CFR 163.003-13 - Construction.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Construction. 163.003-13 Section 163.003-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-13 Construction. (a) General. Each pilot ladder...

46 CFR 163.003-13 - Construction.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Construction. 163.003-13 Section 163.003-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-13 Construction. (a) General. Each pilot ladder...

46 CFR 163.003-13 - Construction.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Construction. 163.003-13 Section 163.003-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-13 Construction. (a) General. Each pilot ladder...

46 CFR 163.003-13 - Construction.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Construction. 163.003-13 Section 163.003-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-13 Construction. (a) General. Each pilot ladder...

29 CFR 1910.26 - Portable metal ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.26 Portable metal ladders. (a... material for the safety of the user. (viii) A metal spreader or locking device of sufficient size and...

46 CFR 160.017-17 - Strength.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Strength. 160.017-17 Section 160.017-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-17 Strength. (a) Each chain ladder must...

46 CFR 163.003-17 - Strength.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Strength. 163.003-17 Section 163.003-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-17 Strength. (a) Each pilot ladder must be...

46 CFR 160.017-17 - Strength.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Strength. 160.017-17 Section 160.017-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-17 Strength. (a) Each chain ladder must...

46 CFR 163.003-17 - Strength.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Strength. 163.003-17 Section 163.003-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-17 Strength. (a) Each pilot ladder must be...

37. INTERIOR VIEW OF TANK FROM THE TOP, SHOWING LADDERS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

37. INTERIOR VIEW OF TANK FROM THE TOP, SHOWING LADDERS ON SIDES AND THE WATERTIGHT DOOR OF THE 18-FOOT LOCK No date - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

46 CFR 163.003-15 - Performance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Performance. 163.003-15 Section 163.003-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-15 Performance. (a) Each pilot ladder must be...

46 CFR 160.017-15 - Performance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Performance. 160.017-15 Section 160.017-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-15 Performance. (a) Each chain ladder...

46 CFR 160.017-15 - Performance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Performance. 160.017-15 Section 160.017-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-15 Performance. (a) Each chain ladder...

46 CFR 163.003-15 - Performance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Performance. 163.003-15 Section 163.003-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-15 Performance. (a) Each pilot ladder must be...

46 CFR 160.017-15 - Performance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Performance. 160.017-15 Section 160.017-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-15 Performance. (a) Each chain ladder...

46 CFR 163.003-15 - Performance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Performance. 163.003-15 Section 163.003-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-15 Performance. (a) Each pilot ladder must be...

46 CFR 160.017-15 - Performance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Performance. 160.017-15 Section 160.017-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-15 Performance. (a) Each chain ladder...

46 CFR 160.017-15 - Performance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Performance. 160.017-15 Section 160.017-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-15 Performance. (a) Each chain ladder...

46 CFR 163.003-15 - Performance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Performance. 163.003-15 Section 163.003-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-15 Performance. (a) Each pilot ladder must be...

46 CFR 163.003-15 - Performance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Performance. 163.003-15 Section 163.003-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-15 Performance. (a) Each pilot ladder must be...

Nestling diets and provisioning rates of sympatric Golden-fronted and Ladder-backed Woodpeckers

USGS Publications Warehouse

Schroeder, Evonne L.; Boal, Clint W.; Glasscock, Selma N.

2013-01-01

We examined comparative food use and provisioning of Golden-fronted (Melanerpes aurifrons) and Ladder-backed (Picoides scalaris) woodpeckers at the Rob and Bessie Welder Wildlife Foundation Refuge, in San Patricio County, Texas. We combined video surveillance and direct observations to monitor provisioning rates and identify items delivered by adult woodpeckers to nestlings. We collected 328 hours of data at Ladder-backed Woodpecker nest cavities and 230 hours of data at Golden-fronted Woodpecker nest cavities. Ladder-backed Woodpecker nestling diets consisted of 100% animal matter, comprised of invertebrate larvae (99%) and invertebrate adults (< 1%). Diets of Golden-fronted Woodpecker nestlings were also high in animal matter (77%) with more invertebrate adults (55%) and fewer invertebrate larvae (27%), but also included vegetable matter (16%). Morisita's measure of overlap suggested a relatively low dietary overlap of 31% between nestlings of these two sympatric woodpecker species. Foraging methods used by these species may explain their low dietary overlap and facilitate their coexistence.

Conjugated ladder polymers by a cyclopentannulation polymerization

DOE PAGES

Bheemireddy, Sambasiva R.; Hautzinger, Matthew P.; Li, Tao; ...

2017-04-03

Here, we report a nontraditional synthesis of cyclopentafused-polycyclic aromatic hydrocarbon embedded ladder polymers using a palladium catalyzed cyclopentannulation polymerization followed by a cyclodehydrogenation reaction. Donor–acceptor type polymers containing a cyclopenta[hi]aceanthrylene acceptor groups can be synthesized by a palladium catalyzed copolymerization between 9,10-dibromoanthracene and a variety of bis(arylethynyl)arenes to give polymers with molecular weights (Mn) of 9–22 kDa. The bis(arylethynyl)arenes were composed of benzene, thiophene, or thieno[3,2- b]thiophene moieties, which provided access to a series of four donor–acceptor copolymers. The polymers were subjected to cyclodehydrogenation with FeCl 3 to access rigid ladder type polymers with the conversion investigated by 13C NMRmore » of isotopically labeled polymers. As a result, the ladder polymers possess broad UV–Vis absorptions and narrow optical band gaps of 1.17–1.29 eV and are p-type semiconductors in organic field effect transistors.« less

Conjugated ladder polymers by a cyclopentannulation polymerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bheemireddy, Sambasiva R.; Hautzinger, Matthew P.; Li, Tao

Here, we report a nontraditional synthesis of cyclopentafused-polycyclic aromatic hydrocarbon embedded ladder polymers using a palladium catalyzed cyclopentannulation polymerization followed by a cyclodehydrogenation reaction. Donor–acceptor type polymers containing a cyclopenta[hi]aceanthrylene acceptor groups can be synthesized by a palladium catalyzed copolymerization between 9,10-dibromoanthracene and a variety of bis(arylethynyl)arenes to give polymers with molecular weights (Mn) of 9–22 kDa. The bis(arylethynyl)arenes were composed of benzene, thiophene, or thieno[3,2- b]thiophene moieties, which provided access to a series of four donor–acceptor copolymers. The polymers were subjected to cyclodehydrogenation with FeCl 3 to access rigid ladder type polymers with the conversion investigated by 13C NMRmore » of isotopically labeled polymers. As a result, the ladder polymers possess broad UV–Vis absorptions and narrow optical band gaps of 1.17–1.29 eV and are p-type semiconductors in organic field effect transistors.« less

Investigation of electronic transport through a ladder-like graphene nanoribbon including random distributed impurities

NASA Astrophysics Data System (ADS)

Esmaili, Esmat; Mardaani, Mohammad; Rabani, Hassan

2018-01-01

The electronic transport of a ladder-like graphene nanoribbon which the on-site or hopping energies of a small part of it can be random is modeled by using the Green's function technique within the nearest neighbor tight-binding approach. We employ a unitary transformation in order to convert the Hamiltonian of the nanoribbon to the Hamiltonian of a tight-binding ladder-like network. In this case, the disturbed part of the system includes the second neighbor hopping interactions. While, the converted Hamiltonian of each ideal part is equivalent to the Hamiltonian of two periodic on-site chains. Therefore, we can insert the self-energies of the alternative on-site tight-binding chains to the inverse of the Green's function matrix of the ladder-like part. In this viewpoint, the conductance is constructed from two trans and cis contributions. The results show that increasing the disorder strength causes the increase and decrease of the conductance of the trans and cis contributions, respectively.

The one step fermionic ladder

NASA Astrophysics Data System (ADS)

Das, Joy Prakash; Setlur, Girish S.

2017-10-01

The one step fermionic ladder refers to two parallel Luttinger Liquids (poles of the ladder) placed such that there is a finite probability of electrons hopping between the two poles at a pair of opposing points along each of the poles. The many-body Green function for such a system is calculated in presence of forward scattering interactions using the powerful non-chiral bosonization technique (NCBT). This technique is based on a non-standard harmonic analysis of the rapidly varying parts of the density fields appropriate for the study of strongly inhomogeneous ladder systems. The closed analytical expression for the correlation function obtained from NCBT is nothing but the series involving the RPA (Random Phase Approximation) diagrams in powers of the forward scattering coupling strength resummed to include only the most singular terms with the source of inhomogeneities treated exactly. Finally the correlation functions are used to study physical phenomena such as Friedel oscillations and the conductance of such systems with the potential difference applied across various ends.

Effect of sieving polymer concentration on separation of 100 bp DNA Ladder by capillary gel electrophoresis

NASA Astrophysics Data System (ADS)

Nakazumi, T.; Hara, Y.

2017-09-01

We studied the effect of sieving polymer concentration on separation of a 100 bp DNA Ladder by capillary gel electrophoresis (CGE) using hydroxyethyl cellulose (HEC) with a molecular size of 1000 k. For measurement purposes, we selected a fused silica capillary with total length of 15 cm and effective length of 7.5 cm; this was applied to compact CGE equipment for a Point-Care-Testing (POCT) system. Measurement results of the 100 bp DNA Ladder sample indicated that small DNA separation was significantly affected by HEC sieving polymer concentration. This was due to the level of entanglement between small DNA molecules and the sieving polymer chain significantly influencing migration time, mobility, and resolution length of the CGE process. We concluded that 1.0 w/v % HEC sieving polymer concentration was optimal for CGE separation of DNA ≥1000bp in the 100 bp DNA Ladder (100-1500 bp) when using the short-length capillary.

Cavity-induced artificial gauge field in a Bose-Hubbard ladder

NASA Astrophysics Data System (ADS)

Halati, Catalin-Mihai; Sheikhan, Ameneh; Kollath, Corinna

2017-12-01

We consider theoretically ultracold interacting bosonic atoms confined to quasi-one-dimensional ladder structures formed by optical lattices and coupled to the field of an optical cavity. The atoms can collect a spatial phase imprint during a cavity-assisted tunneling along a rung via Raman transitions employing a cavity mode and a transverse running wave pump beam. By adiabatic elimination of the cavity field we obtain an effective Hamiltonian for the bosonic atoms, with a self-consistency condition. Using the numerical density-matrix renormalization-group method, we obtain a rich steady-state diagram of self-organized steady states. Transitions between superfluid to Mott-insulating states occur, on top of which we can have Meissner, vortex liquid, and vortex lattice phases. Also a state that explicitly breaks the symmetry between the two legs of the ladder, namely, the biased-ladder phase, is dynamically stabilized. We investigate the influence that a trapping potential has on the stability of the self-organized phases.

Ladder physics in the spin fermion model

NASA Astrophysics Data System (ADS)

Tsvelik, A. M.

2017-05-01

A link is established between the spin fermion (SF) model of the cuprates and the approach based on the analogy between the physics of doped Mott insulators in two dimensions and the physics of fermionic ladders. This enables one to use nonperturbative results derived for fermionic ladders to move beyond the large-N approximation in the SF model. It is shown that the paramagnon exchange postulated in the SF model has exactly the right form to facilitate the emergence of the fully gapped d -Mott state in the region of the Brillouin zone at the hot spots of the Fermi surface. Hence, the SF model provides an adequate description of the pseudogap.

Bound States and Field-Polarized Haldane Modes in a Quantum Spin Ladder.

PubMed

Ward, S; Mena, M; Bouillot, P; Kollath, C; Giamarchi, T; Schmidt, K P; Normand, B; Krämer, K W; Biner, D; Bewley, R; Guidi, T; Boehm, M; McMorrow, D F; Rüegg, Ch

2017-04-28

The challenge of one-dimensional systems is to understand their physics beyond the level of known elementary excitations. By high-resolution neutron spectroscopy in a quantum spin-ladder material, we probe the leading multiparticle excitation by characterizing the two-magnon bound state at zero field. By applying high magnetic fields, we create and select the singlet (longitudinal) and triplet (transverse) excitations of the fully spin-polarized ladder, which have not been observed previously and are close analogs of the modes anticipated in a polarized Haldane chain. Theoretical modeling of the dynamical response demonstrates our complete quantitative understanding of these states.

Assessment and the National Languages Strategy

ERIC Educational Resources Information Center

Jones, Neil

2007-01-01

The Languages Ladder--a new framework for accrediting language proficiency--is a core element of the National Languages Strategy. This paper presents Asset Languages, the system being developed by Cambridge Assessment to implement the Languages Ladder, aiming to set it apart from existing qualification frameworks by accrediting clearly defined…

Development of Processible Electroactive Oligomers and Polymers

DTIC Science & Technology

1991-10-01

of structure and electroactive properties. Electroactive molecules including fused ring (ladder oligomers) dyes , squarylium -heterocyclic moieties...Electroactive molecules including fused ring (ladder oligomers) dyes , squarylium -heterocyclic moieties, phenylpolyenes, thienylpolyenes, carbocyanine dyes ...phenylpolyenes, thienylpolyenes, carbocyanine dyes , and tetraazaannulenes have also been synthetically incorporated into a variety of traditional

29 CFR 1910.27 - Fixed ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) All rungs shall have a minimum diameter of three-fourths inch for metal ladders, except as covered in... appurtenances shall be painted or otherwise treated to resist corrosion and rusting when location demands... areas under floors, are frequently located in an atmosphere that causes corrosion and rusting. To...

16 CFR 1207.5 - Design.

Code of Federal Regulations, 2014 CFR

2014-01-01

... pool slide shall be such that no structural failures of any component part shall cause failures of any... such fasteners shall not cause a failure of the tread under the ladder loading conditions specified in... without failure or permanent deformation. (d) Handrails. Swimming pool slide ladders shall be equipped...

16 CFR 1207.5 - Design.

Code of Federal Regulations, 2012 CFR

2012-01-01

... pool slide shall be such that no structural failures of any component part shall cause failures of any... such fasteners shall not cause a failure of the tread under the ladder loading conditions specified in... without failure or permanent deformation. (d) Handrails. Swimming pool slide ladders shall be equipped...

Distinguishing Internet-facing ICS Devices Using PLC Programming Information

DTIC Science & Technology

2014-06-19

the course of this research. I would also like to thank the faculty and students at AFIT who helped me think through some of these problems. Finally, I...21 FTP 143 IMAP 1900 UPnP 6379 Redis 22 SSH 161 SNMP 2323 Telnet 7777 Oracle 23 Telnet 443 HTTPS 3306 MySQL 8000 Qconn 25 SMTP 445 SMB 3389 RDP 8080...250ms over the course of 10,000 samples provided sufficient data to test for statistically significant changes to ladder logic execution times with a

29 CFR 1926.1053 - Ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

... ascend or descend without continually having to hold, push or pull any part of the device, leaving both... the carrier. When the system is exposed to wind, cable guides for flexible carriers shall be installed... mountings and cable guides shall not reduce the design strength of the ladder. (24) The side rails of...

29 CFR 1926.1053 - Ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

... ascend or descend without continually having to hold, push or pull any part of the device, leaving both... the carrier. When the system is exposed to wind, cable guides for flexible carriers shall be installed... mountings and cable guides shall not reduce the design strength of the ladder. (24) The side rails of...

Tank 188A, detail of valves, pipes, and top access ladder ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Tank 188-A, detail of valves, pipes, and top access ladder on east side. Ordnance warehouse A-199 is in the far distance. View to south. - Mare Island Naval Shipyard, Fresh Water Tanks, East of Mesa Road & north of Kieper Road, Vallejo, Solano County, CA

Evaluation Practice and Theory: Up and down the Ladder of Abstraction

ERIC Educational Resources Information Center

Leviton, Laura C.

2015-01-01

Debra Rog presented the 2014 Eleanor Chelimsky Forum address, offering ways to integrate evaluation theory and practice by abundant use of practice examples. These examples illustrate the effective use of the Ladder of Abstraction from semantics, working from the concrete to the abstract and back again.

Avionics Instrument Systems Specialist Career Ladder: AFSCs 32531, 32551, 31571, and 32591. Occupational Survey Report.

ERIC Educational Resources Information Center

Air Force Occupational Measurement Center, Lackland AFB, TX.

The Avionics Instrument Systems career ladder (AFSC 325X1) provides flight line and shop maintenance training on aircraft instrument systems, electromechancial instruments, components, and test equipment. Duties involve inspecting, removing, installing, repairing, operating, troubleshooting, overhauling, and modifying systems such as flight and…

Educational and Contractual Attributes of the Apprenticeship Programmes of Large Employers in Britain

ERIC Educational Resources Information Center

Ryan, Paul; Gospel, Howard; Lewis, Paul

2006-01-01

The authors consider two quality-related aspects of large employers' apprenticeship programmes. The first is their contribution to national educational objectives, including the creation and strengthening of ladders of vocational attainment. Such ladders already exist in apprenticeship's traditional domains, but the prospects for their wider…

Ladders and Easels and Stools, Oh My!

ERIC Educational Resources Information Center

Greenman, Geri

2002-01-01

Describes an art lesson for high school seniors in an intermediate oil painting class. Explains that the teacher set up a still life with a ladder, easel, and a stool with a white background to capture the shadows. States that the students painted their still life in oil. (CMK)

Analysis of Utah Career Ladder Plans.

ERIC Educational Resources Information Center

Murphy, Michael J.; And Others

This report analyzes the content and development of the 45 school district career ladder plans submitted in 1984 to the Utah State Office of Education. Descriptive commentary and data tables are used to examine (1) the structure and composition of planning committees; (2) teacher evaluation provisions, including changes in evaluation methods, the…

Understanding Phylogenies in Biology: The Influence of a Gestalt Perceptual Principle

ERIC Educational Resources Information Center

Novick, Laura R.; Catley, Kefyn M.

2007-01-01

Cladograms, hierarchical diagrams depicting evolutionary histories among (groups of) species, are commonly drawn in 2 informationally equivalent formats--tree and ladder. The authors hypothesize that these formats are not computationally equivalent because the Gestalt principle of good continuation obscures the hierarchical structure of ladders.…

Parents' Participation on School Councils Analysed through Arnstein's Ladder of Participation

ERIC Educational Resources Information Center

Stelmach, Bonnie

2016-01-01

Although parent school councils are the archetypal arrangement for engaging parents in school improvement planning, their effectiveness is negligible when it comes to building parents' capacity for and confidence in educational decision-making. Using Arnstein's ladder of citizen participation, this qualitative case study investigated the nature…

Ground Radio Operator Career Ladder AFSC 293X3.

DTIC Science & Technology

1981-07-01

formal resident training, OJT, and ,her Air Force management decisions . The structure of jobs within the Ground ! odio Operatoi career ladder was...33 ADJUST ANTENNA TUNING UNITS 33 TYPE RECORDS, REPORTS, OR FORMS :33 OPERATE AUXILLARY GENERATORS 33 A8 ’iT’ TASKS PERFORMED BY SUPERVISORS AND

Ladder physics in the spin fermion model

DOE PAGES

Tsvelik, A. M.

2017-05-01

A link is established between the spin fermion (SF) model of the cuprates and the approach based on the analogy between the physics of doped Mott insulators in two dimensions and the physics of fermionic ladders. This enables one to use nonperturbative results derived for fermionic ladders to move beyond the large-N approximation in the SF model. Here, it is shown that the paramagnon exchange postulated in the SF model has exactly the right form to facilitate the emergence of the fully gapped d-Mott state in the region of the Brillouin zone at the hot spots of the Fermi surface.more » Hence, the SF model provides an adequate description of the pseudogap.« less

Proceedings of an Occupational Analysis Seminar Held at Canberra, Australia, 17-20 September 1979.

DTIC Science & Technology

1979-09-01

stripes a man wears. NO CATEGORY EXAMPLE 48 Career Fields Medical (28 Ladders) 334 Career Ladders Pharmacy 1000+ Specialties . Pharmacist Specialist... uty /Task and Task Factor i TABLE 1, Summaries i 3. The Data Prepatory Programmes take the raw optical scanned or key punched data and: a. re-organize

46 CFR 108.540 - Survival craft muster and embarkation arrangements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Lifesaving Equipment § 108.540 Survival craft muster and... minutes from the time the instruction to board is given. (e) Each davit-launched and free-fall survival... ladder as follows: (1) Each embarkation ladder must be approved under approval series 160.117 or be a...

Fiscal Viability, Conjunctive and Compensatory Models, and Career-Ladder Decisions: An Empirical Investigation.

ERIC Educational Resources Information Center

Mehrens, William A.; And Others

A study was undertaken to explore cost-effective ways of making career ladder teacher evaluation system decisions based on fewer measures, assessing the relationship of observational variables to other data and final decisions, and comparison of compensatory and conjunctive decision models. Data included multiple scores from eight data sources in…

Career Ladders and the Professionalization of Teaching: Down the Up Staircase.

ERIC Educational Resources Information Center

Dunwell, Robert R.

School systems interested in improving teacher performance, effectiveness, and job satisfaction while reducing turnover rates might do better to seek ways to enhance the intrinsic rewards of teaching rather than implement such extrinsic motivators as merit pay plans and career ladders. A review of the research literature brings several important…

29 CFR 1915.72 - Ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sectional area of the side rail. The dimensions of side rails for their total length shall be those...). (b) Construction of portable wood cleated ladders up to 30 feet in length. (1) Wood side rails shall... than one such pocket appears in each 4 feet of length. (5) The width between side rails at the base...

Television Equipment Repair Career Ladder. Occupational Survey Report.

ERIC Educational Resources Information Center

Air Force Occupational Measurement Center, Lackland AFB, TX.

The report describes the results of an Air Force occupational survey of the television equipment repair career ladder. A job inventory, administered to 808 job incumbents, consisted of a background information section and a duty-task list designed to assess the relative amount of time spent on tasks performed in current jobs. The resulting…

Implications of the Texas Mandate for Comprehensive Performance Appraisal.

ERIC Educational Resources Information Center

Nelson, David; And Others

This paper: (1) describes the recently implemented Texas plan for school reform; (2) delineates a major component of Texas reform, the career ladder. In response to a nationwide call for raised educational standards, Texas passed HB 72, a comprehensive education bill implementing a comprehensive "career ladder" model for the testing,…

Integrating stand density management with fuel reduction

Treesearch

Joseph W. Sherlock

2007-01-01

The widespread effort to reduce fuel hazards in western forested ecosystems places significant emphasis on surface and small ladder fuels. Changes in canopy density, for purposes of either reducing potential crown fire impacts or insect/pathogen-related mortality, are less frequently considered. Providing a sound basis for treating more than surface and small ladder...

46 CFR 160.017-27 - Production tests and examination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Production tests and examination. 160.017-27 Section 160.017-27 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-27 Production tests and examination. (a) General. Each ladder...

46 CFR 160.017-27 - Production tests and examination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Production tests and examination. 160.017-27 Section 160.017-27 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-27 Production tests and examination. (a) General. Each ladder...

46 CFR 160.017-21 - Approval tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Approval tests. 160.017-21 Section 160.017-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-21 Approval tests. (a) General. Each approval test must be conducted on a ladder...

46 CFR 160.017-21 - Approval tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Approval tests. 160.017-21 Section 160.017-21 Shipping...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-21 Approval tests. (a) General. Each approval test must be conducted on a ladder of the longest length for which approval has been requested. If...

46 CFR 72.10-45 - Weather deck communications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Weather deck communications. 72.10-45 Section 72.10-45... ARRANGEMENT Means of Escape § 72.10-45 Weather deck communications. (a) Vertical communication shall be provided between the various weather decks by means of permanent inclined ladders. Where ladders are for...

46 CFR 72.10-45 - Weather deck communications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Weather deck communications. 72.10-45 Section 72.10-45... ARRANGEMENT Means of Escape § 72.10-45 Weather deck communications. (a) Vertical communication shall be provided between the various weather decks by means of permanent inclined ladders. Where ladders are for...

46 CFR 72.10-45 - Weather deck communications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Weather deck communications. 72.10-45 Section 72.10-45... ARRANGEMENT Means of Escape § 72.10-45 Weather deck communications. (a) Vertical communication shall be provided between the various weather decks by means of permanent inclined ladders. Where ladders are for...

46 CFR 72.10-45 - Weather deck communications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Weather deck communications. 72.10-45 Section 72.10-45... ARRANGEMENT Means of Escape § 72.10-45 Weather deck communications. (a) Vertical communication shall be provided between the various weather decks by means of permanent inclined ladders. Where ladders are for...

46 CFR 72.10-45 - Weather deck communications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Weather deck communications. 72.10-45 Section 72.10-45... ARRANGEMENT Means of Escape § 72.10-45 Weather deck communications. (a) Vertical communication shall be provided between the various weather decks by means of permanent inclined ladders. Where ladders are for...

29 CFR 1915.72 - Ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

... shipbreaking. (a) General requirements. (1) The use of ladders with broken or missing rungs or steps, broken or... 10d common wire nails or fastened with through bolts or other fasteners of equivalent strength. Cleats... nailed to each rail with five 10d common wire nails or fastened with through bolts or other fasteners of...

29 CFR 1918.24 - Fixed and portable ladders.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and be positively secured or held against shifting or slipping. When conditions are such that a... strength shall be furnished and positively secured or held against shifting or slipping while in use. Steps... securely positioned on a level and firm base. (2) Ladders shall be fitted with slip-resistant bases and/or...

29 CFR 1918.24 - Fixed and portable ladders.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., and be positively secured or held against shifting or slipping. When conditions are such that a... strength shall be furnished and positively secured or held against shifting or slipping while in use. Steps... securely positioned on a level and firm base. (2) Ladders shall be fitted with slip-resistant bases and/or...

29 CFR 1918.24 - Fixed and portable ladders.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., and be positively secured or held against shifting or slipping. When conditions are such that a... strength shall be furnished and positively secured or held against shifting or slipping while in use. Steps... securely positioned on a level and firm base. (2) Ladders shall be fitted with slip-resistant bases and/or...

29 CFR 1918.24 - Fixed and portable ladders.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., and be positively secured or held against shifting or slipping. When conditions are such that a... strength shall be furnished and positively secured or held against shifting or slipping while in use. Steps... securely positioned on a level and firm base. (2) Ladders shall be fitted with slip-resistant bases and/or...

29 CFR 1918.24 - Fixed and portable ladders.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., and be positively secured or held against shifting or slipping. When conditions are such that a... strength shall be furnished and positively secured or held against shifting or slipping while in use. Steps... securely positioned on a level and firm base. (2) Ladders shall be fitted with slip-resistant bases and/or...

Ladder-Type Circuits Revisited

ERIC Educational Resources Information Center

Yoon, Sung Hyun

2007-01-01

Ladder-type circuits where a given unit is repeated infinitely many times are dealt with in many textbooks on electromagnetism as examples of filter circuits. Determining the impedance of such circuits seems to be regarded as simple, which may be due to the fact that the invariance of the infinite system under the operation of adding one more unit…

Literature Ladders: Linking Books and Internet Resources.

ERIC Educational Resources Information Center

Lamb, Annette

2001-01-01

Describes Literature Learning Ladders, a project that uses books for children and young adults as the focal point for technology-rich thematic activities. Explains the use of Internet Web sites to find book information as well as sties that demonstrate how resources can be used as part of technology-based classroom activities. (LRW)

46 CFR 160.017-21 - Approval tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Approval tests. 160.017-21 Section 160.017-21 Shipping...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-21 Approval tests. (a) General. Each approval test must be conducted on a ladder of the longest length for which approval has been requested. If...

A Statewide Decentralized Approach to Public School Reform: The Case of Career Ladders in Utah.

ERIC Educational Resources Information Center

Malen, Betty; Murphy, Michael J.

1985-01-01

In 1984, the Utah legislature enacted a career ladder bill encouraging all local districts to develop plans for restructuring teachers' compensation and promotion options. An independent, bipartisan taskforce then created a statewide, decentralized model that increases educators' power, minimizes merit and staff differentiation, and fosters…

Electronic structure and magnetic properties of the strong-rung spin-1 ladder compound Rb3Ni2(NO3)7

NASA Astrophysics Data System (ADS)

Pchelkina, Z. V.; Mazurenko, V. V.; Volkova, O. S.; Deeva, E. B.; Morozov, I. V.; Shutov, V. V.; Troyanov, S. I.; Werner, J.; Koo, C.; Klingeler, R.; Vasiliev, A. N.

2018-04-01

Rb3Ni2(NO3)7 was obtained by crystallization from anhydrous nitric acid solution of rubidium nitrate and nickel nitrate hexahydrate. The crystal structure determined on single crystals implies isolated spin-1 two-leg ladders of Ni2 + ions connected by (NO3)- groups as basic elements. Magnetic susceptibility, specific heat in magnetic fields up to 9 T, magnetization, and high-frequency electron spin resonance studies performed on powder samples show the absence of long-range magnetic order at T ≥2 K. Electronic structure calculations and the detailed analysis of the experimental data enable quantitative estimates of the relevant parameters of the S =1 ladders in Rb3Ni2(NO3)7 . The rung coupling J1=10.16 K, the leg coupling J2=1.5 K, and the Ising-type anisotropy |A |=8.6 K are obtained. The scenario of a valence-bond solidlike quantum ground state realized in the two-leg Ni2 + ladders is further corroborated by model simulations of the magnetic susceptibility.

Ultra-wideband ladder filter using SH(0) plate wave in thin LiNbO(3) plate and its application to tunable filter.

PubMed

Kadota, Michio; Tanaka, Shuji

2015-05-01

A cognitive radio terminal using vacant frequency bands of digital TV (DTV) channels, i.e., TV white space, strongly requires a compact tunable filter covering a wide frequency range of the DTV band (470 to 710 MHz in Japan). In this study, a T-type ladder filter using ultra-wideband shear horizontal mode plate wave resonators was fabricated, and a low peak insertion loss of 0.8 dB and an ultra-large 6 dB bandwidth of 240 MHz (41%) were measured in the DTV band. In addition, bandpass filters with different center frequencies of 502 and 653 MHz at 6 dB attenuation were numerically synthesized based on the same T-type ladder filter in conjunction with band rejection filters with different frequencies. The results suggest that the combination of the wideband T-type ladder filter and the band rejection filters connected with variable capacitors enables a tunable filter with large tunability of frequency and bandwidth as well as large rejection at the adjacent channels of an available TV white space.

SU(3)_C× SU(2)_L× U(1)_Y( × U(1)_X ) as a symmetry of division algebraic ladder operators

NASA Astrophysics Data System (ADS)

Furey, C.

2018-05-01

We demonstrate a model which captures certain attractive features of SU(5) theory, while providing a possible escape from proton decay. In this paper we show how ladder operators arise from the division algebras R, C, H, and O. From the SU( n) symmetry of these ladder operators, we then demonstrate a model which has much structural similarity to Georgi and Glashow's SU(5) grand unified theory. However, in this case, the transitions leading to proton decay are expected to be blocked, given that they coincide with presumably forbidden transformations which would incorrectly mix distinct algebraic actions. As a result, we find that we are left with G_{sm} = SU(3)_C× SU(2)_L× U(1)_Y / Z_6. Finally, we point out that if U( n) ladder symmetries are used in place of SU( n), it may then be possible to find this same G_{sm}=SU(3)_C× SU(2)_L× U(1)_Y / Z_6, together with an extra U(1)_X symmetry, related to B-L.

E3: Education, Experience, Employment The Economic Ladder to Success

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anne L Seifert

2011-10-01

Science, Technology, Engineering, and Math (STEM) literate citizenry is critical for Idaho's economy to effectively compete and grow in today's global marketplace and enhance Idaho workforce capabilities. Idaho's blueprint presents a collaboration design developed by a group of Idaho stakeholders including state level (STEM) educators, state and federal government, other agencies, and industry across the state. The purpose the Idaho Learn and Earn Blueprint Design is to describe a comprehensive plan for improving STEM education in Idaho through a collaborative partnerships and a series of grant supported projects underpinning this strategic design process building pathways to overcome hurdles in today'smore » economy, and moving communities and families up their economic ladder. The Idaho Learn and Earn Blueprint Design focuses on three industry sectors; energy, advanced manufacturing, and health care. All are important in Idaho and have room for job growth potential among both displaced workers and graduates. Representatives from each sector are members of the design team and assist in developing grants and implementing the actions outlined in the design as the program goes forward. Idaho's current programs are generally institution specific. Each of the state's two-year colleges, along with regional groups and employers, are already working towards improving STEM education across the state. A key aspect of this design is to bring these groups together to focus on four unique goals: (1) Providing industry driven curriculum directly tied to skill based career needs; (2) Enhancing collaboration among stakeholders; (3) Providing access to learn and earn programs; and (4) Improving public and student awareness and interest in targeted industry sector career and educational opportunities.« less

Don/doff support stand for use with rear entry space suits

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J. (Inventor); Tri, Terry O. (Inventor); Spenny, William E. (Inventor); West, Philip R. (Inventor)

1988-01-01

A don/doff support stand for use with rear entry space suits is disclosed. The support stand is designed for use in one-g environments; however, certain features of the stand can be used on future spacecraft, lunar, or planetary bases. The present invention has a retainer which receives a protrucing lug fixed on the torso section of the space suit. When the lug is locked in the retainer, the space suit is held in a generally upright position. In a one-g environment a portable ladder is positioned adjacent to the rear entry of the space suit supported by the stand. The astronaut climbs up the ladder and grasps a hand bar assembly positioned above the rear entry. The astronaut then slips his legs through the open rear entry and down into the abdominal portion of the suite. The astronaut then lowers himself fully into the suit. The portable ladder is then removed and the astronaut can close the rear entry door. The lug is then disengaged from the retainer and the astronaut is free to engage in training exercises in the suit. When suit use is over, the astronaut returns to the stand and inserts the lug into the retainer. A technician repositions the ladder. The astronaut opens the rear entry door, grasps the hand bar assembly and does a chin-up to extricate himself from the suit. The astronaut climbs down the movable ladder while the suit is supported by the stand.

Don/Doff support stand for use with rear entry space suits

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J. (Inventor); Tri, Terry O. (Inventor); Spenny, William E. (Inventor); West, Philip R. (Inventor)

1989-01-01

A don/doff support stand for use with rear entry space suits is disclosed. The support stand is designed for use in one-g environments; however, certain features of the stand can be used on future space-craft, lunar or planetary bases. The present invention has a retainer which receives a protruding lug fixed on the torso section of the space suit. When the lug is locked in the retainer, the space suit is held in a generally upright position. In a one-g environment a portable ladder is positioned adjacent to the rear entry of the space suit supported by the stand. The astronaut climbs up the ladder and grasps a hand bar assembly positioned above the rear entry. The astronaut then slips his legs through the open rear entry and down into the abdominal portion of the suit. The astronaut then lowers himself fully into the suit. The portable ladder is then removed and the astronaut can close the rear entry door. The lug is then disengaged from the retainer and the astronaut is free to engage in training exercises in the suit. When suit use is over, the astronaut returns to the stand and inserts the lug into the retainer. A technician repositions the ladder. The astronaut opens the rear entry door, grasps the hand bar assembly and does a chin-up to extricate himself from the suit. The astronaut climbs down the movable ladder while the suit is supported by the stand.

Evaluation of Five Tests for Sensitivity to Functional Deficits following Cervical or Thoracic Dorsal Column Transection in the Rat

PubMed Central

Eggers, Ruben; Tuinenbreijer, Lizz; Kouwenhoven, Dorette; Verhaagen, Joost; Mason, Matthew R. J.

2016-01-01

The dorsal column lesion model of spinal cord injury targets sensory fibres which originate from the dorsal root ganglia and ascend in the dorsal funiculus. It has the advantages that fibres can be specifically traced from the sciatic nerve, verifiably complete lesions can be performed of the labelled fibres, and it can be used to study sprouting in the central nervous system from the conditioning lesion effect. However, functional deficits from this type of lesion are mild, making assessment of experimental treatment-induced functional recovery difficult. Here, five functional tests were compared for their sensitivity to functional deficits, and hence their suitability to reliably measure recovery of function after dorsal column injury. We assessed the tape removal test, the rope crossing test, CatWalk gait analysis, and the horizontal ladder, and introduce a new test, the inclined rolling ladder. Animals with dorsal column injuries at C4 or T7 level were compared to sham-operated animals for a duration of eight weeks. As well as comparing groups at individual timepoints we also compared the longitudinal data over the whole time course with linear mixed models (LMMs), and for tests where steps are scored as success/error, using generalized LMMs for binomial data. Although, generally, function recovered to sham levels within 2–6 weeks, in most tests we were able to detect significant deficits with whole time-course comparisons. On the horizontal ladder deficits were detected until 5–6 weeks. With the new inclined rolling ladder functional deficits were somewhat more consistent over the testing period and appeared to last for 6–7 weeks. Of the CatWalk parameters base of support was sensitive to cervical and thoracic lesions while hind-paw print-width was affected by cervical lesion only. The inclined rolling ladder test in combination with the horizontal ladder and the CatWalk may prove useful to monitor functional recovery after experimental treatment in this lesion model. PMID:26934672

A Demonstration of Helping Adolescents with Mild Intellectual Disability Climb Ladders

ERIC Educational Resources Information Center

Chan, Kok Hoe Anthony; Varahan, Jayashree Lakshmi; Loh, Peng Loong Daniel; Tan, Sey Ing

2011-01-01

A research team at a vocational school in Singapore, catering mainly to students between the ages of 17-21 with mild intellectual disability, studied how to best address the challenge of enabling students to learn how to climb ladders (a skill necessary at many job placements). They documented the approach used and suggested extrapolations and…

South Dakota Statewide Core Curriculum, Career Ladder and Challenge System: Volumes I and II. Final Report.

ERIC Educational Resources Information Center

1975

The two volume final report of the South Dakota Statewide Core Curriculum, Career Ladder, and Challenge System Project, coordinating associated health and nursing education on a statewide basis to achieve a more systematic production and utilization of health manpower, is presented. Volume 1 includes five chapters: (1) and (2) outlining funding…

Educational Characteristics of Paraprofessionals in Southern California: A Survey of Their Career Ladder Needs.

ERIC Educational Resources Information Center

Ochoa, Alberto M.; Wright, Pamela G.

The purpose of this study was to identify the career ladder needs of paraprofessionals as required by both California State and Federal educational mandates. Findings, gathered by questionnaires returned by 594 aides in seven southern and central Californian counties, are discussed in terms of the following: (1) personal characteristics; (2)…

Chutes and Ladders for the Impatient

ERIC Educational Resources Information Center

Cheteyan, Leslie A.; Hengeveld, Stewart; Jones, Michael A.

2011-01-01

In this paper, we review the rules and game board for "Chutes and Ladders", define a Markov chain to model the game regardless of the spinner range, and describe how properties of Markov chains are used to determine that an optimal spinner range of 15 minimizes the expected number of turns for a player to complete the game. Because the Markov…

Astronaut Alan Bean steps from ladder of Lunar Module for EVA

NASA Technical Reports Server (NTRS)

1969-01-01

Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 lunar landing mission, steps from the ladder of the Lunar Module to join Astronaut Charles Conrad Jr., commander, in extravehicular activity on November 19, 1969. Astronaut Ricard F. Gordon Jr., command module pilot, remained with the Command/Service Modules in lunar orbit.

DETAIL VIEW ON THE MAIN ASSEMBLY LEVEL OF A LADDER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW ON THE MAIN ASSEMBLY LEVEL OF A LADDER TO THE CATWALK AT COLUMN LINE AA-28 SHOWING VERTICAL MECHANICAL DUCT, RETURN AIR FLOOR GRILLE, STEEL INDUSTRIAL SASH WINDOWS AND CROSS BRACING OF SOUTH WALL. - Offutt Air Force Base, Glenn L. Martin-Nebraska Bomber Plant, Building D, Peacekeeper Drive, Bellevue, Sarpy County, NE

Development of Physical Demand Profiles for Four Airman Career Ladders. Interim Report for Period 1 July 1972-1 November 1974.

ERIC Educational Resources Information Center

Koym, Kenneth G.

The document investigates certain physical characteristics of airman occupations in terms of the dexterity, muscular coordination, and sensory discrimination required. It examines the feasibility of estimating physical demands in jobs using incumbent ratings and compares physical demand profiles for four career ladders: (1) avionic instrument…

46 CFR 188.10-56 - Pilot boarding equipment and point of access.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Pilot boarding equipment and point of access. 188.10-56... VESSELS GENERAL PROVISIONS Definition of Terms Used in This Subchapter § 188.10-56 Pilot boarding equipment and point of access. (a) Pilot boarding equipment means a pilot ladder, accomodation ladder, pilot...

Schroedinger operators with the q-ladder symmetry algebras

NASA Technical Reports Server (NTRS)

Skorik, Sergei; Spiridonov, Vyacheslav

1994-01-01

A class of the one-dimensional Schroedinger operators L with the symmetry algebra LB(+/-) = q(+/-2)B(+/-)L, (B(+),B(-)) = P(sub N)(L), is described. Here B(+/-) are the 'q-ladder' operators and P(sub N)(L) is a polynomial of the order N. Peculiarities of the coherent states of this algebra are briefly discussed.

Microwave-induced three-photon coherence of Rydberg atomic states

NASA Astrophysics Data System (ADS)

Kwak, Hyo Min; Jeong, Taek; Lee, Yoon-Seok; Moon, Han Seb

2016-12-01

We investigate the three-photon coherence (TPC) effects of the Rydberg state in a Doppler-broadened four-level ladder-type atomic system for the 5S1/2(F=3)-5P3/2(F‧=4)-50D5/2-51P3/2 transition of 85Rb atoms. Upon interaction of the Rydberg Rb atom of the ladder-type electromagnetically induced transparency (EIT) scheme with a resonant microwave (MW) field, we numerically analyze the spectral features of the Rydberg TPC from two viewpoints, Autler-Townes splitting (AT-splitting) of the Rydberg EIT and three-photon electromagnetically induced absorption (TPEIA). We determine the criterion to differentiate between AT-splitting of the Rydberg EIT and TPEIA in the Doppler-broadened ladder-type atomic system.

Electron spin resonance modes in a strong-leg ladder in the Tomonaga-Luttinger liquid phase

NASA Astrophysics Data System (ADS)

Ozerov, M.; Maksymenko, M.; Wosnitza, J.; Honecker, A.; Landee, C. P.; Turnbull, M. M.; Furuya, S. C.; Giamarchi, T.; Zvyagin, S. A.

2015-12-01

Magnetic excitations in the strong-leg quantum spin ladder compound (C7H10N) 2CuBr4 (known as DIMPY) in the field-induced Tomonaga-Luttinger spin-liquid phase are studied by means of high-field electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode with unusual nonlinear frequency-field dependence is revealed experimentally. Using a combination of analytic and exact-diagonalization methods, we compute the dynamical structure factor and identify this mode with longitudinal excitations in the antisymmetric channel. We argue that these excitations constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder and owe their ESR observability to the uniform Dzyaloshinskii-Moriya interaction.

Fall-induced spinal cord injury: External causes and implications for prevention.

PubMed

Chen, Yuying; Tang, Ying; Allen, Victoria; DeVivo, Michael J

2016-01-01

To document the demographic and clinical profile of persons who sustained spinal cord injury (SCI) as a result of accidental falls and to determine the usual circumstances surrounding the fall-induced SCI. Cohort study. 21 SCI Model Systems centers throughout the United States. 6,408 individuals with traumatic SCI between 2005 and 2014 were recruited from the National SCI Database. 1,877 (29%) of them were injuries caused by falls. Not applicable. External causes of injury documented by the International Classification of Diseases, 10(th) revision, Clinical Modification (ICD-10-CM). Falls on the same level from slipping, tripping, and stumbling were the most common cause of fall-induced SCI (20%), followed by falls from building (16%), stairs and steps (16%), and ladder (9%). People who were 61 years of age and older had the highest frequency of falls on the same level, while those aged 16-45 years had a higher percentage of falls from buildings, usually work-related. The mechanisms of falls also varied by sex and race. Associated injury and vertebral injury occurred frequently among falls from buildings and ladders. High falls were more likely to be work-related and result in thoracic and complete injury, while low falls were more commonly associated with cervical and motor functionally incomplete injury. The study findings of different mechanisms of falls by age, sex, race and medical consequences provide an insight for future interventions aimed at high risk persons, activities, and environmental factors for preventing or reducing fall-induced SCI.

The Advance Mentoring-For Lunch Series for Women Faculty in STEM at the University of Washington

NASA Astrophysics Data System (ADS)

Yen, Joyce W.; Quinn, Kate; Carrigan, Coleen; Litzler, Elizabeth; Riskin, Eve A.

Given the increasingly smaller number of women in science, technology, engineering, and mathematics (STEM) fields as one progresses through the academic pipeline, it is often very difficult for women in STEM faculty positions to find a community of women and identify women mentors, especially at the upper rungs of the academic ladder. Group mentoring opportunities are one strategy to connect women STEM faculty and generate greater interest and success in academic leadership. In 2003 the University of Washington (UW) ADVANCE program introduced the Mentoring-for-Leadership lunch series to encourage women faculty to consider leadership; expose women faculty to various career paths; and build a community of women faculty in STEM. This paper describes the UW program, the literature that informs the program, and the participants' experiences. This paper also offers recommendations for replicating this program at other campuses.

ProbeZT: Simulation of transport coefficients of molecular electronic junctions under environmental effects using Büttiker's probes

NASA Astrophysics Data System (ADS)

Korol, Roman; Kilgour, Michael; Segal, Dvira

2018-03-01

We present our in-house quantum transport package, ProbeZT. This program provides linear response coefficients: electrical and electronic thermal conductances, as well as the thermopower of molecular junctions in which electrons interact with the surrounding thermal environment. Calculations are performed based on the Büttiker probe method, which introduces decoherence, energy exchange and dissipation effects phenomenologically using virtual electrode terminals called probes. The program can realize different types of probes, each introducing various environmental effects, including elastic and inelastic scattering of electrons. The molecular system is described by an arbitrary tight-binding Hamiltonian, allowing the study of different geometries beyond simple one-dimensional wires. Applications of the program to study the thermoelectric performance of molecular junctions are illustrated. The program also has a built-in functionality to simulate electron transport in double-stranded DNA molecules based on a tight-binding (ladder) description of the junction.

Teachers' Career Ladder Policy in Ethiopia: An Opportunity for Professional Growth or ''a Stick Disguised as a Carrot?''

ERIC Educational Resources Information Center

Tekleselassie, Abebayehu A.

2005-01-01

In response to the ever-declining status of the teaching profession, and its adverse effects on the country's educational system, the Federal Ministry of Education in Ethiopia introduced a policy of the teachers' career ladder in 1994. While reformers believe that the introduction of the policy has improved the condition of the teaching…

Dental Laboratory Career Ladder (AFSC 4Y1X1)

DTIC Science & Technology

1994-08-01

analysis identified one job cluster and seven jobs: Base Dental Lab cluster, Orthodontic Appliance Fabricator job, Fixed Restoration Fabricator job, Crown...reline and repair, removable partial denture construction, crown and fixed partial denture construction, fabrication of orthodontic appliances, and...specialized prostheses. Preventive maintenance and safety precautions for dental laboratory equipment are also stressed . Entry into the career ladder

Knowing One's Lot in Life versus Climbing the Social Ladder: The Formation of Redistributive Preferences in Urban China

ERIC Educational Resources Information Center

Smyth, Russell; Mishra, Vinod; Qian, Xiaolei

2010-01-01

This paper examines, how individual preferences for redistribution in general and redistribution to improve access to education, improve social protection for the poor, reduce income inequality and reduce unemployment depend on beliefs about what determines one's lot in life and self-assessed prospects for climbing the social ladder in urban…

29 CFR 1915.74 - Access to vessels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... rigged at the foot of the gangway in such a manner as to prevent employees from falling from the end of the gangway. (7) If the foot of the gangway is more than one foot away from the edge of the apron, the... this section. (d) Jacob's ladders. (1) Jacob's ladders shall be of the double rung or flat tread type...

A Phenomenological Examination of Virtual Game Developers' Experiences Using Jacob's Ladder Pre-Production Design Tactic

ERIC Educational Resources Information Center

Brown-Turner, Jasmine

2017-01-01

Edutainment refers to curriculum and instruction designed with a clear educational purpose, including multi-faceted virtual learning game design. Tools such as the Jacob's Ladder pre-production design tactic have been developed to ensure that voices of both engineers and educators are heard. However, it is unclear how development team members…

Dynamics of a Sliding Ladder Leaning against a Wall

ERIC Educational Resources Information Center

Oliveira, J. B.; Simeão Carvalho, P.; Mota, M. F.; Quintas, M. J.

2015-01-01

This study is about the dynamics of a sliding ladder leaning against a vertical wall. The results are understood by considering the motion divided in two parts: (i) for 0 = t = t[subscript s] with one degree of freedom, and (ii) for t > t[subscript s] with two degrees of freedom, where the separation is determined by the instance t[subscript…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basso, Benjamin; Dixon, Lance J.

We use integrability at weak coupling to compute fishnet diagrams for four-point correlation functions in planar Φ 4 theory. Our results are always multilinear combinations of ladder integrals, which are in turn built out of classical polylogarithms. The Steinmann relations provide a powerful constraint on such linear combinations, which leads to a natural conjecture for any fishnet diagram as the determinant of a matrix of ladder integrals.

Convergence and Periodic Solutions for the Input Impedance of a Standard Ladder Network

ERIC Educational Resources Information Center

Ucak, C.; Acar, C.

2007-01-01

The input impedance of an infinite ladder network is computed by using the recursive relation and by assuming that the input impedance does not change when a new block is added to the network. However, this assumption is not true in general and standard textbooks do not always treat these networks correctly. This paper develops a general solution…

Career Mobility: Implementing the Ladder Concept in Associate Degree and Practical Nursing Curricula.

ERIC Educational Resources Information Center

Story, Donna Ketchum

Designing a career ladder curriculum is not simply taking an existing practical nurse curriculum and an associate degree nursing curriculum and placing one after the other. The curriculum is designed to produce students who are competent practitioners as practical nurses at the end of the first level and then allow them to continue for an…

A Study of Career Ladders and Manpower Development for Non-Management Personnel in the Food Service Industry.

ERIC Educational Resources Information Center

State Univ. of New York, Ithaca. School of Hotel Administration at Cornell Univ.

Because of its failure to provide career ladders for non-management employees, the food service industry is facing increasingly severe manpower shortages and labor turnover. Unnecessary requirements bar entry workers from many jobs, and training opportunities leave much to be desired. This report identifies the problem areas and develops a model…

The snakes and ladders of National Health Service management in England.

PubMed

Powell, Martin

2014-01-01

This article explores managerial careers in the National Health Service (NHS) through the lens of talent management, particularly focusing on how managers view barriers (snakes) and facilitators (ladders) to career progression. There is a significant literature on enablers and barriers to career progression, but much of this focuses on specific groups such as black and minority ethnic and female workers, and there is relatively little material on the general workforce of the NHS. The research design is a mixed method quantitative (questionnaire) and qualitative (interview and focus group) approach consisting of a quasi-probability element that focuses on a maximum variety sample and a purposive element that seeks policy views at central and strategic health authority level, and examines talent management in high-performing NHS organisations. Ladders are identified as follows: volunteering, secondment, networking, mentoring, academic qualifications, development, good role models/managers and appraisal/personal development plan. Snakes are identified as managing expectations; identity and cognitive diversity; location; sector; NHS toxic and favouritism culture; poor talent spotting; credentialism; exclusive approach to talent; and sustainability. It concludes that while previous conceptual and empirical work is fairly clear on any ladders, it is less clear on snakes. Copyright © 2013 John Wiley & Sons, Ltd.

Variant Alleles, Triallelic Patterns, and Point Mutations Observed in Nuclear Short Tandem Repeat Typing of Populations in Bosnia and Serbia

PubMed Central

Huel, René L. M.; Bašić, Lara; Madacki-Todorović, Kamelija; Smajlović, Lejla; Eminović, Izet; Berbić, Irfan; Miloš, Ana; Parsons, Thomas J.

2007-01-01

Aim To present a compendium of off-ladder alleles and other genotyping irregularities relating to rare/unexpected population genetic variation, observed in a large short tandem repeat (STR) database from Bosnia and Serbia. Methods DNA was extracted from blood stain cards relating to reference samples from a population of 32 800 individuals from Bosnia and Serbia, and typed using Promega’s PowerPlex®16 STR kit. Results There were 31 distinct off-ladder alleles were observed in 10 of the 15 STR loci amplified from the PowerPlex®16 STR kit. Of these 31 alleles, 3 have not been previously reported. Furthermore, 16 instances of triallelic patterns were observed in 9 of the 15 loci. Primer binding site mismatches that affected amplification were observed in two loci, D5S818 and D8S1179. Conclusion Instances of deviations from manufacturer’s allelic ladders should be expected and caution taken to properly designate the correct alleles in large DNA databases. Particular care should be taken in kinship matching or paternity cases as incorrect designation of any of these deviations from allelic ladders could lead to false exclusions. PMID:17696304

Spin rotational symmetry breaking by orbital current patterns in two-leg Cu-O Hubbard ladders

NASA Astrophysics Data System (ADS)

Chudzinski, Piotr; Gabay, Marc; Giamarchi, Thierry

2010-03-01

In the weak-coupling limit, we study, as a function of doping, two-leg ladders with a unit cell containing both Cu and O atoms. For purely repulsive interactions, using bosonization and a novel RG scheme, we find that in a broad region of the phase diagram, the ground state consists of a pattern of orbital currents (OCP) defined on the top of an incommensurate density wave. The internal symmetry of the OCP is specific for the ladder structure, different than the ones suggested up to now for 2D cuprates. We focus on this OCP and look for measurable signals of its existence: we compute magnetic fields induced within the ladder and we check what kind of changes in the phase diagram one may expect due to SU(2) spin-rotational symmetry breaking. We also investigate a single impurity problem (incl. OCP): we discuss if Kondo physics is at play, and make qualitative predictions about the nature of impurity backscattering. This enables us to show the influence of SU(2) symmetry breaking on conductivity. We estimate the value of gap opened due to the OCP, give analytic expressions for correlation functions and discuss magnetic properties of a new phase.

A demonstration that electroweak theory can violate parity automatically (leptonic case)

NASA Astrophysics Data System (ADS)

Furey, C.

2018-02-01

We bring to light an electroweak model which has been reappearing in the literature under various guises.1-5 In this model, weak isospin is shown to act automatically on states of only a single chirality (left). This is achieved by building the model exclusively from the raising and lowering operators of the Clifford algebra ℂl(4). That is, states constructed from these ladder operators mimic the behaviour of left- and right-handed electrons and neutrinos under unitary ladder operator symmetry. This ladder operator symmetry is found to be generated uniquely by su(2)L and u(1)Y. Crucially, the model demonstrates how parity can be maximally violated, without the usual step of introducing extra gauge and extra Higgs bosons, or ad hoc projectors.

In-line digital holography with phase-shifting Greek-ladder sieves

NASA Astrophysics Data System (ADS)

Xie, Jing; Zhang, Junyong; Zhang, Yanli; Zhou, Shenlei; Zhu, Jianqiang

2018-04-01

Phase shifting is the key technique in in-line digital holography, but traditional phase shifters have their own limitations in short wavelength regions. Here, phase-shifting Greek-ladder sieves with amplitude-only modulation are introduced into in-line digital holography, which are essentially a kind of diffraction lens with three-dimensional array diffraction-limited foci. In the in-line digital holographic experiment, we design two kinds of sieves by lithography and verify the validity of their phase-shifting function by measuring a 1951 U.S. Air Force resolution test target and three-dimensional array foci. With advantages of high resolving power, low cost, and no limitations at shorter wavelengths, phase-shifting Greek-ladder sieves have great potential in X-ray holography or biochemical microscopy for the next generation of synchrotron light sources.

Influence of Stress State, Stress Orientation, and Rock Properties on the Development of Deformation-Band 'Ladder' Arrays in Porous Sandstone

NASA Astrophysics Data System (ADS)

Schultz, R. A.; Soliva, R.; Fossen, H.

2013-12-01

Deformation bands in porous rocks tend to develop into spatially organized arrays that display a variety of lengths and thicknesses, and their geometries and arrangements are of interest with respect to fluid flow in reservoirs. Field examples of deformation band arrays in layered clastic sequences suggest that the development of classic deformation band arrays, such as ladders and conjugate sets, and the secondary formation of through-going faults appear to be related to the physical properties of the host rock, the orientation of stratigraphic layers relative to the far-field stress state, and the evolution of the local stress state within the developing array. We have identified several field examples that demonstrate changes in band properties, such as type and orientation, as a function of one or more of these three main factors. Normal-sense deformation-band arrays such as those near the San Rafael Swell (Utah) develop three-dimensional ladder-style arrays at a high angle to the maximum compression direction; these cataclastic shear bands form at acute angles to the maximum compression not very different from that of the optimum frictional sliding plane, thus facilitating the eventual nucleation of a through-going fault. At Orange quarry (France), geometrically conjugate sets of reverse-sense compactional shear bands form with angles to the maximum compression direction that inhibit fault nucleation within them; the bands in this case also form at steep enough angles to bedding that stratigraphic heterogeneities within the deforming formation were apparently not important. Two exposures of thrust-sense ladders at Buckskin Gulch (Utah) demonstrate the importance of host-rock properties, bedding-plane involvement, and local stress perturbations on band-array growth. In one ladder, thrust-sense shear deformation bands nucleated along suitably oriented bedding planes, creating overprinting sets of compaction bands that can be attributed to layer properties and local stress changes near the shear-band tips. Two other ladder exposures preserve compaction bands having nearly perpendicular orientations relative the bounding shear bands that define contractional stepovers that also nucleated on bedding planes. These cases suggest that local stress changes within a deformation-band stepover may lead to either rotation of bands or changes in band type relative to bands formed outside the stepover. The development of the common geometries of deformation band arrays, such as ladders, and the deformation paths to faulting thus depend on a combination of stress state, stress orientation, and rock properties.

B-1 Systems Approach to Training. Task Analysis Listings

DTIC Science & Technology

1975-07-01

OFF FUEL VALVES AND PUMPS PHR-OFF FUEL VALVES AND PUMPS = AUTO ^FT TFR MODE LAND SELECTOR SWITCHES TQ *QFF...TFR MODE SWITCH-RIGHT «JFT L TFR MODE SELECT SWITCH TQ * TF1 CHECKLIST TFR MODE SWITCH-LEFT TFR MODE SWITCH-LEFT...DOOR HANDLE ENTRY LADDER CONTROL SWITCH ENTRY LADDER CONTROL SWITCH = DN* 16.1.1.001.OC* SET TANK FILL VALVE SWS ON

The Earnings Ladder. Who's at the Bottom? Who's at the Top? Statistical Brief.

ERIC Educational Resources Information Center

Bureau of the Census (DOC), Washington, DC. Economics and Statistics Administration.

Data collected by the March Current Population Survey were used to identify which groups of year-round, full-time civilian workers aged 16 and older were most likely to be at the top and bottom of the earnings ladder. Women, young workers, less-educated individuals, and Hispanics were most likely to earn less than $13,091 (1992 constant dollars),…

HRD--Leadership Training for Women on the Lower Rungs of the Organizational Ladder: A Qualitative Study

ERIC Educational Resources Information Center

Dugan, Dixie

2010-01-01

The purpose of this case study, HRD--Leadership Training for Women on the Lower Rungs of the Organizational Ladder: A Qualitative Study, was to determine the responses of a group of women to a series of classes on leadership development and to perceive what they might have gained from this experience. These classes were modeled after those offered…

Astronaut Alan Bean steps from ladder of Lunar Module for EVA

NASA Image and Video Library

1969-11-19

AS12-46-6729 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 lunar landing mission, steps from the ladder of the Lunar Module to join astronaut Charles Conrad Jr., commander, in extravehicular activity on Nov. 19, 1969. Astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules in lunar orbit.

Corrosion Control Specialist Career Ladder AFSC 53530, 53550, 53570, and 53690

DTIC Science & Technology

1975-03-01

AD-AO08 189 CORROSION CONTROL SPECIALIST CAREER LADDER AFSC 53530, 53550, 53570, AND 53690 Air Force Occupational Measurement Center Lackland Air... Force Base, Texas 1 March 1975 I DISTRIBUTED BY: National Technical Information Service U. S. DEPARTMENT OF COMMERCE *I 11 5091 OCCUPATIONAL SURVEY...DISCUSSION OF BACKGROUJND INFORMATION --------------------------- xxvi 01L< R PREFACE This report presents the results cf detailed Air Force

The Effect of George Bush's NAFTA on American Workers: Ladder Up or Ladder Down? Briefing Paper.

ERIC Educational Resources Information Center

Faux, Jeff; Lee, Thea

The proposed North American Free Trade Agreement (NAFTA) will result in lower wages, fewer jobs, and generally reduced living standards for the majority of U.S. workers. Substantial costs to the U.S. economy will occur in job and income loss and few off-setting benefits for most workers. Proponents argue that NAFTA will create upward mobility for…

16. View, looking west, of fish ladder and steel frame ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. View, looking west, of fish ladder and steel frame supporting fish trap, both constructed by U.S. Army Corps of Engineers, 1949. One-story wood-frame building with hip roof is a utility shed used for fish-trap operation. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

Two-point resistance of the Möbius ladder

NASA Astrophysics Data System (ADS)

Chair, Noureddine; Dannoun, Elham Mohammed Ali

2015-03-01

Exact formulas for the two-point resistance and the Kirchhoff index of the Möbius ladder are given based on the recently developed analytical approach by Chair (2012 Ann. Phys. 327 2899). The expression for the two-point resistance is written in terms of the two-point resistance of N/2-cycle graph and the Bejaia and the Pisa numbers recently introduced by the first author.

Subjective Social Status and Psychological Distress in Mothers of Young Children.

PubMed

Michelson, Nicole; Riis, Jenna L; Johnson, Sara B

2016-10-01

Introduction Perceptions of social standing have increasingly well-documented relationships with health. Higher subjective social status (SSS) is associated with better psychological well-being among women, and mothers of newborns. The relationship between SSS and psychological distress among mothers of young children, however, is largely unknown. SSS may provide insight into aspects of maternal functioning that are relevant to parenting capacity, as well as insight into future health; in addition, SSS is brief, and may be perceived as less intrusive than other measures of socioeconomic status or mental health. We evaluated the relationship between SSS and psychological distress among mothers of 5-year-old children from diverse socioeconomic backgrounds. Methods One hundred and sixty-two mothers of 5-year old children, who participated in a study of child self-regulation, completed surveys that assessed sociodemographics, mental health, and perceived social support. The MacArthur Scale of SSS used pictures of ten-rung ladders to assess respondents' social position in relation to the US (SES ladder) and their community (community ladder). Quantile regression models were used to assess the relationship between maternal psychological distress (perceived social support, depressive symptoms, anxiety) and the ladders (individually and together), adjusting for maternal age, race, education, and number of children. To examine whether the SSS-health relationships differed by race, the models were also stratified by race. Results Community ladder ranking was positively associated with social support (β = 1.34, SE = 0.33, p < .001), and negatively associated with depressive symptoms (β = -1.34, SE = 0.52, p < .05). SES ladder ranking was positively associated with social support (β = 1.17, SE = 0.52, p < .05). Findings in the full sample were driven by more robust relationships between psychological distress and community SSS among Black/African-American mothers. Discussion The findings suggest that perceived social standing in one's community is associated with maternal psychological well-being. Community SSS may be particularly influential for Black/African-American mothers' well-being.

Using a familiar risk comparison within a risk ladder to improve risk understanding by low numerates: a study of visual attention.

PubMed

Keller, Carmen

2011-07-01

Previous experimental research provides evidence that a familiar risk comparison within a risk ladder is understood by low- and high-numerate individuals. It especially helps low numerates to better evaluate risk. In the present study, an eye tracker was used to capture individuals' visual attention to a familiar risk comparison, such as the risk associated with smoking. Two parameters of information processing-efficiency and level-were derived from visual attention. A random sample of participants from the general population (N= 68) interpreted a given risk level with the help of the risk ladder. Numeracy was negatively correlated with overall visual attention on the risk ladder (r(s) =-0.28, p= 0.01), indicating that the lower the numeracy, the more the time spent looking at the whole risk ladder. Numeracy was positively correlated with the efficiency of processing relevant frequency (r(s) = 0.34, p < 0.001) and relevant textual information (r(s) = 0.34, p < 0.001), but not with the efficiency of processing relevant comparative information and numerical information. There was a significant negative correlation between numeracy and the level of processing of relevant comparative risk information (r(s) =-0.21, p < 0.01), indicating that low numerates processed the comparative risk information more deeply than the high numerates. There was no correlation between numeracy and perceived risk. These results add to previous experimental research, indicating that the smoking risk comparison was crucial for low numerates to evaluate and understand risk. Furthermore, the eye-tracker method is promising for studying information processing and improving risk communication formats. © 2011 Society for Risk Analysis.

Symmetry-broken states in a system of interacting bosons on a two-leg ladder with a uniform Abelian gauge field

NASA Astrophysics Data System (ADS)

Greschner, S.; Piraud, M.; Heidrich-Meisner, F.; McCulloch, I. P.; Schollwöck, U.; Vekua, T.

2016-12-01

We study the quantum phases of bosons with repulsive contact interactions on a two-leg ladder in the presence of a uniform Abelian gauge field. The model realizes many interesting states, including Meissner phases, vortex fluids, vortex lattices, charge density waves, and the biased-ladder phase. Our work focuses on the subset of these states that breaks a discrete symmetry. We use density matrix renormalization group simulations to demonstrate the existence of three vortex-lattice states at different vortex densities and we characterize the phase transitions from these phases into neighboring states. Furthermore, we provide an intuitive explanation of the chiral-current reversal effect that is tied to some of these vortex lattices. We also study a charge-density-wave state that exists at 1/4 particle filling at large interaction strengths and flux values close to half a flux quantum. By changing the system parameters, this state can transition into a completely gapped vortex-lattice Mott-insulating state. We elucidate the stability of these phases against nearest-neighbor interactions on the rungs of the ladder relevant for experimental realizations with a synthetic lattice dimension. A charge-density-wave state at 1/3 particle filling can be stabilized for flux values close to half a flux quantum and for very strong on-site interactions in the presence of strong repulsion on the rungs. Finally, we analytically describe the emergence of these phases in the low-density regime, and, in particular, we obtain the boundaries of the biased-ladder phase, i.e., the phase that features a density imbalance between the legs. We make contact with recent quantum-gas experiments that realized related models and discuss signatures of these quantum states in experimentally accessible observables.

Clarifying the Hubble constant tension with a Bayesian hierarchical model of the local distance ladder

NASA Astrophysics Data System (ADS)

Feeney, Stephen M.; Mortlock, Daniel J.; Dalmasso, Niccolò

2018-05-01

Estimates of the Hubble constant, H0, from the local distance ladder and from the cosmic microwave background (CMB) are discrepant at the ˜3σ level, indicating a potential issue with the standard Λ cold dark matter (ΛCDM) cosmology. A probabilistic (i.e. Bayesian) interpretation of this tension requires a model comparison calculation, which in turn depends strongly on the tails of the H0 likelihoods. Evaluating the tails of the local H0 likelihood requires the use of non-Gaussian distributions to faithfully represent anchor likelihoods and outliers, and simultaneous fitting of the complete distance-ladder data set to ensure correct uncertainty propagation. We have hence developed a Bayesian hierarchical model of the full distance ladder that does not rely on Gaussian distributions and allows outliers to be modelled without arbitrary data cuts. Marginalizing over the full ˜3000-parameter joint posterior distribution, we find H0 = (72.72 ± 1.67) km s-1 Mpc-1 when applied to the outlier-cleaned Riess et al. data, and (73.15 ± 1.78) km s-1 Mpc-1 with supernova outliers reintroduced (the pre-cut Cepheid data set is not available). Using our precise evaluation of the tails of the H0 likelihood, we apply Bayesian model comparison to assess the evidence for deviation from ΛCDM given the distance-ladder and CMB data. The odds against ΛCDM are at worst ˜10:1 when considering the Planck 2015 XIII data, regardless of outlier treatment, considerably less dramatic than naïvely implied by the 2.8σ discrepancy. These odds become ˜60:1 when an approximation to the more-discrepant Planck Intermediate XLVI likelihood is included.

Electronic structure reconstruction across the antiferromagnetic transition in TaFe₁̣₂₃Te₃ spin ladder

DOE PAGES

Xu, Min; Wang, Li -Min; Peng, Rui; ...

2015-02-01

With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe₁̣₂₃Te₃, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe₁̣₂₃Te₃ serves as a simpler platform that containsmore » similar ingredients as the parent compounds of iron-based superconductors.« less

Automatic Digital Switching Specialist Career Ladder: United States Air Force Job Inventory. AFSCs 29530, 29570, and 29590.

ERIC Educational Resources Information Center

Air Force Personnel and Training Research Center, Lackland AFB, TX.

The U. S. Air Force job inventory for the automatic digital switching specialist career ladder is divided into 12 categories, each of which is broken down into a duty-task list. Space is provided for Air Force personnel filling out the inventory to check whether each task is at present part of their duties. The 12 categories are: organizing and…

Upstream dispersal of an invasive crayfish aided by a fish passage facility

USGS Publications Warehouse

Welsh, Stuart A.; Loughman, Zachary J.

2015-01-01

Fish passage facilities for reservoir dams have been used to restore habitat connectivity within riverine networks by allowing upstream passage for native species. These facilities may also support the spread of invasive species, an unintended consequence and potential downside of upstream passage structures. We documented dam passage of the invasive virile crayfish, Orconectes virilis (Hagen, 1870), at fish ladders designed for upstream passage of American eels, Anguilla rostrata (Lesueur, 1817), in the Shenandoah River drainage, USA. Ladder use and upstream passage of 11 virile crayfish occurred from 2007–2014 during periods of low river discharge (<30 m3s–1) and within a wide range of water temperatures from 9.0–28.6 °C. Virile crayfish that used the eel ladders were large adults with a mean carapace length and width of 48.0 mm and 24.1 mm, respectively. Our data demonstrated the use of species-specific fish ladders by a non-target non-native species, which has conservation and management implications for the spread of aquatic invasive species and upstream passage facilities. Specifically, managers should consider implementing long-term monitoring of fish passage facilities with emphasis on detection of invasive species, as well as methods to reduce or eliminate passage of invasive species. 

Influence of seasonal, diel, lunar, and other environmental factors on upstream fish passage in the igarapava fish ladder, Brazil

USGS Publications Warehouse

Bizzotto, P.M.; Godinho, Alexandre L.; Vono, V.; Kynard, B.; Godinho, Hugo P.

2009-01-01

Upstream fish passage was evaluated during 12 months in the vertical-slot Igarapava Fish Ladder constructed around Igarapava Dam, in the heavily dammed Grande River, Southeast Brazil. A video monitoring system was used to observe 61,621 fish that passed the ladder, of which 93.5% were identified to 15 taxa. Among the migratory species, the most abundant were Pimelodus maculatus (33.6% of all fish), Leporinus octofasciatus (31.4%), Leporinus friderici (4.5%), and Prochilodus lineatus (3.1%). Seven taxa were classified as nonmigratory, and of these taxa, the small Bryconamericus stramineus was the most abundant (12.7%) of all fishes. Passage of the 'nonmigratory' taxa upstream in the ladder shows they are migratory in this system and have a strong behavioural drive to move to upstream habitat. Passage of most taxa had a strong seasonal pattern. While some species passed primarily during the day, others showed a distinct nocturnal pattern. Lunar phase and water temperature also strongly affected passage of some taxa. Rainfall and dam discharge had a small or null influence on most taxa; perhaps due to the fairly small catchment area of the reservoir and the highly regulated discharge at Igarapava Dam. ?? 2009 John Wiley & Sons A/S.

[Application of general retention time formula for gradient liquid chromatography in the studies of ladder-like gradient elution].

PubMed

Sun, Xiaoli; Hao, Weiqiang; Wang, Junde; Di, Bin; Chen, Qiang; Zhuang, Wei; Yu, Qiang; Zhang, Peipei

2013-08-01

By not explicitly specifying the type of solvent strength model, the features of ladder-like gradient elution were studied based on the general retention time formula that was derived in our previous work. For the case where the solute is eluted at like gradient, we derived the expression that connects the mobile phase composition (phiR), at which the solute is eluted from the column, with the gradient slope (B). It was shown that phiR will increase with the increase of B in this case. For the case where the solute is eluted at the last isocratic segment of the ladder-like gradient, it was proven that the retention time (tR) will correlate linearly with the reciprocal of the gradient slope (1/B) when the initial and final mobile phase compositions are set to be constant. In experiments, by taking biphenyl as the sample, the values of retention time in isocratic and gradient elution were measured on a C18 column by using a mixture of methanol and water as the mobile phase. The experimental values were found to be well consistent with the theoretical values that were calculated from the expressions. These expressions will be helpful to understand the features of the ladder-like gradient in practice.

The Ladder of Life Detection.

PubMed

Neveu, Marc; Hays, Lindsay E; Voytek, Mary A; New, Michael H; Schulte, Mitchell D

2018-06-04

We describe the history and features of the Ladder of Life Detection, a tool intended to guide the design of investigations to detect microbial life within the practical constraints of robotic space missions. To build the Ladder, we have drawn from lessons learned from previous attempts at detecting life and derived criteria for a measurement (or suite of measurements) to constitute convincing evidence for indigenous life. We summarize features of life as we know it, how specific they are to life, and how they can be measured, and sort these features in a general sense based on their likelihood of indicating life. Because indigenous life is the hypothesis of last resort in interpreting life-detection measurements, we propose a small but expandable set of decision rules determining whether the abiotic hypothesis is disproved. In light of these rules, we evaluate past and upcoming attempts at life detection. The Ladder of Life Detection is not intended to endorse specific biosignatures or instruments for life-detection measurements, and is by no means a definitive, final product. It is intended as a starting point to stimulate discussion, debate, and further research on the characteristics of life, what constitutes a biosignature, and the means to measure them. Key Words: Life detection-Life-detection instruments-Biosignatures-Biomarkers. Astrobiology 18, xxx-xxx.

Walla Walla River Fish Passage Operations Program, 2004-2005 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronson, James P.; Duke, Bill B.

2006-02-01

In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survivalmore » of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2004-2005 project year, there were 590 adult summer steelhead, 31 summer steelhead kelts (Oncorhynchus mykiss), 70 adult bull trout (Salvelinus confluentus); 80 adult and 1 jack spring Chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 13, 2004, and June 16, 2005. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by ODFW in order to enumerate fish passage. Of the total, 143 adult summer steelhead and 15 summer steelhead kelts were enumerated at the west ladder at Nursery Bridge Dam during the video efforts between February 4 and May 23, 2005. Operation of the Little Walla Walla River juvenile trap for trap and haul purposes was not necessary this year.« less

Fall-induced spinal cord injury: External causes and implications for prevention

PubMed Central

Tang, Ying; Allen, Victoria; DeVivo, Michael J

2016-01-01

Objective To document the demographic and clinical profile of persons who sustained spinal cord injury (SCI) as a result of accidental falls and to determine the usual circumstances surrounding the fall-induced SCI. Design Cohort study. Setting 21 SCI Model Systems centers throughout the United States. Participants 6,408 individuals with traumatic SCI between 2005 and 2014 were recruited from the National SCI Database. 1,877 (29%) of them were injuries caused by falls. Interventions Not applicable. Outcomes Measures External causes of injury documented by the International Classification of Diseases, 10th revision, Clinical Modification (ICD-10-CM). Results Falls on the same level from slipping, tripping, and stumbling were the most common cause of fall-induced SCI (20%), followed by falls from building (16%), stairs and steps (16%), and ladder (9%). People who were 61 years of age and older had the highest frequency of falls on the same level, while those aged 16–45 years had a higher percentage of falls from buildings, usually work-related. The mechanisms of falls also varied by sex and race. Associated injury and vertebral injury occurred frequently among falls from buildings and ladders. High falls were more likely to be work-related and result in thoracic and complete injury, while low falls were more commonly associated with cervical and motor functionally incomplete injury. Conclusion The study findings of different mechanisms of falls by age, sex, race and medical consequences provide an insight for future interventions aimed at high risk persons, activities, and environmental factors for preventing or reducing fall-induced SCI. PMID:25832327

Keeping experience at the bedside: the emergency consultant nurse role.

PubMed

Currie, Jane

The consultant nurse concept has not yet been transferred to the military setting. The motivation for developing the role in the NHS was to improve the quality of patient care by strengthening professional leadership and extending the clinical career ladder. The consultant nurse may be defined as an expert in their clinical field, possessing expert leadership and visionary skills. The role is based on four domains: expert practice, professional leadership, education and research. Typically, the emergency consultant nurse spends 50% of their time working clinically, thereby providing senior clinical expertise and adding value to the clinical role. In a military context the consultant nurse role could be perceived as the coming together of the senior command and administrative role and the clinical role. The military has the opportunity to develop a senior clinical emergency nurse role encompassing elements of the civilian consultant nurse model, which may strengthen leadership, provide a central resource of expertise and raise the profile of military nursing. This has the added potential to provide inspiration for junior nurses and retain experienced emergency nurses in the clinical arena.

Castine Report S-15 Project: Shipbuilding Standards

DTIC Science & Technology

1976-01-01

Fixed Square Windows Ships” Extruded Aluminium Alloy Square Windows “ Ships” Foot Steps Ships* Wooden Hand Rail . Pilot Ladders Panama Canal Pilot...Platforms Aluminium Alloy Accommodation Ladders Mouth Pieces for Voice Tube Chain Drwe Type Telegraphs Fittings for Steam Whistle Llfeboats Radial Type...Cast Steel Angle Valves for Compressed Air F 8001-1957 F 8002-1967 F 8003.1975 F 8004.1975 F 8011 1966 F 8013.1969 F 8101.1969 F 8401.1970 F

The hadronic interaction model EPOS

NASA Astrophysics Data System (ADS)

Werner, Klaus

2008-01-01

EPOS is a sophisticated multiple scattering approach based on partons and Pomerons (parton ladders), with special emphasis on high parton densities. The latter aspect, particularly important in proton-nucleus or nucleus-nucleus collisions, is taken care of via an effective treatment of Pomeron-Pomeron interactions, referred to as parton ladder splitting. In addition, collective effects are introduced after separating the high density central core from the peripheral corona. EPOS is the successor of the NEXUS model.

Multiscale Computational Design Optimization of Copper-Strengthened Steel for High Cycle Fatigue

DTIC Science & Technology

2010-03-19

strain energy) and (3) modeling of a slip band (of PSB ladder underlying structure) and attendant crack initiation process. 15. SUBJECT TERMS 16...energy). (C) A modeling of a slip band (of PSB ladder underlying structure) and attendant crack initiation process. Major results obtained are...differentiate the morphology from others, e.g., vein and planar structures of dislocations. Results and Discussion for (C) (C-1) Modeling PSB For modeling

AGARD Flight Test Techniques Series. Volume 8. Flight Testing under Extreme Environmental Conditions

DTIC Science & Technology

1988-01-01

gravity control system operation. The overall objective of fuel system tests is to determine whether the system functions properly at all conditions both... gravity . 3.3.4 Hydraulic System The functional adequacy of the hydraulic system should be evaluated by monitoring operating system temperatures and...mechanical or gravity function of the crew ladder should be evaluated. The ladder should be exposed to freasing rain and icing to evaluate the non

At Sea Personnel Transfer Concepts

DTIC Science & Technology

2006-07-28

transfer at sea. Personnel can be transferred with relatively short notice using a 4” double braided , polyester synthetic highline instead of steel...supporting 1000 lbs at the tip of the ladder, and sustaining a 60000 gal/hr hose firing at any angle. The ladders are capable of supporting this...significant burden for the bridges. To further reduce the tip weight, the vacuum pumps will be stored on the deck of the ship and hosing will be run

Hydrothermal synthesis and characterization of a novel supramolecular network compound of Co(NIA) 2(H 2O) 4 with molecular ladder hydrogen bond chains (NIA=nicotinate)

NASA Astrophysics Data System (ADS)

Jia, Hong-Bin; Yu, Jie-Hui; Xu, Ji-Qing; Ye, Ling; Ding, Hong; Jing, Wei-Jie; Wang, Tie-Gang; Xu, Jia-Ning; Li, Zeng-Chun

2002-10-01

By hydrothermal method, a novel supramolecular compound, Co(NIA) 2(H 2O) 4 was synthesized and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffractometer, indicating that it is a novel polyporous supramolecule with molecular ladder hydrogen-bonded chains. TGA curve shows its thermal stability up to 520 °C.

Pavements Maintenance and Construction Equipment Operator Career Ladders: United States Air Force Job Inventory. AFSCs 55130/31, 55150/51, 55170/71, and 55191.

ERIC Educational Resources Information Center

Air Force Personnel and Training Research Center, Lackland AFB, TX.

The U. S. Air Force job inventory for the pavements maintenance and construction equipment operator career ladders is divided into 26 categories, each of which is broken down into a duty-task list. Space is provided for Air Force personnel filling out the inventory to check whether each task is at present part of their duties. The 26 categories…

(p,q) deformations and (p,q)-vector coherent states of the Jaynes-Cummings model in the rotating wave approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben Geloun, Joseph; Govaerts, Jan; Hounkonnou, M. Norbert

2007-03-15

Classes of (p,q) deformations of the Jaynes-Cummings model in the rotating wave approximation are considered. Diagonalization of the Hamiltonian is performed exactly, leading to useful spectral decompositions of a series of relevant operators. The latter include ladder operators acting between adjacent energy eigenstates within two separate infinite discrete towers, except for a singleton state. These ladder operators allow for the construction of (p,q)-deformed vector coherent states. Using (p,q) arithmetics, explicit and exact solutions to the associated moment problem are displayed, providing new classes of coherent states for such models. Finally, in the limit of decoupled spin sectors, our analysis translatesmore » into (p,q) deformations of the supersymmetric harmonic oscillator, such that the two supersymmetric sectors get intertwined through the action of the ladder operators as well as in the associated coherent states.« less

Low-Field Bi-Skyrmion Formation in a Noncentrosymmetric Chimney Ladder Ferromagnet

NASA Astrophysics Data System (ADS)

Takagi, R.; Yu, X. Z.; White, J. S.; Shibata, K.; Kaneko, Y.; Tatara, G.; Rønnow, H. M.; Tokura, Y.; Seki, S.

2018-01-01

The real-space spin texture and the relevant magnetic parameters were investigated for an easy-axis noncentrosymmetric ferromagnet Cr11 Ge19 with Nowotny chimney ladder structure. Using Lorentz transmission electron microscopy, we report the formation of bi-Skyrmions, i.e., pairs of spin vortices with opposite magnetic helicities. The quantitative evaluation of the magnetocrystalline anisotropy and Dzyaloshinskii-Moriya interaction (DMI) proves that the magnetic dipolar interaction plays a more important role than the DMI on the observed bi-Skyrmion formation. Notably, the critical magnetic field value required for the formation of bi-Skyrmions turned out to be extremely small in this system, which is ascribed to strong easy-axis anisotropy associated with the characteristic helix crystal structure. The family of Nowotny chimney ladder compounds may offer a unique material platform where two distinctive Skyrmion formation mechanisms favoring different topological spin textures can become simultaneously active.

General view of the middeck looking aft and port. In ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the mid-deck looking aft and port. In this view you can clearly see the crew access hatch and the airlock hatch. The hose and ladder in the image are pieces of ground support equipment. The hose is part of the climate control apparatus used while orbiters are being processed. The ladder is used to access the inter-deck passage, leading to the flight deck, while the orbiter is in 1g (earth's gravity). A careful observer will notice a void in the wall near the base of the access ladder, this is the Waste Management Compartment with the Waste Management System, i.e. Space Potty, removed. This view was taken in the Orbiter Processing Facility at the Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Implementability of two-qubit unitary operations over the butterfly network and the ladder network with free classical communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akibue, Seiseki; Murao, Mio

2014-12-04

We investigate distributed implementation of two-qubit unitary operations over two primitive networks, the butterfly network and the ladder network, as a first step to apply network coding for quantum computation. By classifying two-qubit unitary operations in terms of the Kraus-Cirac number, the number of non-zero parameters describing the global part of two-qubit unitary operations, we analyze which class of two-qubit unitary operations is implementable over these networks with free classical communication. For the butterfly network, we show that two classes of two-qubit unitary operations, which contain all Clifford, controlled-unitary and matchgate operations, are implementable over the network. For the laddermore » network, we show that two-qubit unitary operations are implementable over the network if and only if their Kraus-Cirac number do not exceed the number of the bridges of the ladder.« less

Stimulated emission from ladder-type two-photon coherent atomic ensemble.

PubMed

Park, Jiho; Moon, Han Seb

2018-05-28

We investigated the stimulated emission from a ladder-type two-photon coherent atomic ensemble, for the 5S 1/2 - 5P 3/2 - 5D 5/2 transition of 87 Rb atoms. Under the ladder-type two-photon resonance condition obtained using pump and coupling lasers, we observed broad four-wave mixing (FWM) light stimulated from two-photon coherence induced by the seed laser coupled between the ground state of 5S 1/2 and the first excited state of 5P 3/2 . A dip in the FWM spectrum was obtained for three-photon resonance due to V-type two-photon coherence using the pump and seed lasers. From the FWM spectra obtained for varying frequency detuning and seed-laser power, we determined that the seed laser acts as a stimulator for FWM generation, but also acts as a disturber of FWM due to V-type two-photon coherence.

High-pressure electrical resistivity studies for Ba1-xCsxFe2Se3

NASA Astrophysics Data System (ADS)

Kawashima, C.; Soeda, H.; Takahashi, H.; Hawai, T.; Nambu, Y.; Sato, T. J.; Hirata, Y.; Ohgushi, K.

2017-10-01

High-pressure electrical resistance measurements were performed for iron-based ladder material Ba1-xCsxFe2Se3 (x = 0.25 and 0.65) using a diamond anvil cell (DAC). Recent high-pressure study revealed that iron-based ladder material BaFe2S3 exhibits an insulator-metal transition and superconductivity, and this discovery would provide important insight for understanding the mechanism of iron-based superconductors. Therefore, it is intriguing to investigate the high-pressure properties for the iron-based ladder material Ba1-xCsxFe2Se3 system. The parent compounds BaFe2Se3 and CsFe2Se3 show insulating and magnetic ordering features. For Ba1-xCsxFe2Se3 system, no magnetic ordering is observed for x = 0.25 and minimum charge gap was estimated for x = 0.65. The insulator-metal transitions are observed in both materials.

High-pressure electrical resistivity studies for Ba1-xCsxFe2Se3

NASA Astrophysics Data System (ADS)

Kawashima, C.; Soeda, H.; Takahashi, H.; Hawai, T.; Nambu, Y.; Sato, T. J.; Hirata, Y.; Ohgushi, K.

2017-10-01

High-pressure electrical resistance measurements were performed for iron-based ladder material Ba1-xCsxFe2Se3 (x = 0.25 and 0.65) using a diamond anvil cell (DAC). Recent high-pressure study revealed that iron-based ladder material BaFe2S3 exhibits an insulator- metal transition and superconductivity, and this discovery would provide important insight for understanding the mechanism of iron-based superconductors. Therefore, it is intriguing to investigate the high-pressure properties for the iron-based ladder material Ba1-xCsxFe2Se3 system. The parent compounds BaFe2Se3 and CsFe2Se3 show insulating and magnetic ordering features. For Ba1-xCsxFe2Se3 system, no magnetic ordering is observed for x = 0.25 and minimum charge gap was estimated for x = 0.65. The insulator-metal transitions are observed in both materials.

Developing an educational safety program for pharmacy employees.

PubMed

Hayman, J N

1980-02-01

The need for developing educational safety programs for pharmacy employees is discussed. A three-part program is offered as a guide for structuring a departmental safety program. Part I deals with environmental hazards such as wet floors, poor lighting, and cluttered walk areas. Precautions that should be taken to avoid accidental exposure to patients with communicable diseases are also included. Hazards that may result from improper handling of materials or equipment are addressed in Part II. Included are precautions for handling chemicals, needles, ladders, and electrical equipment. Proper methods of lifting heavy objects are also discussed. Part III details plans to protect staff members in the event of a fire. Plans for reporting fires and evacuating the pharmacy and hospital are discussed. The outlined program requires self-study by staff members during initial employee orientation, followed by annual retraining. Employees are tested and graded on safety topics, and training records are filed for future reference. The program outlined is thought to offer a simple yet effective means of acquainting staff members with established institutional and departmental safety procedures.

A framework for evaluating national space activity

NASA Astrophysics Data System (ADS)

Wood, Danielle; Weigel, Annalisa

2012-04-01

Space technology and resources are used around the world to address societal challenges. Space provides valuable satellite services, unique scientific discoveries, surprising technology applications and new economic opportunities. Many developing countries formally recognize the advantages of space resources and pursue national level activity to harness them. There is limited data or documentation on the space activities of developing countries. Meanwhile, traditional approaches to summarize national space activity do not necessarily capture the types of activity that developing countries pursue in space. This is especially true if they do not have a formal national space program or office. Developing countries pursue national space activity through activities of many types—from national satellite programs to commercial use of satellite services to involvement with international space institutions. This research aims to understand and analyze these trends. This paper introduces two analytical frameworks for evaluating space activity at the national level. The frameworks are specifically designed to capture the activity of countries that have traditionally been less involved in space. They take a broad view of space related activity across multiple societal sectors and disciplines. The discussion explains the approach for using the frameworks as well as illustrative examples of how they can be applied as part of a research process. The first framework is called the Mission and Management Ladders. This framework considers specific space projects within countries and ranks them on "Ladders" that measure technical challenge and managerial autonomy. This first method is at a micro level of analysis. The second framework is called the Space Participation Metric (SPM). The SPM can be used to assign a Space Participation score to countries based on their involvement in various space related activities. This second method uses a macro level of analysis. The authors developed both frameworks as part of a long term research program about the space activities of developing countries. This aspect of the research focuses on harnessing multiple techniques to summarize complex, multi-disciplinary information about global space activity.

Extraordinary Spin-Wave Thermal Conductivity in Low-Dimensional Copper Oxides

DTIC Science & Technology

2015-01-23

excitations of spin degrees of freedom. We measmed for the first time the magnon -phonon coupling parameter of a spin-ladder compound over a wide temperatme...the first time the magnon -phonon coupling parameter of a spin-ladder compound over a wide temperature range. We developed advances in the analysis of...Scientific Instruments, (10 2014): 104903. doi: 10.1063/1.4897622 Gregory T. Hohensee, R. B. Wilson, Joseph P. Feser, David G. Cahill. Magnon -phonon

First Responder Problem Solving and Decision Making in Today’s Asymmetrical Environment

DTIC Science & Technology

2008-03-01

Scenario: Earthquake 4 It is January 2, 2008, and you are working a day-tour in Ladder Company 999 located in Queens, New York. • Ladder 999’s...able to perform both. 121 Scenario: Earthquake 4 You find out that at approximately 8:58 am, the New York City area...RESPONDER PROBLEM SOLVING AND DECISION MAKING IN TODAY’S ASYMMETRICAL ENVIRONMENT Neil R. Hintze Battalion Chief, New York City Fire Department B.A

Magneto-optical polarization rotation in a ladder-type atomic system for tunable offset locking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parniak, Michał, E-mail: michal.parniak@fuw.edu.pl; Leszczyński, Adam; Wasilewski, Wojciech

2016-04-18

We demonstrate an easily tunable locking scheme for stabilizing frequency-sum of two lasers on a two-photon ladder transition based on polarization rotation in warm rubidium vapors induced by magnetic field and circularly polarized drive field. Unprecedented tunability of the two-photon offset frequency is due to strong splitting and shifting of magnetic states in external field. In our experimental setup, we achieve two-photon detuning of up to 700 MHz.

Context View from 11' on ladder from southeast corner of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Context View from 11' on ladder from southeast corner of Bottle Village parcel, just inside fence. Doll Head Shrine at far left frame, Living Trailer (c.1960 "Spartanette") in center frame. Little Wishing Well at far right frame. Some shrines and small buildings were destroyed in the January 1994 Northridge earthquake, and only their perimeter walls and foundations exist. Camera facing north northwest. - Grandma Prisbrey's Bottle Village, 4595 Cochran Street, Simi Valley, Ventura County, CA

Apoptosis after gamma irradiation. Is it an important cell death modality?

PubMed Central

Siles, E.; Villalobos, M.; Jones, L.; Guerrero, R.; Eady, J. J.; Valenzuela, M. T.; Núñez, M. I.; McMillan, T. J.; Ruiz de Almodóvar, J. M.

1998-01-01

Apoptosis and necrosis are two different forms of cell death that can be induced by cytotoxic stress, such as ionizing radiation. We have studied the importance of apoptotic death induced after treatment with 6 Gy of gamma-irradiation in a panel of eight human tumour cell lines of different radiosensitivities. Three different techniques based on the detection of DNA fragmentation have been used, a qualitative one--DNA ladder formation --and two quantitative approaches--in situ tailing and comet assay. No statistically significant relationship between the two quantitative assays was found (r= 0.327, P = 0.159) so these methods seem to show different aspects of the process of cell death. The presence of the DNA ladder related well to the end-labelling method in that the least amount of end labelling was seen in samples in which necrotic degradation rather than apoptotic ladders were seen. However, as the results obtained by the comet assay are not in agreement with the DNA ladder experiments, we suggest that the distinction between the degraded DNA produced by apoptosis and necrosis may be difficult by this technique. Finally, although apoptosis has been proposed to be dependent on p53 functionality, and this may explain differences in cellular radiosensitivity, no statistically significant relationship was found between these parameters and apoptosis in the eight cell lines studied. PMID:9862569

Orbital currents in a generalized Hubbard ladder

NASA Astrophysics Data System (ADS)

Fjaerestad, John O.

2004-03-01

We study a phase with orbital currents (d-density wave (DDW)/staggered flux phase) in a generalized Hubbard model on the two-leg ladder at zero temperature. Bosonization and perturbative renormalization-group calculations are used to identify a parameter region with long-range DDW order in the weakly interacting half-filled ladder. Finite-size density-matrix renormalization-group (DMRG) studies of ladders with up to 200 rungs, for rational hole dopings δ and intermediate-strength interactions, find that currents remain large in the doped DDW phase, with no evidence of decay.^1,2,3 Motivated by these results, we consider an effective bosonization description of the doped DDW phase in which quantum fluctuations in the total charge mode are neglected.^3 This leads to an analytically solvable Frenkel-Kontorova-like model which predicts that the staggered rung current and the rung electron density show periodic spatial oscillations with wavelengths 2/δ and 1/δ, respectively, with the density minima located at the zeros (domain walls) of the staggered rung current, in good agreement with the DMRG results. We comment on the question of the nature of the asymptotic current correlations in the doped DDW phase. ^1U. Schollwöck, S. Chakravarty, J. O. Fjaerestad, J. B. Marston, and M. Troyer, Phys. Rev. Lett. 90, 186401 (2003). ^2M. Troyer, invited talk at this meeting. ^3J. O. Fjaerestad, J. B. Marston, and U. Schollwöck, unpublished.

Emotional intelligence, performance, and retention in clinical staff nurses.

PubMed

Codier, Estelle; Kamikawa, Cindy; Kooker, Barbara M; Shoultz, Jan

2009-01-01

Emotional intelligence has been correlated with performance, retention, and organizational commitment in professions other than nursing. A 2006 pilot study provided the first evidence of a correlation between emotional intelligence and performance in clinical staff nurses. A follow-up study was completed, the purpose of which was to explore emotional intelligence, performance level, organizational commitment, and retention. A convenience sample of 350 nurses in a large medical center in urban Hawaii participated in this study. This article reports the findings pertaining to the subset of 193 clinical staff nurses who responded. The Mayer-Salovey-Caruso Emotional Intelligence Test instrument was used to measure emotional intelligence abilities. Performance was defined as ranking on a clinical ladder. Commitment was scored on a Likert scale. The following variables measured retention: total years in nursing, years in current job, total years anticipated in current job, and total anticipated career length. Emotional intelligence scores in clinical staff nurses correlated positively with both performance level and retention variables. Clinical staff nurses with higher emotional intelligence scores demonstrated higher performance, had longer careers, and greater job retention.

Apollo 12 Mission image - Dark view of Astronaut Alan L. Bean climbing down the ladder of the Lunar Module (LM)

NASA Image and Video Library

1969-11-19

AS12-46-6728 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 mission, is about to step off the ladder of the Lunar Module to join astronaut Charles Conrad Jr., mission commander, in extravehicular activity (EVA). Conrad and Bean descended in the Apollo 12 LM to explore the moon while astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules in lunar orbit.

Refrigeration and Cryogenics Career Ladder, AFSc 54530, 54550, and 54570.

DTIC Science & Technology

1983-07-01

STATES AIR FORCE D cl e 00l REFRIGERATION AND CRYOGENICS CAREER LADDER AFSCs 54530, 54550, AND 54570 AFPT 90-545-461 JULY 1983 ,-. 71983 - OCCUPATIONAL...been reviewed and is approved. PAUL T. RINGENBACH, Colonel, USAF WALTER E . DRISKILL, Ph.D. Commander Chief, Occupational Analysis Branch USAF...ASSIGNED SAMPLE AIRMAN 35 35 E -4 22 23 E -5 27 26 E -6 11 12 E -7 5 4 E -8 * E -9 * TOTALS 100 100 DENOTES LESS THAN ONE PERCENT TABLE 3 TAFHS

Mesoscopic Vortex–Meissner currents in ring ladders

NASA Astrophysics Data System (ADS)

Haug, Tobias; Amico, Luigi; Dumke, Rainer; Kwek, Leong-Chuan

2018-07-01

Recent experimental progress have revealed Meissner and Vortex phases in low-dimensional ultracold atoms systems. Atomtronic setups can realize ring ladders, while explicitly taking the finite size of the system into account. This enables the engineering of quantized chiral currents and phase slips in between them. We find that the mesoscopic scale modifies the current. Full control of the lattice configuration reveals a reentrant behavior of Vortex and Meissner phases. Our approach allows a feasible diagnostic of the currents’ configuration through time-of-flight measurements.

Superintegrability of the Fock-Darwin system

NASA Astrophysics Data System (ADS)

Drigho-Filho, E.; Kuru, Ş.; Negro, J.; Nieto, L. M.

2017-08-01

The Fock-Darwin system is analyzed from the point of view of its symmetry properties in the quantum and classical frameworks. The quantum Fock-Darwin system is known to have two sets of ladder operators, a fact which guarantees its solvability. We show that for rational values of the quotient of two relevant frequencies, this system is superintegrable, the quantum symmetries being responsible for the degeneracy of the energy levels. These symmetries are of higher order and close a polynomial algebra. In the classical case, the ladder operators are replaced by ladder functions and the symmetries by constants of motion. We also prove that the rational classical system is superintegrable and its trajectories are closed. The constants of motion are also generators of symmetry transformations in the phase space that have been integrated for some special cases. These transformations connect different trajectories with the same energy. The coherent states of the quantum superintegrable system are found and they reproduce the closed trajectories of the classical one.

System-wide analysis of the transcriptional network of human myelomonocytic leukemia cells predicts attractor structure and phorbol-ester-induced differentiation and dedifferentiation transitions

NASA Astrophysics Data System (ADS)

Sakata, Katsumi; Ohyanagi, Hajime; Sato, Shinji; Nobori, Hiroya; Hayashi, Akiko; Ishii, Hideshi; Daub, Carsten O.; Kawai, Jun; Suzuki, Harukazu; Saito, Toshiyuki

2015-02-01

We present a system-wide transcriptional network structure that controls cell types in the context of expression pattern transitions that correspond to cell type transitions. Co-expression based analyses uncovered a system-wide, ladder-like transcription factor cluster structure composed of nearly 1,600 transcription factors in a human transcriptional network. Computer simulations based on a transcriptional regulatory model deduced from the system-wide, ladder-like transcription factor cluster structure reproduced expression pattern transitions when human THP-1 myelomonocytic leukaemia cells cease proliferation and differentiate under phorbol myristate acetate stimulation. The behaviour of MYC, a reprogramming Yamanaka factor that was suggested to be essential for induced pluripotent stem cells during dedifferentiation, could be interpreted based on the transcriptional regulation predicted by the system-wide, ladder-like transcription factor cluster structure. This study introduces a novel system-wide structure to transcriptional networks that provides new insights into network topology.

Management of pain in advanced disease.

PubMed

Harris, Dylan G

2014-06-01

Pain is common in advanced malignancy but also prevalent in other non-malignant life-limiting diseases such as advanced heart disease; end stage renal failure and multiple sclerosis. Patients with renal or liver impairment need specific consideration, as most analgesics rely on either or both for their metabolism and excretion. Recent evidence-based guidelines and the systematic reviews that have informed their recommendations. The principles of the WHO (World Health Organisation) analgesic ladder are commonly endorsed as a structured approach to the management of pain. For neuropathic pain, the efficacy of different agents is similar and choice of drug more guided by side effects, drug interactions and cost. Evidence supporting the WHO analgesic ladder is disputed and alternatives suggested, but no overwhelming evidence for an alternative approach exists to date. Alternative approaches to the WHO analgesic ladder, new analgesic agents, e.g. rapid onset oral/intranasal fentanyl. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Physical Employment Standards for UK Firefighters

PubMed Central

Stevenson, Richard D.M.; Siddall, Andrew G.; Turner, Philip F.J.; Bilzon, James L.J.

2017-01-01

Objective: The aim of this study was to assess sensitivity and specificity of surrogate physical ability tests as predictors of criterion firefighting task performance and to identify corresponding minimum muscular strength and endurance standards. Methods: Fifty-one (26 male; 25 female) participants completed three criterion tasks (ladder lift, ladder lower, ladder extension) and three corresponding surrogate tests [one-repetition maximum (1RM) seated shoulder press; 1RM seated rope pull-down; repeated 28 kg seated rope pull-down]. Surrogate test standards were calculated that best identified individuals who passed (sensitivity; true positives) and failed (specificity; true negatives) criterion tasks. Results: Best sensitivity/specificity achieved were 1.00/1.00 for a 35 kg seated shoulder press, 0.79/0.92 for a 60 kg rope pull-down, and 0.83/0.93 for 23 repetitions of the 28 kg rope pull-down. Conclusions: These standards represent performance on surrogate tests commensurate with minimum acceptable performance of essential strength-based occupational tasks in UK firefighters. PMID:28045801

Analysis of an "off-ladder" allele at the Penta D short tandem repeat locus.

PubMed

Yang, Y L; Wang, J G; Wang, D X; Zhang, W Y; Liu, X J; Cao, J; Yang, S L

2015-11-25

Kinship testing of a father and his son from Guangxi, China, the location of the Zhuang minority people, was performed using the PowerPlex® 18D System with a short tandem repeat typing kit. The results indicated that both the father and his son had an off-ladder allele at the Penta D locus, with a genetic size larger than that of the maximal standard allelic ladder. To further identify this locus, monogenic amplification, gene cloning, and genetic sequencing were performed. Sequencing analysis demonstrated that the fragment size of the Penta D-OL locus was 469 bp and the core sequence was [AAAGA]21, also called Penta D-21. The rare Penta D-21 allele was found to be distributed among the Zhuang population from the Guangxi Zhuang Autonomous Region of China; therefore, this study improved the range of DNA data available for this locus and enhanced our ability for individual identification of gene loci.

ESR modes in a Strong-Leg Ladder in the Tomonaga-Luttinger Liquid Phase

NASA Astrophysics Data System (ADS)

Zvyagin, S.; Ozerov, M.; Maksymenko, M.; Wosnitza, J.; Honecker, A.; Landee, C. P.; Turnbull, M.; Furuya, S. C.; Giamarchi, T.

Magnetic excitations in the strong-leg quantum spin ladder compound (C7H10N)2CuBr4 (known as DIMPY) in the field-induced Tomonaga-Luttinger spin liquid phase are studied by means of high-field electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode with unusual non-linear frequency-field dependence is revealed experimentally. Using a combination of analytic and exact diagonalization methods, we compute the dynamical structure factor and identify this mode with longitudinal excitations in the antisymmetric channel. We argue that these excitations constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder and owe its ESR observability to the uniform Dzyaloshinskii-Moriya interaction. This work was partially supported by the DFG and Helmholtz Gemeinschaft (Germany), Swiss SNF under Division II, and ERC synergy UQUAM project. We acknowledge the support of the HLD at HZDR, member of the European Magnetic Field Laboratory (EMFL).

FPGA implementation of bit controller in double-tick architecture

NASA Astrophysics Data System (ADS)

Kobylecki, Michał; Kania, Dariusz

2017-11-01

This paper presents a comparison of the two original architectures of programmable bit controllers built on FPGAs. Programmable Logic Controllers (which include, among other things programmable bit controllers) built on FPGAs provide a efficient alternative to the controllers based on microprocessors which are expensive and often too slow. The presented and compared methods allow for the efficient implementation of any bit control algorithm written in Ladder Diagram language into the programmable logic system in accordance with IEC61131-3. In both cases, we have compared the effect of the applied architecture on the performance of executing the same bit control program in relation to its own size.

A circuit model for nonlinear simulation of radio-frequency filters using bulk acoustic wave resonators.

PubMed

Ueda, Masanori; Iwaki, Masafumi; Nishihara, Tokihiro; Satoh, Yoshio; Hashimoto, Ken-ya

2008-04-01

This paper describes a circuit model for the analysis of nonlinearity in the filters based on radiofrequency (RF) bulk acoustic wave (BAW) resonators. The nonlinear output is expressed by a current source connected parallel to the linear resonator. Amplitude of the nonlinear current source is programmed proportional to the product of linear currents flowing in the resonator. Thus, the nonlinear analysis is performed by the common linear analysis, even for complex device structures. The analysis is applied to a ladder-type RF BAW filter, and frequency dependence of the nonlinear output is discussed. Furthermore, this analysis is verified through comparison with experiments.

Algebraic special functions and SO(3,2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celeghini, E., E-mail: celeghini@fi.infn.it; Olmo, M.A. del, E-mail: olmo@fta.uva.es

2013-06-15

A ladder structure of operators is presented for the associated Legendre polynomials and the sphericas harmonics. In both cases these operators belong to the irreducible representation of the Lie algebra so(3,2) with quadratic Casimir equals to −5/4. As both are also bases of square-integrable functions, the universal enveloping algebra of so(3,2) is thus shown to be homomorphic to the space of linear operators acting on the L{sup 2} functions defined on (−1,1)×Z and on the sphere S{sup 2}, respectively. The presence of a ladder structure is suggested to be the general condition to obtain a Lie algebra representation defining inmore » this way the “algebraic special functions” that are proposed to be the connection between Lie algebras and square-integrable functions so that the space of linear operators on the L{sup 2} functions is homomorphic to the universal enveloping algebra. The passage to the group, by means of the exponential map, shows that the associated Legendre polynomials and the spherical harmonics support the corresponding unitary irreducible representation of the group SO(3,2). -- Highlights: •The algebraic ladder structure is constructed for the associated Legendre polynomials (ALP). •ALP and spherical harmonics support a unitary irreducible SO(3,2)-representation. •A ladder structure is the condition to get a Lie group representation defining “algebraic special functions”. •The “algebraic special functions” connect Lie algebras and L{sup 2} functions.« less

Phase transitions and magnetization of the mixed-spin Ising–Heisenberg double sawtooth frustrated ladder

NASA Astrophysics Data System (ADS)

Arian Zad, Hamid; Ananikian, Nerses

2018-04-01

The mixed spin-(1,1/2) Ising–Heisenberg double sawtooth ladder containing a mixture of both spin-1 and spin-1/2 nodal atoms, and the spin-1/2 interstitial dimers are approximately solved by the transfer-matrix method. Here, we study in detail the ground-state phase diagrams, also influences of the bilinear exchange coupling on the rungs and cyclic four-spin exchange interaction in square plaquette of each block on the magnetization and magnetic susceptibility of the suggested ladder at low temperature. Such a double sawtooth ladder may be found in a Shastry-Sutherland lattice-type. In spite of the spin ordering of odd and even blocks being different from each other, due to the commutation relation between all different block Hamiltonians, phase diagrams, magnetization behavior and thermodynamic properties of the model are the same for odd and even blocks. We show that at low temperature, both exchange couplings can change the quality and quantity of the magnetization plateaus versus the magnetic field changes. Specially, we find a new magnetization plateau M/Ms= 5/6 for this model. Besides, we examine the magnetic susceptibility and specific heat of the model in detail. It is proven that behaviors of the magnetization and the magnetic susceptibility coincide at low temperature. The specific heat displays diverse temperature dependencies, which include a Schottky-type peak at a special temperature interval. We observe that with increase of the bilinear exchange coupling on the rungs, second peak temperature dependence grows.

Time-course of programmed cell death during leaf senescence in Eucommia ulmoides.

PubMed

Cao, Jing; Jiang, Feng; Sodmergen; Cui, Keming

2003-02-01

Leaves of Eucommia ulmoidesOliv. harvested between April to November were examined for programmed cell death (PCD) during growth and senescence. Leaves developed in April, becoming fully expanded in late May, remaining unchanged until November when they started to dehisce. Falling leaves retained a green color. Our results showed that (1) mesophyll cells gradually reduced their nuclei from September to November, (2) positive TUNEL signals appeared on the nuclei from August, (3) ladder-like DNA fragmentation occurred in September and October, and (4) a 20-kDa Ca(2+)-dependent DNase appeared in these same months. In fallen leaves, intact mesophyll cell nuclei could not be detected, but a few cells around the vascular bundle had nuclei. Therefore, (1) programmed cell death (PCD) of leaf cells occurred in the leaves of E. ulmoides, (2) the progress of mesophyll cell PCD lasted for more than 2 months, and (3) PCD of leaf cells was asynchronous in natural senescing leaves.

Damage Evaluation for Ti Alloys in Creep based on Incompatibility Field Measurement via EBSD Technique and Micro-Pillar Experiments Toward Identification of Roles of Dislocation Substructures on Fatigue Crack Initiation

DTIC Science & Technology

2011-02-07

Reproduction of a slip band with a PSB -ladder-like internal structure is attempted assuming initial conditions with and without corresponding strain...into heat at the PSB region, the present study extensively examined possible transition mechanisms toward the growth of grooves thereabout and that...arrangements even with the same dislocation density. (2)A slip band-like region having a substructure mimicking PSB ladder is demonstrated to be

Optical Spectra of the Jaynes-Cummings Ladder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laussy, Fabrice P.; Valle, Elena del

2009-06-29

We explore how the Jaynes-Cummings ladder transpires in the emitted spectra of a two-level system in strong coupling with a single mode of light. We focus on the case of very strong coupling, that would be achieved with systems of exceedingly good quality (very long lifetimes for both the emitter and the cavity). We focus on the incoherent regime of excitation, that is realized with semiconductors quantum dots in microcavities, and discuss how reasonable is the understanding of the systems in terms of transitions between dressed states of the Jaynes-Cummings Hamiltonian.

Apollo 12 Mission image - Dark view of Astronaut Alan L. Bean climbing down the ladder of the Lunar Module (LM)

NASA Image and Video Library

1969-11-19

AS12-46-6726 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 mission, starts down the ladder of the Lunar Module (LM) to join astronaut Charles Conrad Jr., mission commander, in extravehicular activity (EVA). While astronauts Conrad and Bean descended in the LM "Intrepid" to explore the Ocean of Storms region of the moon, astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules (CSM) "Yankee Clipper" in lunar orbit.

Bounded solutions in a T-shaped waveguide and the spectral properties of the Dirichlet ladder

NASA Astrophysics Data System (ADS)

Nazarov, S. A.

2014-08-01

The Dirichlet problem is considered on the junction of thin quantum waveguides (of thickness h ≪ 1) in the shape of an infinite two-dimensional ladder. Passage to the limit as h → +0 is discussed. It is shown that the asymptotically correct transmission conditions at nodes of the corresponding one-dimensional quantum graph are Dirichlet conditions rather than the conventional Kirchhoff transmission conditions. The result is obtained by analyzing bounded solutions of a problem in the T-shaped waveguide that the boundary layer phenomenon.

Ising versus S U (2) 2 string-net ladder

NASA Astrophysics Data System (ADS)

Vidal, Julien

2018-03-01

We consider the string-net model obtained from S U (2) 2 fusion rules. These fusion rules are shared by two different sets of anyon theories. In this paper, we study the competition between the two corresponding non-Abelian quantum phases in the ladder geometry. A detailed symmetry analysis shows that the nontrivial low-energy sector corresponds to the transverse-field cluster model that displays a critical point described by the s o (2) 1 conformal field theory. Other sectors are obtained by freezing spins in this model.

Walla Walla River Fish Passage Operations Program, 2003-2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronson, James P.

2004-12-01

In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survivalmore » of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2003-2004 project year, there were 379 adult summer steelhead (Oncorhynchus mykiss), 36 adult bull trout (Salvelinus confluentus); 108 adult and 3 jack spring chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 21, 2003, and June 30, 2004. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by the WWBNPME project in order to radio tag spring chinook adults. A total of 2 adult summer steelhead, 4 bull trout, and 23 adult spring chinook were enumerated at the west ladder at Nursery Bridge Dam during the trapping operations between May 6 and May 23, 2004. Operation of the Little Walla Walla River juvenile trap for trap and haul purposes was not necessary this year. The project transported adult spring chinook from Threemile Dam to the South Fork Walla Walla Brood Holding Facility. A total of 239 spring chinook were outplanted in August for natural spawning in the basin.« less

High power broadband millimeter wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1999-05-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed using this technology, and have been deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts to 50 kilowatts. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies other technologies will have to be considered particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

High Power Broadband Millimeter Wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1998-04-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed and deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts CW to 10 kilowatts Peak at W band over a 2 GHz bandwidth. Also a 50 kW peak power and 10 kW average power device at Ka band with 2 GHz bandwidth has been developed. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies, other technologies will have to be considered, particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

Disclosure of Personalized Rheumatoid Arthritis Risk Using Genetics, Biomarkers, and Lifestyle Factors to Motivate Health Behavior Improvements: A Randomized Controlled Trial.

PubMed

Sparks, Jeffrey A; Iversen, Maura D; Yu, Zhi; Triedman, Nellie A; Prado, Maria G; Miller Kroouze, Rachel; Kalia, Sarah S; Atkinson, Michael L; Mody, Elinor A; Helfgott, Simon M; Todd, Derrick J; Dellaripa, Paul F; Bermas, Bonnie L; Costenbader, Karen H; Deane, Kevin D; Lu, Bing; Green, Robert C; Karlson, Elizabeth W

2018-06-01

To determine the effect of disclosure of rheumatoid arthritis (RA) risk personalized with genetics, biomarkers, and lifestyle factors on health behavior intentions. We performed a randomized controlled trial among first-degree relatives without RA. Subjects assigned to the Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) group received the web-based PRE-RA tool for RA risk factor education and disclosure of personalized RA risk estimates, including genotype/autoantibody results and behaviors (n = 158). Subjects assigned to the comparison arm received standard RA education (n = 80). The primary outcome was readiness for change based on the trans-theoretical model, using validated contemplation ladder scales. Increased motivation to improve RA risk-related behaviors (smoking, diet, exercise, or dental hygiene) was defined as an increase in any ladder score compared to baseline, assessed immediately, 6 weeks, and 6 months post-intervention. Subjects reported behavior change at each visit. We performed intent-to-treat analyses using generalized estimating equations for the binary outcome. Subjects randomized to PRE-RA were more likely to increase ladder scores over post-intervention assessments (relative risk 1.23, 95% confidence interval [95% CI] 1.01, 1.51) than those randomized to nonpersonalized education. At 6 months, 63.9% of PRE-RA subjects and 50.0% of comparison subjects increased motivation to improve behaviors (age-adjusted difference 15.8%; 95% CI 2.8%, 28.8%). Compared to nonpersonalized education, more PRE-RA subjects increased fish intake (45.0% versus 22.1%; P = 0.005), brushed more frequently (40.7% versus 22.9%; P = 0.01), flossed more frequently (55.7% versus 34.8%; P = 0.004), and quit smoking (62.5% versus 0.0% among 11 smokers; P = 0.18). Disclosure of RA risk personalized with genotype/biomarker results and behaviors increased motivation to improve RA risk-related behaviors. Personalized medicine approaches may motivate health behavior improvements for those at risk for RA and provide rationale for larger studies evaluating effects of behavior changes on clinical outcomes, such as RA-related autoantibody production or RA development. © 2017, American College of Rheumatology.

Whole-body vibration in heavy equipment operators of a front-end loader: role of task exposure and tire configuration with and without traction chains.

PubMed

Blood, Ryan P; Rynell, Patrik W; Johnson, Peter W

2012-12-01

This study measured whole-body vibration (WBV) exposures in front-end loader operators, and evaluated the effects of traction chains and work tasks on their WBV exposures. WBV exposures were measured and compared across three different front-end loader tire configurations: (a) stock rubber tires, (b) rubber tires with ladder chains, and (c) rubber tires with basket chains. The operators completed three distinct standardized tasks: driving on a city street, simulated plowing, and a simulated scooping and dumping task. A portable data acquisition system collected tri-axial time weighted and raw WBV data per ISO 2631-1 and 2631-5 standards. In addition, Global Positioning System (GPS) data were collected in order to compare loader speeds across tire conditions and the standardized tasks. Relative to the stock rubber tires, both types of tire chains significantly increased WBV exposures with the ladder chains having substantially higher WBV exposures compared to basket chains. Additionally, there were task dependent differences in WBV exposures. During the driving task, the z-axis (up and down) was the predominant exposure; the plowing task had a more even distribution of exposure across all three axes; while during scooping and dumping task, the x-axis (fore and aft) had the highest WBV exposures. The GPS data indicated that there were significant speed differences across tasks but not between the basket and ladder chain conditions. Tires with ladder chains increased the front-end loader operators' exposure to WBV above the ISO 2631-1 recommended eight hour action limit increasing risk for adverse health effects. Although more expensive, basket chains are recommended over ladder chains since they substantially lowered the front-end loader operator's exposures and may ultimately reduce vibration related wear and tear on the vehicle. In order to reduce a heavy equipment vehicle (HEV) operator's chances for developing low back pain, this study provides information that health and safety professionals can use to reduce whole-body vibration (WBV) exposures when operating front-end wheel loaders with traction chains. Copyright © 2012 National Safety Council and Elsevier Ltd. All rights reserved.

[Ladder step strategy for surgical repair of congenital concealed penis in children].

PubMed

Wang, Fu-Ran; Zhong, Hong-Ji; Chen, Yi; Zhao, Jun-Feng; Li, Yan

2016-11-01

To assess the feasibility of the ladder step strategy in surgical repair of congenital concealed penis in children. This study included 52 children with congenital concealed penis treated in the past two years by surgical repair using the ladder step strategy, which consists of five main steps: cutting the narrow ring of the foreskin, degloving the penile skin, fixing the penile skin at the base, covering the penile shaft, and reshaping the prepuce. The perioperative data of the patients were prospectively collected and statistically described. Of the 52 patients, 20 needed remodeling of the frenulum and 27 received longitudinal incision in the penoscrotal junction to expose and deglove the penile shaft. The advanced scrotal flap technique was applied in 8 children to cover the penile shaft without tension, the pedicled foreskin flap technique employed in 11 to repair the penile skin defect, and excision of the webbed skin of the ventral penis performed in another 44 to remodel the penoscrotal angle. The operation time, blood loss, and postoperative hospital stay were 40－100 minutes, 5－30 ml, and 3－6 days, respectively. Wound bleeding and infection occurred in 1 and 5 cases, respectively. Follow-up examinations at 3 and 6 months after surgery showed that all the children had a satisfactory penile appearance except for some minor complications (2 cases of penile retraction, 2 cases of redundant ventral skin, and 1 case of iatrogenic penile curvature). The ladder step strategy for surgical repair of congenital concealed penis in children is a simple procedure with minor injury and satisfactory appearance of the penis.

Attitude symbology for helmet-mounted displays: lessons learned

NASA Astrophysics Data System (ADS)

Drewery, Chris C.; Davy, Eleanor C.; Dudfield, Helen J.

1997-06-01

This paper will review recent research on attitude symbology on helmet-mounted displays (HMDs) for the air-to-ground mission. General issues concerned with HMDs will be discussed and the lessons learned during the research will be outlined. It is suggested that a sound development approach to HMD symbology is critical since such symbology will constantly follow the pilot's line of sight (LOS). Further, the HMD field-of-view (FOV) is likely to be limited. Hence, if HMDs are to be used operationally for more than weapon aiming a number of human factors issues need to be investigated, such as the optimal method of presenting attitude information. The pitch ladder was designed to be presented along the boresight, directly in the pilot's LOS, at a fixed frame of reference. As pilots are used to and have been trained upon attitude information presented in consistency with the forward LOS, information representative of the pitch ladder may be beneficial on HMDs. None the less, since the pitch ladder was not designed for the HMD, novel formats may be more appropriate. As with all novel attitude symbology, enhanced operational performance must always be demonstrated and substantiated against the conventional existing symbology. Several experiments will be described which compared the pitch ladder to novel symbology, namely: the cylinder display; the arc segmented attitude reference display; and the modified roll-pitch display. These experiments were conducted using a variety of operationally relevant mission tasks and scenarios. The results will be summarized and the lessons learned for prototyping attitude symbology on HMDs will be discussed.

German science and black racism--roots of the Nazi Holocaust.

PubMed

Haas, François

2008-02-01

The Nazi's cornerstone precept of "racial hygiene" gave birth to their policy of "racial cleansing" that led to the murders of millions. It was developed by German physicians and scientists in the late 19th century and is rooted in the period's Social Darwinism that placed blacks at the bottom of the racial ladder. This program was first manifested in the near-extermination of the African Herero people during the German colonial period. After WWI, the fear among the German populace that occupying African troops and their Afro-German children would lead to "bastardization" of the German people formed a unifying racial principle that the Nazis exploited. They extended this mind-set to a variety of "unworthy" groups, leading to the physician-administered racial Nuremberg laws, the Sterilization laws, the secret sterilization of Afro-Germans, and the German euthanasia program. This culminated in the extermination camps.

Education Demonstration Equipment

NASA Astrophysics Data System (ADS)

Nagy, A.; Lee, R. L.

2005-10-01

Several GA Fusion Education Program plasma related demonstration items were developed this year. A 120 V ac powered electromagnetic coil shows eddy current levitation over an aluminum sheet and continuously changing magnetic force interactions using additional permanent magnets. A 300 V dc plasma device, with variable current capability and analog data ports, is used to develop plasma I/V plots. An on-demand (via push button) fully enclosed 24 in. Jacob's ladder provides air plasma and buoyancy effects. A low cost Mason jar vacuum chamber filled with inert gas shows pressure and gas species plasma characteristics when excited by a Tesla coil. These demonstration items are used in the Scientist-In-the-Classroom program, GA facility tours, and teacher seminars to present plasma to students and teachers. Three very popular Build-It workshops were held to enable teachers to build these items and take them back to their classroom.

Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress.

PubMed

Ciniglia, Claudia; Mastrobuoni, Francesco; Scortichini, Marco; Petriccione, Milena

2015-05-01

The allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW.

Non-local electron transport through normal and topological ladder-like atomic systems

NASA Astrophysics Data System (ADS)

Kurzyna, Marcin; Kwapiński, Tomasz

2018-05-01

We propose a locally protected ladder-like atomic system (nanoconductor) on a substrate that is insensitive to external perturbations. The system corresponds to coupled atomic chains fabricated on different surfaces. Electron transport properties of such conductors are studied theoretically using the model tight-binding Su-Schriffer-Hegger (SSH) Hamiltonian and Green's function formalism. We have found that the conductance of the system is almost insensitive to single adatoms and oscillates as a function of the side chain length with very large periods. Non-local character of the electron transport was observed also for topological SSH chains where nontrivial end states survive in the presence of disturbances as well as for different substrates. We have found that the careful inspection of the density of states or charge waves can provide the information about the atom energy levels and hopping amplitudes. Moreover, the ladder-like geometry allows one to distinguish between normal and topological zero-energy states. It is important that topological chains do not reveal Friedel oscillations which are observed in non-topological chains.

Two-leg ladder systems with dipole–dipole Fermion interactions

NASA Astrophysics Data System (ADS)

Mosadeq, Hamid; Asgari, Reza

2018-05-01

The ground-state phase diagram of a two-leg fermionic dipolar ladder with inter-site interactions is studied using density matrix renormalization group (DMRG) techniques. We use a state-of-the-art implementation of the DMRG algorithm and finite size scaling to simulate large system sizes with high accuracy. We also consider two different model systems and explore stable phases in half and quarter filling factors. We find that in the half filling, the charge and spin gaps emerge in a finite value of the dipole–dipole and on-site interactions. In the quarter filling case, s-wave superconducting state, charge density wave, homogenous insulating and phase separation phases occur depend on the interaction values. Moreover, in the dipole–dipole interaction, the D-Mott phase emerges when the hopping terms along the chain and rung are the same, whereas, this phase has been only proposed for the anisotropic Hubbard model. In the half filling case, on the other hand, there is either charge-density wave or charged Mott order phase depends on the orientation of the dipole moments of the particles with respect to the ladder geometry.

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors

DOE PAGES

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii; ...

2018-03-28

The open-circuit voltage (V oc) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. Here in this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our pi-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (ΔE DA), extends electronic delocalization, and hence improves the V oc. More importantly, these devicesmore » showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.« less

Color-suppression of non-planar diagrams in bosonic bound states

NASA Astrophysics Data System (ADS)

Alvarenga Nogueira, J. H.; Ji, Chueng-Ryong; Ydrefors, E.; Frederico, T.

2018-02-01

We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in 3 + 1 space-time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe-Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for Nc = 3, which supports the use of rainbow-ladder truncations in practical non-perturbative calculations within QCD.

Interplay of magnetism and superconductivity in the compressed Fe-ladder compound BaFe 2 Se 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ying, Jianjun; Lei, Hechang; Petrovic, Cedomir

High pressure resistance, susceptibility, and Fe K β x-ray emission spectroscopy measurements were performed on Fe-ladder compound BaFe 2 Se 3 . Pressure-induced superconductivity was observed which is similar to the previously reported superconductivity in the BaFe 2 S 3 samples. The slope of local magnetic moment versus pressure shows an anomaly across the insulator-metal transition pressure in the BaFe 2 Se 3 samples. The local magnetic moment is continuously decreasing with increasing pressure, and the superconductivity appears only when the local magnetic moment value is comparable to the one in the iron-pnictide superconductors. Our results indicate that the compressedmore » BaFe 2 C h 3 ( C h = S , Se) is a new family of iron-based superconductors. Despite the crystal structures completely different from the known iron-based superconducting materials, the magnetism in this Fe-ladder material plays a critical role in superconductivity. This behavior is similar to the other members of iron-based superconducting materials.« less

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors.

PubMed

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii; Awais, Mohammad A; Zhang, Na; Chen, Wei; Yu, Luping

2018-04-25

The open-circuit voltage ( V oc ) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. In this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our π-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (Δ E DA ), extends electronic delocalization, and hence improves the V oc . More importantly, these devices showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii

The open-circuit voltage (V oc) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. Here in this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our pi-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (ΔE DA), extends electronic delocalization, and hence improves the V oc. More importantly, these devicesmore » showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.« less

Broken Time-Reversal Symmetry in Strongly Correlated Ladder Structures

NASA Astrophysics Data System (ADS)

Troyer, Matthias

2004-03-01

A decade after the first detailed numerical investigations of strongly correlated ladder models, exotic and interesting phases are still being discovered. Besides charge and spin density wave states with broken translational symmetry, and resonating valence bond (RVB) type superconductivity, a time reversal symmetry borken phase was recently found at half filling [J.B. Marston et al., Phys. Rev. Lett 89, 056404 (2002)]. In this talk I will present our recent results of density matrix renormalization group (DMRG) calculations [Phys. Rev. Lett. 90, 186401 (2003)], where we provide, for the first time, in a doped strongly correlated system (two-leg ladder), a controlled theoretical demonstration of the existence of this state in which long-range ordered orbital currents are arranged in a staggered pattern. This phase, which we found to coexist with a charge density wave, is known in the literature under the names ``staggered flux phase'', ``orbital antiferromagnetism'' or ``d-density wave (DDW)''. This brings us closer to recent proposals that this order might be realized in the enigmatic pseudogap phase of the cuprate high temperature superconductors.

Can Marginal Rates of Substitution Be Inferred From Happiness Data? Evidence from Residency Choices

PubMed Central

Heffetz, Ori; Kimball, Miles S.; Rees-Jones, Alex

2014-01-01

We survey 561 students from U.S. medical schools shortly after they submit choice rankings over residencies to the National Resident Matching Program. We elicit (a) these choice rankings, (b) anticipated subjective well-being (SWB) rankings, and (c) expected features of the residencies (such as prestige). We find substantial differences between choice and anticipated-SWB rankings in the implied tradeoffs between residency features. In our data, evaluative SWB measures (life satisfaction and Cantril's ladder) imply tradeoffs closer to choice than does affective happiness (even time-integrated), and as close as do multi-measure SWB indices. We discuss implications for using SWB data in applied work. PMID:25404759

Terahertz cascades from nanoparticles

NASA Astrophysics Data System (ADS)

Arnardottir, K. B.; Liew, T. C. H.

2018-05-01

In this article we propose a system capable of terahertz (THz) radiation with quantum yield above unity. The system consists of nanoparticles where the material composition varies along the radial direction of each nanoparticle in such a way that a ladder of equidistant energy levels emerges. By then exciting the highest level of this ladder we produce multiple photons of the same frequency in the THz range. We demonstrate how we can calculate a continuous material composition profile that achieves a high quantum yield and then show that a more experimentally friendly design of a multishell nanoparticle can still result in a high quantum yield.

Quark scalar, axial and tensor charges in the Schwinger-Dyson formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamanaka, Nodoka

2016-01-22

The quark scalar, axial and tensor charges of nucleon are calculated in the Schwinger-Dyson formalism. We first calculate these charges in the rainbow-ladder truncation using the IR cut quark-gluon vertex, and show that the result is in agreement with the known data. We then perform the same calculation with the phenomenological IR singular quark-gluon vertex. In this case, the Schwinger-Dyson equation does not converge. We show that this result suggests the requirement of additional corrections to the rainbow-ladder truncation, due to the interaction between quark and gluons in the deep IR region.

Error-associated behaviors and error rates for robotic geology

NASA Technical Reports Server (NTRS)

Anderson, Robert C.; Thomas, Geb; Wagner, Jacob; Glasgow, Justin

2004-01-01

This study explores human error as a function of the decision-making process. One of many models for human decision-making is Rasmussen's decision ladder [9]. The decision ladder identifies the multiple tasks and states of knowledge involved in decision-making. The tasks and states of knowledge can be classified by the level of cognitive effort required to make the decision, leading to the skill, rule, and knowledge taxonomy (Rasmussen, 1987). Skill based decisions require the least cognitive effort and knowledge based decisions require the greatest cognitive effort. Errors can occur at any of the cognitive levels.

Studies toward brevisulcenal F via convergent strategies for marine ladder polyether synthesis.

PubMed

Katcher, Matthew; Jamison, Timothy F

2018-03-15

Shortly after the initial isolation of marine ladder polyether natural products, biomimetic epoxide-opening cascade reactions were proposed as an efficient strategy for the synthesis of these compounds. However, difficulties in assembling the cascade precursors have limited the realization of these cascades. In this report, we describe strategies that provide convergent access to cascade precursors via regioselective allylation and efficient fragment coupling. We then investigate epoxide-opening cascades promoted by strong bases for the formation of fused tetrahydropyrans. These strategies are evaluated in the context of the synthesis of rings CDEFG of brevisulcenal F.

Geometric effect on second harmonic generation from gold grating

NASA Astrophysics Data System (ADS)

Lu, Jiao; Ding, Baoyong; Huo, Yanyan; Ning, Tingyin

2018-05-01

We numerically investigate second harmonic generation from gold gratings of an ideal rectangular and ladder-shaped cross-section. The SHG efficiency from the gold gratings of the ladder-shaped cross-section is significantly enhanced compared with that from the ideal rectangular cross-section with a maximum enhancement factor of around two. The enhancement is ascribe to the nanostructure dependent local fundamental electric field, the nonlinear sources and thus the far field radiation. Our results have a practical meaning in the explanation of experimental SHG measurement, and the modulation of SHG response in the metallic nanostructure.

Demonstration of the Jaynes-Cummings ladder with Rydberg-dressed atoms

DOE PAGES

Lee, Jongmin; Martin, Michael J.; Jau, Yuan-Yu; ...

2017-04-06

Here, we observe the nonlinearity of the Jaynes-Cummings (JC) ladder in the Autler-Townes spectroscopy of the hyperfine ground states for a Rydberg-dressed two-atom system. The role of the two-level system in the JC model is played by the presence or absence of a collective Rydberg excitation, and the bosonic mode manifests as the number n of single-atom spin flips, symmetrically distributed between the atoms. We also measure the normal-mode splitting and √ n nonlinearity as a function of detuning and Rabi frequency, thereby experimentally establishing the isomorphism with the JC model.

Magnetic phase diagram of a frustrated spin ladder

NASA Astrophysics Data System (ADS)

Sugimoto, Takanori; Mori, Michiyasu; Tohyama, Takami; Maekawa, Sadamichi

2018-04-01

Frustrated spin ladders show magnetization plateaux depending on the rung-exchange interaction and frustration defined by the ratio of first and second neighbor exchange interactions in each chain. This paper reports on its magnetic phase diagram. Using the variational matrix-product state method, we accurately determine phase boundaries. Several kinds of magnetization plateaux are induced by the frustration and the strong correlation among quasiparticles on a lattice. The appropriate description of quasiparticles and their relevant interactions are changed by a magnetic field. We find that the frustration differentiates the triplet quasiparticle from the singlet one in kinetic energy.

Hidden Order and Symmetry Protected Topological States in Quantum Link Ladders

NASA Astrophysics Data System (ADS)

Cardarelli, L.; Greschner, S.; Santos, L.

2017-11-01

We show that, whereas spin-1 /2 one-dimensional U(1) quantum-link models (QLMs) are topologically trivial, when implemented in ladderlike lattices these models may present an intriguing ground-state phase diagram, which includes a symmetry protected topological (SPT) phase that may be readily revealed by analyzing long-range string spin correlations along the ladder legs. We propose a simple scheme for the realization of spin-1 /2 U(1) QLMs based on single-component fermions loaded in an optical lattice with s and p bands, showing that the SPT phase may be experimentally realized by adiabatic preparation.

Clinical Experience and Best Practices Using Epidermal Skin Grafts on Wounds.

PubMed

Kirsner, Robert S; Bernstein, Brent; Bhatia, Animesh; Lantis, John; Le, Lam; Lincoln, Katherine; Liu, Paul; Rodgers, Lee; Shaw, Mark; Young, David

2015-11-01

Over the years, autologous skin grafting has been used extensively to achieve wound closure, optimize a functional scar, and improve aesthetic outcomes for the patient. Although a vast majority of the literature is on the use of full-thickness and split-thickness skin grafts, epidermal skin grafts (ESGs) have emerged as a viable option in the reconstructive ladder when only the epidermal layer is needed. These grafts are distinct from other types of autologous skin grafts in that they can be harvested without anesthesia and leave minimal or no scarring at the donor site. In order to explore the use of ESGs in the continuum of primary wound closure, a multidisciplinary expert panel convened in October 2014, in Las Vegas, NV, to review the scientific basis and clinical uses of epidermal grafting. This publication provides an overview of epidermal grafting, recommendations for graft application, and potential roles for its use in wound care and closure.

Frustrated quantum magnetism in the Kondo lattice on the zigzag ladder

NASA Astrophysics Data System (ADS)

Peschke, Matthias; Rausch, Roman; Potthoff, Michael

2018-03-01

The interplay between the Kondo effect, indirect magnetic interaction, and geometrical frustration is studied in the Kondo lattice on the one-dimensional zigzag ladder. Using the density-matrix renormalization group, the ground-state and various short- and long-range spin- and density-correlation functions are calculated for the model at half filling as a function of the antiferromagnetic Kondo interaction down to J =0.3 t , where t is the nearest-neighbor hopping on the zigzag ladder. Geometrical frustration is shown to lead to at least two critical points: Starting from the strong-J limit, where almost local Kondo screening dominates and where the system is a nonmagnetic Kondo insulator, antiferromagnetic correlations between nearest-neighbor and next-nearest-neighbor local spins become stronger and stronger, until at Jcdim≈0.89 t frustration is alleviated by a spontaneous breaking of translational symmetry and a corresponding transition to a dimerized state. This is characterized by antiferromagnetic correlations along the legs and by alternating antiferro- and ferromagnetic correlations on the rungs of the ladder. A mechanism of partial Kondo screening that has been suggested for the Kondo lattice on the two-dimensional triangular lattice is not realized in the one-dimensional case. Furthermore, within the symmetry-broken dimerized state, there is a magnetic transition to a 90∘ quantum spin spiral with quasi-long-range order at Jcmag≈0.84 t . The quantum-critical point is characterized by a closure of the spin gap (with decreasing J ) and a divergence of the spin-correlation length and of the spin-structure factor S (q ) at wave vector q =π /2 . This is opposed to the model on the one-dimensional bipartite chain, which is known to have a finite spin gap for all J >0 at half filling.

Plaquette order in a dimerized frustrated spin ladder

NASA Astrophysics Data System (ADS)

Shlagman, Ofer; Shimshoni, Efrat

2014-11-01

We study the effect of dimerization (due to, e.g., spin-Peierls instability) on the phase diagram of a frustrated antiferromagnetic spin-1/2 ladder, with weak transverse and diagonal rung coupling. Our analysis focuses on a one-dimensional version of the model (i.e., a single two-leg ladder) where we consider two forms of dimerization on the legs: columnar dimers (CDs) and staggered dimers (SDs). We examine in particular the regime of parameters (corresponding to an intermediate X X Z anisotropy) in which the leg dimerization and the rung coupling terms are equally relevant. In both the CD and SD cases, we find that the effective field theory describing the system is a self-dual sine-Gordon model, which favors ordering and the opening of a gap to excitations. The order parameter, which reflects the interplay between the leg and rung dimerization interactions, represents a crystal of 4-spin plaquettes on which longitudinal and transverse dimers are in a coherent superposition. Depending on the leg dimerization mode, these plaquettes are closed or open, however both types spontaneously break reflection symmetry across the ladder. The closed plaquettes are stable, while the open plaquette order is relatively fragile and the corresponding gap may be tuned to zero under extreme conditions. We further find that a first-order transition occurs from the plaquette order to a valence bond crystal (VBC) of dimers on the legs. This suggests that in a higher-dimensional version of this system, this variety of distinct VBC states with comparable energies leads to the formation of domains. Effectively one-dimensional gapless spinon modes on domain boundaries may account for the experimental observation of spin-liquid behavior in a physical realization of the model.

Compact programmable photonic variable delay devices

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

1999-01-01

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm.sup.2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Alternative formulation of explicitly correlated third-order Møller-Plesset perturbation theory

NASA Astrophysics Data System (ADS)

Ohnishi, Yu-ya; Ten-no, Seiichiro

2013-09-01

The second-order wave operator in the explicitly correlated wave function theory has been newly defined as an extension of the conventional s- and p-wave (SP) ansatz (also referred to as the FIXED amplitude ansatz) based on the linked-diagram theorem. The newly defined second-order wave operator has been applied to the calculation of the F12 correction to the third-order many-body perturbation (MP3) energy. In addition to this new wave operator, the F12 correction with the conventional first-order wave operator has been derived and calculated. Among three components of the MP3 correlation energy, the particle ladder contribution, which has shown the slowest convergence with respect to the basis set size, is fairly ameliorated by employing these F12 corrections. Both the newly defined and conventional formalisms of the F12 corrections exhibit a similar recovery of over 90% of the complete basis set limit of the particle ladder contribution of the MP3 correlation energy with a triple-zeta quality basis set for the neon atom, while the amount is about 75% without the F12 correction. The corrections to the ring term are small but the corrected energy has shown similar recovery as the particle ladder term. The hole ladder term has shown a rapid convergence even without the F12 corrections. Owing to these balanced recoveries, the deviation of the total MP3 correlation energy from the complete basis set limit has been calculated to be about 1 kcal/mol with the triple-zeta quality basis set, which is more than five times smaller than the error without the F12 correction.

Photonic variable delay devices based on optical birefringence

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

2005-01-01

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Molecular Mechanism of Thioflavin-T Binding to the Surface of [beta]-Rich Peptide Self-Assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biancalana, Matthew; Makabe, Koki; Koide, Akiko

A number of small organic molecules have been developed that bind to amyloid fibrils, a subset of which also inhibit fibrillization. Among these, the benzothiol dye Thioflavin-T (ThT) has been used for decades in the diagnosis of protein-misfolding diseases and in kinetic studies of self-assembly (fibrillization). Despite its importance, efforts to characterize the ThT-binding mechanism at the atomic level have been hampered by the inherent insolubility and heterogeneity of peptide self-assemblies. To overcome these challenges, we have developed a minimalist approach to designing a ThT-binding site in a 'peptide self-assembly mimic' (PSAM) scaffold. PSAMs are engineered water-soluble proteins that mimicmore » a segment of beta-rich peptide self-assembly, and they are amenable to standard biophysical techniques and systematic mutagenesis. The PSAM beta-sheet contains rows of repetitive amino acid patterns running perpendicular to the strands (cross-strand ladders) that represent a ubiquitous structural feature of fibril-like surfaces. We successfully designed a ThT-binding site that recapitulates the hallmarks of ThT-fibril interactions by constructing a cross-strand ladder consisting of contiguous tyrosines. The X-ray crystal structures suggest that ThT interacts with the beta-sheet by docking onto surfaces formed by a single tyrosine ladder, rather than in the space between adjacent ladders. Systematic mutagenesis further demonstrated that tyrosine surfaces across four or more beta-strands formed the minimal binding site for ThT. Our work thus provides structural insights into how this widely used dye recognizes a prominent subset of peptide self-assemblies, and proposes a strategy to elucidate the mechanisms of fibril-ligand interactions.« less

Towards a mechanism-based approach to pain diagnosis

PubMed Central

Vardeh, Daniel

2016-01-01

The last few decades have witnessed a huge leap forward in our understanding of the mechanistic underpinnings of pain, both in normal states where it helps protect from injury, and in pathological states where pain evolves from a symptom reflecting tissue injury to become the disease itself. However, despite these scientific advances, chronic pain remains extremely challenging to manage clinically. While the number of potential treatment targets has grown substantially and a strong case has been made for a mechanism-based and individualized approach to pain therapy, arguably clinicians are not much more advanced now than 20 years ago, in their capacity to either diagnose or effectively treat their patients. The gulf between pain research and pain management is as wide as ever. We are still currently unable to apply an evidence-based approach to chronic pain management that reflects mechanistic understanding, and instead, clinical practice remains an empirical and often unsatisfactory journey for patients, whose individual response to treatment cannot be predicted. Here we take a common and difficult to treat pain condition, chronic low back pain, and use its presentation in clinical practice as a framework to highlight what is known about pathophysiological pain mechanisms and how we could potentially detect these to drive rational treatment choice. We discuss how present methods of assessment and management still fall well short, however, of any mechanism-based or precision-medicine approach. Nevertheless, substantial improvements in chronic pain management could be possible if a more strategic and coordinated approach were to evolve, one designed to identify the specific mechanisms driving the presenting pain phenotype. We present an analysis of such an approach, highlighting the major problems in identifying mechanisms in patients, and develop a framework for a pain diagnostic ladder that may prove useful in the future, consisting of successive identification of three steps: pain state, pain mechanism and molecular target. Such an approach could serve as the foundation for a new era of individualized/precision pain medicine. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) and American Pain Society (APS) Pain Taxonomy (AAPT) includes pain mechanisms as one of the 5 dimensions that need to be considered when making a diagnostic classification. The diagnostic ladder proposed in this article is both consistent with and an extension of the AAPT. PMID:27586831

Valence bond and von Neumann entanglement entropy in Heisenberg ladders.

PubMed

Kallin, Ann B; González, Iván; Hastings, Matthew B; Melko, Roger G

2009-09-11

We present a direct comparison of the recently proposed valence bond entanglement entropy and the von Neumann entanglement entropy on spin-1/2 Heisenberg systems using quantum Monte Carlo and density-matrix renormalization group simulations. For one-dimensional chains we show that the valence bond entropy can be either less or greater than the von Neumann entropy; hence, it cannot provide a bound on the latter. On ladder geometries, simulations with up to seven legs are sufficient to indicate that the von Neumann entropy in two dimensions obeys an area law, even though the valence bond entanglement entropy has a multiplicative logarithmic correction.

Missile Facilities (WS-133B, WS-133A/M) Career Ladder, AFSCs 44530G, 44550G, and 44570G.

DTIC Science & Technology

1981-05-01

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Quasi-one-dimensional Bose-Einstein condensation in the spin-1/2 ferromagnetic-leg ladder 3-I-V

NASA Astrophysics Data System (ADS)

Kono, Y.; Kittaka, S.; Yamaguchi, H.; Hosokoshi, Y.; Sakakibara, T.

2018-03-01

Quantum criticality of the spin-1/2 ferromagnetic-leg ladder 3-I-V [=3-(3-iodophenyl)-1,5-diphenylverdazyl] has been examined with respect to the antiferromagnetic to paramagnetic phase transition near the saturation field Hc. The phase boundary Tc(H ) follows the power-law Tc(H ) ∝Hc-H for a wide temperature range. This characteristic behavior is discussed as a quasi-one-dimensional (quasi-1D) Bose-Einstein condensation, which is predicted theoretically for weakly coupled quasi-1D ferromagnets. Thus, 3-I-V provides the first promising candidate for this attractive prediction.

Optimal temperature ladders in replica exchange simulations

NASA Astrophysics Data System (ADS)

Denschlag, Robert; Lingenheil, Martin; Tavan, Paul

2009-04-01

In replica exchange simulations, a temperature ladder with N rungs spans a given temperature interval. Considering systems with heat capacities independent of the temperature, here we address the question of how large N should be chosen for an optimally fast diffusion of the replicas through the temperature space. Using a simple example we show that choosing average acceptance probabilities of about 45% and computing N accordingly maximizes the round trip rates r across the given temperature range. This result differs from previous analyses which suggested smaller average acceptance probabilities of about 23%. We show that the latter choice maximizes the ratio r/N instead of r.

Single-photon superradiant beating from a Doppler-broadened ladder-type atomic ensemble

NASA Astrophysics Data System (ADS)

Lee, Yoon-Seok; Lee, Sang Min; Kim, Heonoh; Moon, Han Seb

2017-12-01

We report on heralded-single-photon superradiant beating in the spontaneous four-wave mixing process of Doppler-broadened ladder-type 87Rb atoms. When Doppler-broadened atoms contribute to two-photon coherence, the detection probability amplitudes of the heralded single photons are coherently superposed despite inhomogeneous broadened atomic media. Single-photon superradiant beating is observed, which constitutes evidence for the coherent superposition of two-photon amplitudes from different velocity classes in the Doppler-broadened atomic ensemble. We present a theoretical model in which the single-photon superradiant beating originates from the interference between wavelength-separated two-photon amplitudes via the reabsorption filtering effect.

Spin waves and magnetic exchange interactions in the spin-ladder compound RbFe 2 Se 3

DOE PAGES

Wang, Meng; Yi, Ming; Jin, Shangjian; ...

2016-07-20

In this paper, we report an inelastic neutron scattering study of the spin waves of the one-dimensional antiferromagnetic spin ladder compound RbFe 2Se 3. The results reveal that the products, SJ's, of the spin S and the magnetic exchange interaction J along the antiferromagnetic (leg) direction and the ferromagnetic (rung) direction are comparable with those for the stripe ordered phase of the parent compounds of the iron-based superconductors. Also, the universality of the SJ's implies nearly universal spin wave dynamics and the irrelevance of the fermiology for the existence of the stripe antiferromagnetic order among various Fe-based materials.

Two unprecedented aromatic guanidines supramolecular chains self-assembled by hydrogen bonding interaction

NASA Astrophysics Data System (ADS)

Zhang, Yunshen; Huang, Yichao; Zhang, Jiangwei; Zhu, Li; Chen, Kun; Hao, Jian

2015-10-01

Two aromatic guanidine derivatives, C6H5N = C(NHCy)2 (1), (n-TBA)C6H5NHC(NHCy)2Mo2O7 (2) (Cy = cyclohexyl), were synthetized with high yields. Both of them self-assembled into supramolecules via H-bond interactions. Single crystal XRD indicated that crystal 1 showed helix chains combining pseudo four-fold and pseudo six-fold symmetries, while crystal 2 presented ladder chains with alternate ring structures. In this paper, a novel way to design ladder-like supramolecular chains from helix chains was presented, using POMs (polyoxometalates) to provide protons to help assembly.

Brevisulcatic acids, marine ladder-frame polyethers from the red tide dinoflagellate Karenia brevisulcata in New Zealand.

PubMed

Suzuki, Rina; Irie, Raku; Harntaweesup, Yanit; Tachibana, Kazuo; Holland, Patrick T; Harwood, D Tim; Shi, Feng; Beuzenberg, Veronica; Itoh, Yoshiyuki; Pascal, Steven; Edwards, Patrick J B; Satake, Masayuki

2014-11-21

The isolation and structural determination of new marine ladder-frame polyethers, brevisulcatic acids-1 (1) and -4 (2) are reported. Brevisulcatic acids were isolated from the dinoflagellate Karenia brevisulcata, which was identified as the causative species of a major red tide event in New Zealand in 1998. The ether ring composition and a β-hydroxy, γ-methylene valeric acid side chain of 1 and 2 are common, but 2 has a γ-lactone as the 5-membered A-ring while 1 is the seco acid analogue. Compound 2 has structural and bioactivity similarities to brevetoxin A.

Study of CP(N-1) theta-vacua by cluster simulation of SU(N) quantum spin ladders.

PubMed

Beard, B B; Pepe, M; Riederer, S; Wiese, U-J

2005-01-14

D-theory provides an alternative lattice regularization of the 2D CP(N-1) quantum field theory in which continuous classical fields emerge from the dimensional reduction of discrete SU(N) quantum spins. Spin ladders consisting of n transversely coupled spin chains lead to a CP(N-1) model with a vacuum angle theta=npi. In D-theory no sign problem arises and an efficient cluster algorithm is used to investigate theta-vacuum effects. At theta=pi there is a first order phase transition with spontaneous breaking of charge conjugation symmetry for CP(N-1) models with N>2.

"The black and white of it": Barbara Grier editing and publishing women of color.

PubMed

Enszer, Julie R

2014-01-01

In the 1970s and 1980s, lesbian-feminist writing and publishing expressed new theoretical insights about race and envisioned new, intersectional identities. Using texts published and edited by Grier in The Ladder and subsequent Ladder anthologies published by Diana Press, archival documents from Diana Press, and the Grier-Naiad Press papers, this article explores Grier's editorial practices and compares Grier's work to other lesbian-feminist editors and publishers to illuminate different generational understandings of racial-ethnic and class formations within lesbianism and feminism and highlight some of the strategies that White publishers like Grier utilized to realize a vision of multicultural publishing.

Generalized Heisenberg Algebras, SUSYQM and Degeneracies: Infinite Well and Morse Potential

NASA Astrophysics Data System (ADS)

Hussin, Véronique; Marquette, Ian

2011-03-01

We consider classical and quantum one and two-dimensional systems with ladder operators that satisfy generalized Heisenberg algebras. In the classical case, this construction is related to the existence of closed trajectories. In particular, we apply these results to the infinite well and Morse potentials. We discuss how the degeneracies of the permutation symmetry of quantum two-dimensional systems can be explained using products of ladder operators. These products satisfy interesting commutation relations. The two-dimensional Morse quantum system is also related to a generalized two-dimensional Morse supersymmetric model. Arithmetical or accidental degeneracies of such system are shown to be associated to additional supersymmetry.

Tunable separations based on a molecular size effect for biomolecules by poly(ethylene glycol) gel-based capillary electrophoresis.

PubMed

Kubo, Takuya; Nishimura, Naoki; Furuta, Hayato; Kubota, Kei; Naito, Toyohiro; Otsuka, Koji

2017-11-10

We report novel capillary gel electrophoresis (CGE) with poly(ethylene glycol) (PEG)-based hydrogels for the effective separations of biomolecules containing sugars and DNAs based on a molecular size effect. The gel capillaries were prepared in a fused silica capillary modified with 3-(trimethoxysilyl)propylmethacrylate using a variety of the PEG-based hydrogels. After the fundamental evaluations in CGE regarding the separation based on the molecular size effect depending on the crosslinking density, the optimized capillary provided the efficient separation of glucose ladder (G1 to G20). In addition, another capillary showed the successful separation of DNA ladder in the range of 10-1100 base pair, which is superior to an authentic acrylamide-based gel capillary. For both glucose and DNA ladders, the separation ranges against the molecular size were simply controllable by alteration of the concentration and/or units of ethylene oxide in the PEG-based crosslinker. Finally, we demonstrated the separations of real samples, which included sugars carved out from monoclonal antibodies, mAbs, and then the efficient separations based on the molecular size effect were achieved. Copyright © 2017 Elsevier B.V. All rights reserved.

Polarization effects in the interaction between multi-level atoms and two optical fields

NASA Astrophysics Data System (ADS)

Colín-Rodríguez, R.; Flores-Mijangos, J.; Hernández-Gómez, S.; Jáuregui, R.; López-Hernández, O.; Mojica-Casique, C.; Ponciano-Ojeda, F.; Ramírez-Martínez, F.; Sahagún, D.; Volke-Sepúlveda, K.; Jiménez-Mier, J.

2015-06-01

Polarized velocity selective spectra for rubidium atoms in a room temperature cell are presented. The experiments were performed in the lambda configuration (D2 manifold) and in the 5s\\to 5{{p}3/2}\\to 5{{d}j} ladder configuration. For the lambda configuration the effect of the probe beam intensity in the absorption and polarization spectra are compared with results of a rate equation approximation. Good overall agreement between experiment and theory is found. The results indicate different saturation rates for each of the atomic transitions. Distinctive polarization signals with hyperfine-resolved components are found for the ladder 5{{d}3/2} and 5{{d}5/2} upper states. Fluorescence detection of the 420 nm that results from the second step in the cascade decay 5{{d}j}\\to 6{{p}{{j\\prime }}}\\to 5s was used in the ladder experiments. This fluorescence was also used for the detection of the 5{{p}3/2}\\to 6{{p}3/2} electric dipole forbidden transition in atomic rubidium that occurs at 911 nm. The 6{{p}3/2} hyperfine structure was resolved in this continuous wave, non-dipole excitation.

Task parameters affecting ergonomic demands and productivity of HVAC duct installation.

PubMed

Mitropoulos, Panagiotis; Hussain, Sanaa; Guarascio-Howard, Linda; Memarian, Babak

2014-01-01

Mechanical installation workers experience work-related musculoskeletal disorders (WMSDs) at high rates. (1) Quantify the ergonomic demands during HVAC installation, (2) identify the tasks and task parameters that generated extreme ergonomic demands, and (3) propose improvements to reduce the WMSDs among mechanical workers. The study focused on installation of rectangular ductwork components using ladders, and analyzed five operations by two mechanical contractors. Using continuous time observational assessment, the videotaped operations were analyzed along two dimensions: (1) the production tasks and durations, and (2) the ergonomic demands for four body regions (neck, arms/shoulders, back, and knees). The analysis identified tasks with low portion of productive time and high portion of extreme postures, and task parameters that generated extreme postures. Duct alignment was the task with the highest portion of extreme postures. The position of the ladder (angle and distance from the duct) was a task parameter that strongly influenced the extreme postures for back, neck and shoulders. Other contributing factors included the difficulty to reach the hand tools when working on the ladder, the congestion of components in the ceiling, and the space between the duct and the ceiling. The identified tasks and factors provide directions for improvement.

Simulation Environment Synchronizing Real Equipment for Manufacturing Cell

NASA Astrophysics Data System (ADS)

Inukai, Toshihiro; Hibino, Hironori; Fukuda, Yoshiro

Recently, manufacturing industries face various problems such as shorter product life cycle, more diversified customer needs. In this situation, it is very important to reduce lead-time of manufacturing system constructions. At the manufacturing system implementation stage, it is important to make and evaluate facility control programs for a manufacturing cell, such as ladder programs for programmable logical controllers (PLCs) rapidly. However, before the manufacturing systems are implemented, methods to evaluate the facility control programs for the equipment while mixing and synchronizing real equipment and virtual factory models on the computers have not been developed. This difficulty is caused by the complexity of the manufacturing system composed of a great variety of equipment, and stopped precise and rapid support of a manufacturing engineering process. In this paper, a manufacturing engineering environment (MEE) to support manufacturing engineering processes using simulation technologies is proposed. MEE consists of a manufacturing cell simulation environment (MCSE) and a distributed simulation environment (DSE). MCSE, which consists of a manufacturing cell simulator and a soft-wiring system, is emphatically proposed in detail. MCSE realizes making and evaluating facility control programs by using virtual factory models on computers before manufacturing systems are implemented.

Turnover among Community Mental Health Workers in Ohio.

PubMed

Bukach, Ashley M; Ejaz, Farida K; Dawson, Nicole; Gitter, Robert J

2017-01-01

This study examined turnover of community mental health workers in 42 randomly selected mental health agencies in Ohio. The turnover rate in 2011 was 26 %. A regression analysis indicated that agencies with lower turnover offered higher maximum pay and were smaller in size, while those offering career advancement opportunities, such as career ladder programs, had higher turnover. The findings suggest that improving wages for workers is likely to reduce turnover. It is also possible that smaller agencies have lower turnover due to stronger relationships with workers and/or more successful hiring practices. Furthermore, turnover that occurs as a result of career advancement could have positive effects and should be examined separate from other types of turnover in the future.

Science in the clinic: a qualitative study of the positioning of MD-PhDs in the everyday clinical setting.

PubMed

Andreassen, Pernille; Christensen, Mette Krogh

2018-05-25

MD-PhDs have been hailed as significant to the advancement of medicine and health care. Yet when it comes to which positions MD-PhDs should be holding in the clinic and the academic world, there seems to be no real consensus. This article examines the ways in which a PhD-degree may contribute to medical doctors' professional practice in the clinic and discusses the positioning of MD-PhDs in the clinic. The study is explorative and qualitative, based on interviews with MD-PhDs, their physician colleagues without a PhD-degree, and their leaders. Positioning theory was applied as the analytical framework for data analysis. We found two opposing positions cutting across the groups of informants with one side critiquing the MD-PhDs for not doing enough research and for using the PhD-degree to climb the career ladder, while the other side emphasized the ways in which MD-PhDs increase the clinical focus on evidence-based medicine and integrate it with clinical decision making, thereby enhancing patient care. A debate is needed to establish more clearly how we wish to position MD-PhDs in the clinic, which in turn will give us a better idea of how many to educate and how to make better use of their competencies.

Medical talent management: a model for physician deployment.

PubMed

Brightman, Baird

2007-01-01

This article aims to provide a focused cost-effective method for triaging physicians into appropriate non-clinical roles to benefit both doctors and healthcare organizations. Reviews a validated career-planning process and customize it for medical talent management. A structured career assessment can differentiate between different physician work styles and direct medical talent into best-fit positions. This allows healthcare organizations to create a more finely tuned career ladder than the familiar "in or out" binary choice. PRACTICAL IMPLICATIONS--Healthcare organizations can invest in cost-effective processes for the optimal utilization of their medical talent. Provides a new use for a well-validated career assessment and planning system. The actual value of this approach should be studied using best-practices in ROI research.

Generation of non-classical correlated photon pairs via a ladder-type atomic configuration: theory and experiment.

PubMed

Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can

2012-05-07

We experimentally generate a non-classical correlated two-color photon pair at 780 and 1529.4 nm in a ladder-type configuration using a hot 85Rb atomic vapor with the production rate of ~10(7)/s. The non-classical correlation between these two photons is demonstrated by strong violation of Cauchy-Schwarz inequality by the factor R = 48 ± 12. Besides, we experimentally investigate the relations between the correlation and some important experimental parameters such as the single-photon detuning, the powers of pumps. We also make a theoretical analysis in detail and the theoretical predictions are in reasonable agreement with our experimental results.

Chiral symmetry restoration at finite temperature and chemical potential in the improved ladder approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taniguchi, Y.; Yoshida, Y.

1997-02-01

The chiral symmetry of QCD is studied at finite temperature and chemical potential using the Schwinger-Dyson equation in the improved ladder approximation. We calculate three order parameters: the vacuum expectation value of the quark bilinear operator, the pion decay constant, and the quark mass gap. We have a second order phase transition at the temperature T{sub c}=169 MeV along the zero chemical potential line, and a first order phase transition at the chemical potential {mu}{sub c}=598 MeV along the zero temperature line. We also calculate the critical exponents of the three order parameters. {copyright} {ital 1997} {ital The American Physicalmore » Society}« less

Programmed cell death of tobacco BY-2 cells induced by still culture conditions is affected by the age of the culture under agitation.

PubMed

Hiraga, Asahi; Kaneta, Tsuyoshi; Sato, Yasushi; Sato, Seiichi

2010-01-25

Evans Blue staining indicated that actively growing tobacco BY-2 cells in the exponential phase died more rapidly than quiescent cells in the stationary phase when the cells cultured under agitation were placed under still conditions. Fifty percent cell death was induced at about 18, 26, 80 and 140 h for early, mid, late exponential- and stationary-phase cells, respectively. Actively growing cells became TUNEL (transferase-mediated dUTP nick end labelling)-positive more rapidly than quiescent cells, suggesting that the cell death evaluated by Evans Blue is accompanied by DNA cleavages. Electrophoresis of genomic DNA showed a typical 'DNA laddering' pattern formed by multiples of about 200 bp internucleosomal units. Chromatin condensation was first detected at least within 24 h by light microscopy, and then cell shrinkage followed. These findings suggest that the death of BY-2 cells induced by still conditions is PCD (programmed cell death).

Interplay between spin frustration and magnetism in the exactly solved two-leg mixed spin ladder

NASA Astrophysics Data System (ADS)

Qi, Yan; Lv, Song-Wei; Du, An; Yu, Nai-sen

2016-11-01

We study a mixed spin-(3/2, 1) ladder system with antiferromagnetic rung coupling and next-nearest-neighbor interaction. The exactly solved Ising-chain model is employed to investigate the ground-state properties and thermodynamics of the low-dimensional ladder system. Our results show that the competition between different exchange couplings brings in a large variety of ground states characterized by various values of normalized magnetization equal to 0, 1/5, 2/5, 3/5, 1. Moreover, an interesting double-peak structure is also detected in the thermal dependence of magnetic susceptibility and specific heat when the frustration comes into play. It is shown that the double-peak phenomenon at zero-field for the case of AF2 ground-state arises from the very strong antiferromagnetic rung coupling, while other cases are attributed to the excitations induced by temperature and external field around the phase boundary. Project supported by the National Natural Science Foundation of China (Grant No. 11547236), the General Project of the Education Department of Liaoning Province, China (Grant No. L2015130), the Fundamental Research Funds for the Central Universities, China (Grant Nos. DC201501065 and DCPY2016014), and the Doctoral Starting-up Foundation of Dalian Nationalities University, China.

An Intrinsically Switchable Ladder-Type Ferroelectric BST-on-Si Composite FBAR Filter.

PubMed

Lee, Seungku; Mortazawi, Amir

2016-03-01

This paper presents a ladder-type bulk acoustic wave (BAW) intrinsically switchable filter based on ferroelectric thin-film bulk acoustic resonators (FBARs). The switchable filter can be turned on and off by the application of an external bias voltage due to the electrostrictive effect in thin-film ferroelectrics. In this paper, Barium Strontium Titanate (BST) is used as the ferroelectric material. A systematic design approach for switchable ladder-type ferroelectric filters is provided based on required filter specifications. A switchable filter is implemented in the form of a BST-on-Si composite structure to control the effective electromechanical coupling coefficient of FBARs. As an experimental verification, a 2.5-stage intrinsically switchable BST-on-Si composite FBAR filter is designed, fabricated, and measured. Measurement results for a typical BST-on-Si composite FBAR show a resonator mechanical quality factor (Q(m)) of 971, as well as a (Q(m)) × f of 2423 GHz. The filter presented here provides a measured insertion loss of 7.8 dB, out-of-band rejection of 26 dB, and fractional bandwidth of 0.33% at 2.5827 GHz when the filter is in the on state at a dc bias of 40 V. In its off state, the filter exhibits an isolation of 31 dB.

Production and Electrical Characterization Tests of the ISL Detector and a Trigger Design for Higgs Boson Searches at CDF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munar Ara, Antoni

2002-01-01

This thesis is structured as follows: Chapter 1. gives a brief review of the Higgs mechanism in the Standard Model and the electroweak symmetry breaking. The Standard Model Higgs boson phenomenology at Tevatron energies is reviewed. Chapter 2. describes the upgraded Fermilab laboratory accelerator complex, and the upgraded CDF detector. Chapter 3. gives a brief overview of the more relevant aspects of the silicon detectors, and the ISL is described in detail. Chapter 4. describes the construction of the ISL ladders, the full custom testing setup (functionality tests, laser test, burn-in test andmore » $$\\beta$$-source measurements), and the problems encountered during the ISL ladders construction. The procedures for ladder grading are also discussed. Chapter 5. describes the multilevel trigger system of the CDF detector, and the trigger primitives available at each level. The most relevant offine event observables are briefly discussed. In Chapter 6 the procedures to estimate the trigger rate and trigger effciency calculation are described. The particularities of triggering in $$p\\bar{p}$$ collisions at high luminosities are discussed. Chapter 7. and Chapter 8. are dedicated to study an effcient trigger strategy for the $$H + W/Z \\to b\\bar{b}jj$$ channel and the $$H + Z \\to b\\bar{b} \

Electromagnetically induced transparency and Autler-Townes splitting in superconducting flux quantum circuits

NASA Astrophysics Data System (ADS)

Sun, Hui-Chen; Liu, Yu-xi; Ian, Hou; You, J. Q.; Il'ichev, E.; Nori, Franco

2014-06-01

We study the microwave absorption of a driven three-level quantum system, which is realized by a superconducting flux quantum circuit (SFQC), with a magnetic driving field applied to the two upper levels. The interaction between the three-level system and its environment is studied within the Born-Markov approximation, and we take into account the effects of the driving field on the damping rates of the three-level system. We study the linear response of the driven three-level SFQC to a weak probe field. The linear magnetic susceptibility of the SFQC can be changed by both the driving field and the bias magnetic flux. When the bias magnetic flux is at the optimal point, the transition from the ground state to the second-excited state is forbidden and the three-level SFQC has a ladder-type transition. Thus, the SFQC responds to the probe field like natural atoms with ladder-type transitions. However, when the bias magnetic flux deviates from the optimal point, the three-level SFQC has a cyclic transition, thus it responds to the probe field like a combination of natural atoms with ladder-type transitions and natural atoms with Λ-type transitions. In particular, we provide detailed discussions on the conditions for realizing electromagnetically induced transparency and Autler-Townes splitting in three-level SFQCs.

SUSY’s Ladder: Reframing sequestering at Large Volume

DOE PAGES

Reece, Matthew; Xue, Wei

2016-04-07

Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague othermore » supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. As a result, this gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.« less

Attitude symbology issues for helmet-mounted displays

NASA Astrophysics Data System (ADS)

Davy, Eleanor C.; Dudfield, Helen J.; Hardiman, Thomas D.; Doyle, Anthony J. R.

1996-06-01

One of the major advantages of HMDs is the display of information wherever the pilot is looking. These displays, however, raise important human factor issues for the optimal method of presenting attitude information. For example, problems may occur when the pilot looks off- boresight and is provided with information that is based upon the forward view of the aircraft (i.e. aircraft-referenced) and is thus incongruent. An experiment was conducted to examine this issue in which a traditional pitch ladder format was compared against the novel 'cylinder' format in an off-boresight attitude control task on a simulated HMD. This task involved recovery from unusual positions (UPs) which were presented at various off-boresight angles. Subjects' initial response times were faster for the pitch ladder format than for the two formats for total recovery times, error rates, height deviations, situational awareness rating technique or the questionnaire data. It was concluded that the performance on the cylinder format may be explained by the subjects' past experience using the pitch ladder or by the lack of information available when the aircraft was slightly nose-up or nose-down. It was suggested that improvements should be made to the cylinder if it is to be further examined in future research. Finally, the implications of this research for future work are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gadella, M.; Negro, J.; Santander, M.

In this paper, we construct a Spectrum Generating Algebra (SGA) for a quantum system with purely continuous spectrum: the quantum free particle in a Lobachevski space with constant negative curvature. The SGA contains the geometrical symmetry algebra of the system plus a subalgebra of operators that give the spectrum of the system and connects the eigenfunctions of the Hamiltonian among themselves. In our case, the geometrical symmetry algebra is so(3,1) and the SGA is so(4,2). We start with a representation of so(4,2) by functions on a realization of the Lobachevski space given by a two-sheeted hyperboloid, where the Lie algebramore » commutators are the usual Poisson-Dirac brackets. Then, we introduce a quantized version of the representation in which functions are replaced by operators on a Hilbert space and Poisson-Dirac brackets by commutators. Eigenfunctions of the Hamiltonian are given and 'naive' ladder operators are identified. The previously defined 'naive' ladder operators shift the eigenvalues by a complex number so that an alternative approach is necessary. This is obtained by a non-self-adjoint function of a linear combination of the ladder operators, which gives the correct relation among the eigenfunctions of the Hamiltonian. We give an eigenfunction expansion of functions over the upper sheet of a two-sheeted hyperboloid in terms of the eigenfunctions of the Hamiltonian.« less

Objective measures of motor dysfunction after compression spinal cord injury in adult rats: correlations with locomotor rating scores.

PubMed

Semler, Joerg; Wellmann, Katharina; Wirth, Felicitas; Stein, Gregor; Angelova, Srebrina; Ashrafi, Mahak; Schempf, Greta; Ankerne, Janina; Ozsoy, Ozlem; Ozsoy, Umut; Schönau, Eckhard; Angelov, Doychin N; Irintchev, Andrey

2011-07-01

Precise assessment of motor deficits after traumatic spinal cord injury (SCI) in rodents is crucial for understanding the mechanisms of functional recovery and testing therapeutic approaches. Here we analyzed the applicability to a rat SCI model of an objective approach, the single-frame motion analysis, created and used for functional analysis in mice. Adult female Wistar rats were subjected to graded compression of the spinal cord. Recovery of locomotion was analyzed using video recordings of beam walking and inclined ladder climbing. Three out of four parameters used in mice appeared suitable: the foot-stepping angle (FSA) and the rump-height index (RHI), measured during beam walking, and for estimating paw placement and body weight support, respectively, and the number of correct ladder steps (CLS), assessing skilled limb movements. These parameters, similar to the Basso, Beattie, and Bresnahan (BBB) locomotor rating scores, correlated with lesion volume and showed significant differences between moderately and severely injured rats at 1-9 weeks after SCI. The beam parameters, but not CLS, correlated well with the BBB scores within ranges of poor and good locomotor abilities. FSA co-varied with RHI only in the severely impaired rats, while RHI and CLS were barely correlated. Our findings suggest that the numerical parameters estimate, as intended by design, predominantly different aspects of locomotion. The use of these objective measures combined with BBB rating provides a time- and cost-efficient opportunity for versatile and reliable functional evaluations in both severely and moderately impaired rats, combining clinical assessment with precise numerical measures.

Multi-material size optimization of a ladder frame chassis

NASA Astrophysics Data System (ADS)

Baker, Michael

The Corporate Average Fuel Economy (CAFE) is an American fuel standard that sets regulations on fuel economy in vehicles. This law ultimately shapes the development and design research for automakers. Reducing the weight of conventional cars offers a way to improve fuel efficiency. This research investigated the optimality of an automobile's ladder frame chassis (LFC) by conducting multi-objective optimization on the LFC in order to reduce the weight of the chassis. The focus of the design and optimization was a ladder frame chassis commonly used for mass production light motor vehicles with an open-top rear cargo area. This thesis is comprised of two major sections. The first looked to perform thickness optimization in the outer walls of the ladder frame. In the second section, many multi-material distributions, including steel and aluminium varieties, were investigated. A simplified model was used to do an initial hand calculation analysis of the problem. This was used to create a baseline validation to compare the theory with the modeling. A CAD model of the LFC was designed. From the CAD model, a finite element model was extracted and joined using weld and bolt connectors. Following this, a linear static analysis was performed to look at displacement and stresses when subjected to loading conditions that simulate harsh driving conditions. The analysis showed significant values of stress and displacement on the ends of the rails, suggesting improvements could be made elsewhere. An optimization scheme was used to find the values of an all steel frame an optimal thickness distribution was found. This provided a 13% weight reduction over the initial model. To advance the analysis a multi-material approach was used to push the weight savings even further. Several material distributions were analyzed and the lightest utilized aluminium in all but the most strenuous subjected components. This enabled a reduction in weight of 15% over the initial model, equivalent to approximately 1 mile per gallon (MPG) in fuel economy.

Nonlinear response from transport theory and quantum field theory at finite temperature

NASA Astrophysics Data System (ADS)

Carrington, M. E.; Defu, Hou; Kobes, R.

2001-07-01

We study the nonlinear response in weakly coupled hot φ4 theory. We obtain an expression for a quadratic shear viscous response coefficient using two different formalisms: transport theory and response theory. The transport theory calculation is done by assuming a local equilibrium form for the distribution function and expanding in the gradient of the local four dimensional velocity field. By performing a Chapman-Enskog expansion on the Boltzmann equation we obtain a hierarchy of equations for the coefficients of the expanded distribution function. To do the response theory calculation we use Zubarev's techniques in nonequilibrium statistical mechanics to derive a generalized Kubo formula. Using this formula allows us to obtain the quadratic shear viscous response from the three-point retarded Green function of the viscous shear stress tensor. We use the closed time path formalism of real time finite temperature field theory to show that this three-point function can be calculated by writing it as an integral equation involving a four-point vertex. This four-point vertex can in turn be obtained from an integral equation which represents the resummation of an infinite series of ladder and extended-ladder diagrams. The connection between transport theory and response theory is made when we show that the integral equation for this four-point vertex has exactly the same form as the equation obtained from the Boltzmann equation for the coefficient of the quadratic term of the gradient expansion of the distribution function. We conclude that calculating the quadratic shear viscous response using transport theory and keeping terms that are quadratic in the gradient of the velocity field in the Chapman-Enskog expansion of the Boltzmann equation is equivalent to calculating the quadratic shear viscous response from response theory using the next-to-linear response Kubo formula, with a vertex given by an infinite resummation of ladder and extended-ladder diagrams.

Ladder Structures and Magnetic Surveys: New Insights into the Near Surface, Three-Dimensional Shape and Orientation of Plutonic Structures in the Tuolumne Intrusive Suite, Yosemite National Park, California

NASA Astrophysics Data System (ADS)

Boyd, J. D.

2017-12-01

The study of pluton emplacement and growth history offers a window into the evolution of the continental crust. Plutons, however, are often largely homogeneous in outcrop, lacking reliable structural markers for tracking their emplacement and growth through time. The ladder structures exposed on the glacially polished surfaces of the Tuolumne Intrusive Suite (TIS) in Yosemite National Park, California are an exception. Ladder structures (LS) are eye-catching concentrations of alternating mafic and felsic mineral assemblages in dominantly cresent-shaped, meter to sub-meter scale bands in outcrop that locally terminate into a mafic band forming a circular-shaped enclosure. Their geochemistry and modal mineralogy diverge sharply from host rock trends with large quantities of magnetite, titanite, and zircon in the mafic assemblages. The limited exposure of LS in outcrops has led to much debate as to their true geometries and orientations. The high concentration of magnetite in the LS is fortuitous in that it allows these features to be investigated by magnetic techniques. The preliminary results of new high resolution magnetic surveys of these LS are presented here. A grid of total magnetic intensity (TMI) was collected across the ladder structures. The TMI's were then inverted and modeled to determine the orientation of the magnetic bodies with depth using PyGMI freeware. With sufficient contrast in the magnetic susceptibility (Km) between the feature being imaged and the host rock, meter to sub-meter scale features can be resolved. The average Km of the LS mafic bands and the host rock is approximately 200-850 x10-3 and 15-20×10-3 SI units respectively. These measurements along with oriented samples were collected to determine input parameters (e.g. anisotropy and remanence) for the geocellular model used in this study.

Structure of the conversion laws in quantum integrable spin chains with short range interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grabowski, M.P.; Mathieu, P.

1995-11-01

The authors present a detailed analysis of the structure of the conservation laws in quantum integrable chains of the XYZ-type and in the Hubbard model. The essential tool for the former class of models is the boost operator, which provides a recursive way of calculating the integrals of motion. With its help, they establish the general form of the XYZ conserved charges in terms of simple polynomials in spin variables and derive recursion relations for the relative coefficients of these polynomials. Although these relations are difficult to solve in general, a subset of the coefficients can be determined. Moreover, formore » two submodels of the XYZ chain, namely the XXX and XY cases, all the charges can be calculated in closed form. Using this approach, the authors rederive the known expressions for the XY charges in a novel way. For the XXX case. a simple description of conserved charges is found in terms of a Catalan tree. This construction is generalized for the su(M) invariant integrable chain. They also investigate the circumstances permitting the existence of a recursive (ladder) operator in general quantum integrable systems. They indicate that a quantum ladder operator can be traced back to the presence of a Hamiltonian mastersymmetry of degree one in the classical continuous version of the model. In this way, quantum chains endowed with a recursive structure can be identified from the properties of their classical relatives. The authors also show that in the quantum continuous limits of the XYZ model, the ladder property of the boost operator disappears. For the Hubbard model they demonstrate the nonexistence of a ladder operator. Nevertheless, the general structure of the conserved charges is indicated, and the expression for the terms linear in the model`s free parameter for all charges is derived in closed form. 62 refs., 4 figs.« less

Two-peak structure in the K-edge RIXS spectra of a spatially frustrated Heisenberg antiferromagnet

NASA Astrophysics Data System (ADS)

Datta, Trinanjan; Luo, Cheng; Yao, Dao-Xin

2014-03-01

Quantum fluctuations due to spatial anisotropy and strong magnetic frustration lead to the formation of a two-peak structure in the K-edge bimagnon RIXS intensity spectra of a Jx-Jy-J2 Heisenberg model on a square lattice. We compute the RIXS intensity, including up to first order 1/S spin wave expansion correction, using the Bethe-Salpeter equation within the ladder approximation scheme. The two-peak feature occurs in both the antiferromagnetic phase and the collinear antiferromagnetic phase. A knowledge of the peak splitting energy from both magnetically ordered regime can provide experimentalists with an alternative means to measure and study the effects of local microscopic exchange constants. Cottrell Research Corporation, NSFC-11074310, NSFC-11275279, Specialized Research Fund for the Doctoral Program of Higher Education.

Static holes in the geometrically frustrated bow-tie ladder

NASA Astrophysics Data System (ADS)

Martins, George B.; Brenig, Wolfram

2008-10-01

We investigate the doping of a geometrically frustrated spin ladder with static holes by a complementary approach using exact diagonalization and quantum dimers. Results for thermodynamic properties, the singlet density of states, the hole-binding energy and the spin correlations will be presented. For the undoped systems the ground state is non-degenerate, with translationally invariant nearest-neighbor spin correlations. For the doped case, we find that static holes polarize their vicinity through a localization of singlets, reducing the frustration. This polarization induces short range repulsive forces between two holes and an oscillatory behavior of the long range two-hole energy. For most quantities investigated, we find very good agreement between the quantum dimer approach and the results from exact diagonalization.

Tunable photonic band gaps and optical nonreciprocity by an RF-driving ladder-type system in moving optical lattice

NASA Astrophysics Data System (ADS)

Ba, Nuo; Zhong, Xin; Wang, Lei; Fei, Jin-You; Zhang, Yan; Bao, Qian-Qian; Xiao, Li

2018-03-01

We investigate photonic transport properties of the 1D moving optical lattices filled with vast cold atoms driven into a four-level ladder-type system and obtain dynamically controlled photonic bandgaps and optical nonreciprocity. It is found that the two obvious optical nonreciprocity can be generated at two well-developed photonic bandgaps based on double dark states in the presence of a radio-frequency field. However, when the radio-frequency field is absence, the only one induced photonic bandgaps with distinguishing optical nonreciprocity can be opened up via single dark state. Dynamic control of the induced photonic bandgaps and optical nonreciprocity could be exploited to achieve all-optical diodes and routing for quantum information networks.

Carbon dioxide dissociation in non-thermal radiofrequency and microwave plasma

NASA Astrophysics Data System (ADS)

Huang, Qiang; Zhang, Diyu; Wang, Dongping; Liu, Kezhao; Kleyn, Aart W.

2017-07-01

We have studied carbon dioxide dissociation in inductively coupled radiofrequency plasma and microwave plasma at low gas pressure. Both systems exhibit features of non-thermal plasma. The highest energy efficiency observed is 59.3% (2.13 mmol kJ-1), exceeding the maximum value of about 45% in case of thermodynamic equilibrium, and a maximum conversion of 80.6% is achieved. Different discharge conditions, such as the source frequency, discharge gas pressure and the addition of argon, will affect the plasma parameters, especially the electron energy distribution. This plays a great role in the energy transfer from non-thermal plasma to the molecular dissociation reaction channel by enabling the ladder climbing of the carbon dioxide molecular vibration. The results indicate the importance of ladder climbing.

Engineering of many-body Majorana states in a topological insulator/s-wave superconductor heterostructure.

PubMed

Hung, Hsiang-Hsuan; Wu, Jiansheng; Sun, Kuei; Chiu, Ching-Kai

2017-06-14

We study a vortex chain in a thin film of a topological insulator with proximity-induced superconductivity-a promising platform to realize Majorana zero modes (MZMs)-by modeling it as a two-leg Majorana ladder. While each pair of MZMs hybridizes through vortex tunneling, we hereby show that MZMs can be stabilized on the ends of the ladder with the presence of tilted external magnetic field and four-Majorana interaction. Furthermore, a fruitful phase diagram is obtained by controlling the direction of magnetic field and the thickness of the sample. We reveal many-body Majorana states and interaction-induced topological phase transitions and also identify trivial-superconducting and commensurate/incommensurate charge-density-wave states in the phase diagram.